Merge pull request #457 from databasus/develop

FIX (playground): Make turnstile mandatory in sign in and sign up

.github/ISSUE_TEMPLATE/bug_report.md

@@ -4,7 +4,9 @@ about: Report a bug or unexpected behavior in Databasus
 labels: bug
 ---
 
-## Databasus version
+## Databasus version (screenshot)
+
+It is displayed in the bottom left corner of the Databasus UI. Please attach screenshot, not just version text
 
 <!-- e.g. 1.4.2 -->
 
@@ -12,6 +14,10 @@ labels: bug
 
 <!-- e.g. Ubuntu 22.04 x64, macOS 14 ARM, Windows 11 x64 -->
 
+## Database type and version (optional, for DB-related bugs)
+
+<!-- e.g. PostgreSQL 16 in Docker, MySQL 8.0 installed on server, MariaDB 11.4 in AWS Cloud -->
+
 ## Describe the bug (please write manually, do not ask AI to summarize)
 
 **What happened:**

.github/workflows/ci-release.yml

@@ -9,9 +9,10 @@ on:
 
 jobs:
   lint-backend:
+    if: github.ref != 'refs/heads/develop'
     runs-on: self-hosted
     container:
-      image: golang:1.24.9
+      image: golang:1.26.1
       volumes:
         - /runner-cache/go-pkg:/go/pkg/mod
         - /runner-cache/go-build:/root/.cache/go-build
@@ -32,7 +33,7 @@ jobs:
 
       - name: Install golangci-lint
         run: |
-          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.7.2
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.11.3
           echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
 
       - name: Install swag for swagger generation
@@ -55,6 +56,7 @@ jobs:
           git diff --exit-code go.mod go.sum || (echo "go mod tidy made changes, please run 'go mod tidy' and commit the changes" && exit 1)
 
   lint-frontend:
+    if: github.ref != 'refs/heads/develop'
     runs-on: ubuntu-latest
     steps:
       - name: Check out code
@@ -86,7 +88,42 @@ jobs:
           cd frontend
           npm run build
 
+  lint-agent:
+    if: github.ref != 'refs/heads/develop'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.26.1"
+          cache-dependency-path: agent/go.sum
+
+      - name: Download Go modules
+        run: |
+          cd agent
+          go mod download
+
+      - name: Install golangci-lint
+        run: |
+          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/HEAD/install.sh | sh -s -- -b $(go env GOPATH)/bin v2.11.3
+          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
+
+      - name: Run golangci-lint
+        run: |
+          cd agent
+          golangci-lint run
+
+      - name: Verify go mod tidy
+        run: |
+          cd agent
+          go mod tidy
+          git diff --exit-code go.mod go.sum || (echo "go mod tidy made changes, please run 'go mod tidy' and commit the changes" && exit 1)
+
   test-frontend:
+    if: github.ref != 'refs/heads/develop'
     runs-on: ubuntu-latest
     needs: [lint-frontend]
     steps:
@@ -108,11 +145,82 @@ jobs:
           cd frontend
           npm run test
 
+  test-agent:
+    if: github.ref != 'refs/heads/develop'
+    runs-on: ubuntu-latest
+    needs: [lint-agent]
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.26.1"
+          cache-dependency-path: agent/go.sum
+
+      - name: Download Go modules
+        run: |
+          cd agent
+          go mod download
+
+      - name: Run Go tests
+        run: |
+          cd agent
+          go test -count=1 -failfast ./internal/...
+
+  e2e-agent:
+    if: github.ref != 'refs/heads/develop'
+    runs-on: ubuntu-latest
+    needs: [lint-agent]
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Run e2e tests
+        run: |
+          cd agent
+          make e2e
+
+      - name: Cleanup
+        if: always()
+        run: |
+          cd agent/e2e
+          docker compose down -v --rmi local || true
+          rm -rf artifacts || true
+
+  e2e-agent-backup-restore:
+    if: github.ref != 'refs/heads/develop'
+    runs-on: ubuntu-latest
+    needs: [lint-agent]
+    strategy:
+      matrix:
+        pg_version: [15, 16, 17, 18]
+      fail-fast: false
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Run backup-restore e2e (PG ${{ matrix.pg_version }})
+        run: |
+          cd agent
+          make e2e-backup-restore PG_VERSION=${{ matrix.pg_version }}
+
+      - name: Cleanup
+        if: always()
+        run: |
+          cd agent/e2e
+          docker compose -f docker-compose.backup-restore.yml down -v --rmi local || true
+          rm -rf artifacts || true
+
+  # Self-hosted: performant high-frequency CPU is used to start many containers and run tests fast. Tests
+  # step is bottle-neck, because we need a lot of containers and cannot parallelize tests due to shared resources
   test-backend:
+    if: github.ref != 'refs/heads/develop'
     runs-on: self-hosted
     needs: [lint-backend]
     container:
-      image: golang:1.24.9
+      image: golang:1.26.1
       options: --privileged -v /var/run/docker.sock:/var/run/docker.sock --add-host=host.docker.internal:host-gateway
       volumes:
         - /runner-cache/go-pkg:/go/pkg/mod
@@ -196,9 +304,6 @@ jobs:
           TEST_MARIADB_114_PORT=33114
           TEST_MARIADB_118_PORT=33118
           TEST_MARIADB_120_PORT=33120
-          # testing Telegram
-          TEST_TELEGRAM_BOT_TOKEN=${{ secrets.TEST_TELEGRAM_BOT_TOKEN }}
-          TEST_TELEGRAM_CHAT_ID=${{ secrets.TEST_TELEGRAM_CHAT_ID }}
           # supabase
           TEST_SUPABASE_HOST=${{ secrets.TEST_SUPABASE_HOST }}
           TEST_SUPABASE_PORT=${{ secrets.TEST_SUPABASE_PORT }}
@@ -407,7 +512,7 @@ jobs:
       - name: Run database migrations
         run: |
           cd backend
-          go install github.com/pressly/goose/v3/cmd/goose@latest
+          go install github.com/pressly/goose/v3/cmd/goose@v3.24.3
           goose up
 
       - name: Run Go tests
@@ -437,11 +542,47 @@ jobs:
 
           echo "Cleanup complete"
 
+  build-and-push-dev:
+    runs-on: self-hosted
+    if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/develop' }}
+    steps:
+      - name: Clean workspace
+        run: |
+          sudo rm -rf "$GITHUB_WORKSPACE"/* || true
+          sudo rm -rf "$GITHUB_WORKSPACE"/.* || true
+
+      - name: Check out code
+        uses: actions/checkout@v4
+
+      - name: Set up QEMU (enables multi-arch emulation)
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push dev image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm64
+          build-args: |
+            APP_VERSION=dev-${{ github.sha }}
+          tags: |
+            databasus/databasus-dev:latest
+            databasus/databasus-dev:${{ github.sha }}
+
   determine-version:
     runs-on: self-hosted
     container:
       image: node:20
-    needs: [test-backend, test-frontend]
+    needs: [test-backend, test-frontend, test-agent, e2e-agent, e2e-agent-backup-restore]
     if: ${{ github.ref == 'refs/heads/main' && !contains(github.event.head_commit.message, '[skip-release]') }}
     outputs:
       should_release: ${{ steps.version_bump.outputs.should_release }}
@@ -532,43 +673,6 @@ jobs:
             echo "No version bump needed"
           fi
 
-  build-only:
-    runs-on: self-hosted
-    needs: [test-backend, test-frontend]
-    if: ${{ github.ref == 'refs/heads/main' && contains(github.event.head_commit.message, '[skip-release]') }}
-    steps:
-      - name: Clean workspace
-        run: |
-          sudo rm -rf "$GITHUB_WORKSPACE"/* || true
-          sudo rm -rf "$GITHUB_WORKSPACE"/.* || true
-
-      - name: Check out code
-        uses: actions/checkout@v4
-
-      - name: Set up QEMU (enables multi-arch emulation)
-        uses: docker/setup-qemu-action@v3
-
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
-
-      - name: Log in to Docker Hub
-        uses: docker/login-action@v3
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Build and push SHA-only tags
-        uses: docker/build-push-action@v5
-        with:
-          context: .
-          push: true
-          platforms: linux/amd64,linux/arm64
-          build-args: |
-            APP_VERSION=dev-${{ github.sha }}
-          tags: |
-            databasus/databasus:latest
-            databasus/databasus:${{ github.sha }}
-
   build-and-push:
     runs-on: self-hosted
     needs: [determine-version]

.gitignore

@@ -5,6 +5,7 @@ databasus-data/
 .env
 pgdata/
 docker-compose.yml
+!agent/e2e/docker-compose.yml
 node_modules/
 .idea
 /articles
@@ -12,3 +13,4 @@ node_modules/
 .DS_Store
 /scripts
 .vscode/settings.json
+.claude

.pre-commit-config.yaml

@@ -41,3 +41,20 @@ repos:
         language: system
         files: ^backend/.*\.go$
         pass_filenames: false
+
+  # Agent checks
+  - repo: local
+    hooks:
+      - id: agent-format-and-lint
+        name: Agent Format & Lint (golangci-lint)
+        entry: bash -c "cd agent && golangci-lint fmt ./internal/... ./cmd/... && golangci-lint run ./internal/... ./cmd/..."
+        language: system
+        files: ^agent/.*\.go$
+        pass_filenames: false
+
+      - id: agent-go-mod-tidy
+        name: Agent Go Mod Tidy
+        entry: bash -c "cd agent && go mod tidy"
+        language: system
+        files: ^agent/.*\.go$
+        pass_filenames: false

AGENTS.md

@@ -73,6 +73,10 @@ This is NOT a strict set of rules, but a set of recommendations to help you writ
    - Patch the answer accordingly
    - Verify edge cases are handled
 
+7. **Fix the reason, not the symptom:**
+   - If you find a bug or issue, ask "Why did this happen?" and fix the root cause
+   - Avoid quick fixes that don't address underlying problems
+
 ### Application guidelines:
 
 **Scale your response to the task:**
@@ -88,6 +92,36 @@ This is NOT a strict set of rules, but a set of recommendations to help you writ
 
 ## Backend guidelines
 
+### Naming
+
+Variables and functions naming are the most important part of code readability. Always choose descriptive and meaningful names that clearly indicate the purpose and intent of the code.
+
+Avoid abbreviations, unless they are widely accepted and unambiguous (e.g., `ID`, `URL`, `HTTP`). Use consistent naming conventions across the codebase.
+
+Do not use one-two letters. For example:
+
+Bad:
+
+```
+    u := users.getUser()
+
+	pr, pw := io.Pipe()
+
+    r := bufio.NewReader(pr)
+```
+
+Good:
+
+```
+    user := users.GetUser()
+
+    pipeReader, pipeWriter := io.Pipe()
+
+    bufferedReader := bufio.NewReader(pipeReader)
+```
+
+Exclusion: widely used variables like "db", "ctx", "req", "res", etc.
+
 ### Code style
 
 **Always place private methods to the bottom of file**

CLAUDE.md

@@ -0,0 +1 @@
+Look at @AGENTS.md

Dockerfile

@@ -22,7 +22,7 @@ RUN npm run build
 
 # ========= BUILD BACKEND =========
 # Backend build stage
-FROM --platform=$BUILDPLATFORM golang:1.24.9 AS backend-build
+FROM --platform=$BUILDPLATFORM golang:1.26.1 AS backend-build
 
 # Make TARGET args available early so tools built here match the final image arch
 ARG TARGETOS
@@ -66,13 +66,52 @@ RUN CGO_ENABLED=0 \
   go build -o /app/main ./cmd/main.go
 
 
+# ========= BUILD AGENT =========
+# Builds the databasus-agent CLI binary for BOTH x86_64 and ARM64.
+# Both architectures are always built because:
+# - Databasus server runs on one arch (e.g. amd64)
+# - The agent runs on remote PostgreSQL servers that may be on a
+#   different arch (e.g. arm64)
+# - The backend serves the correct binary based on the agent's
+#   ?arch= query parameter
+#
+# We cross-compile from the build platform (no QEMU needed) because the
+# agent is pure Go with zero C dependencies.
+# CGO_ENABLED=0 produces fully static binaries — no glibc/musl dependency,
+# so the agent runs on any Linux distro (Alpine, Debian, Ubuntu, RHEL, etc.).
+# APP_VERSION is baked into the binary via -ldflags so the agent can
+# compare its version against the server and auto-update when needed.
+FROM --platform=$BUILDPLATFORM golang:1.26.1 AS agent-build
+
+ARG APP_VERSION=dev
+
+WORKDIR /agent
+
+COPY agent/go.mod ./
+RUN go mod download
+
+COPY agent/ ./
+
+# Build for x86_64 (amd64) — static binary, no glibc dependency
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 \
+    go build -ldflags "-X main.Version=${APP_VERSION}" \
+    -o /agent-binaries/databasus-agent-linux-amd64 ./cmd/main.go
+
+# Build for ARM64 (arm64) — static binary, no glibc dependency
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=arm64 \
+    go build -ldflags "-X main.Version=${APP_VERSION}" \
+    -o /agent-binaries/databasus-agent-linux-arm64 ./cmd/main.go
+
+
 # ========= RUNTIME =========
 FROM debian:bookworm-slim
 
 # Add version metadata to runtime image
 ARG APP_VERSION=dev
+ARG TARGETARCH
 LABEL org.opencontainers.image.version=$APP_VERSION
 ENV APP_VERSION=$APP_VERSION
+ENV CONTAINER_ARCH=$TARGETARCH
 
 # Set production mode for Docker containers
 ENV ENV_MODE=production
@@ -218,6 +257,13 @@ COPY backend/migrations ./migrations
 # Copy UI files
 COPY --from=backend-build /app/ui/build ./ui/build
 
+# Copy cloud static HTML template (injected into index.html at startup when IS_CLOUD=true)
+COPY frontend/cloud-root-content.html /app/cloud-root-content.html
+
+# Copy agent binaries (both architectures) — served by the backend
+# at GET /api/v1/system/agent?arch=amd64|arm64
+COPY --from=agent-build /agent-binaries ./agent-binaries
+
 # Copy .env file (with fallback to .env.production.example)
 COPY backend/.env* /app/
 RUN if [ ! -f /app/.env ]; then \
@@ -269,7 +315,8 @@ window.__RUNTIME_CONFIG__ = {
   GITHUB_CLIENT_ID: '\${GITHUB_CLIENT_ID:-}',
   GOOGLE_CLIENT_ID: '\${GOOGLE_CLIENT_ID:-}',
   IS_EMAIL_CONFIGURED: '\$IS_EMAIL_CONFIGURED',
-  CLOUDFLARE_TURNSTILE_SITE_KEY: '\${CLOUDFLARE_TURNSTILE_SITE_KEY:-}'
+  CLOUDFLARE_TURNSTILE_SITE_KEY: '\${CLOUDFLARE_TURNSTILE_SITE_KEY:-}',
+  CONTAINER_ARCH: '\${CONTAINER_ARCH:-unknown}'
 };
 JSEOF
 
@@ -282,6 +329,23 @@ if [ -n "\${ANALYTICS_SCRIPT:-}" ]; then
   fi
 fi
 
+# Inject static HTML into root div for cloud mode (payment system requires visible legal links)
+if [ "\${IS_CLOUD:-false}" = "true" ]; then
+  if ! grep -q "cloud-static-content" /app/ui/build/index.html 2>/dev/null; then
+    echo "Injecting cloud static HTML content..."
+    perl -i -pe '
+      BEGIN {
+        open my \$fh, "<", "/app/cloud-root-content.html" or die;
+        local \$/;
+        \$c = <\$fh>;
+        close \$fh;
+        \$c =~ s/\\n/ /g;
+      }
+      s/<div id="root"><\\/div>/<div id="root"><!-- cloud-static-content -->\$c<\\/div>/
+    ' /app/ui/build/index.html
+  fi
+fi
+
 # Ensure proper ownership of data directory
 echo "Setting up data directory permissions..."
 mkdir -p /databasus-data/pgdata
@@ -394,6 +458,8 @@ fi
 # Create database and set password for postgres user
 echo "Setting up database and user..."
 gosu postgres \$PG_BIN/psql -p 5437 -h localhost -d postgres << 'SQL'
+
+-- We use stub password, because internal DB is not exposed outside container
 ALTER USER postgres WITH PASSWORD 'Q1234567';
 SELECT 'CREATE DATABASE databasus OWNER postgres'
 WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'databasus')

README.md

@@ -2,7 +2,7 @@
   <img src="assets/logo.svg" alt="Databasus Logo" width="250"/>
 
   <h3>Backup tool for PostgreSQL, MySQL and MongoDB</h3>
-  <p>Databasus is a free, open source and self-hosted tool to backup databases (with focus on PostgreSQL). Make backups with different storages (S3, Google Drive, FTP, etc.) and notifications about progress (Slack, Discord, Telegram, etc.). Previously known as Postgresus (see migration guide).</p>
+  <p>Databasus is a free, open source and self-hosted tool to backup databases (with focus on PostgreSQL). Make backups with different storages (S3, Google Drive, FTP, etc.) and notifications about progress (Slack, Discord, Telegram, etc.)</p>
   
   <!-- Badges -->
    [![PostgreSQL](https://img.shields.io/badge/PostgreSQL-336791?logo=postgresql&logoColor=white)](https://www.postgresql.org/)
@@ -41,7 +41,7 @@
 
 - **PostgreSQL**: 12, 13, 14, 15, 16, 17 and 18
 - **MySQL**: 5.7, 8 and 9
-- **MariaDB**: 10 and 11
+- **MariaDB**: 10, 11 and 12
 - **MongoDB**: 4, 5, 6, 7 and 8
 
 ### 🔄 **Scheduled backups**
@@ -91,14 +91,16 @@ It is also important for Databasus that you are able to decrypt and restore back
 - **Dark & light themes**: Choose the look that suits your workflow
 - **Mobile adaptive**: Check your backups from anywhere on any device
 
-### ☁️ **Works with self-hosted & cloud databases**
+### 🔌 **Connection types**
 
-Databasus works seamlessly with both self-hosted PostgreSQL and cloud-managed databases:
+- **Remote** — Databasus connects directly to the database over the network (recommended in read-only mode). No agent or additional software required. Works with cloud-managed and self-hosted databases
+- **Agent** — A lightweight Databasus agent (written in Go) runs alongside the database. The agent streams backups directly to Databasus, so the database never needs to be exposed publicly. Supports host-installed databases and Docker containers
 
-- **Cloud support**: AWS RDS, Google Cloud SQL, Azure Database for PostgreSQL
-- **Self-hosted**: Any PostgreSQL instance you manage yourself
-- **Why no PITR support?**: Cloud providers already offer native PITR, and external PITR backups cannot be restored to managed cloud databases — making them impractical for cloud-hosted PostgreSQL
-- **Practical granularity**: Hourly and daily backups are sufficient for 99% of projects without the operational complexity of WAL archiving
+### 📦 **Backup types**
+
+- **Logical** — Native dump of the database in its engine-specific binary format. Compressed and streamed directly to storage with no intermediate files
+- **Physical** — File-level copy of the entire database cluster. Faster backup and restore for large datasets compared to logical dumps (requires agent)
+- **Incremental** — Physical base backup combined with continuous WAL segment archiving. Enables Point-in-Time Recovery (PITR) — restore to any second between backups. Designed for disaster recovery and near-zero data loss requirements (requires agent)
 
 ### 🐳 **Self-hosted & secure**
 
@@ -243,7 +245,7 @@ Replace `admin` with the actual email address of the user whose password you wan
 
 ### 💾 Backuping Databasus itself
 
-After installation, it is also recommended to <a href="https://databasus.com/faq/#backup-databasus">backup your Databasus itself</a> or, at least, to copy secret key used for encryption (30 seconds is needed). So you are able to restore from your encrypted backups if you lose access to the server with Databasus or it is corrupted.
+After installation, it is also recommended to <a href="https://databasus.com/faq#backup-databasus">backup your Databasus itself</a> or, at least, to copy secret key used for encryption (30 seconds is needed). So you are able to restore from your encrypted backups if you lose access to the server with Databasus or it is corrupted.
 
 ---
 
@@ -261,12 +263,17 @@ Also you can join our large community of developers, DBAs and DevOps engineers o
 
 There have been questions about AI usage in project development in issues and discussions. As the project focuses on security, reliability and production usage, it's important to explain how AI is used in the development process.
 
+First of all, we are proud to say that Databasus has been accepted into both [Claude for Open Source](https://claude.com/contact-sales/claude-for-oss) by Anthropic and [Codex for Open Source](https://developers.openai.com/codex/community/codex-for-oss/) by OpenAI in March 2026. For us it is one more signal that the project was recognized as important open-source software and was as critical infrastructure worth supporting independently by two of the world's leading AI companies. Read more at [databasus.com/faq](https://databasus.com/faq#oss-programs).
+
+Despite of this, we have the following rules how AI is used in the development process:
+
 AI is used as a helper for:
 
 - verification of code quality and searching for vulnerabilities
 - cleaning up and improving documentation, comments and code
 - assistance during development
 - double-checking PRs and commits after human review
+- additional security analysis of PRs via Codex Security
 
 AI is not used for:
 

agent/.env.example

@@ -0,0 +1,3 @@
+ENV_MODE=development
+AGENT_DB_ID=your-database-id
+AGENT_TOKEN=your-agent-token

agent/.gitignore

@@ -0,0 +1,27 @@
+main
+.env
+docker-compose.yml
+!e2e/docker-compose.yml
+pgdata
+pgdata_test/
+mysqldata/
+mariadbdata/
+main.exe
+swagger/
+swagger/*
+swagger/docs.go
+swagger/swagger.json
+swagger/swagger.yaml
+postgresus-backend.exe
+databasus-backend.exe
+ui/build/*
+pgdata-for-restore/
+temp/
+cmd.exe
+temp/
+valkey-data/
+victoria-logs-data/
+databasus.json
+.test-tmp/
+databasus.log
+wal-queue/

agent/.golangci.yml

@@ -0,0 +1,41 @@
+version: "2"
+
+run:
+  timeout: 5m
+  tests: false
+  concurrency: 4
+
+linters:
+  default: standard
+  enable:
+    - funcorder
+    - bodyclose
+    - errorlint
+    - gocritic
+    - unconvert
+    - misspell
+    - errname
+    - noctx
+    - modernize
+
+  settings:
+    errcheck:
+      check-type-assertions: true
+
+formatters:
+  enable:
+    - gofumpt
+    - golines
+    - gci
+
+  settings:
+    golines:
+      max-len: 120
+    gofumpt:
+      module-path: databasus-agent
+      extra-rules: true
+    gci:
+      sections:
+        - standard
+        - default
+        - localmodule

agent/Makefile

@@ -0,0 +1,41 @@
+.PHONY: run build test lint e2e e2e-clean e2e-backup-restore e2e-backup-restore-clean
+
+-include .env
+export
+
+run:
+	go run cmd/main.go start \
+		--databasus-host http://localhost:4005 \
+		--db-id $(AGENT_DB_ID) \
+		--token $(AGENT_TOKEN) \
+		--pg-host 127.0.0.1 \
+		--pg-port 7433 \
+		--pg-user devuser \
+		--pg-password devpassword \
+		--pg-type docker \
+		--pg-docker-container-name dev-postgres \
+		--pg-wal-dir ./wal-queue \
+		--skip-update
+
+build:
+	CGO_ENABLED=0 go build -ldflags "-X main.Version=$(VERSION)" -o databasus-agent ./cmd/main.go
+
+test:
+	go test -count=1 -failfast ./internal/...
+
+lint:
+	golangci-lint fmt ./cmd/... ./internal/... ./e2e/... && golangci-lint run ./cmd/... ./internal/... ./e2e/...
+
+e2e:
+	cd e2e && docker compose build --no-cache e2e-mock-server
+	cd e2e && docker compose build
+	cd e2e && docker compose run --rm e2e-agent-builder
+	cd e2e && docker compose up -d e2e-postgres e2e-mock-server
+	cd e2e && docker compose run --rm e2e-agent-runner
+	cd e2e && docker compose run --rm e2e-agent-docker
+	cd e2e && docker compose down -v
+
+e2e-clean:
+	cd e2e && docker compose down -v --rmi local
+	cd e2e && docker compose -f docker-compose.backup-restore.yml down -v --rmi local 2>/dev/null || true
+	rm -rf e2e/artifacts

agent/cmd/main.go

@@ -0,0 +1,245 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"fmt"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+	"databasus-agent/internal/features/restore"
+	"databasus-agent/internal/features/start"
+	"databasus-agent/internal/features/upgrade"
+	"databasus-agent/internal/logger"
+)
+
+var Version = "dev"
+
+func main() {
+	if len(os.Args) < 2 {
+		printUsage()
+		os.Exit(1)
+	}
+
+	switch os.Args[1] {
+	case "start":
+		runStart(os.Args[2:])
+	case "_run":
+		runDaemon(os.Args[2:])
+	case "stop":
+		runStop()
+	case "status":
+		runStatus()
+	case "restore":
+		runRestore(os.Args[2:])
+	case "version":
+		fmt.Println(Version)
+	default:
+		fmt.Fprintf(os.Stderr, "unknown command: %s\n", os.Args[1])
+		printUsage()
+		os.Exit(1)
+	}
+}
+
+func runStart(args []string) {
+	fs := flag.NewFlagSet("start", flag.ExitOnError)
+
+	isSkipUpdate := fs.Bool("skip-update", false, "Skip auto-update check")
+
+	cfg := &config.Config{}
+	cfg.LoadFromJSONAndArgs(fs, args)
+
+	if err := cfg.SaveToJSON(); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to save config: %v\n", err)
+	}
+
+	log := logger.GetLogger()
+
+	isDev := checkIsDevelopment()
+	runUpdateCheck(cfg.DatabasusHost, *isSkipUpdate, isDev, log)
+
+	if err := start.Start(cfg, Version, isDev, log); err != nil {
+		if errors.Is(err, upgrade.ErrUpgradeRestart) {
+			reexecAfterUpgrade(log)
+		}
+
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func runDaemon(args []string) {
+	fs := flag.NewFlagSet("_run", flag.ExitOnError)
+
+	if err := fs.Parse(args); err != nil {
+		os.Exit(1)
+	}
+
+	log := logger.GetLogger()
+
+	cfg := &config.Config{}
+	cfg.LoadFromJSON()
+
+	if err := start.RunDaemon(cfg, Version, checkIsDevelopment(), log); err != nil {
+		if errors.Is(err, upgrade.ErrUpgradeRestart) {
+			reexecAfterUpgrade(log)
+		}
+
+		log.Error("Agent exited with error", "error", err)
+		os.Exit(1)
+	}
+}
+
+func runStop() {
+	log := logger.GetLogger()
+
+	if err := start.Stop(log); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func runStatus() {
+	log := logger.GetLogger()
+
+	if err := start.Status(log); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func runRestore(args []string) {
+	fs := flag.NewFlagSet("restore", flag.ExitOnError)
+
+	pgDataDir := fs.String("target-dir", "", "Target pgdata directory (required)")
+	backupID := fs.String("backup-id", "", "Full backup UUID (optional)")
+	targetTime := fs.String("target-time", "", "PITR target time in RFC3339 (optional)")
+	isSkipUpdate := fs.Bool("skip-update", false, "Skip auto-update check")
+
+	cfg := &config.Config{}
+	cfg.LoadFromJSONAndArgs(fs, args)
+
+	if err := cfg.SaveToJSON(); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to save config: %v\n", err)
+	}
+
+	log := logger.GetLogger()
+
+	isDev := checkIsDevelopment()
+	runUpdateCheck(cfg.DatabasusHost, *isSkipUpdate, isDev, log)
+
+	if *pgDataDir == "" {
+		fmt.Fprintln(os.Stderr, "Error: --target-dir is required")
+		os.Exit(1)
+	}
+
+	if cfg.DatabasusHost == "" || cfg.Token == "" {
+		fmt.Fprintln(os.Stderr, "Error: databasus-host and token must be configured")
+		os.Exit(1)
+	}
+
+	if cfg.PgType != "host" && cfg.PgType != "docker" {
+		fmt.Fprintf(os.Stderr, "Error: --pg-type must be 'host' or 'docker', got '%s'\n", cfg.PgType)
+		os.Exit(1)
+	}
+
+	apiClient := api.NewClient(cfg.DatabasusHost, cfg.Token, log)
+	restorer := restore.NewRestorer(apiClient, log, *pgDataDir, *backupID, *targetTime, cfg.PgType)
+
+	ctx := context.Background()
+	if err := restorer.Run(ctx); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func printUsage() {
+	fmt.Fprintln(os.Stderr, "Usage: databasus-agent <command> [flags]")
+	fmt.Fprintln(os.Stderr, "")
+	fmt.Fprintln(os.Stderr, "Commands:")
+	fmt.Fprintln(os.Stderr, "  start    Start the agent (WAL archiving + basebackups)")
+	fmt.Fprintln(os.Stderr, "  stop     Stop a running agent")
+	fmt.Fprintln(os.Stderr, "  status   Show agent status")
+	fmt.Fprintln(os.Stderr, "  restore  Restore a database from backup")
+	fmt.Fprintln(os.Stderr, "  version  Print agent version")
+}
+
+func runUpdateCheck(host string, isSkipUpdate, isDev bool, log *slog.Logger) {
+	if isSkipUpdate {
+		return
+	}
+
+	if host == "" {
+		return
+	}
+
+	apiClient := api.NewClient(host, "", log)
+
+	isUpgraded, err := upgrade.CheckAndUpdate(apiClient, Version, isDev, log)
+	if err != nil {
+		log.Error("Auto-update failed", "error", err)
+		os.Exit(1)
+	}
+
+	if isUpgraded {
+		reexecAfterUpgrade(log)
+	}
+}
+
+func checkIsDevelopment() bool {
+	dir, err := os.Getwd()
+	if err != nil {
+		return false
+	}
+
+	for range 3 {
+		if data, err := os.ReadFile(filepath.Join(dir, ".env")); err == nil {
+			return parseEnvMode(data)
+		}
+
+		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
+			return false
+		}
+
+		dir = filepath.Dir(dir)
+	}
+
+	return false
+}
+
+func parseEnvMode(data []byte) bool {
+	for line := range strings.SplitSeq(string(data), "\n") {
+		line = strings.TrimSpace(line)
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) == 2 && strings.TrimSpace(parts[0]) == "ENV_MODE" {
+			return strings.TrimSpace(parts[1]) == "development"
+		}
+	}
+
+	return false
+}
+
+func reexecAfterUpgrade(log *slog.Logger) {
+	selfPath, err := os.Executable()
+	if err != nil {
+		log.Error("Failed to resolve executable for re-exec", "error", err)
+		os.Exit(1)
+	}
+
+	log.Info("Re-executing after upgrade...")
+
+	if err := syscall.Exec(selfPath, os.Args, os.Environ()); err != nil {
+		log.Error("Failed to re-exec after upgrade", "error", err)
+		os.Exit(1)
+	}
+}

agent/docker-compose.yml.example

@@ -0,0 +1,58 @@
+services:
+  dev-postgres:
+    image: postgres:17
+    container_name: dev-postgres
+    environment:
+      POSTGRES_DB: devdb
+      POSTGRES_USER: devuser
+      POSTGRES_PASSWORD: devpassword
+    ports:
+      - "7433:5432"
+    command:
+      - bash
+      - -c
+      - |
+        mkdir -p /wal-queue && chown postgres:postgres /wal-queue
+        exec docker-entrypoint.sh postgres \
+          -c wal_level=replica \
+          -c max_wal_senders=3 \
+          -c archive_mode=on \
+          -c "archive_command=cp %p /wal-queue/%f"
+    volumes:
+      - ./wal-queue:/wal-queue
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U devuser -d devdb"]
+      interval: 2s
+      timeout: 5s
+      retries: 30
+
+  db-writer:
+    image: postgres:17
+    container_name: dev-db-writer
+    depends_on:
+      dev-postgres:
+        condition: service_healthy
+    environment:
+      PGHOST: dev-postgres
+      PGPORT: "5432"
+      PGUSER: devuser
+      PGPASSWORD: devpassword
+      PGDATABASE: devdb
+    command:
+      - bash
+      - -c
+      - |
+        echo "Waiting for postgres..."
+        until pg_isready -h dev-postgres -U devuser -d devdb; do sleep 1; done
+
+        psql -c "DROP TABLE IF EXISTS wal_generator;"
+        psql -c "CREATE TABLE wal_generator (id SERIAL PRIMARY KEY, data TEXT NOT NULL);"
+        echo "Starting WAL generation loop..."
+        while true; do
+          echo "Inserting ~50MB of data..."
+          psql -c "INSERT INTO wal_generator (data) SELECT repeat(md5(random()::text), 640) FROM generate_series(1, 2500);"
+          echo "Deleting data..."
+          psql -c "DELETE FROM wal_generator;"
+          echo "Cycle complete, sleeping 5s..."
+          sleep 5
+        done

agent/e2e/.gitignore

@@ -0,0 +1,2 @@
+artifacts/
+pgdata/

agent/e2e/Dockerfile.agent-builder

@@ -0,0 +1,13 @@
+# Builds agent binaries with different versions so
+# we can test upgrade behavior (v1 -> v2)
+FROM golang:1.26.1-alpine AS build
+WORKDIR /src
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN CGO_ENABLED=0 go build -ldflags "-X main.Version=v1.0.0" -o /out/agent-v1 ./cmd/main.go
+RUN CGO_ENABLED=0 go build -ldflags "-X main.Version=v2.0.0" -o /out/agent-v2 ./cmd/main.go
+
+FROM alpine:3.21
+COPY --from=build /out/ /out/
+CMD ["cp", "-v", "/out/agent-v1", "/out/agent-v2", "/artifacts/"]

agent/e2e/Dockerfile.agent-docker

@@ -0,0 +1,22 @@
+# Runs backup-restore via docker exec test (test 6). Needs both Docker
+# CLI (for pg_basebackup via docker exec) and PostgreSQL server (for
+# restore verification).
+FROM debian:bookworm-slim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      ca-certificates curl gnupg2 locales postgresql-common && \
+    sed -i '/en_US.UTF-8/s/^# //g' /etc/locale.gen && \
+    locale-gen && \
+    /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y && \
+    apt-get install -y --no-install-recommends \
+      postgresql-17 && \
+    install -m 0755 -d /etc/apt/keyrings && \
+    curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc && \
+    echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian bookworm stable" > /etc/apt/sources.list.d/docker.list && \
+    apt-get update && \
+    apt-get install -y --no-install-recommends docker-ce-cli && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp
+ENTRYPOINT []

agent/e2e/Dockerfile.agent-runner

@@ -0,0 +1,14 @@
+# Runs upgrade and host-mode backup-restore tests (tests 1-5). Needs
+# full PostgreSQL server for backup-restore lifecycle tests.
+FROM debian:bookworm-slim
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      ca-certificates curl gnupg2 postgresql-common && \
+    /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y && \
+    apt-get install -y --no-install-recommends \
+      postgresql-17 && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp
+ENTRYPOINT []

agent/e2e/Dockerfile.backup-restore-runner

@@ -0,0 +1,16 @@
+# Runs backup-restore lifecycle tests with a specific PostgreSQL version.
+# Used for PG version matrix testing (15, 16, 17, 18).
+FROM debian:bookworm-slim
+
+ARG PG_VERSION=17
+
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      ca-certificates curl gnupg2 postgresql-common && \
+    /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y && \
+    apt-get install -y --no-install-recommends \
+      postgresql-${PG_VERSION} && \
+    rm -rf /var/lib/apt/lists/*
+
+WORKDIR /tmp
+ENTRYPOINT []

agent/e2e/Dockerfile.mock-server

@@ -0,0 +1,10 @@
+# Mock databasus API server for version checks and binary downloads. Just
+# serves static responses and files from the `artifacts` directory.
+FROM golang:1.26.1-alpine AS build
+WORKDIR /app
+COPY mock-server/main.go .
+RUN CGO_ENABLED=0 go build -o mock-server main.go
+
+FROM alpine:3.21
+COPY --from=build /app/mock-server /usr/local/bin/mock-server
+ENTRYPOINT ["mock-server"]

agent/e2e/docker-compose.backup-restore.yml

@@ -0,0 +1,33 @@
+services:
+  e2e-br-mock-server:
+    build:
+      context: .
+      dockerfile: Dockerfile.mock-server
+    volumes:
+      - backup-storage:/backup-storage
+    container_name: e2e-br-mock-server
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:4050/health"]
+      interval: 2s
+      timeout: 5s
+      retries: 10
+
+  e2e-br-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.backup-restore-runner
+      args:
+        PG_VERSION: ${PG_VERSION:-17}
+    volumes:
+      - ./artifacts:/opt/agent/artifacts:ro
+      - ./scripts:/opt/agent/scripts:ro
+    depends_on:
+      e2e-br-mock-server:
+        condition: service_healthy
+    container_name: e2e-br-runner
+    command: ["bash", "/opt/agent/scripts/test-pg-host-path.sh"]
+    environment:
+      MOCK_SERVER_OVERRIDE: "http://e2e-br-mock-server:4050"
+
+volumes:
+  backup-storage:

agent/e2e/docker-compose.yml

@@ -0,0 +1,84 @@
+services:
+  e2e-agent-builder:
+    build:
+      context: ..
+      dockerfile: e2e/Dockerfile.agent-builder
+    volumes:
+      - ./artifacts:/artifacts
+    container_name: e2e-agent-builder
+
+  e2e-postgres:
+    image: postgres:17
+    environment:
+      POSTGRES_DB: testdb
+      POSTGRES_USER: testuser
+      POSTGRES_PASSWORD: testpassword
+    container_name: e2e-agent-postgres
+    command:
+      - bash
+      - -c
+      - |
+        mkdir -p /wal-queue && chown postgres:postgres /wal-queue
+        exec docker-entrypoint.sh postgres \
+          -c wal_level=replica \
+          -c max_wal_senders=3 \
+          -c archive_mode=on \
+          -c "archive_command=cp %p /wal-queue/%f"
+    volumes:
+      - ./pgdata:/var/lib/postgresql/data
+      - wal-queue:/wal-queue
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U testuser -d testdb"]
+      interval: 2s
+      timeout: 5s
+      retries: 30
+
+  e2e-mock-server:
+    build:
+      context: .
+      dockerfile: Dockerfile.mock-server
+    volumes:
+      - ./artifacts:/artifacts:ro
+      - backup-storage:/backup-storage
+    container_name: e2e-mock-server
+    healthcheck:
+      test: ["CMD", "wget", "-q", "--spider", "http://localhost:4050/health"]
+      interval: 2s
+      timeout: 5s
+      retries: 10
+
+  e2e-agent-runner:
+    build:
+      context: .
+      dockerfile: Dockerfile.agent-runner
+    volumes:
+      - ./artifacts:/opt/agent/artifacts:ro
+      - ./scripts:/opt/agent/scripts:ro
+    depends_on:
+      e2e-postgres:
+        condition: service_healthy
+      e2e-mock-server:
+        condition: service_healthy
+    container_name: e2e-agent-runner
+    command: ["bash", "/opt/agent/scripts/run-all.sh", "host"]
+
+  e2e-agent-docker:
+    build:
+      context: .
+      dockerfile: Dockerfile.agent-docker
+    volumes:
+      - ./artifacts:/opt/agent/artifacts:ro
+      - ./scripts:/opt/agent/scripts:ro
+      - /var/run/docker.sock:/var/run/docker.sock
+      - wal-queue:/wal-queue
+    depends_on:
+      e2e-postgres:
+        condition: service_healthy
+      e2e-mock-server:
+        condition: service_healthy
+    container_name: e2e-agent-docker
+    command: ["bash", "/opt/agent/scripts/run-all.sh", "docker"]
+
+volumes:
+  wal-queue:
+  backup-storage:

agent/e2e/mock-server/main.go

@@ -0,0 +1,477 @@
+package main
+
+import (
+	"crypto/rand"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+const backupStorageDir = "/backup-storage"
+
+type walSegment struct {
+	BackupID    string
+	SegmentName string
+	FilePath    string
+	SizeBytes   int64
+}
+
+type server struct {
+	mu         sync.RWMutex
+	version    string
+	binaryPath string
+
+	backupID        string
+	backupFilePath  string
+	startSegment    string
+	stopSegment     string
+	isFinalized     bool
+	walSegments     []walSegment
+	backupCreatedAt time.Time
+}
+
+func main() {
+	version := "v2.0.0"
+	binaryPath := "/artifacts/agent-v2"
+	port := "4050"
+
+	_ = os.MkdirAll(backupStorageDir, 0o755)
+
+	s := &server{version: version, binaryPath: binaryPath}
+
+	// System endpoints
+	http.HandleFunc("/api/v1/system/version", s.handleVersion)
+	http.HandleFunc("/api/v1/system/agent", s.handleAgentDownload)
+
+	// Backup endpoints
+	http.HandleFunc("/api/v1/backups/postgres/wal/is-wal-chain-valid-since-last-full-backup", s.handleChainValidity)
+	http.HandleFunc("/api/v1/backups/postgres/wal/next-full-backup-time", s.handleNextBackupTime)
+	http.HandleFunc("/api/v1/backups/postgres/wal/upload/full-start", s.handleFullStart)
+	http.HandleFunc("/api/v1/backups/postgres/wal/upload/full-complete", s.handleFullComplete)
+	http.HandleFunc("/api/v1/backups/postgres/wal/upload/wal", s.handleWalUpload)
+	http.HandleFunc("/api/v1/backups/postgres/wal/error", s.handleError)
+
+	// Restore endpoints
+	http.HandleFunc("/api/v1/backups/postgres/wal/restore/plan", s.handleRestorePlan)
+	http.HandleFunc("/api/v1/backups/postgres/wal/restore/download", s.handleRestoreDownload)
+
+	// Mock control endpoints
+	http.HandleFunc("/mock/set-version", s.handleSetVersion)
+	http.HandleFunc("/mock/set-binary-path", s.handleSetBinaryPath)
+	http.HandleFunc("/mock/backup-status", s.handleBackupStatus)
+	http.HandleFunc("/mock/reset", s.handleReset)
+	http.HandleFunc("/health", s.handleHealth)
+
+	addr := ":" + port
+	log.Printf("Mock server starting on %s (version=%s, binary=%s)", addr, version, binaryPath)
+
+	if err := http.ListenAndServe(addr, nil); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}
+
+// --- System handlers ---
+
+func (s *server) handleVersion(w http.ResponseWriter, _ *http.Request) {
+	s.mu.RLock()
+	v := s.version
+	s.mu.RUnlock()
+
+	log.Printf("GET /api/v1/system/version -> %s", v)
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]string{"version": v})
+}
+
+func (s *server) handleAgentDownload(w http.ResponseWriter, r *http.Request) {
+	s.mu.RLock()
+	path := s.binaryPath
+	s.mu.RUnlock()
+
+	log.Printf("GET /api/v1/system/agent (arch=%s) -> serving %s", r.URL.Query().Get("arch"), path)
+
+	http.ServeFile(w, r, path)
+}
+
+// --- Backup handlers ---
+
+func (s *server) handleChainValidity(w http.ResponseWriter, _ *http.Request) {
+	s.mu.RLock()
+	isFinalized := s.isFinalized
+	s.mu.RUnlock()
+
+	log.Printf("GET chain-validity -> isFinalized=%v", isFinalized)
+
+	w.Header().Set("Content-Type", "application/json")
+
+	if isFinalized {
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"isValid": true,
+		})
+	} else {
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"isValid": false,
+			"error":   "no full backup found",
+		})
+	}
+}
+
+func (s *server) handleNextBackupTime(w http.ResponseWriter, _ *http.Request) {
+	log.Printf("GET next-full-backup-time")
+
+	nextTime := time.Now().UTC().Add(1 * time.Hour)
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]any{
+		"nextFullBackupTime": nextTime.Format(time.RFC3339),
+	})
+}
+
+func (s *server) handleFullStart(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	backupID := generateID()
+	filePath := filepath.Join(backupStorageDir, backupID+".zst")
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		log.Printf("ERROR creating backup file: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	bytesWritten, err := io.Copy(file, r.Body)
+	_ = file.Close()
+
+	if err != nil {
+		log.Printf("ERROR writing backup data: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	s.mu.Lock()
+	s.backupID = backupID
+	s.backupFilePath = filePath
+	s.backupCreatedAt = time.Now().UTC()
+	s.mu.Unlock()
+
+	log.Printf("POST full-start -> backupID=%s, size=%d bytes", backupID, bytesWritten)
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]string{"backupId": backupID})
+}
+
+func (s *server) handleFullComplete(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var body struct {
+		BackupID     string  `json:"backupId"`
+		StartSegment string  `json:"startSegment"`
+		StopSegment  string  `json:"stopSegment"`
+		Error        *string `json:"error,omitempty"`
+	}
+
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	if body.Error != nil {
+		log.Printf("POST full-complete -> backupID=%s ERROR: %s", body.BackupID, *body.Error)
+		w.WriteHeader(http.StatusOK)
+		return
+	}
+
+	s.mu.Lock()
+	s.startSegment = body.StartSegment
+	s.stopSegment = body.StopSegment
+	s.isFinalized = true
+	s.mu.Unlock()
+
+	log.Printf(
+		"POST full-complete -> backupID=%s, start=%s, stop=%s",
+		body.BackupID,
+		body.StartSegment,
+		body.StopSegment,
+	)
+
+	w.WriteHeader(http.StatusOK)
+}
+
+func (s *server) handleWalUpload(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	segmentName := r.Header.Get("X-Wal-Segment-Name")
+	if segmentName == "" {
+		http.Error(w, "missing X-Wal-Segment-Name header", http.StatusBadRequest)
+		return
+	}
+
+	walBackupID := generateID()
+	filePath := filepath.Join(backupStorageDir, walBackupID+".zst")
+
+	file, err := os.Create(filePath)
+	if err != nil {
+		log.Printf("ERROR creating WAL file: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	bytesWritten, err := io.Copy(file, r.Body)
+	_ = file.Close()
+
+	if err != nil {
+		log.Printf("ERROR writing WAL data: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	s.mu.Lock()
+	s.walSegments = append(s.walSegments, walSegment{
+		BackupID:    walBackupID,
+		SegmentName: segmentName,
+		FilePath:    filePath,
+		SizeBytes:   bytesWritten,
+	})
+	s.mu.Unlock()
+
+	log.Printf("POST wal-upload -> segment=%s, walBackupID=%s, size=%d", segmentName, walBackupID, bytesWritten)
+
+	w.WriteHeader(http.StatusNoContent)
+}
+
+func (s *server) handleError(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var body struct {
+		Error string `json:"error"`
+	}
+
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		log.Printf("POST error -> failed to decode: %v", err)
+	} else {
+		log.Printf("POST error -> %s", body.Error)
+	}
+
+	w.WriteHeader(http.StatusOK)
+}
+
+// --- Restore handlers ---
+
+func (s *server) handleRestorePlan(w http.ResponseWriter, _ *http.Request) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if !s.isFinalized {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		_ = json.NewEncoder(w).Encode(map[string]string{
+			"error":   "no_backups",
+			"message": "No full backups available",
+		})
+		return
+	}
+
+	backupFileInfo, err := os.Stat(s.backupFilePath)
+	if err != nil {
+		log.Printf("ERROR stat backup file: %v", err)
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	backupSizeBytes := backupFileInfo.Size()
+	totalSizeBytes := backupSizeBytes
+
+	walSegmentsJSON := make([]map[string]any, 0, len(s.walSegments))
+
+	latestSegment := ""
+
+	for _, segment := range s.walSegments {
+		totalSizeBytes += segment.SizeBytes
+		latestSegment = segment.SegmentName
+
+		walSegmentsJSON = append(walSegmentsJSON, map[string]any{
+			"backupId":    segment.BackupID,
+			"segmentName": segment.SegmentName,
+			"sizeBytes":   segment.SizeBytes,
+		})
+	}
+
+	response := map[string]any{
+		"fullBackup": map[string]any{
+			"id":                        s.backupID,
+			"fullBackupWalStartSegment": s.startSegment,
+			"fullBackupWalStopSegment":  s.stopSegment,
+			"pgVersion":                 "17",
+			"createdAt":                 s.backupCreatedAt.Format(time.RFC3339),
+			"sizeBytes":                 backupSizeBytes,
+		},
+		"walSegments":            walSegmentsJSON,
+		"totalSizeBytes":         totalSizeBytes,
+		"latestAvailableSegment": latestSegment,
+	}
+
+	log.Printf("GET restore-plan -> backupID=%s, walSegments=%d", s.backupID, len(s.walSegments))
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(response)
+}
+
+func (s *server) handleRestoreDownload(w http.ResponseWriter, r *http.Request) {
+	requestedBackupID := r.URL.Query().Get("backupId")
+	if requestedBackupID == "" {
+		http.Error(w, "missing backupId query param", http.StatusBadRequest)
+		return
+	}
+
+	filePath := s.findBackupFile(requestedBackupID)
+	if filePath == "" {
+		log.Printf("GET restore-download -> backupId=%s NOT FOUND", requestedBackupID)
+		http.Error(w, "backup not found", http.StatusNotFound)
+		return
+	}
+
+	log.Printf("GET restore-download -> backupId=%s, file=%s", requestedBackupID, filePath)
+
+	http.ServeFile(w, r, filePath)
+}
+
+// --- Mock control handlers ---
+
+func (s *server) handleSetVersion(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var body struct {
+		Version string `json:"version"`
+	}
+
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	s.mu.Lock()
+	s.version = body.Version
+	s.mu.Unlock()
+
+	log.Printf("POST /mock/set-version -> %s", body.Version)
+
+	_, _ = fmt.Fprintf(w, "version set to %s", body.Version)
+}
+
+func (s *server) handleSetBinaryPath(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var body struct {
+		BinaryPath string `json:"binaryPath"`
+	}
+
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	s.mu.Lock()
+	s.binaryPath = body.BinaryPath
+	s.mu.Unlock()
+
+	log.Printf("POST /mock/set-binary-path -> %s", body.BinaryPath)
+
+	_, _ = fmt.Fprintf(w, "binary path set to %s", body.BinaryPath)
+}
+
+func (s *server) handleBackupStatus(w http.ResponseWriter, _ *http.Request) {
+	s.mu.RLock()
+	isFinalized := s.isFinalized
+	walSegmentCount := len(s.walSegments)
+	s.mu.RUnlock()
+
+	w.Header().Set("Content-Type", "application/json")
+	_ = json.NewEncoder(w).Encode(map[string]any{
+		"isFinalized":     isFinalized,
+		"walSegmentCount": walSegmentCount,
+	})
+}
+
+func (s *server) handleReset(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "POST only", http.StatusMethodNotAllowed)
+		return
+	}
+
+	s.mu.Lock()
+	s.backupID = ""
+	s.backupFilePath = ""
+	s.startSegment = ""
+	s.stopSegment = ""
+	s.isFinalized = false
+	s.walSegments = nil
+	s.backupCreatedAt = time.Time{}
+	s.mu.Unlock()
+
+	// Clean stored files
+	entries, _ := os.ReadDir(backupStorageDir)
+	for _, entry := range entries {
+		_ = os.Remove(filepath.Join(backupStorageDir, entry.Name()))
+	}
+
+	log.Printf("POST /mock/reset -> state cleared")
+
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte("ok"))
+}
+
+func (s *server) handleHealth(w http.ResponseWriter, _ *http.Request) {
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte("ok"))
+}
+
+// --- Private helpers ---
+
+func generateID() string {
+	b := make([]byte, 16)
+	_, _ = rand.Read(b)
+
+	return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x", b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
+}
+
+func (s *server) findBackupFile(backupID string) string {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	if s.backupID == backupID {
+		return s.backupFilePath
+	}
+
+	for _, segment := range s.walSegments {
+		if segment.BackupID == backupID {
+			return segment.FilePath
+		}
+	}
+
+	return ""
+}

agent/e2e/scripts/backup-restore-helpers.sh

@@ -0,0 +1,357 @@
+#!/bin/bash
+# Shared helper functions for backup-restore E2E tests.
+# Source this file from test scripts: source "$(dirname "$0")/backup-restore-helpers.sh"
+
+AGENT="/tmp/test-agent"
+AGENT_PID=""
+
+cleanup_agent() {
+  if [ -n "$AGENT_PID" ]; then
+    kill "$AGENT_PID" 2>/dev/null || true
+    wait "$AGENT_PID" 2>/dev/null || true
+    AGENT_PID=""
+  fi
+
+  pkill -f "test-agent" 2>/dev/null || true
+  for i in $(seq 1 20); do
+    pgrep -f "test-agent" > /dev/null 2>&1 || break
+    sleep 0.5
+  done
+  pkill -9 -f "test-agent" 2>/dev/null || true
+  sleep 0.5
+
+  rm -f "$AGENT" "$AGENT.update" databasus.lock databasus.log databasus.log.old databasus.json 2>/dev/null || true
+}
+
+setup_agent() {
+  local artifacts="${1:-/opt/agent/artifacts}"
+
+  cleanup_agent
+  cp "$artifacts/agent-v1" "$AGENT"
+  chmod +x "$AGENT"
+}
+
+init_pg_local() {
+  local pgdata="$1"
+  local port="$2"
+  local wal_queue="$3"
+  local pg_bin_dir="$4"
+
+  # Stop any leftover PG from previous test runs
+  su postgres -c "$pg_bin_dir/pg_ctl -D $pgdata stop -m immediate" 2>/dev/null || true
+  su postgres -c "$pg_bin_dir/pg_ctl -D /tmp/restore-pgdata stop -m immediate" 2>/dev/null || true
+
+  mkdir -p "$wal_queue"
+  chown postgres:postgres "$wal_queue"
+  rm -rf "$pgdata"
+
+  su postgres -c "$pg_bin_dir/initdb -D $pgdata" > /dev/null
+
+  cat >> "$pgdata/postgresql.conf" <<PGCONF
+wal_level = replica
+archive_mode = on
+archive_command = 'cp %p $wal_queue/%f'
+max_wal_senders = 3
+listen_addresses = 'localhost'
+port = $port
+checkpoint_timeout = 30s
+PGCONF
+
+  echo "local all all trust" > "$pgdata/pg_hba.conf"
+  echo "host all all 127.0.0.1/32 trust" >> "$pgdata/pg_hba.conf"
+  echo "host all all ::1/128 trust" >> "$pgdata/pg_hba.conf"
+  echo "local replication all trust" >> "$pgdata/pg_hba.conf"
+  echo "host replication all 127.0.0.1/32 trust" >> "$pgdata/pg_hba.conf"
+  echo "host replication all ::1/128 trust" >> "$pgdata/pg_hba.conf"
+
+  su postgres -c "$pg_bin_dir/pg_ctl -D $pgdata -l /tmp/pg.log start -w"
+
+  su postgres -c "$pg_bin_dir/psql -p $port -c \"CREATE USER testuser WITH SUPERUSER REPLICATION;\"" > /dev/null 2>&1 || true
+  su postgres -c "$pg_bin_dir/psql -p $port -c \"CREATE DATABASE testdb OWNER testuser;\"" > /dev/null 2>&1 || true
+
+  echo "PostgreSQL initialized and started on port $port"
+}
+
+insert_test_data() {
+  local port="$1"
+  local pg_bin_dir="$2"
+
+  su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb" <<SQL
+CREATE TABLE e2e_test_data (
+    id SERIAL PRIMARY KEY,
+    name TEXT NOT NULL,
+    value INT NOT NULL,
+    created_at TIMESTAMPTZ DEFAULT NOW()
+);
+
+INSERT INTO e2e_test_data (name, value) VALUES
+    ('row1', 100),
+    ('row2', 200),
+    ('row3', 300);
+SQL
+
+  echo "Test data inserted (3 rows)"
+}
+
+force_checkpoint() {
+  local port="$1"
+  local pg_bin_dir="$2"
+
+  su postgres -c "$pg_bin_dir/psql -p $port -c 'CHECKPOINT;'" > /dev/null
+  echo "Checkpoint forced"
+}
+
+run_agent_backup() {
+  local mock_server="$1"
+  local pg_host="$2"
+  local pg_port="$3"
+  local wal_queue="$4"
+  local pg_type="$5"
+  local pg_host_bin_dir="${6:-}"
+  local pg_docker_container="${7:-}"
+
+  # Reset mock server state and set version to match agent (prevents background upgrade loop)
+  curl -sf -X POST "$mock_server/mock/reset" > /dev/null
+  curl -sf -X POST "$mock_server/mock/set-version" \
+    -H "Content-Type: application/json" \
+    -d '{"version":"v1.0.0"}' > /dev/null
+
+  # Build JSON config
+  cd /tmp
+
+  local extra_fields=""
+  if [ -n "$pg_host_bin_dir" ]; then
+    extra_fields="$extra_fields\"pgHostBinDir\": \"$pg_host_bin_dir\","
+  fi
+  if [ -n "$pg_docker_container" ]; then
+    extra_fields="$extra_fields\"pgDockerContainerName\": \"$pg_docker_container\","
+  fi
+
+  cat > databasus.json <<AGENTCONF
+{
+  "databasusHost": "$mock_server",
+  "dbId": "test-db-id",
+  "token": "test-token",
+  "pgHost": "$pg_host",
+  "pgPort": $pg_port,
+  "pgUser": "testuser",
+  "pgPassword": "",
+  ${extra_fields}
+  "pgType": "$pg_type",
+  "pgWalDir": "$wal_queue",
+  "deleteWalAfterUpload": true
+}
+AGENTCONF
+
+  # Run agent daemon in background
+  "$AGENT" _run > /tmp/agent-output.log 2>&1 &
+  AGENT_PID=$!
+
+  echo "Agent started with PID $AGENT_PID"
+}
+
+generate_wal_background() {
+  local port="$1"
+  local pg_bin_dir="$2"
+
+  while true; do
+    su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -c \"
+      INSERT INTO e2e_test_data (name, value)
+      SELECT 'bulk_' || g, g FROM generate_series(1, 1000) g;
+      SELECT pg_switch_wal();
+    \"" > /dev/null 2>&1 || break
+    sleep 2
+  done
+}
+
+generate_wal_docker_background() {
+  local container="$1"
+
+  while true; do
+    docker exec "$container" psql -U testuser -d testdb -c "
+      INSERT INTO e2e_test_data (name, value)
+      SELECT 'bulk_' || g, g FROM generate_series(1, 1000) g;
+      SELECT pg_switch_wal();
+    " > /dev/null 2>&1 || break
+    sleep 2
+  done
+}
+
+wait_for_backup_complete() {
+  local mock_server="$1"
+  local timeout="${2:-120}"
+
+  echo "Waiting for backup to complete (timeout: ${timeout}s)..."
+
+  for i in $(seq 1 "$timeout"); do
+    STATUS=$(curl -sf "$mock_server/mock/backup-status" 2>/dev/null || echo '{}')
+    IS_FINALIZED=$(echo "$STATUS" | grep -o '"isFinalized":true' || true)
+    WAL_COUNT=$(echo "$STATUS" | grep -o '"walSegmentCount":[0-9]*' | grep -o '[0-9]*$' || echo "0")
+
+    if [ -n "$IS_FINALIZED" ] && [ "$WAL_COUNT" -gt 0 ]; then
+      echo "Backup complete: finalized with $WAL_COUNT WAL segments"
+      return 0
+    fi
+
+    sleep 1
+  done
+
+  echo "FAIL: Backup did not complete within ${timeout} seconds"
+  echo "Last status: $STATUS"
+  echo "Agent output:"
+  cat /tmp/agent-output.log 2>/dev/null || true
+  return 1
+}
+
+stop_agent() {
+  if [ -n "$AGENT_PID" ]; then
+    kill "$AGENT_PID" 2>/dev/null || true
+    wait "$AGENT_PID" 2>/dev/null || true
+    AGENT_PID=""
+  fi
+
+  echo "Agent stopped"
+}
+
+stop_pg() {
+  local pgdata="$1"
+  local pg_bin_dir="$2"
+
+  su postgres -c "$pg_bin_dir/pg_ctl -D $pgdata stop -m fast" 2>/dev/null || true
+
+  echo "PostgreSQL stopped"
+}
+
+run_agent_restore() {
+  local mock_server="$1"
+  local restore_dir="$2"
+
+  rm -rf "$restore_dir"
+  mkdir -p "$restore_dir"
+  chown postgres:postgres "$restore_dir"
+
+  cd /tmp
+
+  "$AGENT" restore \
+    --skip-update \
+    --databasus-host "$mock_server" \
+    --token test-token \
+    --target-dir "$restore_dir"
+
+  echo "Agent restore completed"
+}
+
+start_restored_pg() {
+  local restore_dir="$1"
+  local port="$2"
+  local pg_bin_dir="$3"
+
+  # Ensure port is set in restored config
+  if ! grep -q "^port" "$restore_dir/postgresql.conf" 2>/dev/null; then
+    echo "port = $port" >> "$restore_dir/postgresql.conf"
+  fi
+
+  # Ensure listen_addresses is set
+  if ! grep -q "^listen_addresses" "$restore_dir/postgresql.conf" 2>/dev/null; then
+    echo "listen_addresses = 'localhost'" >> "$restore_dir/postgresql.conf"
+  fi
+
+  chown -R postgres:postgres "$restore_dir"
+  chmod 700 "$restore_dir"
+
+  if ! su postgres -c "$pg_bin_dir/pg_ctl -D $restore_dir -l /tmp/pg-restore.log start -w"; then
+    echo "FAIL: PostgreSQL failed to start on restored data"
+    echo "--- pg-restore.log ---"
+    cat /tmp/pg-restore.log 2>/dev/null || echo "(no log file)"
+    echo "--- postgresql.auto.conf ---"
+    cat "$restore_dir/postgresql.auto.conf" 2>/dev/null || echo "(no file)"
+    echo "--- pg_wal/ listing ---"
+    ls -la "$restore_dir/pg_wal/" 2>/dev/null || echo "(no pg_wal dir)"
+    echo "--- databasus-wal-restore/ listing ---"
+    ls -la "$restore_dir/databasus-wal-restore/" 2>/dev/null || echo "(no dir)"
+    echo "--- end diagnostics ---"
+    return 1
+  fi
+
+  echo "PostgreSQL started on restored data"
+}
+
+wait_for_recovery_complete() {
+  local port="$1"
+  local pg_bin_dir="$2"
+  local timeout="${3:-60}"
+
+  echo "Waiting for recovery to complete (timeout: ${timeout}s)..."
+
+  for i in $(seq 1 "$timeout"); do
+    IS_READY=$(su postgres -c "$pg_bin_dir/pg_isready -p $port" 2>&1 || true)
+
+    if echo "$IS_READY" | grep -q "accepting connections"; then
+      IN_RECOVERY=$(su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -t -c 'SELECT pg_is_in_recovery();'" 2>/dev/null | tr -d ' \n' || echo "t")
+
+      if [ "$IN_RECOVERY" = "f" ]; then
+        echo "PostgreSQL recovered and promoted to primary"
+        return 0
+      fi
+    fi
+
+    sleep 1
+  done
+
+  echo "FAIL: PostgreSQL did not recover within ${timeout} seconds"
+  echo "Recovery log:"
+  cat /tmp/pg-restore.log 2>/dev/null || true
+  return 1
+}
+
+verify_restored_data() {
+  local port="$1"
+  local pg_bin_dir="$2"
+
+  ROW_COUNT=$(su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -t -c 'SELECT COUNT(*) FROM e2e_test_data;'" | tr -d ' \n')
+
+  if [ "$ROW_COUNT" -lt 3 ]; then
+    echo "FAIL: Expected at least 3 rows, got $ROW_COUNT"
+    su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -c 'SELECT * FROM e2e_test_data;'"
+    return 1
+  fi
+
+  RESULT=$(su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -t -c \"SELECT value FROM e2e_test_data WHERE name='row1';\"" | tr -d ' \n')
+
+  if [ "$RESULT" != "100" ]; then
+    echo "FAIL: Expected row1 value=100, got $RESULT"
+    return 1
+  fi
+
+  RESULT2=$(su postgres -c "$pg_bin_dir/psql -p $port -U testuser -d testdb -t -c \"SELECT value FROM e2e_test_data WHERE name='row3';\"" | tr -d ' \n')
+
+  if [ "$RESULT2" != "300" ]; then
+    echo "FAIL: Expected row3 value=300, got $RESULT2"
+    return 1
+  fi
+
+  echo "PASS: Found $ROW_COUNT rows, data integrity verified"
+  return 0
+}
+
+find_pg_bin_dir() {
+  # Find the PG bin dir from the installed version
+  local pg_config_path
+  pg_config_path=$(which pg_config 2>/dev/null || true)
+
+  if [ -n "$pg_config_path" ]; then
+    pg_config --bindir
+    return
+  fi
+
+  # Fallback: search common locations
+  for version in 18 17 16 15; do
+    if [ -d "/usr/lib/postgresql/$version/bin" ]; then
+      echo "/usr/lib/postgresql/$version/bin"
+      return
+    fi
+  done
+
+  echo "ERROR: Cannot find PostgreSQL bin directory" >&2
+  return 1
+}

agent/e2e/scripts/run-all.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+set -euo pipefail
+
+MODE="${1:-host}"
+SCRIPT_DIR="$(dirname "$0")"
+PASSED=0
+FAILED=0
+FAILED_NAMES=""
+
+run_test() {
+  local name="$1"
+  local script="$2"
+
+  echo ""
+  echo "========================================"
+  echo "  $name"
+  echo "========================================"
+
+  if bash "$script"; then
+    echo "  PASSED: $name"
+    PASSED=$((PASSED + 1))
+  else
+    echo "  FAILED: $name"
+    FAILED=$((FAILED + 1))
+    FAILED_NAMES="${FAILED_NAMES}\n    - ${name}"
+  fi
+}
+
+if [ "$MODE" = "host" ]; then
+  run_test "Test 1: Upgrade success (v1 -> v2)" "$SCRIPT_DIR/test-upgrade-success.sh"
+  run_test "Test 2: Upgrade skip (version matches)" "$SCRIPT_DIR/test-upgrade-skip.sh"
+  run_test "Test 3: Background upgrade (v1 -> v2 while running)" "$SCRIPT_DIR/test-upgrade-background.sh"
+  run_test "Test 4: Backup-restore via host PATH" "$SCRIPT_DIR/test-pg-host-path.sh"
+  run_test "Test 5: Backup-restore via host bindir" "$SCRIPT_DIR/test-pg-host-bindir.sh"
+
+elif [ "$MODE" = "docker" ]; then
+  run_test "Test 6: Backup-restore via docker exec" "$SCRIPT_DIR/test-pg-docker-exec.sh"
+
+else
+  echo "Unknown mode: $MODE (expected 'host' or 'docker')"
+  exit 1
+fi
+
+echo ""
+echo "========================================"
+echo "  Results: $PASSED passed, $FAILED failed"
+if [ "$FAILED" -gt 0 ]; then
+  echo ""
+  echo "  Failed:"
+  echo -e "$FAILED_NAMES"
+fi
+echo "========================================"
+
+if [ "$FAILED" -gt 0 ]; then
+  exit 1
+fi

agent/e2e/scripts/test-pg-docker-exec.sh

@@ -0,0 +1,95 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$(dirname "$0")"
+source "$SCRIPT_DIR/backup-restore-helpers.sh"
+
+MOCK_SERVER="${MOCK_SERVER_OVERRIDE:-http://e2e-mock-server:4050}"
+PG_CONTAINER="e2e-agent-postgres"
+RESTORE_PGDATA="/tmp/restore-pgdata"
+WAL_QUEUE="/wal-queue"
+PG_PORT=5432
+
+# For restore verification we need a local PG bin dir
+PG_BIN_DIR=$(find_pg_bin_dir)
+echo "Using local PG bin dir for restore verification: $PG_BIN_DIR"
+
+# Verify docker CLI works and PG container is accessible
+if ! docker exec "$PG_CONTAINER" pg_basebackup --version > /dev/null 2>&1; then
+  echo "FAIL: Cannot reach pg_basebackup inside container $PG_CONTAINER (test setup issue)"
+  exit 1
+fi
+
+echo "=== Phase 1: Setup agent ==="
+setup_agent
+
+echo "=== Phase 2: Insert test data into containerized PostgreSQL ==="
+docker exec "$PG_CONTAINER" psql -U testuser -d testdb -c "
+CREATE TABLE IF NOT EXISTS e2e_test_data (
+    id SERIAL PRIMARY KEY,
+    name TEXT NOT NULL,
+    value INT NOT NULL,
+    created_at TIMESTAMPTZ DEFAULT NOW()
+);
+DELETE FROM e2e_test_data;
+INSERT INTO e2e_test_data (name, value) VALUES
+    ('row1', 100),
+    ('row2', 200),
+    ('row3', 300);
+"
+echo "Test data inserted (3 rows)"
+
+echo "=== Phase 3: Start agent backup (docker exec mode) ==="
+curl -sf -X POST "$MOCK_SERVER/mock/reset" > /dev/null
+
+cd /tmp
+cat > databasus.json <<AGENTCONF
+{
+  "databasusHost": "$MOCK_SERVER",
+  "dbId": "test-db-id",
+  "token": "test-token",
+  "pgHost": "$PG_CONTAINER",
+  "pgPort": $PG_PORT,
+  "pgUser": "testuser",
+  "pgPassword": "testpassword",
+  "pgType": "docker",
+  "pgDockerContainerName": "$PG_CONTAINER",
+  "pgWalDir": "$WAL_QUEUE",
+  "deleteWalAfterUpload": true
+}
+AGENTCONF
+
+"$AGENT" _run > /tmp/agent-output.log 2>&1 &
+AGENT_PID=$!
+echo "Agent started with PID $AGENT_PID"
+
+echo "=== Phase 4: Generate WAL in background ==="
+generate_wal_docker_background "$PG_CONTAINER" &
+WAL_GEN_PID=$!
+
+echo "=== Phase 5: Wait for backup to complete ==="
+wait_for_backup_complete "$MOCK_SERVER" 120
+
+echo "=== Phase 6: Stop WAL generator and agent ==="
+kill $WAL_GEN_PID 2>/dev/null || true
+wait $WAL_GEN_PID 2>/dev/null || true
+stop_agent
+
+echo "=== Phase 7: Restore to local directory ==="
+run_agent_restore "$MOCK_SERVER" "$RESTORE_PGDATA"
+
+echo "=== Phase 8: Start local PostgreSQL on restored data ==="
+# Use a different port to avoid conflict with the containerized PG
+RESTORE_PORT=5433
+start_restored_pg "$RESTORE_PGDATA" "$RESTORE_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 9: Wait for recovery ==="
+wait_for_recovery_complete "$RESTORE_PORT" "$PG_BIN_DIR" 60
+
+echo "=== Phase 10: Verify data ==="
+verify_restored_data "$RESTORE_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 11: Cleanup ==="
+stop_pg "$RESTORE_PGDATA" "$PG_BIN_DIR"
+
+echo "pg_basebackup via docker exec: full backup-restore lifecycle passed"

agent/e2e/scripts/test-pg-host-bindir.sh

@@ -0,0 +1,62 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$(dirname "$0")"
+source "$SCRIPT_DIR/backup-restore-helpers.sh"
+
+MOCK_SERVER="${MOCK_SERVER_OVERRIDE:-http://e2e-mock-server:4050}"
+PGDATA="/tmp/pgdata"
+RESTORE_PGDATA="/tmp/restore-pgdata"
+WAL_QUEUE="/tmp/wal-queue"
+PG_PORT=5433
+CUSTOM_BIN_DIR="/opt/pg/bin"
+
+PG_BIN_DIR=$(find_pg_bin_dir)
+echo "Using PG bin dir: $PG_BIN_DIR"
+
+# Copy pg_basebackup to a custom directory (simulates non-PATH installation)
+mkdir -p "$CUSTOM_BIN_DIR"
+cp "$PG_BIN_DIR/pg_basebackup" "$CUSTOM_BIN_DIR/pg_basebackup"
+
+echo "=== Phase 1: Setup agent ==="
+setup_agent
+
+echo "=== Phase 2: Initialize PostgreSQL ==="
+init_pg_local "$PGDATA" "$PG_PORT" "$WAL_QUEUE" "$PG_BIN_DIR"
+
+echo "=== Phase 3: Insert test data ==="
+insert_test_data "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 4: Force checkpoint and start agent backup (using --pg-host-bin-dir) ==="
+force_checkpoint "$PG_PORT" "$PG_BIN_DIR"
+run_agent_backup "$MOCK_SERVER" "127.0.0.1" "$PG_PORT" "$WAL_QUEUE" "host" "$CUSTOM_BIN_DIR"
+
+echo "=== Phase 5: Generate WAL in background ==="
+generate_wal_background "$PG_PORT" "$PG_BIN_DIR" &
+WAL_GEN_PID=$!
+
+echo "=== Phase 6: Wait for backup to complete ==="
+wait_for_backup_complete "$MOCK_SERVER" 120
+
+echo "=== Phase 7: Stop WAL generator, agent, and PostgreSQL ==="
+kill $WAL_GEN_PID 2>/dev/null || true
+wait $WAL_GEN_PID 2>/dev/null || true
+stop_agent
+stop_pg "$PGDATA" "$PG_BIN_DIR"
+
+echo "=== Phase 8: Restore ==="
+run_agent_restore "$MOCK_SERVER" "$RESTORE_PGDATA"
+
+echo "=== Phase 9: Start PostgreSQL on restored data ==="
+start_restored_pg "$RESTORE_PGDATA" "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 10: Wait for recovery ==="
+wait_for_recovery_complete "$PG_PORT" "$PG_BIN_DIR" 60
+
+echo "=== Phase 11: Verify data ==="
+verify_restored_data "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 12: Cleanup ==="
+stop_pg "$RESTORE_PGDATA" "$PG_BIN_DIR"
+
+echo "pg_basebackup via custom bindir: full backup-restore lifecycle passed"

agent/e2e/scripts/test-pg-host-path.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+set -euo pipefail
+
+SCRIPT_DIR="$(dirname "$0")"
+source "$SCRIPT_DIR/backup-restore-helpers.sh"
+
+MOCK_SERVER="${MOCK_SERVER_OVERRIDE:-http://e2e-mock-server:4050}"
+PGDATA="/tmp/pgdata"
+RESTORE_PGDATA="/tmp/restore-pgdata"
+WAL_QUEUE="/tmp/wal-queue"
+PG_PORT=5433
+
+PG_BIN_DIR=$(find_pg_bin_dir)
+echo "Using PG bin dir: $PG_BIN_DIR"
+
+# Verify pg_basebackup is in PATH
+if ! which pg_basebackup > /dev/null 2>&1; then
+  echo "FAIL: pg_basebackup not found in PATH (test setup issue)"
+  exit 1
+fi
+
+echo "=== Phase 1: Setup agent ==="
+setup_agent
+
+echo "=== Phase 2: Initialize PostgreSQL ==="
+init_pg_local "$PGDATA" "$PG_PORT" "$WAL_QUEUE" "$PG_BIN_DIR"
+
+echo "=== Phase 3: Insert test data ==="
+insert_test_data "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 4: Force checkpoint and start agent backup ==="
+force_checkpoint "$PG_PORT" "$PG_BIN_DIR"
+run_agent_backup "$MOCK_SERVER" "127.0.0.1" "$PG_PORT" "$WAL_QUEUE" "host"
+
+echo "=== Phase 5: Generate WAL in background ==="
+generate_wal_background "$PG_PORT" "$PG_BIN_DIR" &
+WAL_GEN_PID=$!
+
+echo "=== Phase 6: Wait for backup to complete ==="
+wait_for_backup_complete "$MOCK_SERVER" 120
+
+echo "=== Phase 7: Stop WAL generator, agent, and PostgreSQL ==="
+kill $WAL_GEN_PID 2>/dev/null || true
+wait $WAL_GEN_PID 2>/dev/null || true
+stop_agent
+stop_pg "$PGDATA" "$PG_BIN_DIR"
+
+echo "=== Phase 8: Restore ==="
+run_agent_restore "$MOCK_SERVER" "$RESTORE_PGDATA"
+
+echo "=== Phase 9: Start PostgreSQL on restored data ==="
+start_restored_pg "$RESTORE_PGDATA" "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 10: Wait for recovery ==="
+wait_for_recovery_complete "$PG_PORT" "$PG_BIN_DIR" 60
+
+echo "=== Phase 11: Verify data ==="
+verify_restored_data "$PG_PORT" "$PG_BIN_DIR"
+
+echo "=== Phase 12: Cleanup ==="
+stop_pg "$RESTORE_PGDATA" "$PG_BIN_DIR"
+
+echo "pg_basebackup in PATH: full backup-restore lifecycle passed"

agent/e2e/scripts/test-upgrade-background.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+set -euo pipefail
+
+ARTIFACTS="/opt/agent/artifacts"
+AGENT="/tmp/test-agent"
+
+# Cleanup from previous runs
+pkill -f "test-agent" 2>/dev/null || true
+for i in $(seq 1 20); do
+  pgrep -f "test-agent" > /dev/null 2>&1 || break
+  sleep 0.5
+done
+pkill -9 -f "test-agent" 2>/dev/null || true
+sleep 0.5
+rm -f "$AGENT" "$AGENT.update" databasus.lock databasus.log databasus.log.old databasus.json 2>/dev/null || true
+
+# Set mock server to v1.0.0 (same as agent — no sync upgrade on start)
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-version \
+  -H "Content-Type: application/json" \
+  -d '{"version":"v1.0.0"}'
+
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-binary-path \
+  -H "Content-Type: application/json" \
+  -d '{"binaryPath":"/artifacts/agent-v1"}'
+
+# Copy v1 binary to writable location
+cp "$ARTIFACTS/agent-v1" "$AGENT"
+chmod +x "$AGENT"
+
+# Verify initial version
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v1.0.0" ]; then
+  echo "FAIL: Expected initial version v1.0.0, got $VERSION"
+  exit 1
+fi
+echo "Initial version: $VERSION"
+
+# Start agent as daemon (versions match → no sync upgrade)
+mkdir -p /tmp/wal
+"$AGENT" start \
+  --databasus-host http://e2e-mock-server:4050 \
+  --db-id test-db-id \
+  --token test-token \
+  --pg-host e2e-postgres \
+  --pg-port 5432 \
+  --pg-user testuser \
+  --pg-password testpassword \
+  --pg-wal-dir /tmp/wal \
+  --pg-type host
+
+echo "Agent started as daemon, waiting for stabilization..."
+sleep 2
+
+# Change mock server to v2.0.0 and point to v2 binary
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-version \
+  -H "Content-Type: application/json" \
+  -d '{"version":"v2.0.0"}'
+
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-binary-path \
+  -H "Content-Type: application/json" \
+  -d '{"binaryPath":"/artifacts/agent-v2"}'
+
+echo "Mock server updated to v2.0.0, waiting for background upgrade..."
+
+# Poll for upgrade (timeout 60s, poll every 3s)
+DEADLINE=$((SECONDS + 60))
+while [ $SECONDS -lt $DEADLINE ]; do
+  VERSION=$("$AGENT" version)
+  if [ "$VERSION" = "v2.0.0" ]; then
+    echo "Binary upgraded to $VERSION"
+    break
+  fi
+  sleep 3
+done
+
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v2.0.0" ]; then
+  echo "FAIL: Expected v2.0.0 after background upgrade, got $VERSION"
+  cat databasus.log 2>/dev/null || true
+  exit 1
+fi
+
+# Verify agent is still running after restart
+sleep 2
+"$AGENT" status || true
+
+# Cleanup
+"$AGENT" stop || true
+
+echo "Background upgrade test passed"

agent/e2e/scripts/test-upgrade-skip.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+set -euo pipefail
+
+ARTIFACTS="/opt/agent/artifacts"
+AGENT="/tmp/test-agent"
+
+# Cleanup from previous runs
+pkill -f "test-agent" 2>/dev/null || true
+for i in $(seq 1 20); do
+  pgrep -f "test-agent" > /dev/null 2>&1 || break
+  sleep 0.5
+done
+pkill -9 -f "test-agent" 2>/dev/null || true
+sleep 0.5
+rm -f "$AGENT" "$AGENT.update" databasus.lock databasus.log databasus.log.old databasus.json 2>/dev/null || true
+
+# Set mock server to return v1.0.0 (same as agent)
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-version \
+  -H "Content-Type: application/json" \
+  -d '{"version":"v1.0.0"}'
+
+# Copy v1 binary to writable location
+cp "$ARTIFACTS/agent-v1" "$AGENT"
+chmod +x "$AGENT"
+
+# Verify initial version
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v1.0.0" ]; then
+  echo "FAIL: Expected initial version v1.0.0, got $VERSION"
+  exit 1
+fi
+
+# Run start — agent should see version matches and skip upgrade
+echo "Running agent start (expecting upgrade skip)..."
+OUTPUT=$("$AGENT" start \
+  --databasus-host http://e2e-mock-server:4050 \
+  --db-id test-db-id \
+  --token test-token \
+  --pg-host e2e-postgres \
+  --pg-port 5432 \
+  --pg-user testuser \
+  --pg-password testpassword \
+  --pg-wal-dir /tmp/wal \
+  --pg-type host 2>&1) || true
+
+echo "$OUTPUT"
+
+# Verify output contains "up to date"
+if ! echo "$OUTPUT" | grep -qi "up to date"; then
+  echo "FAIL: Expected output to contain 'up to date'"
+  exit 1
+fi
+
+# Verify binary is still v1
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v1.0.0" ]; then
+  echo "FAIL: Expected version v1.0.0 (unchanged), got $VERSION"
+  exit 1
+fi
+
+echo "Upgrade correctly skipped, version still $VERSION"
+
+# Cleanup daemon
+"$AGENT" stop || true

agent/e2e/scripts/test-upgrade-success.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+set -euo pipefail
+
+ARTIFACTS="/opt/agent/artifacts"
+AGENT="/tmp/test-agent"
+
+# Cleanup from previous runs
+pkill -f "test-agent" 2>/dev/null || true
+for i in $(seq 1 20); do
+  pgrep -f "test-agent" > /dev/null 2>&1 || break
+  sleep 0.5
+done
+pkill -9 -f "test-agent" 2>/dev/null || true
+sleep 0.5
+rm -f "$AGENT" "$AGENT.update" databasus.lock databasus.log databasus.log.old databasus.json 2>/dev/null || true
+
+# Ensure mock server returns v2.0.0 and serves v2 binary
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-version \
+  -H "Content-Type: application/json" \
+  -d '{"version":"v2.0.0"}'
+
+curl -sf -X POST http://e2e-mock-server:4050/mock/set-binary-path \
+  -H "Content-Type: application/json" \
+  -d '{"binaryPath":"/artifacts/agent-v2"}'
+
+# Copy v1 binary to writable location
+cp "$ARTIFACTS/agent-v1" "$AGENT"
+chmod +x "$AGENT"
+
+# Verify initial version
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v1.0.0" ]; then
+  echo "FAIL: Expected initial version v1.0.0, got $VERSION"
+  exit 1
+fi
+echo "Initial version: $VERSION"
+
+# Run start — agent will:
+# 1. Fetch version from mock (v2.0.0 != v1.0.0)
+# 2. Download v2 binary from mock
+# 3. Replace itself on disk
+# 4. Re-exec with same args
+# 5. Re-exec'd v2 fetches version (v2.0.0 == v2.0.0) → skips update
+# 6. Proceeds to start → verifies pg_basebackup + DB → exits 0 (stub)
+echo "Running agent start (expecting upgrade v1 -> v2)..."
+OUTPUT=$("$AGENT" start \
+  --databasus-host http://e2e-mock-server:4050 \
+  --db-id test-db-id \
+  --token test-token \
+  --pg-host e2e-postgres \
+  --pg-port 5432 \
+  --pg-user testuser \
+  --pg-password testpassword \
+  --pg-wal-dir /tmp/wal \
+  --pg-type host 2>&1) || true
+
+echo "$OUTPUT"
+
+# Verify binary on disk is now v2
+VERSION=$("$AGENT" version)
+if [ "$VERSION" != "v2.0.0" ]; then
+  echo "FAIL: Expected upgraded version v2.0.0, got $VERSION"
+  exit 1
+fi
+
+echo "Binary upgraded successfully to $VERSION"
+
+# Cleanup daemon
+"$AGENT" stop || true

agent/go.mod

@@ -0,0 +1,22 @@
+module databasus-agent
+
+go 1.26.1
+
+require (
+	github.com/go-resty/resty/v2 v2.17.2
+	github.com/jackc/pgx/v5 v5.8.0
+	github.com/klauspost/compress v1.18.4
+	github.com/stretchr/testify v1.11.1
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
+	github.com/kr/text v0.2.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rogpeppe/go-internal v1.14.1 // indirect
+	golang.org/x/net v0.43.0 // indirect
+	golang.org/x/text v0.29.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

agent/go.sum

@@ -0,0 +1,43 @@
+github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-resty/resty/v2 v2.17.2 h1:FQW5oHYcIlkCNrMD2lloGScxcHJ0gkjshV3qcQAyHQk=
+github.com/go-resty/resty/v2 v2.17.2/go.mod h1:kCKZ3wWmwJaNc7S29BRtUhJwy7iqmn+2mLtQrOyQlVA=
+github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
+github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 h1:iCEnooe7UlwOQYpKFhBabPMi4aNAfoODPEFNiAnClxo=
+github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761/go.mod h1:5TJZWKEWniPve33vlWYSoGYefn3gLQRzjfDlhSJ9ZKM=
+github.com/jackc/pgx/v5 v5.8.0 h1:TYPDoleBBme0xGSAX3/+NujXXtpZn9HBONkQC7IEZSo=
+github.com/jackc/pgx/v5 v5.8.0/go.mod h1:QVeDInX2m9VyzvNeiCJVjCkNFqzsNb43204HshNSZKw=
+github.com/jackc/puddle/v2 v2.2.2 h1:PR8nw+E/1w0GLuRFSmiioY6UooMp6KJv0/61nB7icHo=
+github.com/jackc/puddle/v2 v2.2.2/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/klauspost/compress v1.18.4 h1:RPhnKRAQ4Fh8zU2FY/6ZFDwTVTxgJ/EMydqSTzE9a2c=
+github.com/klauspost/compress v1.18.4/go.mod h1:R0h/fSBs8DE4ENlcrlib3PsXS61voFxhIs2DeRhCvJ4=
+github.com/kr/pretty v0.3.0 h1:WgNl7dwNpEZ6jJ9k1snq4pZsg7DOEN8hP9Xw0Tsjwk0=
+github.com/kr/pretty v0.3.0/go.mod h1:640gp4NfQd8pI5XOwp5fnNeVWj67G7CFk/SaSQn7NBk=
+github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
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agent/internal/config/config.go

@@ -0,0 +1,272 @@
+package config
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+
+	"databasus-agent/internal/logger"
+)
+
+var log = logger.GetLogger()
+
+const configFileName = "databasus.json"
+
+type Config struct {
+	DatabasusHost          string `json:"databasusHost"`
+	DbID                   string `json:"dbId"`
+	Token                  string `json:"token"`
+	PgHost                 string `json:"pgHost"`
+	PgPort                 int    `json:"pgPort"`
+	PgUser                 string `json:"pgUser"`
+	PgPassword             string `json:"pgPassword"`
+	PgType                 string `json:"pgType"`
+	PgHostBinDir           string `json:"pgHostBinDir"`
+	PgDockerContainerName  string `json:"pgDockerContainerName"`
+	PgWalDir               string `json:"pgWalDir"`
+	IsDeleteWalAfterUpload *bool  `json:"deleteWalAfterUpload"`
+
+	flags parsedFlags
+}
+
+// LoadFromJSONAndArgs reads databasus.json into the struct
+// and overrides JSON values with any explicitly provided CLI flags.
+func (c *Config) LoadFromJSONAndArgs(fs *flag.FlagSet, args []string) {
+	c.loadFromJSON()
+	c.applyDefaults()
+	c.initSources()
+
+	c.flags.databasusHost = fs.String(
+		"databasus-host",
+		"",
+		"Databasus server URL (e.g. http://your-server:4005)",
+	)
+	c.flags.dbID = fs.String("db-id", "", "Database ID")
+	c.flags.token = fs.String("token", "", "Agent token")
+	c.flags.pgHost = fs.String("pg-host", "", "PostgreSQL host")
+	c.flags.pgPort = fs.Int("pg-port", 0, "PostgreSQL port")
+	c.flags.pgUser = fs.String("pg-user", "", "PostgreSQL user")
+	c.flags.pgPassword = fs.String("pg-password", "", "PostgreSQL password")
+	c.flags.pgType = fs.String("pg-type", "", "PostgreSQL type: host or docker")
+	c.flags.pgHostBinDir = fs.String("pg-host-bin-dir", "", "Path to PG bin directory (host mode)")
+	c.flags.pgDockerContainerName = fs.String("pg-docker-container-name", "", "Docker container name (docker mode)")
+	c.flags.pgWalDir = fs.String("pg-wal-dir", "", "Path to WAL queue directory")
+
+	if err := fs.Parse(args); err != nil {
+		os.Exit(1)
+	}
+
+	c.applyFlags()
+	log.Info("========= Loading config ============")
+	c.logConfigSources()
+	log.Info("========= Config has been loaded ====")
+}
+
+// SaveToJSON writes the current struct to databasus.json.
+func (c *Config) SaveToJSON() error {
+	data, err := json.MarshalIndent(c, "", "  ")
+	if err != nil {
+		return err
+	}
+
+	return os.WriteFile(configFileName, data, 0o644)
+}
+
+func (c *Config) LoadFromJSON() {
+	c.loadFromJSON()
+	c.applyDefaults()
+}
+
+func (c *Config) loadFromJSON() {
+	data, err := os.ReadFile(configFileName)
+	if err != nil {
+		if os.IsNotExist(err) {
+			log.Info("No databasus.json found, will create on save")
+			return
+		}
+
+		log.Warn("Failed to read databasus.json", "error", err)
+
+		return
+	}
+
+	if err := json.Unmarshal(data, c); err != nil {
+		log.Warn("Failed to parse databasus.json", "error", err)
+
+		return
+	}
+
+	log.Info("Configuration loaded from " + configFileName)
+}
+
+func (c *Config) applyDefaults() {
+	if c.PgPort == 0 {
+		c.PgPort = 5432
+	}
+
+	if c.PgType == "" {
+		c.PgType = "host"
+	}
+
+	if c.IsDeleteWalAfterUpload == nil {
+		v := true
+		c.IsDeleteWalAfterUpload = &v
+	}
+}
+
+func (c *Config) initSources() {
+	c.flags.sources = map[string]string{
+		"databasus-host":           "not configured",
+		"db-id":                    "not configured",
+		"token":                    "not configured",
+		"pg-host":                  "not configured",
+		"pg-port":                  "not configured",
+		"pg-user":                  "not configured",
+		"pg-password":              "not configured",
+		"pg-type":                  "not configured",
+		"pg-host-bin-dir":          "not configured",
+		"pg-docker-container-name": "not configured",
+		"pg-wal-dir":               "not configured",
+		"delete-wal-after-upload":  "not configured",
+	}
+
+	if c.DatabasusHost != "" {
+		c.flags.sources["databasus-host"] = configFileName
+	}
+
+	if c.DbID != "" {
+		c.flags.sources["db-id"] = configFileName
+	}
+
+	if c.Token != "" {
+		c.flags.sources["token"] = configFileName
+	}
+
+	if c.PgHost != "" {
+		c.flags.sources["pg-host"] = configFileName
+	}
+
+	// PgPort always has a value after applyDefaults
+	c.flags.sources["pg-port"] = configFileName
+
+	if c.PgUser != "" {
+		c.flags.sources["pg-user"] = configFileName
+	}
+
+	if c.PgPassword != "" {
+		c.flags.sources["pg-password"] = configFileName
+	}
+
+	// PgType always has a value after applyDefaults
+	c.flags.sources["pg-type"] = configFileName
+
+	if c.PgHostBinDir != "" {
+		c.flags.sources["pg-host-bin-dir"] = configFileName
+	}
+
+	if c.PgDockerContainerName != "" {
+		c.flags.sources["pg-docker-container-name"] = configFileName
+	}
+
+	if c.PgWalDir != "" {
+		c.flags.sources["pg-wal-dir"] = configFileName
+	}
+
+	// IsDeleteWalAfterUpload always has a value after applyDefaults
+	c.flags.sources["delete-wal-after-upload"] = configFileName
+}
+
+func (c *Config) applyFlags() {
+	if c.flags.databasusHost != nil && *c.flags.databasusHost != "" {
+		c.DatabasusHost = *c.flags.databasusHost
+		c.flags.sources["databasus-host"] = "command line args"
+	}
+
+	if c.flags.dbID != nil && *c.flags.dbID != "" {
+		c.DbID = *c.flags.dbID
+		c.flags.sources["db-id"] = "command line args"
+	}
+
+	if c.flags.token != nil && *c.flags.token != "" {
+		c.Token = *c.flags.token
+		c.flags.sources["token"] = "command line args"
+	}
+
+	if c.flags.pgHost != nil && *c.flags.pgHost != "" {
+		c.PgHost = *c.flags.pgHost
+		c.flags.sources["pg-host"] = "command line args"
+	}
+
+	if c.flags.pgPort != nil && *c.flags.pgPort != 0 {
+		c.PgPort = *c.flags.pgPort
+		c.flags.sources["pg-port"] = "command line args"
+	}
+
+	if c.flags.pgUser != nil && *c.flags.pgUser != "" {
+		c.PgUser = *c.flags.pgUser
+		c.flags.sources["pg-user"] = "command line args"
+	}
+
+	if c.flags.pgPassword != nil && *c.flags.pgPassword != "" {
+		c.PgPassword = *c.flags.pgPassword
+		c.flags.sources["pg-password"] = "command line args"
+	}
+
+	if c.flags.pgType != nil && *c.flags.pgType != "" {
+		c.PgType = *c.flags.pgType
+		c.flags.sources["pg-type"] = "command line args"
+	}
+
+	if c.flags.pgHostBinDir != nil && *c.flags.pgHostBinDir != "" {
+		c.PgHostBinDir = *c.flags.pgHostBinDir
+		c.flags.sources["pg-host-bin-dir"] = "command line args"
+	}
+
+	if c.flags.pgDockerContainerName != nil && *c.flags.pgDockerContainerName != "" {
+		c.PgDockerContainerName = *c.flags.pgDockerContainerName
+		c.flags.sources["pg-docker-container-name"] = "command line args"
+	}
+
+	if c.flags.pgWalDir != nil && *c.flags.pgWalDir != "" {
+		c.PgWalDir = *c.flags.pgWalDir
+		c.flags.sources["pg-wal-dir"] = "command line args"
+	}
+}
+
+func (c *Config) logConfigSources() {
+	log.Info("databasus-host", "value", c.DatabasusHost, "source", c.flags.sources["databasus-host"])
+	log.Info("db-id", "value", c.DbID, "source", c.flags.sources["db-id"])
+	log.Info("token", "value", maskSensitive(c.Token), "source", c.flags.sources["token"])
+	log.Info("pg-host", "value", c.PgHost, "source", c.flags.sources["pg-host"])
+	log.Info("pg-port", "value", c.PgPort, "source", c.flags.sources["pg-port"])
+	log.Info("pg-user", "value", c.PgUser, "source", c.flags.sources["pg-user"])
+	log.Info("pg-password", "value", maskSensitive(c.PgPassword), "source", c.flags.sources["pg-password"])
+	log.Info("pg-type", "value", c.PgType, "source", c.flags.sources["pg-type"])
+	log.Info("pg-host-bin-dir", "value", c.PgHostBinDir, "source", c.flags.sources["pg-host-bin-dir"])
+	log.Info(
+		"pg-docker-container-name",
+		"value",
+		c.PgDockerContainerName,
+		"source",
+		c.flags.sources["pg-docker-container-name"],
+	)
+	log.Info("pg-wal-dir", "value", c.PgWalDir, "source", c.flags.sources["pg-wal-dir"])
+	log.Info(
+		"delete-wal-after-upload",
+		"value",
+		fmt.Sprintf("%v", *c.IsDeleteWalAfterUpload),
+		"source",
+		c.flags.sources["delete-wal-after-upload"],
+	)
+}
+
+func maskSensitive(value string) string {
+	if value == "" {
+		return "(not set)"
+	}
+
+	visibleLen := max(len(value)/4, 1)
+
+	return value[:visibleLen] + "***"
+}

agent/internal/config/config_test.go

@@ -0,0 +1,301 @@
+package config
+
+import (
+	"encoding/json"
+	"flag"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_LoadFromJSONAndArgs_ValuesLoadedFromJSON(t *testing.T) {
+	dir := setupTempDir(t)
+	writeConfigJSON(t, dir, Config{
+		DatabasusHost: "http://json-host:4005",
+		DbID:          "json-db-id",
+		Token:         "json-token",
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{})
+
+	assert.Equal(t, "http://json-host:4005", cfg.DatabasusHost)
+	assert.Equal(t, "json-db-id", cfg.DbID)
+	assert.Equal(t, "json-token", cfg.Token)
+}
+
+func Test_LoadFromJSONAndArgs_ValuesLoadedFromArgs_WhenNoJSON(t *testing.T) {
+	setupTempDir(t)
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--databasus-host", "http://arg-host:4005",
+		"--db-id", "arg-db-id",
+		"--token", "arg-token",
+	})
+
+	assert.Equal(t, "http://arg-host:4005", cfg.DatabasusHost)
+	assert.Equal(t, "arg-db-id", cfg.DbID)
+	assert.Equal(t, "arg-token", cfg.Token)
+}
+
+func Test_LoadFromJSONAndArgs_ArgsOverrideJSON(t *testing.T) {
+	dir := setupTempDir(t)
+	writeConfigJSON(t, dir, Config{
+		DatabasusHost: "http://json-host:4005",
+		DbID:          "json-db-id",
+		Token:         "json-token",
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--databasus-host", "http://arg-host:9999",
+		"--db-id", "arg-db-id-override",
+		"--token", "arg-token-override",
+	})
+
+	assert.Equal(t, "http://arg-host:9999", cfg.DatabasusHost)
+	assert.Equal(t, "arg-db-id-override", cfg.DbID)
+	assert.Equal(t, "arg-token-override", cfg.Token)
+}
+
+func Test_LoadFromJSONAndArgs_PartialArgsOverrideJSON(t *testing.T) {
+	dir := setupTempDir(t)
+	writeConfigJSON(t, dir, Config{
+		DatabasusHost: "http://json-host:4005",
+		DbID:          "json-db-id",
+		Token:         "json-token",
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--databasus-host", "http://arg-host-only:4005",
+	})
+
+	assert.Equal(t, "http://arg-host-only:4005", cfg.DatabasusHost)
+	assert.Equal(t, "json-db-id", cfg.DbID)
+	assert.Equal(t, "json-token", cfg.Token)
+}
+
+func Test_SaveToJSON_ConfigSavedCorrectly(t *testing.T) {
+	setupTempDir(t)
+
+	deleteWal := true
+	cfg := &Config{
+		DatabasusHost:          "http://save-host:4005",
+		DbID:                   "save-db-id",
+		Token:                  "save-token",
+		IsDeleteWalAfterUpload: &deleteWal,
+	}
+
+	err := cfg.SaveToJSON()
+	require.NoError(t, err)
+
+	saved := readConfigJSON(t)
+
+	assert.Equal(t, "http://save-host:4005", saved.DatabasusHost)
+	assert.Equal(t, "save-db-id", saved.DbID)
+	assert.Equal(t, "save-token", saved.Token)
+}
+
+func Test_SaveToJSON_AfterArgsOverrideJSON_SavedFileContainsMergedValues(t *testing.T) {
+	dir := setupTempDir(t)
+	writeConfigJSON(t, dir, Config{
+		DatabasusHost: "http://json-host:4005",
+		DbID:          "json-db-id",
+		Token:         "json-token",
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--databasus-host", "http://override-host:9999",
+	})
+
+	err := cfg.SaveToJSON()
+	require.NoError(t, err)
+
+	saved := readConfigJSON(t)
+
+	assert.Equal(t, "http://override-host:9999", saved.DatabasusHost)
+	assert.Equal(t, "json-db-id", saved.DbID)
+	assert.Equal(t, "json-token", saved.Token)
+}
+
+func Test_LoadFromJSONAndArgs_PgFieldsLoadedFromJSON(t *testing.T) {
+	dir := setupTempDir(t)
+	deleteWal := false
+	writeConfigJSON(t, dir, Config{
+		DatabasusHost:          "http://json-host:4005",
+		DbID:                   "json-db-id",
+		Token:                  "json-token",
+		PgHost:                 "pg-json-host",
+		PgPort:                 5433,
+		PgUser:                 "pg-json-user",
+		PgPassword:             "pg-json-pass",
+		PgType:                 "docker",
+		PgHostBinDir:           "/usr/bin",
+		PgDockerContainerName:  "pg-container",
+		PgWalDir:               "/opt/wal",
+		IsDeleteWalAfterUpload: &deleteWal,
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{})
+
+	assert.Equal(t, "pg-json-host", cfg.PgHost)
+	assert.Equal(t, 5433, cfg.PgPort)
+	assert.Equal(t, "pg-json-user", cfg.PgUser)
+	assert.Equal(t, "pg-json-pass", cfg.PgPassword)
+	assert.Equal(t, "docker", cfg.PgType)
+	assert.Equal(t, "/usr/bin", cfg.PgHostBinDir)
+	assert.Equal(t, "pg-container", cfg.PgDockerContainerName)
+	assert.Equal(t, "/opt/wal", cfg.PgWalDir)
+	assert.Equal(t, false, *cfg.IsDeleteWalAfterUpload)
+}
+
+func Test_LoadFromJSONAndArgs_PgFieldsLoadedFromArgs(t *testing.T) {
+	setupTempDir(t)
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--pg-host", "arg-pg-host",
+		"--pg-port", "5433",
+		"--pg-user", "arg-pg-user",
+		"--pg-password", "arg-pg-pass",
+		"--pg-type", "docker",
+		"--pg-host-bin-dir", "/custom/bin",
+		"--pg-docker-container-name", "my-pg",
+		"--pg-wal-dir", "/var/wal",
+	})
+
+	assert.Equal(t, "arg-pg-host", cfg.PgHost)
+	assert.Equal(t, 5433, cfg.PgPort)
+	assert.Equal(t, "arg-pg-user", cfg.PgUser)
+	assert.Equal(t, "arg-pg-pass", cfg.PgPassword)
+	assert.Equal(t, "docker", cfg.PgType)
+	assert.Equal(t, "/custom/bin", cfg.PgHostBinDir)
+	assert.Equal(t, "my-pg", cfg.PgDockerContainerName)
+	assert.Equal(t, "/var/wal", cfg.PgWalDir)
+}
+
+func Test_LoadFromJSONAndArgs_PgArgsOverrideJSON(t *testing.T) {
+	dir := setupTempDir(t)
+	writeConfigJSON(t, dir, Config{
+		PgHost:   "json-host",
+		PgPort:   5432,
+		PgUser:   "json-user",
+		PgType:   "host",
+		PgWalDir: "/json/wal",
+	})
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{
+		"--pg-host", "arg-host",
+		"--pg-port", "5433",
+		"--pg-user", "arg-user",
+		"--pg-type", "docker",
+		"--pg-docker-container-name", "my-container",
+		"--pg-wal-dir", "/arg/wal",
+	})
+
+	assert.Equal(t, "arg-host", cfg.PgHost)
+	assert.Equal(t, 5433, cfg.PgPort)
+	assert.Equal(t, "arg-user", cfg.PgUser)
+	assert.Equal(t, "docker", cfg.PgType)
+	assert.Equal(t, "my-container", cfg.PgDockerContainerName)
+	assert.Equal(t, "/arg/wal", cfg.PgWalDir)
+}
+
+func Test_LoadFromJSONAndArgs_DefaultsApplied_WhenNoJSONAndNoArgs(t *testing.T) {
+	setupTempDir(t)
+
+	cfg := &Config{}
+	fs := flag.NewFlagSet("test", flag.ContinueOnError)
+	cfg.LoadFromJSONAndArgs(fs, []string{})
+
+	assert.Equal(t, 5432, cfg.PgPort)
+	assert.Equal(t, "host", cfg.PgType)
+	require.NotNil(t, cfg.IsDeleteWalAfterUpload)
+	assert.Equal(t, true, *cfg.IsDeleteWalAfterUpload)
+}
+
+func Test_SaveToJSON_PgFieldsSavedCorrectly(t *testing.T) {
+	setupTempDir(t)
+
+	deleteWal := false
+	cfg := &Config{
+		DatabasusHost:          "http://host:4005",
+		DbID:                   "db-id",
+		Token:                  "token",
+		PgHost:                 "pg-host",
+		PgPort:                 5433,
+		PgUser:                 "pg-user",
+		PgPassword:             "pg-pass",
+		PgType:                 "docker",
+		PgHostBinDir:           "/usr/bin",
+		PgDockerContainerName:  "pg-container",
+		PgWalDir:               "/opt/wal",
+		IsDeleteWalAfterUpload: &deleteWal,
+	}
+
+	err := cfg.SaveToJSON()
+	require.NoError(t, err)
+
+	saved := readConfigJSON(t)
+
+	assert.Equal(t, "pg-host", saved.PgHost)
+	assert.Equal(t, 5433, saved.PgPort)
+	assert.Equal(t, "pg-user", saved.PgUser)
+	assert.Equal(t, "pg-pass", saved.PgPassword)
+	assert.Equal(t, "docker", saved.PgType)
+	assert.Equal(t, "/usr/bin", saved.PgHostBinDir)
+	assert.Equal(t, "pg-container", saved.PgDockerContainerName)
+	assert.Equal(t, "/opt/wal", saved.PgWalDir)
+	require.NotNil(t, saved.IsDeleteWalAfterUpload)
+	assert.Equal(t, false, *saved.IsDeleteWalAfterUpload)
+}
+
+func setupTempDir(t *testing.T) string {
+	t.Helper()
+
+	origDir, err := os.Getwd()
+	require.NoError(t, err)
+
+	dir := t.TempDir()
+	require.NoError(t, os.Chdir(dir))
+
+	t.Cleanup(func() { os.Chdir(origDir) })
+
+	return dir
+}
+
+func writeConfigJSON(t *testing.T, dir string, cfg Config) {
+	t.Helper()
+
+	data, err := json.MarshalIndent(cfg, "", "  ")
+	require.NoError(t, err)
+
+	require.NoError(t, os.WriteFile(dir+"/"+configFileName, data, 0o644))
+}
+
+func readConfigJSON(t *testing.T) Config {
+	t.Helper()
+
+	data, err := os.ReadFile(configFileName)
+	require.NoError(t, err)
+
+	var cfg Config
+	require.NoError(t, json.Unmarshal(data, &cfg))
+
+	return cfg
+}

agent/internal/config/dto.go

@@ -0,0 +1,17 @@
+package config
+
+type parsedFlags struct {
+	databasusHost         *string
+	dbID                  *string
+	token                 *string
+	pgHost                *string
+	pgPort                *int
+	pgUser                *string
+	pgPassword            *string
+	pgType                *string
+	pgHostBinDir          *string
+	pgDockerContainerName *string
+	pgWalDir              *string
+
+	sources map[string]string
+}

agent/internal/features/api/api.go

@@ -0,0 +1,376 @@
+package api
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"net/url"
+	"os"
+	"time"
+
+	"github.com/go-resty/resty/v2"
+)
+
+const (
+	chainValidPath      = "/api/v1/backups/postgres/wal/is-wal-chain-valid-since-last-full-backup"
+	nextBackupTimePath  = "/api/v1/backups/postgres/wal/next-full-backup-time"
+	walUploadPath       = "/api/v1/backups/postgres/wal/upload/wal"
+	fullStartPath       = "/api/v1/backups/postgres/wal/upload/full-start"
+	fullCompletePath    = "/api/v1/backups/postgres/wal/upload/full-complete"
+	reportErrorPath     = "/api/v1/backups/postgres/wal/error"
+	restorePlanPath     = "/api/v1/backups/postgres/wal/restore/plan"
+	restoreDownloadPath = "/api/v1/backups/postgres/wal/restore/download"
+	versionPath         = "/api/v1/system/version"
+	agentBinaryPath     = "/api/v1/system/agent"
+
+	apiCallTimeout   = 30 * time.Second
+	maxRetryAttempts = 3
+	retryBaseDelay   = 1 * time.Second
+)
+
+// For stream uploads (basebackup and WAL segments) the standard resty client is not used,
+// because it buffers the entire body in memory before sending.
+type Client struct {
+	json       *resty.Client
+	streamHTTP *http.Client
+	host       string
+	token      string
+	log        *slog.Logger
+}
+
+func NewClient(host, token string, log *slog.Logger) *Client {
+	setAuth := func(_ *resty.Client, req *resty.Request) error {
+		if token != "" {
+			req.SetHeader("Authorization", token)
+		}
+
+		return nil
+	}
+
+	jsonClient := resty.New().
+		SetTimeout(apiCallTimeout).
+		SetRetryCount(maxRetryAttempts - 1).
+		SetRetryWaitTime(retryBaseDelay).
+		SetRetryMaxWaitTime(4 * retryBaseDelay).
+		AddRetryCondition(func(resp *resty.Response, err error) bool {
+			return err != nil || resp.StatusCode() >= 500
+		}).
+		OnBeforeRequest(setAuth)
+
+	return &Client{
+		json:       jsonClient,
+		streamHTTP: &http.Client{},
+		host:       host,
+		token:      token,
+		log:        log,
+	}
+}
+
+func (c *Client) CheckWalChainValidity(ctx context.Context) (*WalChainValidityResponse, error) {
+	var resp WalChainValidityResponse
+
+	httpResp, err := c.json.R().
+		SetContext(ctx).
+		SetResult(&resp).
+		Get(c.buildURL(chainValidPath))
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.checkResponse(httpResp, "check WAL chain validity"); err != nil {
+		return nil, err
+	}
+
+	return &resp, nil
+}
+
+func (c *Client) GetNextFullBackupTime(ctx context.Context) (*NextFullBackupTimeResponse, error) {
+	var resp NextFullBackupTimeResponse
+
+	httpResp, err := c.json.R().
+		SetContext(ctx).
+		SetResult(&resp).
+		Get(c.buildURL(nextBackupTimePath))
+	if err != nil {
+		return nil, err
+	}
+
+	if err := c.checkResponse(httpResp, "get next full backup time"); err != nil {
+		return nil, err
+	}
+
+	return &resp, nil
+}
+
+func (c *Client) ReportBackupError(ctx context.Context, errMsg string) error {
+	httpResp, err := c.json.R().
+		SetContext(ctx).
+		SetBody(reportErrorRequest{Error: errMsg}).
+		Post(c.buildURL(reportErrorPath))
+	if err != nil {
+		return err
+	}
+
+	return c.checkResponse(httpResp, "report backup error")
+}
+
+func (c *Client) UploadBasebackup(
+	ctx context.Context,
+	body io.Reader,
+) (*UploadBasebackupResponse, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.buildURL(fullStartPath), body)
+	if err != nil {
+		return nil, fmt.Errorf("create upload request: %w", err)
+	}
+
+	c.setStreamHeaders(req)
+	req.Header.Set("Content-Type", "application/octet-stream")
+
+	resp, err := c.streamHTTP.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("upload request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		respBody, _ := io.ReadAll(resp.Body)
+
+		return nil, fmt.Errorf("upload failed with status %d: %s", resp.StatusCode, string(respBody))
+	}
+
+	var result UploadBasebackupResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, fmt.Errorf("decode upload response: %w", err)
+	}
+
+	return &result, nil
+}
+
+func (c *Client) FinalizeBasebackup(
+	ctx context.Context,
+	backupID string,
+	startSegment string,
+	stopSegment string,
+) error {
+	resp, err := c.json.R().
+		SetContext(ctx).
+		SetBody(finalizeBasebackupRequest{
+			BackupID:     backupID,
+			StartSegment: startSegment,
+			StopSegment:  stopSegment,
+		}).
+		Post(c.buildURL(fullCompletePath))
+	if err != nil {
+		return fmt.Errorf("finalize request: %w", err)
+	}
+
+	if resp.StatusCode() != http.StatusOK {
+		return fmt.Errorf("finalize failed with status %d: %s", resp.StatusCode(), resp.String())
+	}
+
+	return nil
+}
+
+func (c *Client) FinalizeBasebackupWithError(
+	ctx context.Context,
+	backupID string,
+	errMsg string,
+) error {
+	resp, err := c.json.R().
+		SetContext(ctx).
+		SetBody(finalizeBasebackupRequest{
+			BackupID: backupID,
+			Error:    &errMsg,
+		}).
+		Post(c.buildURL(fullCompletePath))
+	if err != nil {
+		return fmt.Errorf("finalize-with-error request: %w", err)
+	}
+
+	if resp.StatusCode() != http.StatusOK {
+		return fmt.Errorf("finalize-with-error failed with status %d: %s", resp.StatusCode(), resp.String())
+	}
+
+	return nil
+}
+
+func (c *Client) UploadWalSegment(
+	ctx context.Context,
+	segmentName string,
+	body io.Reader,
+) (*UploadWalSegmentResult, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, c.buildURL(walUploadPath), body)
+	if err != nil {
+		return nil, fmt.Errorf("create WAL upload request: %w", err)
+	}
+
+	c.setStreamHeaders(req)
+	req.Header.Set("Content-Type", "application/octet-stream")
+	req.Header.Set("X-Wal-Segment-Name", segmentName)
+
+	resp, err := c.streamHTTP.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("upload request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	switch resp.StatusCode {
+	case http.StatusNoContent:
+		return &UploadWalSegmentResult{IsGapDetected: false}, nil
+
+	case http.StatusConflict:
+		var errResp uploadErrorResponse
+
+		if err := json.NewDecoder(resp.Body).Decode(&errResp); err != nil {
+			return &UploadWalSegmentResult{IsGapDetected: true}, nil
+		}
+
+		return &UploadWalSegmentResult{
+			IsGapDetected:       true,
+			ExpectedSegmentName: errResp.ExpectedSegmentName,
+			ReceivedSegmentName: errResp.ReceivedSegmentName,
+		}, nil
+
+	default:
+		respBody, _ := io.ReadAll(resp.Body)
+
+		return nil, fmt.Errorf("upload failed with status %d: %s", resp.StatusCode, string(respBody))
+	}
+}
+
+func (c *Client) GetRestorePlan(
+	ctx context.Context,
+	backupID string,
+) (*GetRestorePlanResponse, *GetRestorePlanErrorResponse, error) {
+	request := c.json.R().SetContext(ctx)
+
+	if backupID != "" {
+		request.SetQueryParam("backupId", backupID)
+	}
+
+	httpResp, err := request.Get(c.buildURL(restorePlanPath))
+	if err != nil {
+		return nil, nil, fmt.Errorf("get restore plan: %w", err)
+	}
+
+	switch httpResp.StatusCode() {
+	case http.StatusOK:
+		var response GetRestorePlanResponse
+		if err := json.Unmarshal(httpResp.Body(), &response); err != nil {
+			return nil, nil, fmt.Errorf("decode restore plan response: %w", err)
+		}
+
+		return &response, nil, nil
+
+	case http.StatusBadRequest:
+		var errorResponse GetRestorePlanErrorResponse
+		if err := json.Unmarshal(httpResp.Body(), &errorResponse); err != nil {
+			return nil, nil, fmt.Errorf("decode restore plan error: %w", err)
+		}
+
+		return nil, &errorResponse, nil
+
+	default:
+		return nil, nil, fmt.Errorf("get restore plan: server returned status %d: %s",
+			httpResp.StatusCode(), httpResp.String())
+	}
+}
+
+func (c *Client) DownloadBackupFile(
+	ctx context.Context,
+	backupID string,
+) (io.ReadCloser, error) {
+	requestURL := c.buildURL(restoreDownloadPath) + "?" + url.Values{"backupId": {backupID}}.Encode()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, requestURL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create download request: %w", err)
+	}
+
+	c.setStreamHeaders(req)
+
+	resp, err := c.streamHTTP.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("download backup file: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		respBody, _ := io.ReadAll(resp.Body)
+		_ = resp.Body.Close()
+
+		return nil, fmt.Errorf("download backup file: server returned status %d: %s",
+			resp.StatusCode, string(respBody))
+	}
+
+	return resp.Body, nil
+}
+
+func (c *Client) FetchServerVersion(ctx context.Context) (string, error) {
+	var ver versionResponse
+
+	httpResp, err := c.json.R().
+		SetContext(ctx).
+		SetResult(&ver).
+		Get(c.buildURL(versionPath))
+	if err != nil {
+		return "", err
+	}
+
+	if err := c.checkResponse(httpResp, "fetch server version"); err != nil {
+		return "", err
+	}
+
+	return ver.Version, nil
+}
+
+func (c *Client) DownloadAgentBinary(ctx context.Context, arch, destPath string) error {
+	requestURL := c.buildURL(agentBinaryPath) + "?" + url.Values{"arch": {arch}}.Encode()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, requestURL, nil)
+	if err != nil {
+		return fmt.Errorf("create agent download request: %w", err)
+	}
+
+	c.setStreamHeaders(req)
+
+	resp, err := c.streamHTTP.Do(req)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	if resp.StatusCode != http.StatusOK {
+		return fmt.Errorf("server returned %d for agent download", resp.StatusCode)
+	}
+
+	file, err := os.Create(destPath)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = file.Close() }()
+
+	_, err = io.Copy(file, resp.Body)
+
+	return err
+}
+
+func (c *Client) buildURL(path string) string {
+	return c.host + path
+}
+
+func (c *Client) checkResponse(resp *resty.Response, method string) error {
+	if resp.StatusCode() >= 400 {
+		return fmt.Errorf("%s: server returned status %d: %s", method, resp.StatusCode(), resp.String())
+	}
+
+	return nil
+}
+
+func (c *Client) setStreamHeaders(req *http.Request) {
+	if c.token != "" {
+		req.Header.Set("Authorization", c.token)
+	}
+}

agent/internal/features/api/dto.go

@@ -0,0 +1,72 @@
+package api
+
+import "time"
+
+type WalChainValidityResponse struct {
+	IsValid               bool   `json:"isValid"`
+	Error                 string `json:"error,omitempty"`
+	LastContiguousSegment string `json:"lastContiguousSegment,omitempty"`
+}
+
+type NextFullBackupTimeResponse struct {
+	NextFullBackupTime *time.Time `json:"nextFullBackupTime"`
+}
+
+type UploadWalSegmentResult struct {
+	IsGapDetected       bool
+	ExpectedSegmentName string
+	ReceivedSegmentName string
+}
+
+type reportErrorRequest struct {
+	Error string `json:"error"`
+}
+
+type versionResponse struct {
+	Version string `json:"version"`
+}
+
+type UploadBasebackupResponse struct {
+	BackupID string `json:"backupId"`
+}
+
+type finalizeBasebackupRequest struct {
+	BackupID     string  `json:"backupId"`
+	StartSegment string  `json:"startSegment"`
+	StopSegment  string  `json:"stopSegment"`
+	Error        *string `json:"error,omitempty"`
+}
+
+type uploadErrorResponse struct {
+	Error               string `json:"error"`
+	ExpectedSegmentName string `json:"expectedSegmentName"`
+	ReceivedSegmentName string `json:"receivedSegmentName"`
+}
+
+type RestorePlanFullBackup struct {
+	BackupID                  string    `json:"id"`
+	FullBackupWalStartSegment string    `json:"fullBackupWalStartSegment"`
+	FullBackupWalStopSegment  string    `json:"fullBackupWalStopSegment"`
+	PgVersion                 string    `json:"pgVersion"`
+	CreatedAt                 time.Time `json:"createdAt"`
+	SizeBytes                 int64     `json:"sizeBytes"`
+}
+
+type RestorePlanWalSegment struct {
+	BackupID    string `json:"backupId"`
+	SegmentName string `json:"segmentName"`
+	SizeBytes   int64  `json:"sizeBytes"`
+}
+
+type GetRestorePlanResponse struct {
+	FullBackup             RestorePlanFullBackup   `json:"fullBackup"`
+	WalSegments            []RestorePlanWalSegment `json:"walSegments"`
+	TotalSizeBytes         int64                   `json:"totalSizeBytes"`
+	LatestAvailableSegment string                  `json:"latestAvailableSegment"`
+}
+
+type GetRestorePlanErrorResponse struct {
+	Error                 string `json:"error"`
+	Message               string `json:"message"`
+	LastContiguousSegment string `json:"lastContiguousSegment,omitempty"`
+}

agent/internal/features/full_backup/backuper.go

@@ -0,0 +1,298 @@
+package full_backup
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"sync/atomic"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+)
+
+const (
+	checkInterval = 30 * time.Second
+	retryDelay    = 1 * time.Minute
+	uploadTimeout = 30 * time.Minute
+)
+
+var retryDelayOverride *time.Duration
+
+type CmdBuilder func(ctx context.Context) *exec.Cmd
+
+// FullBackuper runs pg_basebackup when the WAL chain is broken or a scheduled backup is due.
+//
+// Every 30 seconds it checks two conditions via the Databasus API:
+//  1. WAL chain validity — if broken or no full backup exists, triggers an immediate basebackup.
+//  2. Scheduled backup time — if the next full backup time has passed, triggers a basebackup.
+//
+// Only one basebackup runs at a time (guarded by atomic bool).
+// On failure the error is reported to the server and the backup retries after 1 minute, indefinitely.
+// WAL segment uploads (handled by wal.Streamer) continue independently and are not paused.
+//
+// pg_basebackup runs as "pg_basebackup -Ft -D - -X fetch --verbose --checkpoint=fast".
+// Stdout (tar) is zstd-compressed and uploaded to the server.
+// Stderr is parsed for WAL start/stop segment names (LSN → segment arithmetic).
+type FullBackuper struct {
+	cfg        *config.Config
+	apiClient  *api.Client
+	log        *slog.Logger
+	isRunning  atomic.Bool
+	cmdBuilder CmdBuilder
+}
+
+func NewFullBackuper(cfg *config.Config, apiClient *api.Client, log *slog.Logger) *FullBackuper {
+	backuper := &FullBackuper{
+		cfg:       cfg,
+		apiClient: apiClient,
+		log:       log,
+	}
+
+	backuper.cmdBuilder = backuper.defaultCmdBuilder
+
+	return backuper
+}
+
+func (backuper *FullBackuper) Run(ctx context.Context) {
+	backuper.log.Info("Full backuper started")
+
+	backuper.checkAndRunIfNeeded(ctx)
+
+	ticker := time.NewTicker(checkInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			backuper.log.Info("Full backuper stopping")
+			return
+		case <-ticker.C:
+			backuper.checkAndRunIfNeeded(ctx)
+		}
+	}
+}
+
+func (backuper *FullBackuper) checkAndRunIfNeeded(ctx context.Context) {
+	if backuper.isRunning.Load() {
+		backuper.log.Debug("Skipping check: basebackup already in progress")
+		return
+	}
+
+	chainResp, err := backuper.apiClient.CheckWalChainValidity(ctx)
+	if err != nil {
+		backuper.log.Error("Failed to check WAL chain validity", "error", err)
+		return
+	}
+
+	if !chainResp.IsValid {
+		backuper.log.Info("WAL chain is invalid, triggering basebackup",
+			"error", chainResp.Error,
+			"lastContiguousSegment", chainResp.LastContiguousSegment,
+		)
+
+		backuper.runBasebackupWithRetry(ctx)
+
+		return
+	}
+
+	nextTimeResp, err := backuper.apiClient.GetNextFullBackupTime(ctx)
+	if err != nil {
+		backuper.log.Error("Failed to check next full backup time", "error", err)
+		return
+	}
+
+	if nextTimeResp.NextFullBackupTime == nil || !nextTimeResp.NextFullBackupTime.After(time.Now().UTC()) {
+		backuper.log.Info("Scheduled full backup is due, triggering basebackup")
+		backuper.runBasebackupWithRetry(ctx)
+
+		return
+	}
+
+	backuper.log.Debug("No basebackup needed",
+		"nextFullBackupTime", nextTimeResp.NextFullBackupTime,
+	)
+}
+
+func (backuper *FullBackuper) runBasebackupWithRetry(ctx context.Context) {
+	if !backuper.isRunning.CompareAndSwap(false, true) {
+		backuper.log.Debug("Skipping basebackup: already running")
+		return
+	}
+	defer backuper.isRunning.Store(false)
+
+	for {
+		if ctx.Err() != nil {
+			return
+		}
+
+		backuper.log.Info("Starting pg_basebackup")
+
+		err := backuper.executeAndUploadBasebackup(ctx)
+		if err == nil {
+			backuper.log.Info("Basebackup completed successfully")
+			return
+		}
+
+		backuper.log.Error("Basebackup failed", "error", err)
+		backuper.reportError(ctx, err.Error())
+
+		delay := retryDelay
+		if retryDelayOverride != nil {
+			delay = *retryDelayOverride
+		}
+
+		backuper.log.Info("Retrying basebackup after delay", "delay", delay)
+
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(delay):
+		}
+	}
+}
+
+func (backuper *FullBackuper) executeAndUploadBasebackup(ctx context.Context) error {
+	cmd := backuper.cmdBuilder(ctx)
+
+	var stderrBuf bytes.Buffer
+	cmd.Stderr = &stderrBuf
+
+	stdoutPipe, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("create stdout pipe: %w", err)
+	}
+
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("start pg_basebackup: %w", err)
+	}
+
+	// Phase 1: Stream compressed data via io.Pipe directly to the API.
+	pipeReader, pipeWriter := io.Pipe()
+	go backuper.compressAndStream(pipeWriter, stdoutPipe)
+
+	uploadCtx, cancel := context.WithTimeout(ctx, uploadTimeout)
+	defer cancel()
+
+	uploadResp, uploadErr := backuper.apiClient.UploadBasebackup(uploadCtx, pipeReader)
+
+	cmdErr := cmd.Wait()
+
+	if uploadErr != nil {
+		stderrStr := stderrBuf.String()
+		if stderrStr != "" {
+			return fmt.Errorf("upload basebackup: %w (pg_basebackup stderr: %s)", uploadErr, stderrStr)
+		}
+
+		return fmt.Errorf("upload basebackup: %w", uploadErr)
+	}
+
+	if cmdErr != nil {
+		errMsg := fmt.Sprintf("pg_basebackup exited with error: %v (stderr: %s)", cmdErr, stderrBuf.String())
+		_ = backuper.apiClient.FinalizeBasebackupWithError(ctx, uploadResp.BackupID, errMsg)
+
+		return fmt.Errorf("%s", errMsg)
+	}
+
+	// Phase 2: Parse stderr for WAL segments and finalize the backup.
+	stderrStr := stderrBuf.String()
+	backuper.log.Debug("pg_basebackup stderr", "stderr", stderrStr)
+
+	startSegment, stopSegment, err := ParseBasebackupStderr(stderrStr)
+	if err != nil {
+		errMsg := fmt.Sprintf("parse pg_basebackup stderr: %v", err)
+		_ = backuper.apiClient.FinalizeBasebackupWithError(ctx, uploadResp.BackupID, errMsg)
+
+		return fmt.Errorf("parse pg_basebackup stderr: %w", err)
+	}
+
+	backuper.log.Info("Basebackup WAL segments parsed",
+		"startSegment", startSegment,
+		"stopSegment", stopSegment,
+		"backupId", uploadResp.BackupID,
+	)
+
+	if err := backuper.apiClient.FinalizeBasebackup(ctx, uploadResp.BackupID, startSegment, stopSegment); err != nil {
+		return fmt.Errorf("finalize basebackup: %w", err)
+	}
+
+	return nil
+}
+
+func (backuper *FullBackuper) compressAndStream(pipeWriter *io.PipeWriter, reader io.Reader) {
+	encoder, err := zstd.NewWriter(pipeWriter,
+		zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(5)),
+		zstd.WithEncoderCRC(true),
+	)
+	if err != nil {
+		_ = pipeWriter.CloseWithError(fmt.Errorf("create zstd encoder: %w", err))
+		return
+	}
+
+	if _, err := io.Copy(encoder, reader); err != nil {
+		_ = encoder.Close()
+		_ = pipeWriter.CloseWithError(fmt.Errorf("compress: %w", err))
+		return
+	}
+
+	if err := encoder.Close(); err != nil {
+		_ = pipeWriter.CloseWithError(fmt.Errorf("close encoder: %w", err))
+		return
+	}
+
+	_ = pipeWriter.Close()
+}
+
+func (backuper *FullBackuper) reportError(ctx context.Context, errMsg string) {
+	if err := backuper.apiClient.ReportBackupError(ctx, errMsg); err != nil {
+		backuper.log.Error("Failed to report error to server", "error", err)
+	}
+}
+
+func (backuper *FullBackuper) defaultCmdBuilder(ctx context.Context) *exec.Cmd {
+	switch backuper.cfg.PgType {
+	case "docker":
+		return backuper.buildDockerCmd(ctx)
+	default:
+		return backuper.buildHostCmd(ctx)
+	}
+}
+
+func (backuper *FullBackuper) buildHostCmd(ctx context.Context) *exec.Cmd {
+	binary := "pg_basebackup"
+	if backuper.cfg.PgHostBinDir != "" {
+		binary = filepath.Join(backuper.cfg.PgHostBinDir, "pg_basebackup")
+	}
+
+	cmd := exec.CommandContext(ctx, binary,
+		"-Ft", "-D", "-", "-X", "fetch", "--verbose", "--checkpoint=fast",
+		"-h", backuper.cfg.PgHost,
+		"-p", fmt.Sprintf("%d", backuper.cfg.PgPort),
+		"-U", backuper.cfg.PgUser,
+	)
+
+	cmd.Env = append(os.Environ(), "PGPASSWORD="+backuper.cfg.PgPassword)
+
+	return cmd
+}
+
+func (backuper *FullBackuper) buildDockerCmd(ctx context.Context) *exec.Cmd {
+	cmd := exec.CommandContext(ctx, "docker", "exec",
+		"-e", "PGPASSWORD="+backuper.cfg.PgPassword,
+		"-i", backuper.cfg.PgDockerContainerName,
+		"pg_basebackup",
+		"-Ft", "-D", "-", "-X", "fetch", "--verbose", "--checkpoint=fast",
+		"-h", "localhost",
+		"-p", "5432",
+		"-U", backuper.cfg.PgUser,
+	)
+
+	return cmd
+}

agent/internal/features/full_backup/backuper_test.go

@@ -0,0 +1,673 @@
+package full_backup
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"os/exec"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+	"databasus-agent/internal/logger"
+)
+
+const (
+	testChainValidPath     = "/api/v1/backups/postgres/wal/is-wal-chain-valid-since-last-full-backup"
+	testNextBackupTimePath = "/api/v1/backups/postgres/wal/next-full-backup-time"
+	testFullStartPath      = "/api/v1/backups/postgres/wal/upload/full-start"
+	testFullCompletePath   = "/api/v1/backups/postgres/wal/upload/full-complete"
+	testReportErrorPath    = "/api/v1/backups/postgres/wal/error"
+
+	testBackupID = "test-backup-id-1234"
+)
+
+func Test_RunFullBackup_WhenChainBroken_BasebackupTriggered(t *testing.T) {
+	var mu sync.Mutex
+	var uploadReceived bool
+	var uploadHeaders http.Header
+	var finalizeReceived bool
+	var finalizeBody map[string]any
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid:               false,
+				Error:                 "wal_chain_broken",
+				LastContiguousSegment: "000000010000000100000011",
+			})
+		case testFullStartPath:
+			mu.Lock()
+			uploadReceived = true
+			uploadHeaders = r.Header.Clone()
+			mu.Unlock()
+
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			mu.Lock()
+			finalizeReceived = true
+			_ = json.NewDecoder(r.Body).Decode(&finalizeBody)
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "test-backup-data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return finalizeReceived
+	}, 5*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.True(t, uploadReceived)
+	assert.Equal(t, "application/octet-stream", uploadHeaders.Get("Content-Type"))
+	assert.Equal(t, "test-token", uploadHeaders.Get("Authorization"))
+
+	assert.True(t, finalizeReceived)
+	assert.Equal(t, testBackupID, finalizeBody["backupId"])
+	assert.Equal(t, "000000010000000000000002", finalizeBody["startSegment"])
+	assert.Equal(t, "000000010000000000000002", finalizeBody["stopSegment"])
+}
+
+func Test_RunFullBackup_WhenScheduledBackupDue_BasebackupTriggered(t *testing.T) {
+	var mu sync.Mutex
+	var finalizeReceived bool
+
+	pastTime := time.Now().UTC().Add(-1 * time.Hour)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{IsValid: true})
+		case testNextBackupTimePath:
+			writeJSON(w, api.NextFullBackupTimeResponse{NextFullBackupTime: &pastTime})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			mu.Lock()
+			finalizeReceived = true
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "scheduled-backup-data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return finalizeReceived
+	}, 5*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.True(t, finalizeReceived)
+}
+
+func Test_RunFullBackup_WhenNoFullBackupExists_ImmediateBasebackupTriggered(t *testing.T) {
+	var mu sync.Mutex
+	var finalizeReceived bool
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			mu.Lock()
+			finalizeReceived = true
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "first-backup-data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return finalizeReceived
+	}, 5*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.True(t, finalizeReceived)
+}
+
+func Test_RunFullBackup_WhenUploadFails_RetriesAfterDelay(t *testing.T) {
+	var mu sync.Mutex
+	var uploadAttempts int
+	var errorReported bool
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+
+			mu.Lock()
+			uploadAttempts++
+			attempt := uploadAttempts
+			mu.Unlock()
+
+			if attempt == 1 {
+				w.WriteHeader(http.StatusInternalServerError)
+				_, _ = w.Write([]byte(`{"error":"storage unavailable"}`))
+				return
+			}
+
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		case testReportErrorPath:
+			mu.Lock()
+			errorReported = true
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "retry-backup-data", validStderr())
+
+	origRetryDelay := retryDelay
+	setRetryDelay(100 * time.Millisecond)
+	defer setRetryDelay(origRetryDelay)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return uploadAttempts >= 2
+	}, 10*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.GreaterOrEqual(t, uploadAttempts, 2)
+	assert.True(t, errorReported)
+}
+
+func Test_RunFullBackup_WhenAlreadyRunning_SkipsExecution(t *testing.T) {
+	var mu sync.Mutex
+	var uploadCount int
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+
+			mu.Lock()
+			uploadCount++
+			mu.Unlock()
+
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "data", validStderr())
+
+	fb.isRunning.Store(true)
+
+	fb.checkAndRunIfNeeded(context.Background())
+
+	mu.Lock()
+	count := uploadCount
+	mu.Unlock()
+
+	assert.Equal(t, 0, count, "should not trigger backup when already running")
+}
+
+func Test_RunFullBackup_WhenContextCancelled_StopsCleanly(t *testing.T) {
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+			w.WriteHeader(http.StatusInternalServerError)
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		case testReportErrorPath:
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "data", validStderr())
+
+	origRetryDelay := retryDelay
+	setRetryDelay(5 * time.Second)
+	defer setRetryDelay(origRetryDelay)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
+	defer cancel()
+
+	done := make(chan struct{})
+	go func() {
+		fb.Run(ctx)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(5 * time.Second):
+		t.Fatal("Run should have stopped after context cancellation")
+	}
+}
+
+func Test_RunFullBackup_WhenChainValidAndNotScheduled_NoBasebackupTriggered(t *testing.T) {
+	var uploadReceived atomic.Bool
+
+	futureTime := time.Now().UTC().Add(24 * time.Hour)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{IsValid: true})
+		case testNextBackupTimePath:
+			writeJSON(w, api.NextFullBackupTimeResponse{NextFullBackupTime: &futureTime})
+		case testFullStartPath:
+			uploadReceived.Store(true)
+
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	assert.False(t, uploadReceived.Load(), "should not trigger backup when chain valid and not scheduled")
+}
+
+func Test_RunFullBackup_WhenStderrParsingFails_FinalizesWithErrorAndRetries(t *testing.T) {
+	var mu sync.Mutex
+	var errorReported bool
+	var finalizeWithErrorReceived bool
+	var finalizeBody map[string]any
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			mu.Lock()
+			finalizeWithErrorReceived = true
+			_ = json.NewDecoder(r.Body).Decode(&finalizeBody)
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		case testReportErrorPath:
+			mu.Lock()
+			errorReported = true
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "data", "pg_basebackup: unexpected output with no LSN info")
+
+	origRetryDelay := retryDelay
+	setRetryDelay(100 * time.Millisecond)
+	defer setRetryDelay(origRetryDelay)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return errorReported
+	}, 2*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.True(t, errorReported)
+	assert.True(t, finalizeWithErrorReceived, "should finalize with error when stderr parsing fails")
+	assert.Equal(t, testBackupID, finalizeBody["backupId"])
+	assert.NotNil(t, finalizeBody["error"], "finalize should include error message")
+}
+
+func Test_RunFullBackup_WhenNextBackupTimeNull_BasebackupTriggered(t *testing.T) {
+	var mu sync.Mutex
+	var finalizeReceived bool
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{IsValid: true})
+		case testNextBackupTimePath:
+			writeJSON(w, api.NextFullBackupTimeResponse{NextFullBackupTime: nil})
+		case testFullStartPath:
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			mu.Lock()
+			finalizeReceived = true
+			mu.Unlock()
+
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "first-run-data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return finalizeReceived
+	}, 5*time.Second)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	assert.True(t, finalizeReceived)
+}
+
+func Test_RunFullBackup_WhenChainValidityReturns401_NoBasebackupTriggered(t *testing.T) {
+	var uploadReceived atomic.Bool
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			w.WriteHeader(http.StatusUnauthorized)
+			_, _ = w.Write([]byte(`{"error":"invalid token"}`))
+		case testFullStartPath:
+			uploadReceived.Store(true)
+
+			_, _ = io.ReadAll(r.Body)
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, "data", validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	assert.False(t, uploadReceived.Load(), "should not trigger backup when API returns 401")
+}
+
+func Test_RunFullBackup_WhenUploadSucceeds_BodyIsZstdCompressed(t *testing.T) {
+	var mu sync.Mutex
+	var receivedBody []byte
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testChainValidPath:
+			writeJSON(w, api.WalChainValidityResponse{
+				IsValid: false,
+				Error:   "no_full_backup",
+			})
+		case testFullStartPath:
+			body, _ := io.ReadAll(r.Body)
+
+			mu.Lock()
+			receivedBody = body
+			mu.Unlock()
+
+			writeJSON(w, map[string]string{"backupId": testBackupID})
+		case testFullCompletePath:
+			w.WriteHeader(http.StatusOK)
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	originalContent := "test-backup-content-for-compression-check"
+	fb := newTestFullBackuper(server.URL)
+	fb.cmdBuilder = mockCmdBuilder(t, originalContent, validStderr())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	go fb.Run(ctx)
+	waitForCondition(t, func() bool {
+		mu.Lock()
+		defer mu.Unlock()
+		return len(receivedBody) > 0
+	}, 5*time.Second)
+	cancel()
+
+	mu.Lock()
+	body := receivedBody
+	mu.Unlock()
+
+	decoder, err := zstd.NewReader(nil)
+	require.NoError(t, err)
+	defer decoder.Close()
+
+	decompressed, err := decoder.DecodeAll(body, nil)
+	require.NoError(t, err)
+	assert.Equal(t, originalContent, string(decompressed))
+}
+
+func newTestServer(t *testing.T, handler http.HandlerFunc) *httptest.Server {
+	t.Helper()
+
+	server := httptest.NewServer(handler)
+	t.Cleanup(server.Close)
+
+	return server
+}
+
+func newTestFullBackuper(serverURL string) *FullBackuper {
+	cfg := &config.Config{
+		DatabasusHost: serverURL,
+		DbID:          "test-db-id",
+		Token:         "test-token",
+		PgHost:        "localhost",
+		PgPort:        5432,
+		PgUser:        "postgres",
+		PgPassword:    "password",
+		PgType:        "host",
+	}
+
+	apiClient := api.NewClient(serverURL, cfg.Token, logger.GetLogger())
+
+	return NewFullBackuper(cfg, apiClient, logger.GetLogger())
+}
+
+func mockCmdBuilder(t *testing.T, stdoutContent, stderrContent string) CmdBuilder {
+	t.Helper()
+
+	return func(ctx context.Context) *exec.Cmd {
+		cmd := exec.CommandContext(ctx, os.Args[0],
+			"-test.run=TestHelperProcess",
+			"--",
+			stdoutContent,
+			stderrContent,
+		)
+
+		cmd.Env = append(os.Environ(), "GO_TEST_HELPER_PROCESS=1")
+
+		return cmd
+	}
+}
+
+func TestHelperProcess(t *testing.T) {
+	if os.Getenv("GO_TEST_HELPER_PROCESS") != "1" {
+		return
+	}
+
+	args := os.Args
+	for i, arg := range args {
+		if arg == "--" {
+			args = args[i+1:]
+			break
+		}
+	}
+
+	if len(args) >= 1 {
+		_, _ = fmt.Fprint(os.Stdout, args[0])
+	}
+
+	if len(args) >= 2 {
+		_, _ = fmt.Fprint(os.Stderr, args[1])
+	}
+
+	os.Exit(0)
+}
+
+func validStderr() string {
+	return `pg_basebackup: initiating base backup, waiting for checkpoint to complete
+pg_basebackup: checkpoint completed
+pg_basebackup: write-ahead log start point: 0/2000028 on timeline 1
+pg_basebackup: starting background WAL receiver
+pg_basebackup: write-ahead log end point: 0/2000100
+pg_basebackup: waiting for background process to finish streaming ...
+pg_basebackup: syncing data to disk ...
+pg_basebackup: base backup completed`
+}
+
+func writeJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+
+	if err := json.NewEncoder(w).Encode(v); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+	}
+}
+
+func waitForCondition(t *testing.T, condition func() bool, timeout time.Duration) {
+	t.Helper()
+
+	deadline := time.Now().Add(timeout)
+
+	for time.Now().Before(deadline) {
+		if condition() {
+			return
+		}
+
+		time.Sleep(50 * time.Millisecond)
+	}
+
+	t.Fatalf("condition not met within %v", timeout)
+}
+
+func setRetryDelay(d time.Duration) {
+	retryDelayOverride = &d
+}
+
+func init() {
+	retryDelayOverride = nil
+}

agent/internal/features/full_backup/stderr_parser.go

@@ -0,0 +1,75 @@
+package full_backup
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+const defaultWalSegmentSize uint32 = 16 * 1024 * 1024 // 16 MB
+
+var (
+	startLSNRegex = regexp.MustCompile(`write-ahead log start point: ([0-9A-Fa-f]+/[0-9A-Fa-f]+)`)
+	stopLSNRegex  = regexp.MustCompile(`write-ahead log end point: ([0-9A-Fa-f]+/[0-9A-Fa-f]+)`)
+)
+
+func ParseBasebackupStderr(stderr string) (startSegment, stopSegment string, err error) {
+	startMatch := startLSNRegex.FindStringSubmatch(stderr)
+	if len(startMatch) < 2 {
+		return "", "", fmt.Errorf("failed to parse start WAL location from pg_basebackup stderr")
+	}
+
+	stopMatch := stopLSNRegex.FindStringSubmatch(stderr)
+	if len(stopMatch) < 2 {
+		return "", "", fmt.Errorf("failed to parse stop WAL location from pg_basebackup stderr")
+	}
+
+	startSegment, err = LSNToSegmentName(startMatch[1], 1, defaultWalSegmentSize)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to convert start LSN to segment name: %w", err)
+	}
+
+	stopSegment, err = LSNToSegmentName(stopMatch[1], 1, defaultWalSegmentSize)
+	if err != nil {
+		return "", "", fmt.Errorf("failed to convert stop LSN to segment name: %w", err)
+	}
+
+	return startSegment, stopSegment, nil
+}
+
+func LSNToSegmentName(lsn string, timelineID, walSegmentSize uint32) (string, error) {
+	high, low, err := parseLSN(lsn)
+	if err != nil {
+		return "", err
+	}
+
+	segmentsPerXLogID := uint32(0x100000000 / uint64(walSegmentSize))
+	logID := high
+	segmentOffset := low / walSegmentSize
+
+	if segmentOffset >= segmentsPerXLogID {
+		return "", fmt.Errorf("segment offset %d exceeds segments per XLogId %d", segmentOffset, segmentsPerXLogID)
+	}
+
+	return fmt.Sprintf("%08X%08X%08X", timelineID, logID, segmentOffset), nil
+}
+
+func parseLSN(lsn string) (high, low uint32, err error) {
+	parts := strings.SplitN(lsn, "/", 2)
+	if len(parts) != 2 {
+		return 0, 0, fmt.Errorf("invalid LSN format: %q (expected X/Y)", lsn)
+	}
+
+	highVal, err := strconv.ParseUint(parts[0], 16, 32)
+	if err != nil {
+		return 0, 0, fmt.Errorf("invalid LSN high part %q: %w", parts[0], err)
+	}
+
+	lowVal, err := strconv.ParseUint(parts[1], 16, 32)
+	if err != nil {
+		return 0, 0, fmt.Errorf("invalid LSN low part %q: %w", parts[1], err)
+	}
+
+	return uint32(highVal), uint32(lowVal), nil
+}

agent/internal/features/full_backup/stderr_parser_test.go

@@ -0,0 +1,157 @@
+package full_backup
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ParseBasebackupStderr_WithPG17FetchOutput_ExtractsCorrectSegments(t *testing.T) {
+	stderr := `pg_basebackup: initiating base backup, waiting for checkpoint to complete
+pg_basebackup: checkpoint completed
+pg_basebackup: write-ahead log start point: 0/2000028 on timeline 1
+pg_basebackup: starting background WAL receiver
+pg_basebackup: write-ahead log end point: 0/2000100
+pg_basebackup: waiting for background process to finish streaming ...
+pg_basebackup: syncing data to disk ...
+pg_basebackup: renaming backup_manifest.tmp to backup_manifest
+pg_basebackup: base backup completed`
+
+	startSeg, stopSeg, err := ParseBasebackupStderr(stderr)
+
+	require.NoError(t, err)
+	assert.Equal(t, "000000010000000000000002", startSeg)
+	assert.Equal(t, "000000010000000000000002", stopSeg)
+}
+
+func Test_ParseBasebackupStderr_WithHighLSNValues_ExtractsCorrectSegments(t *testing.T) {
+	stderr := `pg_basebackup: write-ahead log start point: 1/AB000028 on timeline 1
+pg_basebackup: write-ahead log end point: 1/AC000000`
+
+	startSeg, stopSeg, err := ParseBasebackupStderr(stderr)
+
+	require.NoError(t, err)
+	assert.Equal(t, "0000000100000001000000AB", startSeg)
+	assert.Equal(t, "0000000100000001000000AC", stopSeg)
+}
+
+func Test_ParseBasebackupStderr_WithHighLogID_ExtractsCorrectSegments(t *testing.T) {
+	stderr := `pg_basebackup: write-ahead log start point: A/FF000028 on timeline 1
+pg_basebackup: write-ahead log end point: B/1000000`
+
+	startSeg, stopSeg, err := ParseBasebackupStderr(stderr)
+
+	require.NoError(t, err)
+	assert.Equal(t, "000000010000000A000000FF", startSeg)
+	assert.Equal(t, "000000010000000B00000001", stopSeg)
+}
+
+func Test_ParseBasebackupStderr_WhenStartLSNMissing_ReturnsError(t *testing.T) {
+	stderr := `pg_basebackup: write-ahead log end point: 0/2000100
+pg_basebackup: base backup completed`
+
+	_, _, err := ParseBasebackupStderr(stderr)
+
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "failed to parse start WAL location")
+}
+
+func Test_ParseBasebackupStderr_WhenStopLSNMissing_ReturnsError(t *testing.T) {
+	stderr := `pg_basebackup: write-ahead log start point: 0/2000028 on timeline 1
+pg_basebackup: base backup completed`
+
+	_, _, err := ParseBasebackupStderr(stderr)
+
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "failed to parse stop WAL location")
+}
+
+func Test_ParseBasebackupStderr_WhenEmptyStderr_ReturnsError(t *testing.T) {
+	_, _, err := ParseBasebackupStderr("")
+
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "failed to parse start WAL location")
+}
+
+func Test_LSNToSegmentName_WithBoundaryValues_ConvertsCorrectly(t *testing.T) {
+	tests := []struct {
+		name     string
+		lsn      string
+		timeline uint32
+		segSize  uint32
+		expected string
+	}{
+		{
+			name:     "first segment",
+			lsn:      "0/1000000",
+			timeline: 1,
+			segSize:  16 * 1024 * 1024,
+			expected: "000000010000000000000001",
+		},
+		{
+			name:     "segment at boundary FF",
+			lsn:      "0/FF000000",
+			timeline: 1,
+			segSize:  16 * 1024 * 1024,
+			expected: "0000000100000000000000FF",
+		},
+		{
+			name:     "segment in second log file",
+			lsn:      "1/0",
+			timeline: 1,
+			segSize:  16 * 1024 * 1024,
+			expected: "000000010000000100000000",
+		},
+		{
+			name:     "segment with offset within 16MB",
+			lsn:      "0/200ABCD",
+			timeline: 1,
+			segSize:  16 * 1024 * 1024,
+			expected: "000000010000000000000002",
+		},
+		{
+			name:     "zero LSN",
+			lsn:      "0/0",
+			timeline: 1,
+			segSize:  16 * 1024 * 1024,
+			expected: "000000010000000000000000",
+		},
+		{
+			name:     "high timeline ID",
+			lsn:      "0/1000000",
+			timeline: 2,
+			segSize:  16 * 1024 * 1024,
+			expected: "000000020000000000000001",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result, err := LSNToSegmentName(tt.lsn, tt.timeline, tt.segSize)
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}
+
+func Test_LSNToSegmentName_WithInvalidLSN_ReturnsError(t *testing.T) {
+	tests := []struct {
+		name string
+		lsn  string
+	}{
+		{name: "no slash", lsn: "012345"},
+		{name: "empty string", lsn: ""},
+		{name: "invalid hex high", lsn: "GG/0"},
+		{name: "invalid hex low", lsn: "0/ZZ"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := LSNToSegmentName(tt.lsn, 1, 16*1024*1024)
+
+			require.Error(t, err)
+		})
+	}
+}

agent/internal/features/restore/restorer.go

@@ -0,0 +1,444 @@
+package restore
+
+import (
+	"archive/tar"
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+
+	"databasus-agent/internal/features/api"
+)
+
+const (
+	walRestoreDir            = "databasus-wal-restore"
+	maxRetryAttempts         = 3
+	retryBaseDelay           = 1 * time.Second
+	recoverySignalFile       = "recovery.signal"
+	autoConfFile             = "postgresql.auto.conf"
+	dockerContainerPgDataDir = "/var/lib/postgresql/data"
+)
+
+var retryDelayOverride *time.Duration
+
+type Restorer struct {
+	apiClient       *api.Client
+	log             *slog.Logger
+	targetPgDataDir string
+	backupID        string
+	targetTime      string
+	pgType          string
+}
+
+func NewRestorer(
+	apiClient *api.Client,
+	log *slog.Logger,
+	targetPgDataDir string,
+	backupID string,
+	targetTime string,
+	pgType string,
+) *Restorer {
+	return &Restorer{
+		apiClient,
+		log,
+		targetPgDataDir,
+		backupID,
+		targetTime,
+		pgType,
+	}
+}
+
+func (r *Restorer) Run(ctx context.Context) error {
+	var parsedTargetTime *time.Time
+
+	if r.targetTime != "" {
+		parsed, err := time.Parse(time.RFC3339, r.targetTime)
+		if err != nil {
+			return fmt.Errorf("invalid --target-time format (expected RFC3339, e.g. 2026-02-28T14:30:00Z): %w", err)
+		}
+
+		parsedTargetTime = &parsed
+	}
+
+	if err := r.validateTargetPgDataDir(); err != nil {
+		return err
+	}
+
+	plan, err := r.getRestorePlanFromServer(ctx)
+	if err != nil {
+		return err
+	}
+
+	r.logRestorePlan(plan, parsedTargetTime)
+
+	r.log.Info("Downloading and extracting basebackup...")
+	if err := r.downloadAndExtractBasebackup(ctx, plan.FullBackup.BackupID); err != nil {
+		return fmt.Errorf("basebackup download failed: %w", err)
+	}
+	r.log.Info("Basebackup extracted successfully")
+
+	if err := r.downloadAllWalSegments(ctx, plan.WalSegments); err != nil {
+		return err
+	}
+
+	if err := r.configurePostgresRecovery(parsedTargetTime); err != nil {
+		return fmt.Errorf("failed to configure recovery: %w", err)
+	}
+
+	if err := os.Chmod(r.targetPgDataDir, 0o700); err != nil {
+		return fmt.Errorf("set PGDATA permissions: %w", err)
+	}
+
+	r.printCompletionMessage()
+
+	return nil
+}
+
+func (r *Restorer) validateTargetPgDataDir() error {
+	info, err := os.Stat(r.targetPgDataDir)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return fmt.Errorf("target pgdata directory does not exist: %s", r.targetPgDataDir)
+		}
+
+		return fmt.Errorf("cannot access target pgdata directory: %w", err)
+	}
+
+	if !info.IsDir() {
+		return fmt.Errorf("target pgdata path is not a directory: %s", r.targetPgDataDir)
+	}
+
+	entries, err := os.ReadDir(r.targetPgDataDir)
+	if err != nil {
+		return fmt.Errorf("cannot read target pgdata directory: %w", err)
+	}
+
+	if len(entries) > 0 {
+		return fmt.Errorf("target pgdata directory is not empty: %s", r.targetPgDataDir)
+	}
+
+	return nil
+}
+
+func (r *Restorer) getRestorePlanFromServer(ctx context.Context) (*api.GetRestorePlanResponse, error) {
+	plan, planErr, err := r.apiClient.GetRestorePlan(ctx, r.backupID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch restore plan: %w", err)
+	}
+
+	if planErr != nil {
+		if planErr.LastContiguousSegment != "" {
+			return nil, fmt.Errorf("restore plan error: %s (last contiguous segment: %s)",
+				planErr.Message, planErr.LastContiguousSegment)
+		}
+
+		return nil, fmt.Errorf("restore plan error: %s", planErr.Message)
+	}
+
+	return plan, nil
+}
+
+func (r *Restorer) logRestorePlan(plan *api.GetRestorePlanResponse, parsedTargetTime *time.Time) {
+	recoveryTarget := "full recovery (all available WAL)"
+	if parsedTargetTime != nil {
+		recoveryTarget = parsedTargetTime.Format(time.RFC3339)
+	}
+
+	r.log.Info("Restore plan",
+		"fullBackupID", plan.FullBackup.BackupID,
+		"fullBackupCreatedAt", plan.FullBackup.CreatedAt.Format(time.RFC3339),
+		"pgVersion", plan.FullBackup.PgVersion,
+		"walSegmentCount", len(plan.WalSegments),
+		"totalDownloadSize", formatSizeBytes(plan.TotalSizeBytes),
+		"latestAvailableSegment", plan.LatestAvailableSegment,
+		"recoveryTarget", recoveryTarget,
+	)
+}
+
+func (r *Restorer) downloadAndExtractBasebackup(ctx context.Context, backupID string) error {
+	body, err := r.apiClient.DownloadBackupFile(ctx, backupID)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = body.Close() }()
+
+	zstdReader, err := zstd.NewReader(body)
+	if err != nil {
+		return fmt.Errorf("create zstd decompressor: %w", err)
+	}
+	defer zstdReader.Close()
+
+	tarReader := tar.NewReader(zstdReader)
+
+	return r.extractTarArchive(tarReader)
+}
+
+func (r *Restorer) extractTarArchive(tarReader *tar.Reader) error {
+	for {
+		header, err := tarReader.Next()
+		if errors.Is(err, io.EOF) {
+			return nil
+		}
+
+		if err != nil {
+			return fmt.Errorf("read tar entry: %w", err)
+		}
+
+		targetPath := filepath.Join(r.targetPgDataDir, header.Name)
+
+		relativePath, err := filepath.Rel(r.targetPgDataDir, targetPath)
+		if err != nil || strings.HasPrefix(relativePath, "..") {
+			return fmt.Errorf("tar entry attempts path traversal: %s", header.Name)
+		}
+
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(targetPath, os.FileMode(header.Mode)); err != nil {
+				return fmt.Errorf("create directory %s: %w", header.Name, err)
+			}
+
+		case tar.TypeReg:
+			parentDir := filepath.Dir(targetPath)
+			if err := os.MkdirAll(parentDir, 0o755); err != nil {
+				return fmt.Errorf("create parent directory for %s: %w", header.Name, err)
+			}
+
+			file, err := os.OpenFile(targetPath, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(header.Mode))
+			if err != nil {
+				return fmt.Errorf("create file %s: %w", header.Name, err)
+			}
+
+			if _, err := io.Copy(file, tarReader); err != nil {
+				_ = file.Close()
+				return fmt.Errorf("write file %s: %w", header.Name, err)
+			}
+
+			_ = file.Close()
+
+		case tar.TypeSymlink:
+			if err := os.Symlink(header.Linkname, targetPath); err != nil {
+				return fmt.Errorf("create symlink %s: %w", header.Name, err)
+			}
+
+		case tar.TypeLink:
+			linkTarget := filepath.Join(r.targetPgDataDir, header.Linkname)
+			if err := os.Link(linkTarget, targetPath); err != nil {
+				return fmt.Errorf("create hard link %s: %w", header.Name, err)
+			}
+
+		default:
+			r.log.Warn("Skipping unsupported tar entry type",
+				"name", header.Name,
+				"type", header.Typeflag,
+			)
+		}
+	}
+}
+
+func (r *Restorer) downloadAllWalSegments(ctx context.Context, segments []api.RestorePlanWalSegment) error {
+	walRestorePath := filepath.Join(r.targetPgDataDir, walRestoreDir)
+	if err := os.MkdirAll(walRestorePath, 0o755); err != nil {
+		return fmt.Errorf("create WAL restore directory: %w", err)
+	}
+
+	for segmentIndex, segment := range segments {
+		if err := r.downloadWalSegmentWithRetry(ctx, segment, segmentIndex, len(segments)); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (r *Restorer) downloadWalSegmentWithRetry(
+	ctx context.Context,
+	segment api.RestorePlanWalSegment,
+	segmentIndex int,
+	segmentsTotal int,
+) error {
+	r.log.Info("Downloading WAL segment",
+		"segment", segment.SegmentName,
+		"progress", fmt.Sprintf("%d/%d", segmentIndex+1, segmentsTotal),
+	)
+
+	var lastErr error
+
+	for attempt := range maxRetryAttempts {
+		if err := r.downloadWalSegment(ctx, segment); err != nil {
+			lastErr = err
+
+			delay := r.getRetryDelay(attempt)
+			r.log.Warn("WAL segment download failed, retrying",
+				"segment", segment.SegmentName,
+				"attempt", attempt+1,
+				"maxAttempts", maxRetryAttempts,
+				"retryDelay", delay,
+				"error", err,
+			)
+
+			select {
+			case <-ctx.Done():
+				return ctx.Err()
+			case <-time.After(delay):
+				continue
+			}
+		}
+
+		return nil
+	}
+
+	return fmt.Errorf("failed to download WAL segment %s after %d attempts: %w",
+		segment.SegmentName, maxRetryAttempts, lastErr)
+}
+
+func (r *Restorer) downloadWalSegment(ctx context.Context, segment api.RestorePlanWalSegment) error {
+	body, err := r.apiClient.DownloadBackupFile(ctx, segment.BackupID)
+	if err != nil {
+		return err
+	}
+	defer func() { _ = body.Close() }()
+
+	zstdReader, err := zstd.NewReader(body)
+	if err != nil {
+		return fmt.Errorf("create zstd decompressor: %w", err)
+	}
+	defer zstdReader.Close()
+
+	segmentPath := filepath.Join(r.targetPgDataDir, walRestoreDir, segment.SegmentName)
+
+	file, err := os.Create(segmentPath)
+	if err != nil {
+		return fmt.Errorf("create WAL segment file: %w", err)
+	}
+	defer func() { _ = file.Close() }()
+
+	if _, err := io.Copy(file, zstdReader); err != nil {
+		return fmt.Errorf("write WAL segment: %w", err)
+	}
+
+	return nil
+}
+
+func (r *Restorer) configurePostgresRecovery(parsedTargetTime *time.Time) error {
+	recoverySignalPath := filepath.Join(r.targetPgDataDir, recoverySignalFile)
+	if err := os.WriteFile(recoverySignalPath, []byte{}, 0o644); err != nil {
+		return fmt.Errorf("create recovery.signal: %w", err)
+	}
+
+	walRestoreAbsPath, err := r.resolveWalRestorePath()
+	if err != nil {
+		return err
+	}
+
+	autoConfPath := filepath.Join(r.targetPgDataDir, autoConfFile)
+
+	autoConfFile, err := os.OpenFile(autoConfPath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		return fmt.Errorf("open postgresql.auto.conf: %w", err)
+	}
+	defer func() { _ = autoConfFile.Close() }()
+
+	var configLines strings.Builder
+	configLines.WriteString("\n# Added by databasus-agent restore\n")
+	fmt.Fprintf(&configLines, "restore_command = 'cp %s/%%f %%p'\n", walRestoreAbsPath)
+	fmt.Fprintf(&configLines, "recovery_end_command = 'rm -rf %s'\n", walRestoreAbsPath)
+	configLines.WriteString("recovery_target_action = 'promote'\n")
+
+	if parsedTargetTime != nil {
+		fmt.Fprintf(&configLines, "recovery_target_time = '%s'\n", parsedTargetTime.Format(time.RFC3339))
+	}
+
+	if _, err := autoConfFile.WriteString(configLines.String()); err != nil {
+		return fmt.Errorf("write to postgresql.auto.conf: %w", err)
+	}
+
+	return nil
+}
+
+func (r *Restorer) printCompletionMessage() {
+	absPgDataDir, _ := filepath.Abs(r.targetPgDataDir)
+	isDocker := r.pgType == "docker"
+
+	fmt.Printf("\nRestore complete. PGDATA directory is ready at %s.\n", absPgDataDir)
+
+	fmt.Print(`
+What happens when you start PostgreSQL:
+  1. PostgreSQL detects recovery.signal and enters recovery mode
+  2. It replays WAL from the basebackup's consistency point
+  3. It executes restore_command to fetch WAL segments from databasus-wal-restore/
+  4. WAL replay continues until target_time (if PITR) or end of available WAL
+  5. recovery_end_command automatically removes databasus-wal-restore/
+  6. PostgreSQL promotes to primary and removes recovery.signal
+  7. Normal operations resume
+`)
+
+	if isDocker {
+		fmt.Printf(`
+Start PostgreSQL by launching a container with the restored data mounted:
+  docker run -d -v %s:%s postgres:<VERSION>
+
+Or if you have an existing container:
+  docker start <CONTAINER_NAME>
+
+Ensure %s is mounted as the container's pgdata volume at %s.
+`, absPgDataDir, dockerContainerPgDataDir, absPgDataDir, dockerContainerPgDataDir)
+	} else {
+		fmt.Printf(`
+Start PostgreSQL:
+  pg_ctl -D %s start
+
+Note: If you move the PGDATA directory before starting PostgreSQL,
+update restore_command and recovery_end_command paths in
+postgresql.auto.conf accordingly.
+`, absPgDataDir)
+	}
+}
+
+func (r *Restorer) resolveWalRestorePath() (string, error) {
+	if r.pgType == "docker" {
+		return dockerContainerPgDataDir + "/" + walRestoreDir, nil
+	}
+
+	absPgDataDir, err := filepath.Abs(r.targetPgDataDir)
+	if err != nil {
+		return "", fmt.Errorf("resolve absolute path: %w", err)
+	}
+
+	absPgDataDir = filepath.ToSlash(absPgDataDir)
+
+	return absPgDataDir + "/" + walRestoreDir, nil
+}
+
+func (r *Restorer) getRetryDelay(attempt int) time.Duration {
+	if retryDelayOverride != nil {
+		return *retryDelayOverride
+	}
+
+	return retryBaseDelay * time.Duration(1<<attempt)
+}
+
+func formatSizeBytes(sizeBytes int64) string {
+	const (
+		kilobyte = 1024
+		megabyte = 1024 * kilobyte
+		gigabyte = 1024 * megabyte
+	)
+
+	switch {
+	case sizeBytes >= gigabyte:
+		return fmt.Sprintf("%.2f GB", float64(sizeBytes)/float64(gigabyte))
+	case sizeBytes >= megabyte:
+		return fmt.Sprintf("%.2f MB", float64(sizeBytes)/float64(megabyte))
+	case sizeBytes >= kilobyte:
+		return fmt.Sprintf("%.2f KB", float64(sizeBytes)/float64(kilobyte))
+	default:
+		return fmt.Sprintf("%d B", sizeBytes)
+	}
+}

agent/internal/features/restore/restorer_test.go

@@ -0,0 +1,712 @@
+package restore
+
+import (
+	"archive/tar"
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"databasus-agent/internal/features/api"
+	"databasus-agent/internal/logger"
+)
+
+const (
+	testRestorePlanPath     = "/api/v1/backups/postgres/wal/restore/plan"
+	testRestoreDownloadPath = "/api/v1/backups/postgres/wal/restore/download"
+
+	testFullBackupID = "full-backup-id-1234"
+	testWalSegment1  = "000000010000000100000001"
+	testWalSegment2  = "000000010000000100000002"
+)
+
+func Test_RunRestore_WhenBasebackupAndWalSegmentsAvailable_FilesExtractedAndRecoveryConfigured(t *testing.T) {
+	tarFiles := map[string][]byte{
+		"PG_VERSION":      []byte("16"),
+		"base/1/somefile": []byte("table-data"),
+	}
+	zstdTarData := createZstdTar(t, tarFiles)
+	walData1 := createZstdData(t, []byte("wal-segment-1-data"))
+	walData2 := createZstdData(t, []byte("wal-segment-2-data"))
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:                  testFullBackupID,
+					FullBackupWalStartSegment: testWalSegment1,
+					FullBackupWalStopSegment:  testWalSegment1,
+					PgVersion:                 "16",
+					CreatedAt:                 time.Now().UTC(),
+					SizeBytes:                 1024,
+				},
+				WalSegments: []api.RestorePlanWalSegment{
+					{BackupID: "wal-1", SegmentName: testWalSegment1, SizeBytes: 512},
+					{BackupID: "wal-2", SegmentName: testWalSegment2, SizeBytes: 512},
+				},
+				TotalSizeBytes:         2048,
+				LatestAvailableSegment: testWalSegment2,
+			})
+
+		case testRestoreDownloadPath:
+			backupID := r.URL.Query().Get("backupId")
+			switch backupID {
+			case testFullBackupID:
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = w.Write(zstdTarData)
+			case "wal-1":
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = w.Write(walData1)
+			case "wal-2":
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = w.Write(walData2)
+			default:
+				w.WriteHeader(http.StatusBadRequest)
+			}
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	pgVersionContent, err := os.ReadFile(filepath.Join(targetDir, "PG_VERSION"))
+	require.NoError(t, err)
+	assert.Equal(t, "16", string(pgVersionContent))
+
+	someFileContent, err := os.ReadFile(filepath.Join(targetDir, "base", "1", "somefile"))
+	require.NoError(t, err)
+	assert.Equal(t, "table-data", string(someFileContent))
+
+	walSegment1Content, err := os.ReadFile(filepath.Join(targetDir, walRestoreDir, testWalSegment1))
+	require.NoError(t, err)
+	assert.Equal(t, "wal-segment-1-data", string(walSegment1Content))
+
+	walSegment2Content, err := os.ReadFile(filepath.Join(targetDir, walRestoreDir, testWalSegment2))
+	require.NoError(t, err)
+	assert.Equal(t, "wal-segment-2-data", string(walSegment2Content))
+
+	recoverySignalPath := filepath.Join(targetDir, "recovery.signal")
+	recoverySignalInfo, err := os.Stat(recoverySignalPath)
+	require.NoError(t, err)
+	assert.Equal(t, int64(0), recoverySignalInfo.Size())
+
+	autoConfContent, err := os.ReadFile(filepath.Join(targetDir, "postgresql.auto.conf"))
+	require.NoError(t, err)
+	autoConfStr := string(autoConfContent)
+
+	assert.Contains(t, autoConfStr, "restore_command")
+	assert.Contains(t, autoConfStr, walRestoreDir)
+	assert.Contains(t, autoConfStr, "recovery_target_action = 'promote'")
+	assert.Contains(t, autoConfStr, "recovery_end_command")
+	assert.NotContains(t, autoConfStr, "recovery_target_time")
+}
+
+func Test_RunRestore_WhenTargetTimeProvided_RecoveryTargetTimeWrittenToConfig(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(zstdTarData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "2026-02-28T14:30:00Z", "")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	autoConfContent, err := os.ReadFile(filepath.Join(targetDir, "postgresql.auto.conf"))
+	require.NoError(t, err)
+
+	assert.Contains(t, string(autoConfContent), "recovery_target_time = '2026-02-28T14:30:00Z'")
+}
+
+func Test_RunRestore_WhenPgDataDirNotEmpty_ReturnsError(t *testing.T) {
+	targetDir := createTestTargetDir(t)
+
+	err := os.WriteFile(filepath.Join(targetDir, "existing-file"), []byte("data"), 0o644)
+	require.NoError(t, err)
+
+	restorer := newTestRestorer("http://localhost:0", targetDir, "", "", "")
+
+	err = restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "not empty")
+}
+
+func Test_RunRestore_WhenPgDataDirDoesNotExist_ReturnsError(t *testing.T) {
+	nonExistentDir := filepath.Join(os.TempDir(), "databasus-test-nonexistent-dir-12345")
+
+	restorer := newTestRestorer("http://localhost:0", nonExistentDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "does not exist")
+}
+
+func Test_RunRestore_WhenNoBackupsAvailable_ReturnsError(t *testing.T) {
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		_ = json.NewEncoder(w).Encode(api.GetRestorePlanErrorResponse{
+			Error:   "no_backups",
+			Message: "No full backups available",
+		})
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "No full backups available")
+}
+
+func Test_RunRestore_WhenWalChainBroken_ReturnsError(t *testing.T) {
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusBadRequest)
+		_ = json.NewEncoder(w).Encode(api.GetRestorePlanErrorResponse{
+			Error:                 "wal_chain_broken",
+			Message:               "WAL chain broken",
+			LastContiguousSegment: testWalSegment1,
+		})
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "WAL chain broken")
+	assert.Contains(t, err.Error(), testWalSegment1)
+}
+
+func Test_DownloadWalSegment_WhenFirstAttemptFails_RetriesAndSucceeds(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+	walData := createZstdData(t, []byte("wal-segment-data"))
+
+	var mu sync.Mutex
+	var walDownloadAttempts int
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments: []api.RestorePlanWalSegment{
+					{BackupID: "wal-1", SegmentName: testWalSegment1, SizeBytes: 512},
+				},
+				TotalSizeBytes:         1536,
+				LatestAvailableSegment: testWalSegment1,
+			})
+
+		case testRestoreDownloadPath:
+			backupID := r.URL.Query().Get("backupId")
+			if backupID == testFullBackupID {
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = w.Write(zstdTarData)
+				return
+			}
+
+			mu.Lock()
+			walDownloadAttempts++
+			attempt := walDownloadAttempts
+			mu.Unlock()
+
+			if attempt == 1 {
+				w.WriteHeader(http.StatusInternalServerError)
+				_, _ = w.Write([]byte(`{"error":"storage unavailable"}`))
+				return
+			}
+
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(walData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	origDelay := retryDelayOverride
+	testDelay := 10 * time.Millisecond
+	retryDelayOverride = &testDelay
+	defer func() { retryDelayOverride = origDelay }()
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	mu.Lock()
+	attempts := walDownloadAttempts
+	mu.Unlock()
+
+	assert.Equal(t, 2, attempts)
+
+	walContent, err := os.ReadFile(filepath.Join(targetDir, walRestoreDir, testWalSegment1))
+	require.NoError(t, err)
+	assert.Equal(t, "wal-segment-data", string(walContent))
+}
+
+func Test_DownloadWalSegment_WhenAllAttemptsFail_ReturnsErrorWithSegmentName(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments: []api.RestorePlanWalSegment{
+					{BackupID: "wal-1", SegmentName: testWalSegment1, SizeBytes: 512},
+				},
+				TotalSizeBytes:         1536,
+				LatestAvailableSegment: testWalSegment1,
+			})
+
+		case testRestoreDownloadPath:
+			backupID := r.URL.Query().Get("backupId")
+			if backupID == testFullBackupID {
+				w.Header().Set("Content-Type", "application/octet-stream")
+				_, _ = w.Write(zstdTarData)
+				return
+			}
+
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte(`{"error":"storage unavailable"}`))
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	origDelay := retryDelayOverride
+	testDelay := 10 * time.Millisecond
+	retryDelayOverride = &testDelay
+	defer func() { retryDelayOverride = origDelay }()
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), testWalSegment1)
+	assert.Contains(t, err.Error(), "3 attempts")
+}
+
+func Test_RunRestore_WhenInvalidTargetTimeFormat_ReturnsError(t *testing.T) {
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer("http://localhost:0", targetDir, "", "not-a-valid-time", "")
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "invalid --target-time format")
+}
+
+func Test_RunRestore_WhenBasebackupDownloadFails_ReturnsError(t *testing.T) {
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.WriteHeader(http.StatusInternalServerError)
+			_, _ = w.Write([]byte(`{"error":"storage error"}`))
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "basebackup download failed")
+}
+
+func Test_RunRestore_WhenNoWalSegmentsInPlan_BasebackupRestoredSuccessfully(t *testing.T) {
+	tarFiles := map[string][]byte{
+		"PG_VERSION":        []byte("16"),
+		"global/pg_control": []byte("control-data"),
+	}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(zstdTarData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	pgVersionContent, err := os.ReadFile(filepath.Join(targetDir, "PG_VERSION"))
+	require.NoError(t, err)
+	assert.Equal(t, "16", string(pgVersionContent))
+
+	walRestoreDirInfo, err := os.Stat(filepath.Join(targetDir, walRestoreDir))
+	require.NoError(t, err)
+	assert.True(t, walRestoreDirInfo.IsDir())
+
+	_, err = os.Stat(filepath.Join(targetDir, "recovery.signal"))
+	require.NoError(t, err)
+
+	autoConfContent, err := os.ReadFile(filepath.Join(targetDir, "postgresql.auto.conf"))
+	require.NoError(t, err)
+	assert.Contains(t, string(autoConfContent), "restore_command")
+}
+
+func Test_RunRestore_WhenMakingApiCalls_AuthTokenIncludedInRequests(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	var receivedAuthHeaders atomic.Int32
+	var mu sync.Mutex
+	var authHeaderValues []string
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		authHeader := r.Header.Get("Authorization")
+		if authHeader != "" {
+			receivedAuthHeaders.Add(1)
+
+			mu.Lock()
+			authHeaderValues = append(authHeaderValues, authHeader)
+			mu.Unlock()
+		}
+
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(zstdTarData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	assert.GreaterOrEqual(t, int(receivedAuthHeaders.Load()), 2)
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	for _, headerValue := range authHeaderValues {
+		assert.Equal(t, "test-token", headerValue)
+	}
+}
+
+func Test_ConfigurePostgresRecovery_WhenPgTypeHost_UsesHostAbsolutePath(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(zstdTarData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "host")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	autoConfContent, err := os.ReadFile(filepath.Join(targetDir, "postgresql.auto.conf"))
+	require.NoError(t, err)
+	autoConfStr := string(autoConfContent)
+
+	absTargetDir, _ := filepath.Abs(targetDir)
+	absTargetDir = filepath.ToSlash(absTargetDir)
+	expectedWalPath := absTargetDir + "/" + walRestoreDir
+
+	assert.Contains(t, autoConfStr, fmt.Sprintf("restore_command = 'cp %s/%%f %%p'", expectedWalPath))
+	assert.Contains(t, autoConfStr, fmt.Sprintf("recovery_end_command = 'rm -rf %s'", expectedWalPath))
+	assert.NotContains(t, autoConfStr, "/var/lib/postgresql/data")
+}
+
+func Test_ConfigurePostgresRecovery_WhenPgTypeDocker_UsesContainerPath(t *testing.T) {
+	tarFiles := map[string][]byte{"PG_VERSION": []byte("16")}
+	zstdTarData := createZstdTar(t, tarFiles)
+
+	server := newTestServer(t, func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case testRestorePlanPath:
+			writeJSON(w, api.GetRestorePlanResponse{
+				FullBackup: api.RestorePlanFullBackup{
+					BackupID:  testFullBackupID,
+					PgVersion: "16",
+					CreatedAt: time.Now().UTC(),
+					SizeBytes: 1024,
+				},
+				WalSegments:            []api.RestorePlanWalSegment{},
+				TotalSizeBytes:         1024,
+				LatestAvailableSegment: "",
+			})
+
+		case testRestoreDownloadPath:
+			w.Header().Set("Content-Type", "application/octet-stream")
+			_, _ = w.Write(zstdTarData)
+
+		default:
+			w.WriteHeader(http.StatusNotFound)
+		}
+	})
+
+	targetDir := createTestTargetDir(t)
+	restorer := newTestRestorer(server.URL, targetDir, "", "", "docker")
+
+	err := restorer.Run(context.Background())
+	require.NoError(t, err)
+
+	autoConfContent, err := os.ReadFile(filepath.Join(targetDir, "postgresql.auto.conf"))
+	require.NoError(t, err)
+	autoConfStr := string(autoConfContent)
+
+	expectedWalPath := "/var/lib/postgresql/data/" + walRestoreDir
+
+	assert.Contains(t, autoConfStr, fmt.Sprintf("restore_command = 'cp %s/%%f %%p'", expectedWalPath))
+	assert.Contains(t, autoConfStr, fmt.Sprintf("recovery_end_command = 'rm -rf %s'", expectedWalPath))
+
+	absTargetDir, _ := filepath.Abs(targetDir)
+	absTargetDir = filepath.ToSlash(absTargetDir)
+	assert.NotContains(t, autoConfStr, absTargetDir)
+}
+
+func newTestServer(t *testing.T, handler http.HandlerFunc) *httptest.Server {
+	t.Helper()
+
+	server := httptest.NewServer(handler)
+	t.Cleanup(server.Close)
+
+	return server
+}
+
+func createTestTargetDir(t *testing.T) string {
+	t.Helper()
+
+	baseDir := filepath.Join(".", ".test-tmp")
+	if err := os.MkdirAll(baseDir, 0o755); err != nil {
+		t.Fatalf("failed to create base test dir: %v", err)
+	}
+
+	dir, err := os.MkdirTemp(baseDir, t.Name()+"-*")
+	if err != nil {
+		t.Fatalf("failed to create test target dir: %v", err)
+	}
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll(dir)
+	})
+
+	return dir
+}
+
+func createZstdTar(t *testing.T, files map[string][]byte) []byte {
+	t.Helper()
+
+	var tarBuffer bytes.Buffer
+	tarWriter := tar.NewWriter(&tarBuffer)
+
+	createdDirs := make(map[string]bool)
+
+	for name, content := range files {
+		dir := filepath.Dir(name)
+		if dir != "." && !createdDirs[dir] {
+			parts := strings.Split(filepath.ToSlash(dir), "/")
+			for partIndex := range parts {
+				partialDir := strings.Join(parts[:partIndex+1], "/")
+				if !createdDirs[partialDir] {
+					err := tarWriter.WriteHeader(&tar.Header{
+						Name:     partialDir + "/",
+						Typeflag: tar.TypeDir,
+						Mode:     0o755,
+					})
+					require.NoError(t, err)
+
+					createdDirs[partialDir] = true
+				}
+			}
+		}
+
+		err := tarWriter.WriteHeader(&tar.Header{
+			Name:     name,
+			Size:     int64(len(content)),
+			Mode:     0o644,
+			Typeflag: tar.TypeReg,
+		})
+		require.NoError(t, err)
+
+		_, err = tarWriter.Write(content)
+		require.NoError(t, err)
+	}
+
+	require.NoError(t, tarWriter.Close())
+
+	var zstdBuffer bytes.Buffer
+
+	encoder, err := zstd.NewWriter(&zstdBuffer,
+		zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(5)),
+		zstd.WithEncoderCRC(true),
+	)
+	require.NoError(t, err)
+
+	_, err = encoder.Write(tarBuffer.Bytes())
+	require.NoError(t, err)
+	require.NoError(t, encoder.Close())
+
+	return zstdBuffer.Bytes()
+}
+
+func createZstdData(t *testing.T, data []byte) []byte {
+	t.Helper()
+
+	var buffer bytes.Buffer
+
+	encoder, err := zstd.NewWriter(&buffer,
+		zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(5)),
+		zstd.WithEncoderCRC(true),
+	)
+	require.NoError(t, err)
+
+	_, err = encoder.Write(data)
+	require.NoError(t, err)
+	require.NoError(t, encoder.Close())
+
+	return buffer.Bytes()
+}
+
+func newTestRestorer(serverURL, targetPgDataDir, backupID, targetTime, pgType string) *Restorer {
+	apiClient := api.NewClient(serverURL, "test-token", logger.GetLogger())
+
+	return NewRestorer(apiClient, logger.GetLogger(), targetPgDataDir, backupID, targetTime, pgType)
+}
+
+func writeJSON(w http.ResponseWriter, value any) {
+	w.Header().Set("Content-Type", "application/json")
+
+	if err := json.NewEncoder(w).Encode(value); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+	}
+}

agent/internal/features/start/daemon.go

@@ -0,0 +1,121 @@
+//go:build !windows
+
+package start
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"os/exec"
+	"syscall"
+	"time"
+)
+
+const (
+	logFileName        = "databasus.log"
+	stopTimeout        = 30 * time.Second
+	stopPollInterval   = 500 * time.Millisecond
+	daemonStartupDelay = 500 * time.Millisecond
+)
+
+func Stop(log *slog.Logger) error {
+	pid, err := ReadLockFilePID()
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			return errors.New("agent is not running (no lock file found)")
+		}
+
+		return fmt.Errorf("failed to read lock file: %w", err)
+	}
+
+	if !isProcessAlive(pid) {
+		_ = os.Remove(lockFileName)
+		return fmt.Errorf("agent is not running (stale lock file removed, PID %d)", pid)
+	}
+
+	log.Info("Sending SIGTERM to agent", "pid", pid)
+
+	if err := syscall.Kill(pid, syscall.SIGTERM); err != nil {
+		return fmt.Errorf("failed to send SIGTERM to PID %d: %w", pid, err)
+	}
+
+	deadline := time.Now().Add(stopTimeout)
+	for time.Now().Before(deadline) {
+		if !isProcessAlive(pid) {
+			log.Info("Agent stopped", "pid", pid)
+			return nil
+		}
+
+		time.Sleep(stopPollInterval)
+	}
+
+	return fmt.Errorf("agent (PID %d) did not stop within %s — process may be stuck", pid, stopTimeout)
+}
+
+func Status(log *slog.Logger) error {
+	pid, err := ReadLockFilePID()
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			fmt.Println("Agent is not running")
+			return nil
+		}
+
+		return fmt.Errorf("failed to read lock file: %w", err)
+	}
+
+	if isProcessAlive(pid) {
+		fmt.Printf("Agent is running (PID %d)\n", pid)
+	} else {
+		fmt.Println("Agent is not running (stale lock file)")
+		_ = os.Remove(lockFileName)
+	}
+
+	return nil
+}
+
+func spawnDaemon(log *slog.Logger) (int, error) {
+	execPath, err := os.Executable()
+	if err != nil {
+		return 0, fmt.Errorf("failed to resolve executable path: %w", err)
+	}
+
+	args := []string{"_run"}
+
+	logFile, err := os.OpenFile(logFileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		return 0, fmt.Errorf("failed to open log file %s: %w", logFileName, err)
+	}
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		_ = logFile.Close()
+		return 0, fmt.Errorf("failed to get working directory: %w", err)
+	}
+
+	cmd := exec.CommandContext(context.Background(), execPath, args...)
+	cmd.Dir = cwd
+	cmd.Stderr = logFile
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+
+	if err := cmd.Start(); err != nil {
+		_ = logFile.Close()
+		return 0, fmt.Errorf("failed to start daemon process: %w", err)
+	}
+
+	pid := cmd.Process.Pid
+
+	// Detach — we don't wait for the child
+	_ = logFile.Close()
+
+	time.Sleep(daemonStartupDelay)
+
+	if !isProcessAlive(pid) {
+		return 0, fmt.Errorf("daemon process (PID %d) exited immediately — check %s for details", pid, logFileName)
+	}
+
+	log.Info("Daemon spawned", "pid", pid, "log", logFileName)
+
+	return pid, nil
+}

agent/internal/features/start/daemon_windows.go

@@ -0,0 +1,20 @@
+//go:build windows
+
+package start
+
+import (
+	"errors"
+	"log/slog"
+)
+
+func Stop(log *slog.Logger) error {
+	return errors.New("stop is not supported on Windows — use Ctrl+C in the terminal where the agent is running")
+}
+
+func Status(log *slog.Logger) error {
+	return errors.New("status is not supported on Windows — check the terminal where the agent is running")
+}
+
+func spawnDaemon(_ *slog.Logger) (int, error) {
+	return 0, errors.New("daemon mode is not supported on Windows")
+}

agent/internal/features/start/lock.go

@@ -0,0 +1,132 @@
+//go:build !windows
+
+package start
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"strconv"
+	"strings"
+	"syscall"
+)
+
+const lockFileName = "databasus.lock"
+
+func AcquireLock(log *slog.Logger) (*os.File, error) {
+	f, err := os.OpenFile(lockFileName, os.O_CREATE|os.O_RDWR, 0o644)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open lock file: %w", err)
+	}
+
+	err = syscall.Flock(int(f.Fd()), syscall.LOCK_EX|syscall.LOCK_NB)
+	if err == nil {
+		if err := writePID(f); err != nil {
+			_ = f.Close()
+			return nil, err
+		}
+
+		log.Info("Process lock acquired", "pid", os.Getpid(), "lockFile", lockFileName)
+
+		return f, nil
+	}
+
+	if !errors.Is(err, syscall.EWOULDBLOCK) {
+		_ = f.Close()
+		return nil, fmt.Errorf("failed to acquire lock: %w", err)
+	}
+
+	pid, pidErr := readLockPID(f)
+	_ = f.Close()
+
+	if pidErr != nil {
+		return nil, fmt.Errorf("another instance is already running")
+	}
+
+	return nil, fmt.Errorf("another instance is already running (PID %d)", pid)
+}
+
+func ReleaseLock(f *os.File) {
+	_ = syscall.Flock(int(f.Fd()), syscall.LOCK_UN)
+
+	lockedStat, lockedErr := f.Stat()
+	_ = f.Close()
+
+	if lockedErr != nil {
+		_ = os.Remove(lockFileName)
+		return
+	}
+
+	diskStat, diskErr := os.Stat(lockFileName)
+	if diskErr != nil {
+		return
+	}
+
+	if os.SameFile(lockedStat, diskStat) {
+		_ = os.Remove(lockFileName)
+	}
+}
+
+func ReadLockFilePID() (int, error) {
+	f, err := os.Open(lockFileName)
+	if err != nil {
+		return 0, err
+	}
+	defer func() { _ = f.Close() }()
+
+	return readLockPID(f)
+}
+
+func writePID(f *os.File) error {
+	if err := f.Truncate(0); err != nil {
+		return fmt.Errorf("failed to truncate lock file: %w", err)
+	}
+
+	if _, err := f.Seek(0, io.SeekStart); err != nil {
+		return fmt.Errorf("failed to seek lock file: %w", err)
+	}
+
+	if _, err := fmt.Fprintf(f, "%d\n", os.Getpid()); err != nil {
+		return fmt.Errorf("failed to write PID to lock file: %w", err)
+	}
+
+	return f.Sync()
+}
+
+func readLockPID(f *os.File) (int, error) {
+	if _, err := f.Seek(0, io.SeekStart); err != nil {
+		return 0, err
+	}
+
+	data, err := io.ReadAll(f)
+	if err != nil {
+		return 0, err
+	}
+
+	s := strings.TrimSpace(string(data))
+	if s == "" {
+		return 0, errors.New("lock file is empty")
+	}
+
+	pid, err := strconv.Atoi(s)
+	if err != nil {
+		return 0, fmt.Errorf("invalid PID in lock file: %w", err)
+	}
+
+	return pid, nil
+}
+
+func isProcessAlive(pid int) bool {
+	err := syscall.Kill(pid, 0)
+	if err == nil {
+		return true
+	}
+
+	if errors.Is(err, syscall.EPERM) {
+		return true
+	}
+
+	return false
+}

agent/internal/features/start/lock_test.go

@@ -0,0 +1,148 @@
+//go:build !windows
+
+package start
+
+import (
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"databasus-agent/internal/logger"
+)
+
+func Test_AcquireLock_LockFileCreatedWithPID(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	data, err := os.ReadFile(lockFileName)
+	require.NoError(t, err)
+
+	pid, err := strconv.Atoi(strings.TrimSpace(string(data)))
+	require.NoError(t, err)
+	assert.Equal(t, os.Getpid(), pid)
+}
+
+func Test_AcquireLock_SecondAcquireFails_WhenFirstHeld(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	first, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(first)
+
+	second, err := AcquireLock(log)
+	assert.Nil(t, second)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "another instance is already running")
+	assert.Contains(t, err.Error(), fmt.Sprintf("PID %d", os.Getpid()))
+}
+
+func Test_AcquireLock_StaleLockReacquired_WhenProcessDead(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	err := os.WriteFile(lockFileName, []byte("999999999\n"), 0o644)
+	require.NoError(t, err)
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	data, err := os.ReadFile(lockFileName)
+	require.NoError(t, err)
+
+	pid, err := strconv.Atoi(strings.TrimSpace(string(data)))
+	require.NoError(t, err)
+	assert.Equal(t, os.Getpid(), pid)
+}
+
+func Test_ReleaseLock_LockFileRemoved(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+
+	ReleaseLock(lockFile)
+
+	_, err = os.Stat(lockFileName)
+	assert.True(t, os.IsNotExist(err))
+}
+
+func Test_AcquireLock_ReacquiredAfterRelease(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	first, err := AcquireLock(log)
+	require.NoError(t, err)
+	ReleaseLock(first)
+
+	second, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(second)
+
+	data, err := os.ReadFile(lockFileName)
+	require.NoError(t, err)
+
+	pid, err := strconv.Atoi(strings.TrimSpace(string(data)))
+	require.NoError(t, err)
+	assert.Equal(t, os.Getpid(), pid)
+}
+
+func Test_isProcessAlive_ReturnsTrueForSelf(t *testing.T) {
+	assert.True(t, isProcessAlive(os.Getpid()))
+}
+
+func Test_isProcessAlive_ReturnsFalseForNonExistentPID(t *testing.T) {
+	assert.False(t, isProcessAlive(999999999))
+}
+
+func Test_readLockPID_ParsesValidPID(t *testing.T) {
+	setupTempDir(t)
+
+	f, err := os.CreateTemp("", "lock-test-*")
+	require.NoError(t, err)
+	defer os.Remove(f.Name())
+
+	_, err = f.WriteString("12345\n")
+	require.NoError(t, err)
+
+	pid, err := readLockPID(f)
+	require.NoError(t, err)
+	assert.Equal(t, 12345, pid)
+}
+
+func Test_readLockPID_ReturnsErrorForEmptyFile(t *testing.T) {
+	setupTempDir(t)
+
+	f, err := os.CreateTemp("", "lock-test-*")
+	require.NoError(t, err)
+	defer os.Remove(f.Name())
+
+	_, err = readLockPID(f)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "lock file is empty")
+}
+
+func setupTempDir(t *testing.T) string {
+	t.Helper()
+
+	origDir, err := os.Getwd()
+	require.NoError(t, err)
+
+	dir := t.TempDir()
+	require.NoError(t, os.Chdir(dir))
+
+	t.Cleanup(func() { _ = os.Chdir(origDir) })
+
+	return dir
+}

agent/internal/features/start/lock_watcher.go

@@ -0,0 +1,90 @@
+//go:build !windows
+
+package start
+
+import (
+	"context"
+	"log/slog"
+	"os"
+	"syscall"
+	"time"
+)
+
+const lockWatchInterval = 5 * time.Second
+
+type LockWatcher struct {
+	originalInode uint64
+	cancel        context.CancelFunc
+	log           *slog.Logger
+}
+
+func NewLockWatcher(lockFile *os.File, cancel context.CancelFunc, log *slog.Logger) (*LockWatcher, error) {
+	inode, err := getFileInode(lockFile)
+	if err != nil {
+		return nil, err
+	}
+
+	return &LockWatcher{
+		originalInode: inode,
+		cancel:        cancel,
+		log:           log,
+	}, nil
+}
+
+func (w *LockWatcher) Run(ctx context.Context) {
+	ticker := time.NewTicker(lockWatchInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			w.check()
+		}
+	}
+}
+
+func (w *LockWatcher) check() {
+	info, err := os.Stat(lockFileName)
+	if err != nil {
+		w.log.Error("Lock file disappeared, shutting down", "file", lockFileName, "error", err)
+		w.cancel()
+
+		return
+	}
+
+	currentInode, err := getStatInode(info)
+	if err != nil {
+		w.log.Error("Failed to read lock file inode, shutting down", "error", err)
+		w.cancel()
+
+		return
+	}
+
+	if currentInode != w.originalInode {
+		w.log.Error("Lock file was replaced (inode changed), shutting down",
+			"originalInode", w.originalInode,
+			"currentInode", currentInode,
+		)
+		w.cancel()
+	}
+}
+
+func getFileInode(f *os.File) (uint64, error) {
+	info, err := f.Stat()
+	if err != nil {
+		return 0, err
+	}
+
+	return getStatInode(info)
+}
+
+func getStatInode(info os.FileInfo) (uint64, error) {
+	stat, ok := info.Sys().(*syscall.Stat_t)
+	if !ok {
+		return 0, os.ErrInvalid
+	}
+
+	return stat.Ino, nil
+}

agent/internal/features/start/lock_watcher_test.go

@@ -0,0 +1,110 @@
+//go:build !windows
+
+package start
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"databasus-agent/internal/logger"
+)
+
+func Test_NewLockWatcher_CapturesInode(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	_, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	watcher, err := NewLockWatcher(lockFile, cancel, log)
+	require.NoError(t, err)
+	assert.NotZero(t, watcher.originalInode)
+}
+
+func Test_LockWatcher_FileUnchanged_ContextNotCancelled(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	watcher, err := NewLockWatcher(lockFile, cancel, log)
+	require.NoError(t, err)
+
+	watcher.check()
+	watcher.check()
+	watcher.check()
+
+	select {
+	case <-ctx.Done():
+		t.Fatal("context should not be cancelled when lock file is unchanged")
+	default:
+	}
+}
+
+func Test_LockWatcher_FileDeleted_CancelsContext(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	watcher, err := NewLockWatcher(lockFile, cancel, log)
+	require.NoError(t, err)
+
+	err = os.Remove(lockFileName)
+	require.NoError(t, err)
+
+	watcher.check()
+
+	select {
+	case <-ctx.Done():
+	default:
+		t.Fatal("context should be cancelled when lock file is deleted")
+	}
+}
+
+func Test_LockWatcher_FileReplacedWithDifferentInode_CancelsContext(t *testing.T) {
+	setupTempDir(t)
+	log := logger.GetLogger()
+
+	lockFile, err := AcquireLock(log)
+	require.NoError(t, err)
+	defer ReleaseLock(lockFile)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	watcher, err := NewLockWatcher(lockFile, cancel, log)
+	require.NoError(t, err)
+
+	err = os.Remove(lockFileName)
+	require.NoError(t, err)
+
+	err = os.WriteFile(lockFileName, []byte("99999\n"), 0o644)
+	require.NoError(t, err)
+
+	watcher.check()
+
+	select {
+	case <-ctx.Done():
+	default:
+		t.Fatal("context should be cancelled when lock file inode changes")
+	}
+}

agent/internal/features/start/lock_watcher_windows.go

@@ -0,0 +1,17 @@
+//go:build windows
+
+package start
+
+import (
+	"context"
+	"log/slog"
+	"os"
+)
+
+type LockWatcher struct{}
+
+func NewLockWatcher(_ *os.File, _ context.CancelFunc, _ *slog.Logger) (*LockWatcher, error) {
+	return &LockWatcher{}, nil
+}
+
+func (w *LockWatcher) Run(_ context.Context) {}

agent/internal/features/start/lock_windows.go

@@ -0,0 +1,18 @@
+package start
+
+import (
+	"log/slog"
+	"os"
+)
+
+func AcquireLock(log *slog.Logger) (*os.File, error) {
+	log.Warn("Process locking is not supported on Windows, skipping")
+
+	return nil, nil
+}
+
+func ReleaseLock(f *os.File) {
+	if f != nil {
+		_ = f.Close()
+	}
+}

agent/internal/features/start/start.go

@@ -0,0 +1,325 @@
+package start
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/jackc/pgx/v5"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+	full_backup "databasus-agent/internal/features/full_backup"
+	"databasus-agent/internal/features/upgrade"
+	"databasus-agent/internal/features/wal"
+)
+
+const (
+	pgBasebackupVerifyTimeout = 10 * time.Second
+	dbVerifyTimeout           = 10 * time.Second
+	minPgMajorVersion         = 15
+)
+
+func Start(cfg *config.Config, agentVersion string, isDev bool, log *slog.Logger) error {
+	if err := validateConfig(cfg); err != nil {
+		return err
+	}
+
+	if err := verifyPgBasebackup(cfg, log); err != nil {
+		return err
+	}
+
+	if err := verifyDatabase(cfg, log); err != nil {
+		return err
+	}
+
+	if runtime.GOOS == "windows" {
+		return RunDaemon(cfg, agentVersion, isDev, log)
+	}
+
+	pid, err := spawnDaemon(log)
+	if err != nil {
+		return err
+	}
+
+	fmt.Printf("Agent started in background (PID %d)\n", pid)
+
+	return nil
+}
+
+func RunDaemon(cfg *config.Config, agentVersion string, isDev bool, log *slog.Logger) error {
+	lockFile, err := AcquireLock(log)
+	if err != nil {
+		return err
+	}
+	defer ReleaseLock(lockFile)
+
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer cancel()
+
+	watcher, err := NewLockWatcher(lockFile, cancel, log)
+	if err != nil {
+		return fmt.Errorf("failed to initialize lock watcher: %w", err)
+	}
+	go watcher.Run(ctx)
+
+	apiClient := api.NewClient(cfg.DatabasusHost, cfg.Token, log)
+
+	var backgroundUpgrader *upgrade.BackgroundUpgrader
+	if agentVersion != "dev" && runtime.GOOS != "windows" {
+		backgroundUpgrader = upgrade.NewBackgroundUpgrader(apiClient, agentVersion, isDev, cancel, log)
+		go backgroundUpgrader.Run(ctx)
+	}
+
+	fullBackuper := full_backup.NewFullBackuper(cfg, apiClient, log)
+	go fullBackuper.Run(ctx)
+
+	streamer := wal.NewStreamer(cfg, apiClient, log)
+	streamer.Run(ctx)
+
+	if backgroundUpgrader != nil {
+		backgroundUpgrader.WaitForCompletion(30 * time.Second)
+
+		if backgroundUpgrader.IsUpgraded() {
+			return upgrade.ErrUpgradeRestart
+		}
+	}
+
+	log.Info("Agent stopped")
+
+	return nil
+}
+
+func validateConfig(cfg *config.Config) error {
+	if cfg.DatabasusHost == "" {
+		return errors.New("argument databasus-host is required")
+	}
+
+	if cfg.DbID == "" {
+		return errors.New("argument db-id is required")
+	}
+
+	if cfg.Token == "" {
+		return errors.New("argument token is required")
+	}
+
+	if cfg.PgHost == "" {
+		return errors.New("argument pg-host is required")
+	}
+
+	if cfg.PgPort <= 0 {
+		return errors.New("argument pg-port must be a positive number")
+	}
+
+	if cfg.PgUser == "" {
+		return errors.New("argument pg-user is required")
+	}
+
+	if cfg.PgType != "host" && cfg.PgType != "docker" {
+		return fmt.Errorf("argument pg-type must be 'host' or 'docker', got '%s'", cfg.PgType)
+	}
+
+	if cfg.PgWalDir == "" {
+		return errors.New("argument pg-wal-dir is required")
+	}
+
+	if cfg.PgType == "docker" && cfg.PgDockerContainerName == "" {
+		return errors.New("argument pg-docker-container-name is required when pg-type is 'docker'")
+	}
+
+	return nil
+}
+
+func verifyPgBasebackup(cfg *config.Config, log *slog.Logger) error {
+	switch cfg.PgType {
+	case "host":
+		return verifyPgBasebackupHost(cfg, log)
+	case "docker":
+		return verifyPgBasebackupDocker(cfg, log)
+	default:
+		return fmt.Errorf("unexpected pg-type: %s", cfg.PgType)
+	}
+}
+
+func verifyPgBasebackupHost(cfg *config.Config, log *slog.Logger) error {
+	binary := "pg_basebackup"
+	if cfg.PgHostBinDir != "" {
+		binary = filepath.Join(cfg.PgHostBinDir, "pg_basebackup")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), pgBasebackupVerifyTimeout)
+	defer cancel()
+
+	output, err := exec.CommandContext(ctx, binary, "--version").CombinedOutput()
+	if err != nil {
+		if cfg.PgHostBinDir != "" {
+			return fmt.Errorf(
+				"pg_basebackup not found at '%s': %w. Verify pg-host-bin-dir is correct",
+				binary, err,
+			)
+		}
+
+		return fmt.Errorf(
+			"pg_basebackup not found in PATH: %w. Install PostgreSQL client tools or set pg-host-bin-dir",
+			err,
+		)
+	}
+
+	log.Info("pg_basebackup verified", "version", strings.TrimSpace(string(output)))
+
+	return nil
+}
+
+func verifyPgBasebackupDocker(cfg *config.Config, log *slog.Logger) error {
+	ctx, cancel := context.WithTimeout(context.Background(), pgBasebackupVerifyTimeout)
+	defer cancel()
+
+	output, err := exec.CommandContext(ctx,
+		"docker", "exec", cfg.PgDockerContainerName,
+		"pg_basebackup", "--version",
+	).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf(
+			"pg_basebackup not available in container '%s': %w. "+
+				"Check that the container is running and pg_basebackup is installed inside it",
+			cfg.PgDockerContainerName, err,
+		)
+	}
+
+	log.Info("pg_basebackup verified (docker)",
+		"container", cfg.PgDockerContainerName,
+		"version", strings.TrimSpace(string(output)),
+	)
+
+	return nil
+}
+
+func verifyDatabase(cfg *config.Config, log *slog.Logger) error {
+	switch cfg.PgType {
+	case "docker":
+		return verifyDatabaseDocker(cfg, log)
+	default:
+		return verifyDatabaseHost(cfg, log)
+	}
+}
+
+func verifyDatabaseHost(cfg *config.Config, log *slog.Logger) error {
+	connStr := fmt.Sprintf(
+		"host=%s port=%d user=%s password=%s dbname=postgres sslmode=disable",
+		cfg.PgHost, cfg.PgPort, cfg.PgUser, cfg.PgPassword,
+	)
+
+	ctx, cancel := context.WithTimeout(context.Background(), dbVerifyTimeout)
+	defer cancel()
+
+	conn, err := pgx.Connect(ctx, connStr)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to connect to PostgreSQL at %s:%d as user '%s': %w",
+			cfg.PgHost, cfg.PgPort, cfg.PgUser, err,
+		)
+	}
+	defer func() { _ = conn.Close(ctx) }()
+
+	if err := conn.Ping(ctx); err != nil {
+		return fmt.Errorf("PostgreSQL ping failed at %s:%d: %w",
+			cfg.PgHost, cfg.PgPort, err,
+		)
+	}
+
+	var versionNumStr string
+	if err := conn.QueryRow(ctx, "SHOW server_version_num").Scan(&versionNumStr); err != nil {
+		return fmt.Errorf("failed to query PostgreSQL version: %w", err)
+	}
+
+	majorVersion, err := parsePgVersionNum(versionNumStr)
+	if err != nil {
+		return fmt.Errorf("failed to parse PostgreSQL version '%s': %w", versionNumStr, err)
+	}
+
+	if majorVersion < minPgMajorVersion {
+		return fmt.Errorf(
+			"PostgreSQL %d is not supported, minimum required version is %d",
+			majorVersion, minPgMajorVersion,
+		)
+	}
+
+	log.Info("PostgreSQL connection verified",
+		"host", cfg.PgHost,
+		"port", cfg.PgPort,
+		"user", cfg.PgUser,
+		"version", majorVersion,
+	)
+
+	return nil
+}
+
+func verifyDatabaseDocker(cfg *config.Config, log *slog.Logger) error {
+	ctx, cancel := context.WithTimeout(context.Background(), dbVerifyTimeout)
+	defer cancel()
+
+	query := "SELECT current_setting('server_version_num')"
+
+	cmd := exec.CommandContext(ctx,
+		"docker", "exec",
+		"-e", "PGPASSWORD="+cfg.PgPassword,
+		cfg.PgDockerContainerName,
+		"psql", "-h", "localhost", "-p", "5432", "-U", cfg.PgUser,
+		"-d", "postgres", "-t", "-A", "-c", query,
+	)
+
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf(
+			"failed to connect to PostgreSQL in container '%s' as user '%s': %w (output: %s)",
+			cfg.PgDockerContainerName, cfg.PgUser, err, strings.TrimSpace(string(output)),
+		)
+	}
+
+	versionNumStr := strings.TrimSpace(string(output))
+
+	majorVersion, err := parsePgVersionNum(versionNumStr)
+	if err != nil {
+		return fmt.Errorf("failed to parse PostgreSQL version '%s': %w", versionNumStr, err)
+	}
+
+	if majorVersion < minPgMajorVersion {
+		return fmt.Errorf(
+			"PostgreSQL %d is not supported, minimum required version is %d",
+			majorVersion, minPgMajorVersion,
+		)
+	}
+
+	log.Info("PostgreSQL connection verified (docker)",
+		"container", cfg.PgDockerContainerName,
+		"user", cfg.PgUser,
+		"version", majorVersion,
+	)
+
+	return nil
+}
+
+func parsePgVersionNum(versionNumStr string) (int, error) {
+	versionNum, err := strconv.Atoi(strings.TrimSpace(versionNumStr))
+	if err != nil {
+		return 0, fmt.Errorf("invalid version number: %w", err)
+	}
+
+	if versionNum <= 0 {
+		return 0, fmt.Errorf("invalid version number: %d", versionNum)
+	}
+
+	majorVersion := versionNum / 10000
+
+	return majorVersion, nil
+}

agent/internal/features/start/start_test.go

@@ -0,0 +1,84 @@
+package start
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ParsePgVersionNum_SupportedVersions_ReturnsMajorVersion(t *testing.T) {
+	tests := []struct {
+		name          string
+		versionNumStr string
+		expectedMajor int
+	}{
+		{name: "PG 15.0", versionNumStr: "150000", expectedMajor: 15},
+		{name: "PG 15.4", versionNumStr: "150004", expectedMajor: 15},
+		{name: "PG 16.0", versionNumStr: "160000", expectedMajor: 16},
+		{name: "PG 16.3", versionNumStr: "160003", expectedMajor: 16},
+		{name: "PG 17.2", versionNumStr: "170002", expectedMajor: 17},
+		{name: "PG 18.0", versionNumStr: "180000", expectedMajor: 18},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			major, err := parsePgVersionNum(tt.versionNumStr)
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expectedMajor, major)
+			assert.GreaterOrEqual(t, major, minPgMajorVersion)
+		})
+	}
+}
+
+func Test_ParsePgVersionNum_UnsupportedVersions_ReturnsMajorVersionBelow15(t *testing.T) {
+	tests := []struct {
+		name          string
+		versionNumStr string
+		expectedMajor int
+	}{
+		{name: "PG 12.5", versionNumStr: "120005", expectedMajor: 12},
+		{name: "PG 13.0", versionNumStr: "130000", expectedMajor: 13},
+		{name: "PG 14.12", versionNumStr: "140012", expectedMajor: 14},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			major, err := parsePgVersionNum(tt.versionNumStr)
+
+			require.NoError(t, err)
+			assert.Equal(t, tt.expectedMajor, major)
+			assert.Less(t, major, minPgMajorVersion)
+		})
+	}
+}
+
+func Test_ParsePgVersionNum_InvalidInput_ReturnsError(t *testing.T) {
+	tests := []struct {
+		name          string
+		versionNumStr string
+	}{
+		{name: "empty string", versionNumStr: ""},
+		{name: "non-numeric", versionNumStr: "abc"},
+		{name: "negative number", versionNumStr: "-1"},
+		{name: "zero", versionNumStr: "0"},
+		{name: "float", versionNumStr: "15.4"},
+		{name: "whitespace only", versionNumStr: "   "},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			_, err := parsePgVersionNum(tt.versionNumStr)
+
+			require.Error(t, err)
+		})
+	}
+}
+
+func Test_ParsePgVersionNum_WithWhitespace_ParsesCorrectly(t *testing.T) {
+	major, err := parsePgVersionNum("  150004  ")
+
+	require.NoError(t, err)
+	assert.Equal(t, 15, major)
+}

agent/internal/features/upgrade/background_upgrader.go

@@ -0,0 +1,88 @@
+package upgrade
+
+import (
+	"context"
+	"log/slog"
+	"sync/atomic"
+	"time"
+
+	"databasus-agent/internal/features/api"
+)
+
+const backgroundCheckInterval = 10 * time.Second
+
+type BackgroundUpgrader struct {
+	apiClient      *api.Client
+	currentVersion string
+	isDev          bool
+	cancel         context.CancelFunc
+	isUpgraded     atomic.Bool
+	log            *slog.Logger
+	done           chan struct{}
+}
+
+func NewBackgroundUpgrader(
+	apiClient *api.Client,
+	currentVersion string,
+	isDev bool,
+	cancel context.CancelFunc,
+	log *slog.Logger,
+) *BackgroundUpgrader {
+	return &BackgroundUpgrader{
+		apiClient,
+		currentVersion,
+		isDev,
+		cancel,
+		atomic.Bool{},
+		log,
+		make(chan struct{}),
+	}
+}
+
+func (u *BackgroundUpgrader) Run(ctx context.Context) {
+	defer close(u.done)
+
+	ticker := time.NewTicker(backgroundCheckInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+			if u.checkAndUpgrade() {
+				return
+			}
+		}
+	}
+}
+
+func (u *BackgroundUpgrader) IsUpgraded() bool {
+	return u.isUpgraded.Load()
+}
+
+func (u *BackgroundUpgrader) WaitForCompletion(timeout time.Duration) {
+	select {
+	case <-u.done:
+	case <-time.After(timeout):
+	}
+}
+
+func (u *BackgroundUpgrader) checkAndUpgrade() bool {
+	isUpgraded, err := CheckAndUpdate(u.apiClient, u.currentVersion, u.isDev, u.log)
+	if err != nil {
+		u.log.Warn("Background update check failed", "error", err)
+
+		return false
+	}
+
+	if !isUpgraded {
+		return false
+	}
+
+	u.log.Info("Background upgrade complete, restarting...")
+	u.isUpgraded.Store(true)
+	u.cancel()
+
+	return true
+}

agent/internal/features/upgrade/errors.go

@@ -0,0 +1,5 @@
+package upgrade
+
+import "errors"
+
+var ErrUpgradeRestart = errors.New("agent upgraded, restart required")

agent/internal/features/upgrade/upgrader.go

@@ -0,0 +1,89 @@
+package upgrade
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"databasus-agent/internal/features/api"
+)
+
+// CheckAndUpdate checks if a new version is available and upgrades the binary on disk.
+// Returns (true, nil) if the binary was upgraded, (false, nil) if already up to date,
+// or (false, err) on failure. Callers are responsible for re-exec or restart signaling.
+func CheckAndUpdate(apiClient *api.Client, currentVersion string, isDev bool, log *slog.Logger) (bool, error) {
+	if isDev {
+		log.Info("Skipping update check (development mode)")
+
+		return false, nil
+	}
+
+	serverVersion, err := apiClient.FetchServerVersion(context.Background())
+	if err != nil {
+		log.Warn("Could not reach server for update check", "error", err)
+
+		return false, fmt.Errorf(
+			"unable to check version, please verify Databasus server is available: %w",
+			err,
+		)
+	}
+
+	if serverVersion == currentVersion {
+		log.Info("Agent version is up to date", "version", currentVersion)
+
+		return false, nil
+	}
+
+	log.Info("Updating agent...", "current", currentVersion, "target", serverVersion)
+
+	selfPath, err := os.Executable()
+	if err != nil {
+		return false, fmt.Errorf("failed to determine executable path: %w", err)
+	}
+
+	tempPath := selfPath + ".update"
+
+	defer func() {
+		_ = os.Remove(tempPath)
+	}()
+
+	if err := apiClient.DownloadAgentBinary(context.Background(), runtime.GOARCH, tempPath); err != nil {
+		return false, fmt.Errorf("failed to download update: %w", err)
+	}
+
+	if err := os.Chmod(tempPath, 0o755); err != nil {
+		return false, fmt.Errorf("failed to set permissions on update: %w", err)
+	}
+
+	if err := verifyBinary(tempPath, serverVersion); err != nil {
+		return false, fmt.Errorf("update verification failed: %w", err)
+	}
+
+	if err := os.Rename(tempPath, selfPath); err != nil {
+		return false, fmt.Errorf("failed to replace binary (try --skip-update if this persists): %w", err)
+	}
+
+	log.Info("Agent binary updated", "version", serverVersion)
+
+	return true, nil
+}
+
+func verifyBinary(binaryPath, expectedVersion string) error {
+	cmd := exec.CommandContext(context.Background(), binaryPath, "version")
+
+	output, err := cmd.Output()
+	if err != nil {
+		return fmt.Errorf("binary failed to execute: %w", err)
+	}
+
+	got := strings.TrimSpace(string(output))
+	if got != expectedVersion {
+		return fmt.Errorf("version mismatch: expected %q, got %q", expectedVersion, got)
+	}
+
+	return nil
+}

agent/internal/features/wal/streamer.go

@@ -0,0 +1,191 @@
+package wal
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+)
+
+const (
+	pollInterval  = 10 * time.Second
+	uploadTimeout = 5 * time.Minute
+)
+
+var segmentNameRegex = regexp.MustCompile(`^[0-9A-Fa-f]{24}$`)
+
+type Streamer struct {
+	cfg       *config.Config
+	apiClient *api.Client
+	log       *slog.Logger
+}
+
+func NewStreamer(cfg *config.Config, apiClient *api.Client, log *slog.Logger) *Streamer {
+	return &Streamer{
+		cfg:       cfg,
+		apiClient: apiClient,
+		log:       log,
+	}
+}
+
+func (s *Streamer) Run(ctx context.Context) {
+	s.log.Info("WAL streamer started", "pgWalDir", s.cfg.PgWalDir)
+
+	s.processQueue(ctx)
+
+	ticker := time.NewTicker(pollInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ctx.Done():
+			s.log.Info("WAL streamer stopping")
+			return
+		case <-ticker.C:
+			s.processQueue(ctx)
+		}
+	}
+}
+
+func (s *Streamer) processQueue(ctx context.Context) {
+	segments, err := s.listSegments()
+	if err != nil {
+		s.log.Error("Failed to list WAL segments", "error", err)
+		return
+	}
+
+	if len(segments) == 0 {
+		s.log.Info("No WAL segments pending", "dir", s.cfg.PgWalDir)
+		return
+	}
+
+	s.log.Info("WAL segments pending upload", "dir", s.cfg.PgWalDir, "count", len(segments))
+
+	for _, segmentName := range segments {
+		if ctx.Err() != nil {
+			return
+		}
+
+		if err := s.uploadSegment(ctx, segmentName); err != nil {
+			s.log.Error("Failed to upload WAL segment",
+				"segment", segmentName,
+				"error", err,
+			)
+			return
+		}
+	}
+}
+
+func (s *Streamer) listSegments() ([]string, error) {
+	entries, err := os.ReadDir(s.cfg.PgWalDir)
+	if err != nil {
+		return nil, fmt.Errorf("read wal dir: %w", err)
+	}
+
+	var segments []string
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+
+		name := entry.Name()
+
+		if strings.HasSuffix(name, ".tmp") {
+			continue
+		}
+
+		if !segmentNameRegex.MatchString(name) {
+			continue
+		}
+
+		segments = append(segments, name)
+	}
+
+	sort.Strings(segments)
+
+	return segments, nil
+}
+
+func (s *Streamer) uploadSegment(ctx context.Context, segmentName string) error {
+	filePath := filepath.Join(s.cfg.PgWalDir, segmentName)
+
+	pr, pw := io.Pipe()
+
+	go s.compressAndStream(pw, filePath)
+
+	uploadCtx, cancel := context.WithTimeout(ctx, uploadTimeout)
+	defer cancel()
+
+	s.log.Info("Uploading WAL segment", "segment", segmentName)
+
+	result, err := s.apiClient.UploadWalSegment(uploadCtx, segmentName, pr)
+	if err != nil {
+		return err
+	}
+
+	if result.IsGapDetected {
+		s.log.Warn("WAL chain gap detected",
+			"segment", segmentName,
+			"expected", result.ExpectedSegmentName,
+			"received", result.ReceivedSegmentName,
+		)
+
+		return fmt.Errorf("gap detected for segment %s", segmentName)
+	}
+
+	s.log.Info("WAL segment uploaded", "segment", segmentName)
+
+	if *s.cfg.IsDeleteWalAfterUpload {
+		if err := os.Remove(filePath); err != nil {
+			s.log.Warn("Failed to delete uploaded WAL segment",
+				"segment", segmentName,
+				"error", err,
+			)
+		}
+	}
+
+	return nil
+}
+
+func (s *Streamer) compressAndStream(pw *io.PipeWriter, filePath string) {
+	f, err := os.Open(filePath)
+	if err != nil {
+		_ = pw.CloseWithError(fmt.Errorf("open file: %w", err))
+		return
+	}
+	defer func() { _ = f.Close() }()
+
+	encoder, err := zstd.NewWriter(pw,
+		zstd.WithEncoderLevel(zstd.EncoderLevelFromZstd(5)),
+		zstd.WithEncoderCRC(true),
+	)
+	if err != nil {
+		_ = pw.CloseWithError(fmt.Errorf("create zstd encoder: %w", err))
+		return
+	}
+
+	if _, err := io.Copy(encoder, f); err != nil {
+		_ = encoder.Close()
+		_ = pw.CloseWithError(fmt.Errorf("compress: %w", err))
+		return
+	}
+
+	if err := encoder.Close(); err != nil {
+		_ = pw.CloseWithError(fmt.Errorf("close encoder: %w", err))
+		return
+	}
+
+	_ = pw.Close()
+}

agent/internal/features/wal/streamer_test.go

@@ -0,0 +1,348 @@
+package wal
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"sync"
+	"testing"
+	"time"
+
+	"github.com/klauspost/compress/zstd"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"databasus-agent/internal/config"
+	"databasus-agent/internal/features/api"
+	"databasus-agent/internal/logger"
+)
+
+func Test_UploadSegment_SingleSegment_ServerReceivesCorrectHeadersAndBody(t *testing.T) {
+	walDir := createTestWalDir(t)
+	segmentContent := []byte("test-wal-segment-data-for-upload")
+	writeTestSegment(t, walDir, "000000010000000100000001", segmentContent)
+
+	var receivedHeaders http.Header
+	var receivedBody []byte
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		receivedHeaders = r.Header.Clone()
+
+		body, err := io.ReadAll(r.Body)
+		require.NoError(t, err)
+		receivedBody = body
+
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	require.NotNil(t, receivedHeaders)
+	assert.Equal(t, "test-token", receivedHeaders.Get("Authorization"))
+	assert.Equal(t, "application/octet-stream", receivedHeaders.Get("Content-Type"))
+	assert.Equal(t, "000000010000000100000001", receivedHeaders.Get("X-Wal-Segment-Name"))
+
+	decompressed := decompressZstd(t, receivedBody)
+	assert.Equal(t, segmentContent, decompressed)
+}
+
+func Test_UploadSegments_MultipleSegmentsOutOfOrder_UploadedInAscendingOrder(t *testing.T) {
+	walDir := createTestWalDir(t)
+	writeTestSegment(t, walDir, "000000010000000100000003", []byte("third"))
+	writeTestSegment(t, walDir, "000000010000000100000001", []byte("first"))
+	writeTestSegment(t, walDir, "000000010000000100000002", []byte("second"))
+
+	var mu sync.Mutex
+	var uploadOrder []string
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		uploadOrder = append(uploadOrder, r.Header.Get("X-Wal-Segment-Name"))
+		mu.Unlock()
+
+		_, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	require.Len(t, uploadOrder, 3)
+	assert.Equal(t, "000000010000000100000001", uploadOrder[0])
+	assert.Equal(t, "000000010000000100000002", uploadOrder[1])
+	assert.Equal(t, "000000010000000100000003", uploadOrder[2])
+}
+
+func Test_UploadSegments_DirectoryHasTmpFiles_TmpFilesIgnored(t *testing.T) {
+	walDir := createTestWalDir(t)
+	writeTestSegment(t, walDir, "000000010000000100000001", []byte("real segment"))
+	writeTestSegment(t, walDir, "000000010000000100000002.tmp", []byte("partial copy"))
+
+	var mu sync.Mutex
+	var uploadedSegments []string
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		mu.Lock()
+		uploadedSegments = append(uploadedSegments, r.Header.Get("X-Wal-Segment-Name"))
+		mu.Unlock()
+
+		_, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	require.Len(t, uploadedSegments, 1)
+	assert.Equal(t, "000000010000000100000001", uploadedSegments[0])
+}
+
+func Test_UploadSegment_DeleteEnabled_FileRemovedAfterUpload(t *testing.T) {
+	walDir := createTestWalDir(t)
+	segmentName := "000000010000000100000001"
+	writeTestSegment(t, walDir, segmentName, []byte("segment data"))
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	isDeleteEnabled := true
+	cfg := createTestConfig(walDir, server.URL)
+	cfg.IsDeleteWalAfterUpload = &isDeleteEnabled
+	apiClient := api.NewClient(server.URL, cfg.Token, logger.GetLogger())
+	streamer := NewStreamer(cfg, apiClient, logger.GetLogger())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	_, err := os.Stat(filepath.Join(walDir, segmentName))
+	assert.True(t, os.IsNotExist(err), "segment file should be deleted after successful upload")
+}
+
+func Test_UploadSegment_DeleteDisabled_FileKeptAfterUpload(t *testing.T) {
+	walDir := createTestWalDir(t)
+	segmentName := "000000010000000100000001"
+	writeTestSegment(t, walDir, segmentName, []byte("segment data"))
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	isDeleteDisabled := false
+	cfg := createTestConfig(walDir, server.URL)
+	cfg.IsDeleteWalAfterUpload = &isDeleteDisabled
+	apiClient := api.NewClient(server.URL, cfg.Token, logger.GetLogger())
+	streamer := NewStreamer(cfg, apiClient, logger.GetLogger())
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	_, err := os.Stat(filepath.Join(walDir, segmentName))
+	assert.NoError(t, err, "segment file should be kept when delete is disabled")
+}
+
+func Test_UploadSegment_ServerReturns500_FileKeptInQueue(t *testing.T) {
+	walDir := createTestWalDir(t)
+	segmentName := "000000010000000100000001"
+	writeTestSegment(t, walDir, segmentName, []byte("segment data"))
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.ReadAll(r.Body)
+		w.WriteHeader(http.StatusInternalServerError)
+		_, _ = w.Write([]byte(`{"error":"internal server error"}`))
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	_, err := os.Stat(filepath.Join(walDir, segmentName))
+	assert.NoError(t, err, "segment file should remain in queue after server error")
+}
+
+func Test_ProcessQueue_EmptyDirectory_NoUploads(t *testing.T) {
+	walDir := createTestWalDir(t)
+
+	uploadCount := 0
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		uploadCount++
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	assert.Equal(t, 0, uploadCount, "no uploads should occur for empty directory")
+}
+
+func Test_Run_ContextCancelled_StopsImmediately(t *testing.T) {
+	walDir := createTestWalDir(t)
+
+	streamer := newTestStreamer(walDir, "http://localhost:0")
+
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	done := make(chan struct{})
+	go func() {
+		streamer.Run(ctx)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+	case <-time.After(2 * time.Second):
+		t.Fatal("Run should have stopped immediately when context is already cancelled")
+	}
+}
+
+func Test_UploadSegment_ServerReturns409_FileNotDeleted(t *testing.T) {
+	walDir := createTestWalDir(t)
+	segmentName := "000000010000000100000005"
+	writeTestSegment(t, walDir, segmentName, []byte("gap segment"))
+
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = io.ReadAll(r.Body)
+
+		w.Header().Set("Content-Type", "application/json")
+		w.WriteHeader(http.StatusConflict)
+
+		resp := map[string]string{
+			"error":               "gap_detected",
+			"expectedSegmentName": "000000010000000100000003",
+			"receivedSegmentName": segmentName,
+		}
+		_ = json.NewEncoder(w).Encode(resp)
+	}))
+	defer server.Close()
+
+	streamer := newTestStreamer(walDir, server.URL)
+
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	go streamer.Run(ctx)
+	time.Sleep(500 * time.Millisecond)
+	cancel()
+
+	_, err := os.Stat(filepath.Join(walDir, segmentName))
+	assert.NoError(t, err, "segment file should not be deleted on gap detection")
+}
+
+func newTestStreamer(walDir, serverURL string) *Streamer {
+	cfg := createTestConfig(walDir, serverURL)
+	apiClient := api.NewClient(serverURL, cfg.Token, logger.GetLogger())
+
+	return NewStreamer(cfg, apiClient, logger.GetLogger())
+}
+
+func createTestWalDir(t *testing.T) string {
+	t.Helper()
+
+	baseDir := filepath.Join(".", ".test-tmp")
+	if err := os.MkdirAll(baseDir, 0o755); err != nil {
+		t.Fatalf("failed to create base test dir: %v", err)
+	}
+
+	dir, err := os.MkdirTemp(baseDir, t.Name()+"-*")
+	if err != nil {
+		t.Fatalf("failed to create test wal dir: %v", err)
+	}
+
+	t.Cleanup(func() {
+		_ = os.RemoveAll(dir)
+	})
+
+	return dir
+}
+
+func writeTestSegment(t *testing.T, dir, name string, content []byte) {
+	t.Helper()
+
+	if err := os.WriteFile(filepath.Join(dir, name), content, 0o644); err != nil {
+		t.Fatalf("failed to write test segment %s: %v", name, err)
+	}
+}
+
+func createTestConfig(walDir, serverURL string) *config.Config {
+	isDeleteEnabled := true
+
+	return &config.Config{
+		DatabasusHost:          serverURL,
+		DbID:                   "test-db-id",
+		Token:                  "test-token",
+		PgWalDir:               walDir,
+		IsDeleteWalAfterUpload: &isDeleteEnabled,
+	}
+}
+
+func decompressZstd(t *testing.T, data []byte) []byte {
+	t.Helper()
+
+	decoder, err := zstd.NewReader(nil)
+	require.NoError(t, err)
+	defer decoder.Close()
+
+	decoded, err := decoder.DecodeAll(data, nil)
+	require.NoError(t, err)
+
+	return decoded
+}

agent/internal/logger/logger.go

@@ -0,0 +1,119 @@
+package logger
+
+import (
+	"fmt"
+	"io"
+	"log/slog"
+	"os"
+	"sync"
+	"time"
+)
+
+const (
+	logFileName    = "databasus.log"
+	oldLogFileName = "databasus.log.old"
+	maxLogFileSize = 5 * 1024 * 1024 // 5MB
+)
+
+type rotatingWriter struct {
+	mu          sync.Mutex
+	file        *os.File
+	currentSize int64
+	maxSize     int64
+	logPath     string
+	oldLogPath  string
+}
+
+func (w *rotatingWriter) Write(p []byte) (int, error) {
+	w.mu.Lock()
+	defer w.mu.Unlock()
+
+	if w.currentSize+int64(len(p)) > w.maxSize {
+		if err := w.rotate(); err != nil {
+			return 0, fmt.Errorf("failed to rotate log file: %w", err)
+		}
+	}
+
+	n, err := w.file.Write(p)
+	w.currentSize += int64(n)
+
+	return n, err
+}
+
+func (w *rotatingWriter) rotate() error {
+	if err := w.file.Close(); err != nil {
+		return fmt.Errorf("failed to close %s: %w", w.logPath, err)
+	}
+
+	if err := os.Remove(w.oldLogPath); err != nil && !os.IsNotExist(err) {
+		return fmt.Errorf("failed to remove %s: %w", w.oldLogPath, err)
+	}
+
+	if err := os.Rename(w.logPath, w.oldLogPath); err != nil {
+		return fmt.Errorf("failed to rename %s to %s: %w", w.logPath, w.oldLogPath, err)
+	}
+
+	f, err := os.OpenFile(w.logPath, os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		return fmt.Errorf("failed to create new %s: %w", w.logPath, err)
+	}
+
+	w.file = f
+	w.currentSize = 0
+
+	return nil
+}
+
+var (
+	loggerInstance *slog.Logger
+	once           sync.Once
+)
+
+func GetLogger() *slog.Logger {
+	once.Do(func() {
+		initialize()
+	})
+
+	return loggerInstance
+}
+
+func initialize() {
+	writer := buildWriter()
+
+	loggerInstance = slog.New(slog.NewTextHandler(writer, &slog.HandlerOptions{
+		Level: slog.LevelInfo,
+		ReplaceAttr: func(groups []string, a slog.Attr) slog.Attr {
+			if a.Key == slog.TimeKey {
+				a.Value = slog.StringValue(time.Now().Format("2006/01/02 15:04:05"))
+			}
+			if a.Key == slog.LevelKey {
+				return slog.Attr{}
+			}
+
+			return a
+		},
+	}))
+}
+
+func buildWriter() io.Writer {
+	f, err := os.OpenFile(logFileName, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0o644)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Warning: failed to open %s for logging: %v\n", logFileName, err)
+		return os.Stdout
+	}
+
+	var currentSize int64
+	if info, err := f.Stat(); err == nil {
+		currentSize = info.Size()
+	}
+
+	rw := &rotatingWriter{
+		file:        f,
+		currentSize: currentSize,
+		maxSize:     maxLogFileSize,
+		logPath:     logFileName,
+		oldLogPath:  oldLogFileName,
+	}
+
+	return io.MultiWriter(os.Stdout, rw)
+}

agent/internal/logger/logger_test.go

@@ -0,0 +1,128 @@
+package logger
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_Write_DataWrittenToFile(t *testing.T) {
+	rw, logPath, _ := setupRotatingWriter(t, 1024)
+
+	data := []byte("hello world\n")
+	n, err := rw.Write(data)
+
+	require.NoError(t, err)
+	assert.Equal(t, len(data), n)
+	assert.Equal(t, int64(len(data)), rw.currentSize)
+
+	content, err := os.ReadFile(logPath)
+	require.NoError(t, err)
+	assert.Equal(t, string(data), string(content))
+}
+
+func Test_Write_WhenLimitExceeded_FileRotated(t *testing.T) {
+	rw, logPath, oldLogPath := setupRotatingWriter(t, 100)
+
+	firstData := []byte(strings.Repeat("A", 80))
+	_, err := rw.Write(firstData)
+	require.NoError(t, err)
+
+	secondData := []byte(strings.Repeat("B", 30))
+	_, err = rw.Write(secondData)
+	require.NoError(t, err)
+
+	oldContent, err := os.ReadFile(oldLogPath)
+	require.NoError(t, err)
+	assert.Equal(t, string(firstData), string(oldContent))
+
+	newContent, err := os.ReadFile(logPath)
+	require.NoError(t, err)
+	assert.Equal(t, string(secondData), string(newContent))
+
+	assert.Equal(t, int64(len(secondData)), rw.currentSize)
+}
+
+func Test_Write_WhenOldFileExists_OldFileReplaced(t *testing.T) {
+	rw, _, oldLogPath := setupRotatingWriter(t, 100)
+
+	require.NoError(t, os.WriteFile(oldLogPath, []byte("stale data"), 0o644))
+
+	_, err := rw.Write([]byte(strings.Repeat("A", 80)))
+	require.NoError(t, err)
+
+	_, err = rw.Write([]byte(strings.Repeat("B", 30)))
+	require.NoError(t, err)
+
+	oldContent, err := os.ReadFile(oldLogPath)
+	require.NoError(t, err)
+	assert.Equal(t, strings.Repeat("A", 80), string(oldContent))
+}
+
+func Test_Write_MultipleSmallWrites_CurrentSizeAccumulated(t *testing.T) {
+	rw, _, _ := setupRotatingWriter(t, 1024)
+
+	var totalWritten int64
+	for i := 0; i < 10; i++ {
+		data := []byte("line\n")
+		n, err := rw.Write(data)
+		require.NoError(t, err)
+
+		totalWritten += int64(n)
+	}
+
+	assert.Equal(t, totalWritten, rw.currentSize)
+	assert.Equal(t, int64(50), rw.currentSize)
+}
+
+func Test_Write_ExactlyAtBoundary_NoRotationUntilNextByte(t *testing.T) {
+	rw, logPath, oldLogPath := setupRotatingWriter(t, 100)
+
+	exactData := []byte(strings.Repeat("X", 100))
+	_, err := rw.Write(exactData)
+	require.NoError(t, err)
+
+	_, err = os.Stat(oldLogPath)
+	assert.True(t, os.IsNotExist(err), ".old file should not exist yet")
+
+	content, err := os.ReadFile(logPath)
+	require.NoError(t, err)
+	assert.Equal(t, string(exactData), string(content))
+
+	_, err = rw.Write([]byte("Z"))
+	require.NoError(t, err)
+
+	_, err = os.Stat(oldLogPath)
+	assert.NoError(t, err, ".old file should exist after exceeding limit")
+
+	assert.Equal(t, int64(1), rw.currentSize)
+}
+
+func setupRotatingWriter(t *testing.T, maxSize int64) (*rotatingWriter, string, string) {
+	t.Helper()
+
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "test.log")
+	oldLogPath := filepath.Join(dir, "test.log.old")
+
+	f, err := os.OpenFile(logPath, os.O_CREATE|os.O_WRONLY, 0o644)
+	require.NoError(t, err)
+
+	rw := &rotatingWriter{
+		file:        f,
+		currentSize: 0,
+		maxSize:     maxSize,
+		logPath:     logPath,
+		oldLogPath:  oldLogPath,
+	}
+
+	t.Cleanup(func() {
+		rw.file.Close()
+	})
+
+	return rw, logPath, oldLogPath
+}

backend/.env.development.example

@@ -45,9 +45,6 @@ TEST_MINIO_PORT=9000
 TEST_MINIO_CONSOLE_PORT=9001
 # testing NAS
 TEST_NAS_PORT=7006
-# testing Telegram
-TEST_TELEGRAM_BOT_TOKEN=
-TEST_TELEGRAM_CHAT_ID=
 # testing Azure Blob Storage
 TEST_AZURITE_BLOB_PORT=10000
 # supabase

backend/.golangci.yml

@@ -7,6 +7,16 @@ run:
 
 linters:
   default: standard
+  enable:
+    - funcorder
+    - bodyclose
+    - errorlint
+    - gocritic
+    - unconvert
+    - misspell
+    - errname
+    - noctx
+    - modernize
 
   settings:
     errcheck:
@@ -14,6 +24,18 @@ linters:
 
 formatters:
   enable:
-    - gofmt
+    - gofumpt
     - golines
-    - goimports
+    - gci
+
+  settings:
+    golines:
+      max-len: 120
+    gofumpt:
+      module-path: databasus-backend
+      extra-rules: true
+    gci:
+      sections:
+        - standard
+        - default
+        - localmodule

backend/cmd/main.go

@@ -12,11 +12,18 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/gin-contrib/cors"
+	"github.com/gin-contrib/gzip"
+	"github.com/gin-gonic/gin"
+	swaggerFiles "github.com/swaggo/files"
+	ginSwagger "github.com/swaggo/gin-swagger"
+
 	"databasus-backend/internal/config"
 	"databasus-backend/internal/features/audit_logs"
-	"databasus-backend/internal/features/backups/backups"
 	"databasus-backend/internal/features/backups/backups/backuping"
+	backups_controllers "databasus-backend/internal/features/backups/backups/controllers"
 	backups_download "databasus-backend/internal/features/backups/backups/download"
+	backups_services "databasus-backend/internal/features/backups/backups/services"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
 	"databasus-backend/internal/features/disk"
@@ -27,7 +34,9 @@ import (
 	"databasus-backend/internal/features/restores"
 	"databasus-backend/internal/features/restores/restoring"
 	"databasus-backend/internal/features/storages"
+	system_agent "databasus-backend/internal/features/system/agent"
 	system_healthcheck "databasus-backend/internal/features/system/healthcheck"
+	system_version "databasus-backend/internal/features/system/version"
 	task_cancellation "databasus-backend/internal/features/tasks/cancellation"
 	users_controllers "databasus-backend/internal/features/users/controllers"
 	users_middleware "databasus-backend/internal/features/users/middleware"
@@ -38,12 +47,6 @@ import (
 	files_utils "databasus-backend/internal/util/files"
 	"databasus-backend/internal/util/logger"
 	_ "databasus-backend/swagger" // swagger docs
-
-	"github.com/gin-contrib/cors"
-	"github.com/gin-contrib/gzip"
-	"github.com/gin-gonic/gin"
-	swaggerFiles "github.com/swaggo/files"
-	ginSwagger "github.com/swaggo/gin-swagger"
 )
 
 // @title Databasus Backend API
@@ -80,7 +83,6 @@ func main() {
 		config.GetEnv().TempFolder,
 		config.GetEnv().DataFolder,
 	})
-
 	if err != nil {
 		log.Error("Failed to ensure directories", "error", err)
 		os.Exit(1)
@@ -147,7 +149,7 @@ func handlePasswordReset(log *slog.Logger) {
 	resetPassword(*email, *newPassword, log)
 }
 
-func resetPassword(email string, newPassword string, log *slog.Logger) {
+func resetPassword(email, newPassword string, log *slog.Logger) {
 	log.Info("Resetting password...")
 
 	userService := users_services.GetUserService()
@@ -209,7 +211,11 @@ func setUpRoutes(r *gin.Engine) {
 	userController := users_controllers.GetUserController()
 	userController.RegisterRoutes(v1)
 	system_healthcheck.GetHealthcheckController().RegisterRoutes(v1)
-	backups.GetBackupController().RegisterPublicRoutes(v1)
+	system_version.GetVersionController().RegisterRoutes(v1)
+	system_agent.GetAgentController().RegisterRoutes(v1)
+	backups_controllers.GetBackupController().RegisterPublicRoutes(v1)
+	backups_controllers.GetPostgresWalBackupController().RegisterRoutes(v1)
+	databases.GetDatabaseController().RegisterPublicRoutes(v1)
 
 	// Setup auth middleware
 	userService := users_services.GetUserService()
@@ -226,7 +232,7 @@ func setUpRoutes(r *gin.Engine) {
 	notifiers.GetNotifierController().RegisterRoutes(protected)
 	storages.GetStorageController().RegisterRoutes(protected)
 	databases.GetDatabaseController().RegisterRoutes(protected)
-	backups.GetBackupController().RegisterRoutes(protected)
+	backups_controllers.GetBackupController().RegisterRoutes(protected)
 	restores.GetRestoreController().RegisterRoutes(protected)
 	healthcheck_config.GetHealthcheckConfigController().RegisterRoutes(protected)
 	healthcheck_attempt.GetHealthcheckAttemptController().RegisterRoutes(protected)
@@ -238,7 +244,7 @@ func setUpRoutes(r *gin.Engine) {
 
 func setUpDependencies() {
 	databases.SetupDependencies()
-	backups.SetupDependencies()
+	backups_services.SetupDependencies()
 	restores.SetupDependencies()
 	healthcheck_config.SetupDependencies()
 	audit_logs.SetupDependencies()
@@ -347,7 +353,9 @@ func generateSwaggerDocs(log *slog.Logger) {
 		return
 	}
 
-	cmd := exec.Command("swag", "init", "-d", currentDir, "-g", "cmd/main.go", "-o", "swagger")
+	cmd := exec.CommandContext(
+		context.Background(), "swag", "init", "-d", currentDir, "-g", "cmd/main.go", "-o", "swagger",
+	)
 
 	output, err := cmd.CombinedOutput()
 	if err != nil {
@@ -361,7 +369,7 @@ func generateSwaggerDocs(log *slog.Logger) {
 func runMigrations(log *slog.Logger) {
 	log.Info("Running database migrations...")
 
-	cmd := exec.Command("goose", "-dir", "./migrations", "up")
+	cmd := exec.CommandContext(context.Background(), "goose", "-dir", "./migrations", "up")
 	cmd.Env = append(
 		os.Environ(),
 		"GOOSE_DRIVER=postgres",

backend/go.mod

@@ -1,6 +1,6 @@
 module databasus-backend
 
-go 1.24.9
+go 1.26.1
 
 require (
 	github.com/Azure/azure-sdk-for-go/sdk/azcore v1.20.0

backend/internal/config/config.go

@@ -1,9 +1,6 @@
 package config
 
 import (
-	env_utils "databasus-backend/internal/util/env"
-	"databasus-backend/internal/util/logger"
-	"databasus-backend/internal/util/tools"
 	"os"
 	"path/filepath"
 	"strings"
@@ -11,6 +8,10 @@ import (
 
 	"github.com/ilyakaznacheev/cleanenv"
 	"github.com/joho/godotenv"
+
+	env_utils "databasus-backend/internal/util/env"
+	"databasus-backend/internal/util/logger"
+	"databasus-backend/internal/util/tools"
 )
 
 var log = logger.GetLogger()
@@ -29,7 +30,7 @@ type EnvVariables struct {
 	MongodbInstallDir    string            `env:"MONGODB_INSTALL_DIR"`
 
 	// Internal database
-	DatabaseDsn string `env:"DATABASE_DSN"    required:"true"`
+	DatabaseDsn string `env:"DATABASE_DSN" required:"true"`
 	// Internal Valkey
 	ValkeyHost     string `env:"VALKEY_HOST"     required:"true"`
 	ValkeyPort     string `env:"VALKEY_PORT"     required:"true"`
@@ -108,10 +109,6 @@ type EnvVariables struct {
 	CloudflareTurnstileSecretKey string `env:"CLOUDFLARE_TURNSTILE_SECRET_KEY"`
 	CloudflareTurnstileSiteKey   string `env:"CLOUDFLARE_TURNSTILE_SITE_KEY"`
 
-	// testing Telegram
-	TestTelegramBotToken string `env:"TEST_TELEGRAM_BOT_TOKEN"`
-	TestTelegramChatID   string `env:"TEST_TELEGRAM_CHAT_ID"`
-
 	// testing Supabase
 	TestSupabaseHost     string `env:"TEST_SUPABASE_HOST"`
 	TestSupabasePort     string `env:"TEST_SUPABASE_PORT"`
@@ -124,6 +121,7 @@ type EnvVariables struct {
 	SMTPPort     int    `env:"SMTP_PORT"`
 	SMTPUser     string `env:"SMTP_USER"`
 	SMTPPassword string `env:"SMTP_PASSWORD"`
+	SMTPFrom     string `env:"SMTP_FROM"`
 
 	// Application URL (optional) - used for email links
 	DatabasusURL string `env:"DATABASUS_URL"`
@@ -363,15 +361,6 @@ func loadEnvVariables() {
 			os.Exit(1)
 		}
 
-		if env.TestTelegramBotToken == "" {
-			log.Error("TEST_TELEGRAM_BOT_TOKEN is empty")
-			os.Exit(1)
-		}
-
-		if env.TestTelegramChatID == "" {
-			log.Error("TEST_TELEGRAM_CHAT_ID is empty")
-			os.Exit(1)
-		}
 	}
 
 	log.Info("Environment variables loaded successfully!")

backend/internal/features/audit_logs/background_service_test.go

@@ -1,17 +1,17 @@
 package audit_logs
 
 import (
-	"databasus-backend/internal/storage"
 	"fmt"
 	"testing"
 	"time"
 
-	user_enums "databasus-backend/internal/features/users/enums"
-	users_testing "databasus-backend/internal/features/users/testing"
-
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
 	"gorm.io/gorm"
+
+	user_enums "databasus-backend/internal/features/users/enums"
+	users_testing "databasus-backend/internal/features/users/testing"
+	"databasus-backend/internal/storage"
 )
 
 func Test_CleanOldAuditLogs_DeletesLogsOlderThanOneYear(t *testing.T) {

backend/internal/features/audit_logs/controller.go

@@ -4,10 +4,10 @@ import (
 	"errors"
 	"net/http"
 
-	user_models "databasus-backend/internal/features/users/models"
-
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
+
+	user_models "databasus-backend/internal/features/users/models"
 )
 
 type AuditLogController struct {

backend/internal/features/audit_logs/controller_test.go

@@ -6,15 +6,15 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+
 	user_enums "databasus-backend/internal/features/users/enums"
 	users_middleware "databasus-backend/internal/features/users/middleware"
 	users_services "databasus-backend/internal/features/users/services"
 	users_testing "databasus-backend/internal/features/users/testing"
 	test_utils "databasus-backend/internal/util/testing"
-
-	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
-	"github.com/stretchr/testify/assert"
 )
 
 func Test_GetGlobalAuditLogs_WithDifferentUserRoles_EnforcesPermissionsCorrectly(t *testing.T) {

backend/internal/features/audit_logs/di.go

@@ -8,14 +8,18 @@ import (
 	"databasus-backend/internal/util/logger"
 )
 
-var auditLogRepository = &AuditLogRepository{}
-var auditLogService = &AuditLogService{
-	auditLogRepository,
-	logger.GetLogger(),
-}
+var (
+	auditLogRepository = &AuditLogRepository{}
+	auditLogService    = &AuditLogService{
+		auditLogRepository,
+		logger.GetLogger(),
+	}
+)
+
 var auditLogController = &AuditLogController{
 	auditLogService,
 }
+
 var auditLogBackgroundService = &AuditLogBackgroundService{
 	auditLogService: auditLogService,
 	logger:          logger.GetLogger(),

backend/internal/features/audit_logs/repository.go

@@ -1,10 +1,11 @@
 package audit_logs
 
 import (
-	"databasus-backend/internal/storage"
 	"time"
 
 	"github.com/google/uuid"
+
+	"databasus-backend/internal/storage"
 )
 
 type AuditLogRepository struct{}
@@ -21,7 +22,7 @@ func (r *AuditLogRepository) GetGlobal(
 	limit, offset int,
 	beforeDate *time.Time,
 ) ([]*AuditLogDTO, error) {
-	var auditLogs = make([]*AuditLogDTO, 0)
+	auditLogs := make([]*AuditLogDTO, 0)
 
 	sql := `
 		SELECT 
@@ -37,7 +38,7 @@ func (r *AuditLogRepository) GetGlobal(
 		LEFT JOIN users u ON al.user_id = u.id
 		LEFT JOIN workspaces w ON al.workspace_id = w.id`
 
-	args := []interface{}{}
+	args := []any{}
 
 	if beforeDate != nil {
 		sql += " WHERE al.created_at < ?"
@@ -57,7 +58,7 @@ func (r *AuditLogRepository) GetByUser(
 	limit, offset int,
 	beforeDate *time.Time,
 ) ([]*AuditLogDTO, error) {
-	var auditLogs = make([]*AuditLogDTO, 0)
+	auditLogs := make([]*AuditLogDTO, 0)
 
 	sql := `
 		SELECT 
@@ -74,7 +75,7 @@ func (r *AuditLogRepository) GetByUser(
 		LEFT JOIN workspaces w ON al.workspace_id = w.id
 		WHERE al.user_id = ?`
 
-	args := []interface{}{userID}
+	args := []any{userID}
 
 	if beforeDate != nil {
 		sql += " AND al.created_at < ?"
@@ -94,7 +95,7 @@ func (r *AuditLogRepository) GetByWorkspace(
 	limit, offset int,
 	beforeDate *time.Time,
 ) ([]*AuditLogDTO, error) {
-	var auditLogs = make([]*AuditLogDTO, 0)
+	auditLogs := make([]*AuditLogDTO, 0)
 
 	sql := `
 		SELECT 
@@ -111,7 +112,7 @@ func (r *AuditLogRepository) GetByWorkspace(
 		LEFT JOIN workspaces w ON al.workspace_id = w.id
 		WHERE al.workspace_id = ?`
 
-	args := []interface{}{workspaceID}
+	args := []any{workspaceID}
 
 	if beforeDate != nil {
 		sql += " AND al.created_at < ?"

backend/internal/features/audit_logs/service.go

@@ -4,10 +4,10 @@ import (
 	"log/slog"
 	"time"
 
+	"github.com/google/uuid"
+
 	user_enums "databasus-backend/internal/features/users/enums"
 	user_models "databasus-backend/internal/features/users/models"
-
-	"github.com/google/uuid"
 )
 
 type AuditLogService struct {

backend/internal/features/audit_logs/service_test.go

@@ -4,11 +4,11 @@ import (
 	"testing"
 	"time"
 
-	user_enums "databasus-backend/internal/features/users/enums"
-	users_testing "databasus-backend/internal/features/users/testing"
-
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
+
+	user_enums "databasus-backend/internal/features/users/enums"
+	users_testing "databasus-backend/internal/features/users/testing"
 )
 
 func Test_AuditLogs_WorkspaceSpecificLogs(t *testing.T) {

backend/internal/features/backups/backups/backuping/backuper_test.go

@@ -5,6 +5,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/mock"
+
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
@@ -14,9 +17,6 @@ import (
 	users_testing "databasus-backend/internal/features/users/testing"
 	workspaces_testing "databasus-backend/internal/features/workspaces/testing"
 	cache_utils "databasus-backend/internal/util/cache"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/mock"
 )
 
 func Test_BackupExecuted_NotificationSent(t *testing.T) {

backend/internal/features/backups/backups/backuping/cleaner.go

@@ -59,6 +59,10 @@ func (c *BackupCleaner) Run(ctx context.Context) {
 				if err := c.cleanExceededBackups(); err != nil {
 					c.logger.Error("Failed to clean exceeded backups", "error", err)
 				}
+
+				if err := c.cleanStaleUploadedBasebackups(); err != nil {
+					c.logger.Error("Failed to clean stale uploaded basebackups", "error", err)
+				}
 			}
 		}
 	})
@@ -80,8 +84,7 @@ func (c *BackupCleaner) DeleteBackup(backup *backups_core.Backup) error {
 		return err
 	}
 
-	err = storage.DeleteFile(c.fieldEncryptor, backup.FileName)
-	if err != nil {
+	if err := storage.DeleteFile(c.fieldEncryptor, backup.FileName); err != nil {
 		// we do not return error here, because sometimes clean up performed
 		// before unavailable storage removal or change - therefore we should
 		// proceed even in case of error. It's possible that some S3 or
@@ -101,6 +104,67 @@ func (c *BackupCleaner) AddBackupRemoveListener(listener backups_core.BackupRemo
 	c.backupRemoveListeners = append(c.backupRemoveListeners, listener)
 }
 
+func (c *BackupCleaner) cleanStaleUploadedBasebackups() error {
+	staleBackups, err := c.backupRepository.FindStaleUploadedBasebackups(
+		time.Now().UTC().Add(-10 * time.Minute),
+	)
+	if err != nil {
+		return fmt.Errorf("failed to find stale uploaded basebackups: %w", err)
+	}
+
+	for _, backup := range staleBackups {
+		staleStorage, storageErr := c.storageService.GetStorageByID(backup.StorageID)
+		if storageErr != nil {
+			c.logger.Error(
+				"Failed to get storage for stale basebackup cleanup",
+				"backupId", backup.ID,
+				"storageId", backup.StorageID,
+				"error", storageErr,
+			)
+		} else {
+			if err := staleStorage.DeleteFile(c.fieldEncryptor, backup.FileName); err != nil {
+				c.logger.Error(
+					"Failed to delete stale basebackup file",
+					"backupId", backup.ID,
+					"fileName", backup.FileName,
+					"error", err,
+				)
+			}
+
+			metadataFileName := backup.FileName + ".metadata"
+			if err := staleStorage.DeleteFile(c.fieldEncryptor, metadataFileName); err != nil {
+				c.logger.Error(
+					"Failed to delete stale basebackup metadata file",
+					"backupId", backup.ID,
+					"fileName", metadataFileName,
+					"error", err,
+				)
+			}
+		}
+
+		failMsg := "basebackup finalization timed out after 10 minutes"
+		backup.Status = backups_core.BackupStatusFailed
+		backup.FailMessage = &failMsg
+
+		if err := c.backupRepository.Save(backup); err != nil {
+			c.logger.Error(
+				"Failed to mark stale uploaded basebackup as failed",
+				"backupId", backup.ID,
+				"error", err,
+			)
+			continue
+		}
+
+		c.logger.Info(
+			"Marked stale uploaded basebackup as failed and cleaned storage",
+			"backupId", backup.ID,
+			"databaseId", backup.DatabaseID,
+		)
+	}
+
+	return nil
+}
+
 func (c *BackupCleaner) cleanByRetentionPolicy() error {
 	enabledBackupConfigs, err := c.backupConfigService.GetBackupConfigsWithEnabledBackups()
 	if err != nil {
@@ -408,6 +472,10 @@ func buildGFSKeepSet(
 ) map[uuid.UUID]bool {
 	keep := make(map[uuid.UUID]bool)
 
+	if len(backups) == 0 {
+		return keep
+	}
+
 	hoursSeen := make(map[string]bool)
 	daysSeen := make(map[string]bool)
 	weeksSeen := make(map[string]bool)
@@ -416,6 +484,54 @@ func buildGFSKeepSet(
 
 	hoursKept, daysKept, weeksKept, monthsKept, yearsKept := 0, 0, 0, 0, 0
 
+	// Compute per-level time-window cutoffs so higher-frequency slots
+	// cannot absorb backups that belong to lower-frequency levels.
+	ref := backups[0].CreatedAt
+
+	rawHourlyCutoff := ref.Add(-time.Duration(hours) * time.Hour)
+	rawDailyCutoff := ref.Add(-time.Duration(days) * 24 * time.Hour)
+	rawWeeklyCutoff := ref.Add(-time.Duration(weeks) * 7 * 24 * time.Hour)
+	rawMonthlyCutoff := ref.AddDate(0, -months, 0)
+	rawYearlyCutoff := ref.AddDate(-years, 0, 0)
+
+	// Hierarchical capping: each level's window cannot extend further back
+	// than the nearest active lower-frequency level's window.
+	yearlyCutoff := rawYearlyCutoff
+
+	monthlyCutoff := rawMonthlyCutoff
+	if years > 0 {
+		monthlyCutoff = laterOf(monthlyCutoff, yearlyCutoff)
+	}
+
+	weeklyCutoff := rawWeeklyCutoff
+	if months > 0 {
+		weeklyCutoff = laterOf(weeklyCutoff, monthlyCutoff)
+	} else if years > 0 {
+		weeklyCutoff = laterOf(weeklyCutoff, yearlyCutoff)
+	}
+
+	dailyCutoff := rawDailyCutoff
+	switch {
+	case weeks > 0:
+		dailyCutoff = laterOf(dailyCutoff, weeklyCutoff)
+	case months > 0:
+		dailyCutoff = laterOf(dailyCutoff, monthlyCutoff)
+	case years > 0:
+		dailyCutoff = laterOf(dailyCutoff, yearlyCutoff)
+	}
+
+	hourlyCutoff := rawHourlyCutoff
+	switch {
+	case days > 0:
+		hourlyCutoff = laterOf(hourlyCutoff, dailyCutoff)
+	case weeks > 0:
+		hourlyCutoff = laterOf(hourlyCutoff, weeklyCutoff)
+	case months > 0:
+		hourlyCutoff = laterOf(hourlyCutoff, monthlyCutoff)
+	case years > 0:
+		hourlyCutoff = laterOf(hourlyCutoff, yearlyCutoff)
+	}
+
 	for _, backup := range backups {
 		t := backup.CreatedAt
 
@@ -426,31 +542,31 @@ func buildGFSKeepSet(
 		monthKey := t.Format("2006-01")
 		yearKey := t.Format("2006")
 
-		if hours > 0 && hoursKept < hours && !hoursSeen[hourKey] {
+		if hours > 0 && hoursKept < hours && !hoursSeen[hourKey] && t.After(hourlyCutoff) {
 			keep[backup.ID] = true
 			hoursSeen[hourKey] = true
 			hoursKept++
 		}
 
-		if days > 0 && daysKept < days && !daysSeen[dayKey] {
+		if days > 0 && daysKept < days && !daysSeen[dayKey] && t.After(dailyCutoff) {
 			keep[backup.ID] = true
 			daysSeen[dayKey] = true
 			daysKept++
 		}
 
-		if weeks > 0 && weeksKept < weeks && !weeksSeen[weekKey] {
+		if weeks > 0 && weeksKept < weeks && !weeksSeen[weekKey] && t.After(weeklyCutoff) {
 			keep[backup.ID] = true
 			weeksSeen[weekKey] = true
 			weeksKept++
 		}
 
-		if months > 0 && monthsKept < months && !monthsSeen[monthKey] {
+		if months > 0 && monthsKept < months && !monthsSeen[monthKey] && t.After(monthlyCutoff) {
 			keep[backup.ID] = true
 			monthsSeen[monthKey] = true
 			monthsKept++
 		}
 
-		if years > 0 && yearsKept < years && !yearsSeen[yearKey] {
+		if years > 0 && yearsKept < years && !yearsSeen[yearKey] && t.After(yearlyCutoff) {
 			keep[backup.ID] = true
 			yearsSeen[yearKey] = true
 			yearsKept++
@@ -459,3 +575,11 @@ func buildGFSKeepSet(
 
 	return keep
 }
+
+func laterOf(a, b time.Time) time.Time {
+	if a.After(b) {
+		return a
+	}
+
+	return b
+}

backend/internal/features/backups/backups/backuping/cleaner_test.go

@@ -4,6 +4,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
@@ -15,9 +18,6 @@ import (
 	workspaces_testing "databasus-backend/internal/features/workspaces/testing"
 	"databasus-backend/internal/storage"
 	"databasus-backend/internal/util/period"
-
-	"github.com/google/uuid"
-	"github.com/stretchr/testify/assert"
 )
 
 func Test_CleanOldBackups_DeletesBackupsOlderThanRetentionTimePeriod(t *testing.T) {
@@ -697,160 +697,6 @@ func Test_CleanByCount_DoesNotDeleteInProgressBackups(t *testing.T) {
 	assert.True(t, inProgressFound, "In-progress backup should not be deleted by count policy")
 }
 
-func Test_CleanByGFS_KeepsCorrectBackupsPerSlot(t *testing.T) {
-	router := CreateTestRouter()
-	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
-	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
-	storage := storages.CreateTestStorage(workspace.ID)
-	notifier := notifiers.CreateTestNotifier(workspace.ID)
-	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
-
-	defer func() {
-		backups, _ := backupRepository.FindByDatabaseID(database.ID)
-		for _, backup := range backups {
-			backupRepository.DeleteByID(backup.ID)
-		}
-
-		databases.RemoveTestDatabase(database)
-		time.Sleep(50 * time.Millisecond)
-		notifiers.RemoveTestNotifier(notifier)
-		storages.RemoveTestStorage(storage.ID)
-		workspaces_testing.RemoveTestWorkspace(workspace, router)
-	}()
-
-	interval := createTestInterval()
-
-	backupConfig := &backups_config.BackupConfig{
-		DatabaseID:          database.ID,
-		IsBackupsEnabled:    true,
-		RetentionPolicyType: backups_config.RetentionPolicyTypeGFS,
-		RetentionGfsDays:    3,
-		RetentionGfsWeeks:   0,
-		RetentionGfsMonths:  0,
-		RetentionGfsYears:   0,
-		StorageID:           &storage.ID,
-		BackupIntervalID:    interval.ID,
-		BackupInterval:      interval,
-	}
-	_, err := backups_config.GetBackupConfigService().SaveBackupConfig(backupConfig)
-	assert.NoError(t, err)
-
-	now := time.Now().UTC()
-
-	// Create 5 backups on 5 different days; only the 3 newest days should be kept
-	var backupIDs []uuid.UUID
-	for i := 0; i < 5; i++ {
-		backup := &backups_core.Backup{
-			ID:           uuid.New(),
-			DatabaseID:   database.ID,
-			StorageID:    storage.ID,
-			Status:       backups_core.BackupStatusCompleted,
-			BackupSizeMb: 10,
-			CreatedAt:    now.Add(-time.Duration(4-i) * 24 * time.Hour).Truncate(24 * time.Hour),
-		}
-		err = backupRepository.Save(backup)
-		assert.NoError(t, err)
-		backupIDs = append(backupIDs, backup.ID)
-	}
-
-	cleaner := GetBackupCleaner()
-	err = cleaner.cleanByRetentionPolicy()
-	assert.NoError(t, err)
-
-	remainingBackups, err := backupRepository.FindByDatabaseID(database.ID)
-	assert.NoError(t, err)
-	assert.Equal(t, 3, len(remainingBackups))
-
-	remainingIDs := make(map[uuid.UUID]bool)
-	for _, backup := range remainingBackups {
-		remainingIDs[backup.ID] = true
-	}
-	assert.False(t, remainingIDs[backupIDs[0]], "Oldest daily backup should be deleted")
-	assert.False(t, remainingIDs[backupIDs[1]], "2nd oldest daily backup should be deleted")
-	assert.True(t, remainingIDs[backupIDs[2]], "3rd backup should remain")
-	assert.True(t, remainingIDs[backupIDs[3]], "4th backup should remain")
-	assert.True(t, remainingIDs[backupIDs[4]], "Newest backup should remain")
-}
-
-func Test_CleanByGFS_WithWeeklyAndMonthlySlots_KeepsWiderSpread(t *testing.T) {
-	router := CreateTestRouter()
-	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
-	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
-	storage := storages.CreateTestStorage(workspace.ID)
-	notifier := notifiers.CreateTestNotifier(workspace.ID)
-	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
-
-	defer func() {
-		backups, _ := backupRepository.FindByDatabaseID(database.ID)
-		for _, backup := range backups {
-			backupRepository.DeleteByID(backup.ID)
-		}
-
-		databases.RemoveTestDatabase(database)
-		time.Sleep(50 * time.Millisecond)
-		notifiers.RemoveTestNotifier(notifier)
-		storages.RemoveTestStorage(storage.ID)
-		workspaces_testing.RemoveTestWorkspace(workspace, router)
-	}()
-
-	interval := createTestInterval()
-
-	backupConfig := &backups_config.BackupConfig{
-		DatabaseID:          database.ID,
-		IsBackupsEnabled:    true,
-		RetentionPolicyType: backups_config.RetentionPolicyTypeGFS,
-		RetentionGfsDays:    2,
-		RetentionGfsWeeks:   2,
-		RetentionGfsMonths:  1,
-		RetentionGfsYears:   0,
-		StorageID:           &storage.ID,
-		BackupIntervalID:    interval.ID,
-		BackupInterval:      interval,
-	}
-	_, err := backups_config.GetBackupConfigService().SaveBackupConfig(backupConfig)
-	assert.NoError(t, err)
-
-	now := time.Now().UTC()
-
-	// Create one backup per week for 6 weeks (each on Monday of that week)
-	// GFS should keep: 2 daily (most recent 2 unique days) + 2 weekly + 1 monthly = up to 5 unique
-	var createdIDs []uuid.UUID
-	for i := 0; i < 6; i++ {
-		weekOffset := time.Duration(5-i) * 7 * 24 * time.Hour
-		backup := &backups_core.Backup{
-			ID:           uuid.New(),
-			DatabaseID:   database.ID,
-			StorageID:    storage.ID,
-			Status:       backups_core.BackupStatusCompleted,
-			BackupSizeMb: 10,
-			CreatedAt:    now.Add(-weekOffset).Truncate(24 * time.Hour),
-		}
-		err = backupRepository.Save(backup)
-		assert.NoError(t, err)
-		createdIDs = append(createdIDs, backup.ID)
-	}
-
-	cleaner := GetBackupCleaner()
-	err = cleaner.cleanByRetentionPolicy()
-	assert.NoError(t, err)
-
-	remainingBackups, err := backupRepository.FindByDatabaseID(database.ID)
-	assert.NoError(t, err)
-
-	// We should have at most 5 backups kept (2 daily + 2 weekly + 1 monthly, but with overlap possible)
-	// The exact count depends on how many unique periods are covered
-	assert.LessOrEqual(t, len(remainingBackups), 5)
-	assert.GreaterOrEqual(t, len(remainingBackups), 1)
-
-	// The two most recent backups should always be retained (daily slots)
-	remainingIDs := make(map[uuid.UUID]bool)
-	for _, backup := range remainingBackups {
-		remainingIDs[backup.ID] = true
-	}
-	assert.True(t, remainingIDs[createdIDs[4]], "Second newest backup should be retained (daily)")
-	assert.True(t, remainingIDs[createdIDs[5]], "Newest backup should be retained (daily)")
-}
-
 // Test_DeleteBackup_WhenStorageDeleteFails_BackupStillRemovedFromDatabase verifies resilience
 // when storage becomes unavailable. Even if storage.DeleteFile fails (e.g., storage is offline,
 // credentials changed, or storage was deleted), the backup record should still be removed from
@@ -897,292 +743,6 @@ func Test_DeleteBackup_WhenStorageDeleteFails_BackupStillRemovedFromDatabase(t *
 	assert.Nil(t, deletedBackup)
 }
 
-func Test_CleanByGFS_WithHourlySlots_KeepsCorrectBackups(t *testing.T) {
-	router := CreateTestRouter()
-	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
-	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
-	testStorage := storages.CreateTestStorage(workspace.ID)
-	notifier := notifiers.CreateTestNotifier(workspace.ID)
-	database := databases.CreateTestDatabase(workspace.ID, testStorage, notifier)
-
-	defer func() {
-		backups, _ := backupRepository.FindByDatabaseID(database.ID)
-		for _, backup := range backups {
-			backupRepository.DeleteByID(backup.ID)
-		}
-
-		databases.RemoveTestDatabase(database)
-		time.Sleep(50 * time.Millisecond)
-		notifiers.RemoveTestNotifier(notifier)
-		storages.RemoveTestStorage(testStorage.ID)
-		workspaces_testing.RemoveTestWorkspace(workspace, router)
-	}()
-
-	interval := createTestInterval()
-
-	backupConfig := &backups_config.BackupConfig{
-		DatabaseID:          database.ID,
-		IsBackupsEnabled:    true,
-		RetentionPolicyType: backups_config.RetentionPolicyTypeGFS,
-		RetentionGfsHours:   3,
-		StorageID:           &testStorage.ID,
-		BackupIntervalID:    interval.ID,
-		BackupInterval:      interval,
-	}
-	_, err := backups_config.GetBackupConfigService().SaveBackupConfig(backupConfig)
-	assert.NoError(t, err)
-
-	now := time.Now().UTC()
-
-	// Create 5 backups spaced 1 hour apart; only the 3 newest hours should be kept
-	var backupIDs []uuid.UUID
-	for i := 0; i < 5; i++ {
-		backup := &backups_core.Backup{
-			ID:           uuid.New(),
-			DatabaseID:   database.ID,
-			StorageID:    testStorage.ID,
-			Status:       backups_core.BackupStatusCompleted,
-			BackupSizeMb: 10,
-			CreatedAt:    now.Add(-time.Duration(4-i) * time.Hour).Truncate(time.Hour),
-		}
-		err = backupRepository.Save(backup)
-		assert.NoError(t, err)
-		backupIDs = append(backupIDs, backup.ID)
-	}
-
-	cleaner := GetBackupCleaner()
-	err = cleaner.cleanByRetentionPolicy()
-	assert.NoError(t, err)
-
-	remainingBackups, err := backupRepository.FindByDatabaseID(database.ID)
-	assert.NoError(t, err)
-	assert.Equal(t, 3, len(remainingBackups))
-
-	remainingIDs := make(map[uuid.UUID]bool)
-	for _, backup := range remainingBackups {
-		remainingIDs[backup.ID] = true
-	}
-	assert.False(t, remainingIDs[backupIDs[0]], "Oldest hourly backup should be deleted")
-	assert.False(t, remainingIDs[backupIDs[1]], "2nd oldest hourly backup should be deleted")
-	assert.True(t, remainingIDs[backupIDs[2]], "3rd backup should remain")
-	assert.True(t, remainingIDs[backupIDs[3]], "4th backup should remain")
-	assert.True(t, remainingIDs[backupIDs[4]], "Newest backup should remain")
-}
-
-func Test_BuildGFSKeepSet(t *testing.T) {
-	// Fixed reference time: a Wednesday mid-month to avoid boundary edge cases in the default tests.
-	// Use time.Date for determinism across test runs.
-	ref := time.Date(2025, 6, 18, 12, 0, 0, 0, time.UTC) // Wednesday, 2025-06-18
-
-	day := 24 * time.Hour
-	week := 7 * day
-
-	newBackup := func(createdAt time.Time) *backups_core.Backup {
-		return &backups_core.Backup{ID: uuid.New(), CreatedAt: createdAt}
-	}
-
-	// backupsEveryDay returns n backups, newest-first, each 1 day apart.
-	backupsEveryDay := func(n int) []*backups_core.Backup {
-		bs := make([]*backups_core.Backup, n)
-		for i := 0; i < n; i++ {
-			bs[i] = newBackup(ref.Add(-time.Duration(i) * day))
-		}
-		return bs
-	}
-
-	// backupsEveryWeek returns n backups, newest-first, each 7 days apart.
-	backupsEveryWeek := func(n int) []*backups_core.Backup {
-		bs := make([]*backups_core.Backup, n)
-		for i := 0; i < n; i++ {
-			bs[i] = newBackup(ref.Add(-time.Duration(i) * week))
-		}
-		return bs
-	}
-
-	hour := time.Hour
-
-	// backupsEveryHour returns n backups, newest-first, each 1 hour apart.
-	backupsEveryHour := func(n int) []*backups_core.Backup {
-		bs := make([]*backups_core.Backup, n)
-		for i := 0; i < n; i++ {
-			bs[i] = newBackup(ref.Add(-time.Duration(i) * hour))
-		}
-		return bs
-	}
-
-	tests := []struct {
-		name         string
-		backups      []*backups_core.Backup
-		hours        int
-		days         int
-		weeks        int
-		months       int
-		years        int
-		keptIndices  []int   // which indices in backups should be kept
-		deletedRange *[2]int // optional: all indices in [from, to) must be deleted
-	}{
-		{
-			name:        "OnlyHourlySlots_KeepsNewest3Of5",
-			backups:     backupsEveryHour(5),
-			hours:       3,
-			keptIndices: []int{0, 1, 2},
-		},
-		{
-			name: "SameHourDedup_OnlyNewestKeptForHourlySlot",
-			backups: []*backups_core.Backup{
-				newBackup(ref.Truncate(hour).Add(45 * time.Minute)),
-				newBackup(ref.Truncate(hour).Add(10 * time.Minute)),
-			},
-			hours:       1,
-			keptIndices: []int{0},
-		},
-		{
-			name:        "OnlyDailySlots_KeepsNewest3Of5",
-			backups:     backupsEveryDay(5),
-			days:        3,
-			keptIndices: []int{0, 1, 2},
-		},
-		{
-			name:        "OnlyDailySlots_FewerBackupsThanSlots_KeepsAll",
-			backups:     backupsEveryDay(2),
-			days:        5,
-			keptIndices: []int{0, 1},
-		},
-		{
-			name:        "OnlyWeeklySlots_KeepsNewest2Weeks",
-			backups:     backupsEveryWeek(4),
-			weeks:       2,
-			keptIndices: []int{0, 1},
-		},
-		{
-			name: "OnlyMonthlySlots_KeepsNewest2Months",
-			backups: []*backups_core.Backup{
-				newBackup(time.Date(2025, 6, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2025, 5, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2025, 4, 1, 12, 0, 0, 0, time.UTC)),
-			},
-			months:      2,
-			keptIndices: []int{0, 1},
-		},
-		{
-			name: "OnlyYearlySlots_KeepsNewest2Years",
-			backups: []*backups_core.Backup{
-				newBackup(time.Date(2025, 6, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2024, 6, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2023, 6, 1, 12, 0, 0, 0, time.UTC)),
-			},
-			years:       2,
-			keptIndices: []int{0, 1},
-		},
-		{
-			name: "SameDayDedup_OnlyNewestKeptForDailySlot",
-			backups: []*backups_core.Backup{
-				// Two backups on the same day; newest-first order
-				newBackup(ref.Truncate(day).Add(10 * time.Hour)),
-				newBackup(ref.Truncate(day).Add(2 * time.Hour)),
-			},
-			days:        1,
-			keptIndices: []int{0},
-		},
-		{
-			name: "SameWeekDedup_OnlyNewestKeptForWeeklySlot",
-			backups: []*backups_core.Backup{
-				// ref is Wednesday; add Thursday of same week
-				newBackup(ref.Add(1 * day)), // Thursday same week
-				newBackup(ref),              // Wednesday same week
-			},
-			weeks:       1,
-			keptIndices: []int{0},
-		},
-		{
-			name: "AdditiveSlots_NewestFillsDailyAndWeeklyAndMonthly",
-			// Newest backup fills daily + weekly + monthly simultaneously
-			backups: []*backups_core.Backup{
-				newBackup(time.Date(2025, 6, 18, 12, 0, 0, 0, time.UTC)), // newest
-				newBackup(time.Date(2025, 6, 11, 12, 0, 0, 0, time.UTC)), // 1 week ago
-				newBackup(time.Date(2025, 5, 18, 12, 0, 0, 0, time.UTC)), // 1 month ago
-				newBackup(time.Date(2025, 4, 18, 12, 0, 0, 0, time.UTC)), // 2 months ago
-			},
-			days:        1,
-			weeks:       2,
-			months:      2,
-			keptIndices: []int{0, 1, 2},
-		},
-		{
-			name: "YearBoundary_CorrectlySplitsAcrossYears",
-			backups: []*backups_core.Backup{
-				newBackup(time.Date(2025, 1, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2024, 12, 31, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2024, 6, 1, 12, 0, 0, 0, time.UTC)),
-				newBackup(time.Date(2023, 6, 1, 12, 0, 0, 0, time.UTC)),
-			},
-			years:       2,
-			keptIndices: []int{0, 1}, // 2025 and 2024 kept; 2024-06 and 2023 deleted
-		},
-		{
-			name: "ISOWeekBoundary_Jan1UsesCorrectISOWeek",
-			// 2025-01-01 is ISO week 1 of 2025; 2024-12-28 is ISO week 52 of 2024
-			backups: []*backups_core.Backup{
-				newBackup(time.Date(2025, 1, 1, 12, 0, 0, 0, time.UTC)),   // ISO week 2025-W01
-				newBackup(time.Date(2024, 12, 28, 12, 0, 0, 0, time.UTC)), // ISO week 2024-W52
-			},
-			weeks:       2,
-			keptIndices: []int{0, 1}, // different ISO weeks → both kept
-		},
-		{
-			name:        "EmptyBackups_ReturnsEmptyKeepSet",
-			backups:     []*backups_core.Backup{},
-			hours:       3,
-			days:        3,
-			weeks:       2,
-			months:      1,
-			years:       1,
-			keptIndices: []int{},
-		},
-		{
-			name:        "AllZeroSlots_KeepsNothing",
-			backups:     backupsEveryDay(5),
-			hours:       0,
-			days:        0,
-			weeks:       0,
-			months:      0,
-			years:       0,
-			keptIndices: []int{},
-		},
-		{
-			name:    "AllSlotsActive_FullCombination",
-			backups: backupsEveryWeek(12),
-			days:    2,
-			weeks:   3,
-			months:  2,
-			years:   1,
-			// 2 daily (indices 0,1) + 3rd weekly slot (index 2) + 2nd monthly slot (index 3 or later).
-			// Additive slots: newest fills daily+weekly+monthly+yearly; each subsequent week fills another weekly,
-			// and a backup ~4 weeks later fills the 2nd monthly slot.
-			keptIndices: []int{0, 1, 2, 3},
-		},
-	}
-
-	for _, tc := range tests {
-		t.Run(tc.name, func(t *testing.T) {
-			keepSet := buildGFSKeepSet(tc.backups, tc.hours, tc.days, tc.weeks, tc.months, tc.years)
-
-			keptIndexSet := make(map[int]bool, len(tc.keptIndices))
-			for _, idx := range tc.keptIndices {
-				keptIndexSet[idx] = true
-			}
-
-			for i, backup := range tc.backups {
-				if keptIndexSet[i] {
-					assert.True(t, keepSet[backup.ID], "backup at index %d should be kept", i)
-				} else {
-					assert.False(t, keepSet[backup.ID], "backup at index %d should be deleted", i)
-				}
-			}
-		})
-	}
-}
-
 func Test_CleanByTimePeriod_SkipsRecentBackup_EvenIfOlderThanRetention(t *testing.T) {
 	router := CreateTestRouter()
 	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
@@ -1354,114 +914,6 @@ func Test_CleanByCount_SkipsRecentBackup_EvenIfOverLimit(t *testing.T) {
 	assert.True(t, remainingIDs[newestBackup.ID], "Newest backup should be preserved")
 }
 
-func Test_CleanByGFS_SkipsRecentBackup_WhenNotInKeepSet(t *testing.T) {
-	router := CreateTestRouter()
-	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
-	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
-	storage := storages.CreateTestStorage(workspace.ID)
-	notifier := notifiers.CreateTestNotifier(workspace.ID)
-	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
-
-	defer func() {
-		backups, _ := backupRepository.FindByDatabaseID(database.ID)
-		for _, backup := range backups {
-			backupRepository.DeleteByID(backup.ID)
-		}
-
-		databases.RemoveTestDatabase(database)
-		time.Sleep(50 * time.Millisecond)
-		notifiers.RemoveTestNotifier(notifier)
-		storages.RemoveTestStorage(storage.ID)
-		workspaces_testing.RemoveTestWorkspace(workspace, router)
-	}()
-
-	interval := createTestInterval()
-
-	// Keep only 1 daily slot. We create 2 old backups plus two recent backups on today.
-	// Backups are ordered newest-first, so the 15-min-old backup fills the single daily slot.
-	// The 30-min-old backup is the same day → not in the GFS keep-set, but it is still recent
-	// (within grace period) and must be preserved.
-	backupConfig := &backups_config.BackupConfig{
-		DatabaseID:          database.ID,
-		IsBackupsEnabled:    true,
-		RetentionPolicyType: backups_config.RetentionPolicyTypeGFS,
-		RetentionGfsDays:    1,
-		StorageID:           &storage.ID,
-		BackupIntervalID:    interval.ID,
-		BackupInterval:      interval,
-	}
-	_, err := backups_config.GetBackupConfigService().SaveBackupConfig(backupConfig)
-	assert.NoError(t, err)
-
-	now := time.Now().UTC()
-
-	oldBackup1 := &backups_core.Backup{
-		ID:           uuid.New(),
-		DatabaseID:   database.ID,
-		StorageID:    storage.ID,
-		Status:       backups_core.BackupStatusCompleted,
-		BackupSizeMb: 10,
-		CreatedAt:    now.Add(-3 * 24 * time.Hour).Truncate(24 * time.Hour),
-	}
-	oldBackup2 := &backups_core.Backup{
-		ID:           uuid.New(),
-		DatabaseID:   database.ID,
-		StorageID:    storage.ID,
-		Status:       backups_core.BackupStatusCompleted,
-		BackupSizeMb: 10,
-		CreatedAt:    now.Add(-2 * 24 * time.Hour).Truncate(24 * time.Hour),
-	}
-	// Newest backup today — will fill the single GFS daily slot.
-	newestTodayBackup := &backups_core.Backup{
-		ID:           uuid.New(),
-		DatabaseID:   database.ID,
-		StorageID:    storage.ID,
-		Status:       backups_core.BackupStatusCompleted,
-		BackupSizeMb: 10,
-		CreatedAt:    now.Add(-15 * time.Minute),
-	}
-	// Slightly older backup, also today — NOT in GFS keep-set (duplicate day),
-	// but within the 60-minute grace period so it must survive.
-	recentNotInKeepSet := &backups_core.Backup{
-		ID:           uuid.New(),
-		DatabaseID:   database.ID,
-		StorageID:    storage.ID,
-		Status:       backups_core.BackupStatusCompleted,
-		BackupSizeMb: 10,
-		CreatedAt:    now.Add(-30 * time.Minute),
-	}
-
-	for _, b := range []*backups_core.Backup{oldBackup1, oldBackup2, newestTodayBackup, recentNotInKeepSet} {
-		err = backupRepository.Save(b)
-		assert.NoError(t, err)
-	}
-
-	cleaner := GetBackupCleaner()
-	err = cleaner.cleanByRetentionPolicy()
-	assert.NoError(t, err)
-
-	remainingBackups, err := backupRepository.FindByDatabaseID(database.ID)
-	assert.NoError(t, err)
-
-	remainingIDs := make(map[uuid.UUID]bool)
-	for _, backup := range remainingBackups {
-		remainingIDs[backup.ID] = true
-	}
-
-	assert.False(t, remainingIDs[oldBackup1.ID], "Old backup 1 should be deleted by GFS")
-	assert.False(t, remainingIDs[oldBackup2.ID], "Old backup 2 should be deleted by GFS")
-	assert.True(
-		t,
-		remainingIDs[newestTodayBackup.ID],
-		"Newest backup fills GFS daily slot and must remain",
-	)
-	assert.True(
-		t,
-		remainingIDs[recentNotInKeepSet.ID],
-		"Recent backup not in keep-set must be preserved by grace period",
-	)
-}
-
 func Test_CleanExceededBackups_SkipsRecentBackup_WhenOverTotalSizeLimit(t *testing.T) {
 	router := CreateTestRouter()
 	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
@@ -1552,6 +1004,191 @@ func (m *mockBackupRemoveListener) OnBeforeBackupRemove(backup *backups_core.Bac
 	return nil
 }
 
+func Test_CleanStaleUploadedBasebackups_MarksAsFailed(t *testing.T) {
+	router := CreateTestRouter()
+	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
+	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
+	storage := storages.CreateTestStorage(workspace.ID)
+	notifier := notifiers.CreateTestNotifier(workspace.ID)
+	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
+
+	defer func() {
+		backups, _ := backupRepository.FindByDatabaseID(database.ID)
+		for _, backup := range backups {
+			backupRepository.DeleteByID(backup.ID)
+		}
+
+		databases.RemoveTestDatabase(database)
+		time.Sleep(50 * time.Millisecond)
+		notifiers.RemoveTestNotifier(notifier)
+		storages.RemoveTestStorage(storage.ID)
+		workspaces_testing.RemoveTestWorkspace(workspace, router)
+	}()
+
+	staleTime := time.Now().UTC().Add(-15 * time.Minute)
+	walBackupType := backups_core.PgWalBackupTypeFullBackup
+	staleBackup := &backups_core.Backup{
+		ID:                uuid.New(),
+		DatabaseID:        database.ID,
+		StorageID:         storage.ID,
+		Status:            backups_core.BackupStatusInProgress,
+		PgWalBackupType:   &walBackupType,
+		UploadCompletedAt: &staleTime,
+		CreatedAt:         staleTime,
+	}
+
+	err := backupRepository.Save(staleBackup)
+	assert.NoError(t, err)
+
+	cleaner := GetBackupCleaner()
+	err = cleaner.cleanStaleUploadedBasebackups()
+	assert.NoError(t, err)
+
+	updated, err := backupRepository.FindByID(staleBackup.ID)
+	assert.NoError(t, err)
+	assert.Equal(t, backups_core.BackupStatusFailed, updated.Status)
+	assert.NotNil(t, updated.FailMessage)
+	assert.Contains(t, *updated.FailMessage, "finalization timed out")
+}
+
+func Test_CleanStaleUploadedBasebackups_SkipsRecentUploads(t *testing.T) {
+	router := CreateTestRouter()
+	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
+	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
+	storage := storages.CreateTestStorage(workspace.ID)
+	notifier := notifiers.CreateTestNotifier(workspace.ID)
+	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
+
+	defer func() {
+		backups, _ := backupRepository.FindByDatabaseID(database.ID)
+		for _, backup := range backups {
+			backupRepository.DeleteByID(backup.ID)
+		}
+
+		databases.RemoveTestDatabase(database)
+		time.Sleep(50 * time.Millisecond)
+		notifiers.RemoveTestNotifier(notifier)
+		storages.RemoveTestStorage(storage.ID)
+		workspaces_testing.RemoveTestWorkspace(workspace, router)
+	}()
+
+	recentTime := time.Now().UTC().Add(-2 * time.Minute)
+	walBackupType := backups_core.PgWalBackupTypeFullBackup
+	recentBackup := &backups_core.Backup{
+		ID:                uuid.New(),
+		DatabaseID:        database.ID,
+		StorageID:         storage.ID,
+		Status:            backups_core.BackupStatusInProgress,
+		PgWalBackupType:   &walBackupType,
+		UploadCompletedAt: &recentTime,
+		CreatedAt:         recentTime,
+	}
+
+	err := backupRepository.Save(recentBackup)
+	assert.NoError(t, err)
+
+	cleaner := GetBackupCleaner()
+	err = cleaner.cleanStaleUploadedBasebackups()
+	assert.NoError(t, err)
+
+	updated, err := backupRepository.FindByID(recentBackup.ID)
+	assert.NoError(t, err)
+	assert.Equal(t, backups_core.BackupStatusInProgress, updated.Status)
+}
+
+func Test_CleanStaleUploadedBasebackups_SkipsActiveStreaming(t *testing.T) {
+	router := CreateTestRouter()
+	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
+	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
+	storage := storages.CreateTestStorage(workspace.ID)
+	notifier := notifiers.CreateTestNotifier(workspace.ID)
+	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
+
+	defer func() {
+		backups, _ := backupRepository.FindByDatabaseID(database.ID)
+		for _, backup := range backups {
+			backupRepository.DeleteByID(backup.ID)
+		}
+
+		databases.RemoveTestDatabase(database)
+		time.Sleep(50 * time.Millisecond)
+		notifiers.RemoveTestNotifier(notifier)
+		storages.RemoveTestStorage(storage.ID)
+		workspaces_testing.RemoveTestWorkspace(workspace, router)
+	}()
+
+	walBackupType := backups_core.PgWalBackupTypeFullBackup
+	activeBackup := &backups_core.Backup{
+		ID:              uuid.New(),
+		DatabaseID:      database.ID,
+		StorageID:       storage.ID,
+		Status:          backups_core.BackupStatusInProgress,
+		PgWalBackupType: &walBackupType,
+		CreatedAt:       time.Now().UTC().Add(-30 * time.Minute),
+	}
+
+	err := backupRepository.Save(activeBackup)
+	assert.NoError(t, err)
+
+	cleaner := GetBackupCleaner()
+	err = cleaner.cleanStaleUploadedBasebackups()
+	assert.NoError(t, err)
+
+	updated, err := backupRepository.FindByID(activeBackup.ID)
+	assert.NoError(t, err)
+	assert.Equal(t, backups_core.BackupStatusInProgress, updated.Status)
+	assert.Nil(t, updated.UploadCompletedAt)
+}
+
+func Test_CleanStaleUploadedBasebackups_CleansStorageFiles(t *testing.T) {
+	router := CreateTestRouter()
+	owner := users_testing.CreateTestUser(users_enums.UserRoleMember)
+	workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", owner, router)
+	storage := storages.CreateTestStorage(workspace.ID)
+	notifier := notifiers.CreateTestNotifier(workspace.ID)
+	database := databases.CreateTestDatabase(workspace.ID, storage, notifier)
+
+	defer func() {
+		backups, _ := backupRepository.FindByDatabaseID(database.ID)
+		for _, backup := range backups {
+			backupRepository.DeleteByID(backup.ID)
+		}
+
+		databases.RemoveTestDatabase(database)
+		time.Sleep(50 * time.Millisecond)
+		notifiers.RemoveTestNotifier(notifier)
+		storages.RemoveTestStorage(storage.ID)
+		workspaces_testing.RemoveTestWorkspace(workspace, router)
+	}()
+
+	staleTime := time.Now().UTC().Add(-15 * time.Minute)
+	walBackupType := backups_core.PgWalBackupTypeFullBackup
+	staleBackup := &backups_core.Backup{
+		ID:                uuid.New(),
+		DatabaseID:        database.ID,
+		StorageID:         storage.ID,
+		Status:            backups_core.BackupStatusInProgress,
+		PgWalBackupType:   &walBackupType,
+		UploadCompletedAt: &staleTime,
+		BackupSizeMb:      500,
+		FileName:          "stale-basebackup-test-file",
+		CreatedAt:         staleTime,
+	}
+
+	err := backupRepository.Save(staleBackup)
+	assert.NoError(t, err)
+
+	cleaner := GetBackupCleaner()
+	err = cleaner.cleanStaleUploadedBasebackups()
+	assert.NoError(t, err)
+
+	updated, err := backupRepository.FindByID(staleBackup.ID)
+	assert.NoError(t, err)
+	assert.Equal(t, backups_core.BackupStatusFailed, updated.Status)
+	assert.NotNil(t, updated.FailMessage)
+	assert.Contains(t, *updated.FailMessage, "finalization timed out")
+}
+
 func createTestInterval() *intervals.Interval {
 	timeOfDay := "04:00"
 	interval := &intervals.Interval{

backend/internal/features/backups/backups/backuping/mocks.go

@@ -6,15 +6,15 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/mock"
+
 	common "databasus-backend/internal/features/backups/backups/common"
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
 	"databasus-backend/internal/features/notifiers"
 	"databasus-backend/internal/features/storages"
-
-	"github.com/google/uuid"
-	"github.com/stretchr/testify/mock"
 )
 
 type MockNotificationSender struct {

backend/internal/features/backups/backups/backuping/registry.go

@@ -10,10 +10,10 @@ import (
 	"sync/atomic"
 	"time"
 
-	cache_utils "databasus-backend/internal/util/cache"
-
 	"github.com/google/uuid"
 	"github.com/valkey-io/valkey-go"
+
+	cache_utils "databasus-backend/internal/util/cache"
 )
 
 const (
@@ -415,7 +415,7 @@ func (r *BackupNodesRegistry) UnsubscribeNodeForBackupsAssignments() error {
 	return nil
 }
 
-func (r *BackupNodesRegistry) PublishBackupCompletion(nodeID uuid.UUID, backupID uuid.UUID) error {
+func (r *BackupNodesRegistry) PublishBackupCompletion(nodeID, backupID uuid.UUID) error {
 	ctx := context.Background()
 
 	message := BackupCompletionMessage{
@@ -437,7 +437,7 @@ func (r *BackupNodesRegistry) PublishBackupCompletion(nodeID uuid.UUID, backupID
 }
 
 func (r *BackupNodesRegistry) SubscribeForBackupsCompletions(
-	handler func(nodeID uuid.UUID, backupID uuid.UUID),
+	handler func(nodeID, backupID uuid.UUID),
 ) error {
 	ctx := context.Background()
 

backend/internal/features/backups/backups/backuping/registry_test.go

@@ -9,11 +9,11 @@ import (
 	"testing"
 	"time"
 
-	cache_utils "databasus-backend/internal/util/cache"
-	"databasus-backend/internal/util/logger"
-
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
+
+	cache_utils "databasus-backend/internal/util/cache"
+	"databasus-backend/internal/util/logger"
 )
 
 func Test_HearthbeatNodeInRegistry_RegistersNodeWithTTL(t *testing.T) {
@@ -903,7 +903,7 @@ func Test_SubscribeForBackupsCompletions_ReceivesCompletedBackups(t *testing.T)
 
 	receivedBackupID := make(chan uuid.UUID, 1)
 	receivedNodeID := make(chan uuid.UUID, 1)
-	handler := func(nodeID uuid.UUID, backupID uuid.UUID) {
+	handler := func(nodeID, backupID uuid.UUID) {
 		receivedNodeID <- nodeID
 		receivedBackupID <- backupID
 	}
@@ -940,7 +940,7 @@ func Test_SubscribeForBackupsCompletions_ParsesJsonCorrectly(t *testing.T) {
 	defer registry.UnsubscribeForBackupsCompletions()
 
 	receivedBackups := make(chan uuid.UUID, 2)
-	handler := func(nodeID uuid.UUID, backupID uuid.UUID) {
+	handler := func(nodeID, backupID uuid.UUID) {
 		receivedBackups <- backupID
 	}
 
@@ -969,7 +969,7 @@ func Test_SubscribeForBackupsCompletions_HandlesInvalidJson(t *testing.T) {
 	defer registry.UnsubscribeForBackupsCompletions()
 
 	receivedBackupID := make(chan uuid.UUID, 1)
-	handler := func(nodeID uuid.UUID, backupID uuid.UUID) {
+	handler := func(nodeID, backupID uuid.UUID) {
 		receivedBackupID <- backupID
 	}
 
@@ -997,7 +997,7 @@ func Test_UnsubscribeForBackupsCompletions_StopsReceivingMessages(t *testing.T)
 	backupID2 := uuid.New()
 
 	receivedBackupID := make(chan uuid.UUID, 2)
-	handler := func(nodeID uuid.UUID, backupID uuid.UUID) {
+	handler := func(nodeID, backupID uuid.UUID) {
 		receivedBackupID <- backupID
 	}
 
@@ -1032,7 +1032,7 @@ func Test_SubscribeForBackupsCompletions_WhenAlreadySubscribed_ReturnsError(t *t
 	registry := createTestRegistry()
 	defer registry.UnsubscribeForBackupsCompletions()
 
-	handler := func(nodeID uuid.UUID, backupID uuid.UUID) {}
+	handler := func(nodeID, backupID uuid.UUID) {}
 
 	err := registry.SubscribeForBackupsCompletions(handler)
 	assert.NoError(t, err)
@@ -1064,9 +1064,9 @@ func Test_MultipleSubscribers_EachReceivesCompletionMessages(t *testing.T) {
 	receivedBackups2 := make(chan uuid.UUID, 3)
 	receivedBackups3 := make(chan uuid.UUID, 3)
 
-	handler1 := func(nodeID uuid.UUID, backupID uuid.UUID) { receivedBackups1 <- backupID }
-	handler2 := func(nodeID uuid.UUID, backupID uuid.UUID) { receivedBackups2 <- backupID }
-	handler3 := func(nodeID uuid.UUID, backupID uuid.UUID) { receivedBackups3 <- backupID }
+	handler1 := func(nodeID, backupID uuid.UUID) { receivedBackups1 <- backupID }
+	handler2 := func(nodeID, backupID uuid.UUID) { receivedBackups2 <- backupID }
+	handler3 := func(nodeID, backupID uuid.UUID) { receivedBackups3 <- backupID }
 
 	err := registry1.SubscribeForBackupsCompletions(handler1)
 	assert.NoError(t, err)

backend/internal/features/backups/backups/backuping/scheduler.go

@@ -15,7 +15,6 @@ import (
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
 	task_cancellation "databasus-backend/internal/features/tasks/cancellation"
-	files_utils "databasus-backend/internal/util/files"
 )
 
 const (
@@ -171,13 +170,7 @@ func (s *BackupsScheduler) StartBackup(database *databases.Database, isCallNotif
 	timestamp := time.Now().UTC()
 
 	backup := &backups_core.Backup{
-		ID: backupID,
-		FileName: fmt.Sprintf(
-			"%s-%s-%s",
-			files_utils.SanitizeFilename(database.Name),
-			timestamp.Format("20060102-150405"),
-			backupID.String(),
-		),
+		ID:           backupID,
 		DatabaseID:   backupConfig.DatabaseID,
 		StorageID:    *backupConfig.StorageID,
 		Status:       backups_core.BackupStatusInProgress,
@@ -185,6 +178,8 @@ func (s *BackupsScheduler) StartBackup(database *databases.Database, isCallNotif
 		CreatedAt:    timestamp,
 	}
 
+	backup.GenerateFilename(database.Name)
+
 	if err := s.backupRepository.Save(backup); err != nil {
 		s.logger.Error(
 			"Failed to save backup",
@@ -347,6 +342,10 @@ func (s *BackupsScheduler) runPendingBackups() error {
 				continue
 			}
 
+			if database.IsAgentManagedBackup() {
+				continue
+			}
+
 			s.StartBackup(database, remainedBackupTryCount == 1)
 			continue
 		}
@@ -446,7 +445,7 @@ func (s *BackupsScheduler) calculateLeastBusyNode() (*uuid.UUID, error) {
 	return &bestNode.ID, nil
 }
 
-func (s *BackupsScheduler) onBackupCompleted(nodeID uuid.UUID, backupID uuid.UUID) {
+func (s *BackupsScheduler) onBackupCompleted(nodeID, backupID uuid.UUID) {
 	// Verify this task is actually a backup (registry contains multiple task types)
 	_, err := s.backupRepository.FindByID(backupID)
 	if err != nil {

backend/internal/features/backups/backups/backuping/scheduler_test.go

@@ -1,6 +1,13 @@
 package backuping
 
 import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/assert"
+
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
@@ -12,13 +19,130 @@ import (
 	workspaces_testing "databasus-backend/internal/features/workspaces/testing"
 	cache_utils "databasus-backend/internal/util/cache"
 	"databasus-backend/internal/util/period"
-	"testing"
-	"time"
-
-	"github.com/google/uuid"
-	"github.com/stretchr/testify/assert"
 )
 
+func Test_RunPendingBackups_ByDatabaseType_OnlySchedulesNonAgentManagedBackups(t *testing.T) {
+	type testCase struct {
+		name              string
+		createDatabase    func(workspaceID uuid.UUID, storage *storages.Storage, notifier *notifiers.Notifier) *databases.Database
+		isBackupExpected  bool
+		needsBackuperNode bool
+	}
+
+	testCases := []testCase{
+		{
+			name: "PostgreSQL PG_DUMP - backup runs",
+			createDatabase: func(workspaceID uuid.UUID, storage *storages.Storage, notifier *notifiers.Notifier) *databases.Database {
+				return databases.CreateTestDatabase(workspaceID, storage, notifier)
+			},
+			isBackupExpected:  true,
+			needsBackuperNode: true,
+		},
+		{
+			name: "PostgreSQL WAL_V1 - backup skipped (agent-managed)",
+			createDatabase: func(workspaceID uuid.UUID, _ *storages.Storage, notifier *notifiers.Notifier) *databases.Database {
+				return databases.CreateTestPostgresWalDatabase(workspaceID, notifier)
+			},
+			isBackupExpected:  false,
+			needsBackuperNode: false,
+		},
+		{
+			name: "MariaDB - backup runs",
+			createDatabase: func(workspaceID uuid.UUID, _ *storages.Storage, notifier *notifiers.Notifier) *databases.Database {
+				return databases.CreateTestMariadbDatabase(workspaceID, notifier)
+			},
+			isBackupExpected:  true,
+			needsBackuperNode: true,
+		},
+		{
+			name: "MongoDB - backup runs",
+			createDatabase: func(workspaceID uuid.UUID, _ *storages.Storage, notifier *notifiers.Notifier) *databases.Database {
+				return databases.CreateTestMongodbDatabase(workspaceID, notifier)
+			},
+			isBackupExpected:  true,
+			needsBackuperNode: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			cache_utils.ClearAllCache()
+
+			var backuperNode *BackuperNode
+			var cancel context.CancelFunc
+
+			if tc.needsBackuperNode {
+				backuperNode = CreateTestBackuperNode()
+				cancel = StartBackuperNodeForTest(t, backuperNode)
+				defer StopBackuperNodeForTest(t, cancel, backuperNode)
+			}
+
+			user := users_testing.CreateTestUser(users_enums.UserRoleAdmin)
+			router := CreateTestRouter()
+			workspace := workspaces_testing.CreateTestWorkspace("Test Workspace", user, router)
+			storage := storages.CreateTestStorage(workspace.ID)
+			notifier := notifiers.CreateTestNotifier(workspace.ID)
+			database := tc.createDatabase(workspace.ID, storage, notifier)
+
+			defer func() {
+				backups, _ := backupRepository.FindByDatabaseID(database.ID)
+				for _, backup := range backups {
+					backupRepository.DeleteByID(backup.ID)
+				}
+
+				databases.RemoveTestDatabase(database)
+				time.Sleep(50 * time.Millisecond)
+				storages.RemoveTestStorage(storage.ID)
+				notifiers.RemoveTestNotifier(notifier)
+				workspaces_testing.RemoveTestWorkspace(workspace, router)
+			}()
+
+			backupConfig, err := backups_config.GetBackupConfigService().GetBackupConfigByDbId(database.ID)
+			assert.NoError(t, err)
+
+			timeOfDay := "04:00"
+			backupConfig.BackupInterval = &intervals.Interval{
+				Interval:  intervals.IntervalDaily,
+				TimeOfDay: &timeOfDay,
+			}
+			backupConfig.IsBackupsEnabled = true
+			backupConfig.RetentionPolicyType = backups_config.RetentionPolicyTypeTimePeriod
+			backupConfig.RetentionTimePeriod = period.PeriodWeek
+			backupConfig.Storage = storage
+			backupConfig.StorageID = &storage.ID
+
+			_, err = backups_config.GetBackupConfigService().SaveBackupConfig(backupConfig)
+			assert.NoError(t, err)
+
+			// add old backup (24h ago)
+			backupRepository.Save(&backups_core.Backup{
+				DatabaseID: database.ID,
+				StorageID:  storage.ID,
+				Status:     backups_core.BackupStatusCompleted,
+				CreatedAt:  time.Now().UTC().Add(-24 * time.Hour),
+			})
+
+			GetBackupsScheduler().runPendingBackups()
+
+			if tc.isBackupExpected {
+				WaitForBackupCompletion(t, database.ID, 1, 10*time.Second)
+
+				backups, err := backupRepository.FindByDatabaseID(database.ID)
+				assert.NoError(t, err)
+				assert.Len(t, backups, 2)
+			} else {
+				time.Sleep(100 * time.Millisecond)
+
+				backups, err := backupRepository.FindByDatabaseID(database.ID)
+				assert.NoError(t, err)
+				assert.Len(t, backups, 1)
+			}
+
+			time.Sleep(200 * time.Millisecond)
+		})
+	}
+}
+
 func Test_RunPendingBackups_WhenLastBackupWasYesterday_CreatesNewBackup(t *testing.T) {
 	cache_utils.ClearAllCache()
 	backuperNode := CreateTestBackuperNode()

backend/internal/features/backups/backups/backuping/testing.go

@@ -8,6 +8,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	"databasus-backend/internal/features/backups/backups/usecases"
 	backups_config "databasus-backend/internal/features/backups/config"
@@ -19,9 +22,6 @@ import (
 	workspaces_testing "databasus-backend/internal/features/workspaces/testing"
 	"databasus-backend/internal/util/encryption"
 	"databasus-backend/internal/util/logger"
-
-	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 )
 
 func CreateTestRouter() *gin.Engine {

backend/internal/features/backups/backups/common/dto.go

@@ -1,10 +1,11 @@
 package common
 
 import (
-	backups_config "databasus-backend/internal/features/backups/config"
 	"errors"
 
 	"github.com/google/uuid"
+
+	backups_config "databasus-backend/internal/features/backups/config"
 )
 
 type BackupMetadata struct {

backend/internal/features/backups/backups/common/interfaces.go

@@ -7,6 +7,10 @@ type CountingWriter struct {
 	BytesWritten int64
 }
 
+func NewCountingWriter(writer io.Writer) *CountingWriter {
+	return &CountingWriter{Writer: writer}
+}
+
 func (cw *CountingWriter) Write(p []byte) (n int, err error) {
 	n, err = cw.Writer.Write(p)
 	cw.BytesWritten += int64(n)
@@ -16,7 +20,3 @@ func (cw *CountingWriter) Write(p []byte) (n int, err error) {
 func (cw *CountingWriter) GetBytesWritten() int64 {
 	return cw.BytesWritten
 }
-
-func NewCountingWriter(writer io.Writer) *CountingWriter {
-	return &CountingWriter{Writer: writer}
-}

backend/internal/features/backups/backups/controllers/controller.go

@@ -1,12 +1,8 @@
-package backups
+package backups_controllers
 
 import (
 	"context"
-	backups_core "databasus-backend/internal/features/backups/backups/core"
-	backups_download "databasus-backend/internal/features/backups/backups/download"
-	"databasus-backend/internal/features/databases"
-	users_middleware "databasus-backend/internal/features/users/middleware"
-	files_utils "databasus-backend/internal/util/files"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -14,10 +10,18 @@ import (
 
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"
+
+	backups_core "databasus-backend/internal/features/backups/backups/core"
+	backups_download "databasus-backend/internal/features/backups/backups/download"
+	backups_dto "databasus-backend/internal/features/backups/backups/dto"
+	backups_services "databasus-backend/internal/features/backups/backups/services"
+	"databasus-backend/internal/features/databases"
+	users_middleware "databasus-backend/internal/features/users/middleware"
+	files_utils "databasus-backend/internal/util/files"
 )
 
 type BackupController struct {
-	backupService *BackupService
+	backupService *backups_services.BackupService
 }
 
 func (c *BackupController) RegisterRoutes(router *gin.RouterGroup) {
@@ -42,7 +46,7 @@ func (c *BackupController) RegisterPublicRoutes(router *gin.RouterGroup) {
 // @Param database_id query string true "Database ID"
 // @Param limit query int false "Number of items per page" default(10)
 // @Param offset query int false "Offset for pagination" default(0)
-// @Success 200 {object} GetBackupsResponse
+// @Success 200 {object} backups_dto.GetBackupsResponse
 // @Failure 400
 // @Failure 401
 // @Failure 500
@@ -54,7 +58,7 @@ func (c *BackupController) GetBackups(ctx *gin.Context) {
 		return
 	}
 
-	var request GetBackupsRequest
+	var request backups_dto.GetBackupsRequest
 	if err := ctx.ShouldBindQuery(&request); err != nil {
 		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
@@ -81,7 +85,7 @@ func (c *BackupController) GetBackups(ctx *gin.Context) {
 // @Tags backups
 // @Accept json
 // @Produce json
-// @Param request body MakeBackupRequest true "Backup creation data"
+// @Param request body backups_dto.MakeBackupRequest true "Backup creation data"
 // @Success 200 {object} map[string]string
 // @Failure 400
 // @Failure 401
@@ -94,7 +98,7 @@ func (c *BackupController) MakeBackup(ctx *gin.Context) {
 		return
 	}
 
-	var request MakeBackupRequest
+	var request backups_dto.MakeBackupRequest
 	if err := ctx.ShouldBindJSON(&request); err != nil {
 		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
 		return
@@ -195,7 +199,7 @@ func (c *BackupController) GenerateDownloadToken(ctx *gin.Context) {
 
 	response, err := c.backupService.GenerateDownloadToken(user, id)
 	if err != nil {
-		if err == backups_download.ErrDownloadAlreadyInProgress {
+		if errors.Is(err, backups_download.ErrDownloadAlreadyInProgress) {
 			ctx.JSON(
 				http.StatusConflict,
 				gin.H{
@@ -246,7 +250,7 @@ func (c *BackupController) GetFile(ctx *gin.Context) {
 
 	downloadToken, rateLimiter, err := c.backupService.ValidateDownloadToken(token)
 	if err != nil {
-		if err == backups_download.ErrDownloadAlreadyInProgress {
+		if errors.Is(err, backups_download.ErrDownloadAlreadyInProgress) {
 			ctx.JSON(
 				http.StatusConflict,
 				gin.H{
@@ -310,10 +314,6 @@ func (c *BackupController) GetFile(ctx *gin.Context) {
 	c.backupService.WriteAuditLogForDownload(downloadToken.UserID, backup, database)
 }
 
-type MakeBackupRequest struct {
-	DatabaseID uuid.UUID `json:"database_id" binding:"required"`
-}
-
 func (c *BackupController) generateBackupFilename(
 	backup *backups_core.Backup,
 	database *databases.Database,

backend/internal/features/backups/backups/controllers/controller_test.go

@@ -1,4 +1,4 @@
-package backups
+package backups_controllers
 
 import (
 	"context"
@@ -24,11 +24,14 @@ import (
 	backups_common "databasus-backend/internal/features/backups/backups/common"
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_download "databasus-backend/internal/features/backups/backups/download"
+	backups_dto "databasus-backend/internal/features/backups/backups/dto"
+	backups_services "databasus-backend/internal/features/backups/backups/services"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
 	"databasus-backend/internal/features/databases/databases/postgresql"
 	"databasus-backend/internal/features/storages"
 	local_storage "databasus-backend/internal/features/storages/models/local"
+	task_cancellation "databasus-backend/internal/features/tasks/cancellation"
 	users_dto "databasus-backend/internal/features/users/dto"
 	users_enums "databasus-backend/internal/features/users/enums"
 	users_services "databasus-backend/internal/features/users/services"
@@ -119,7 +122,7 @@ func Test_GetBackups_PermissionsEnforced(t *testing.T) {
 			)
 
 			if tt.expectSuccess {
-				var response GetBackupsResponse
+				var response backups_dto.GetBackupsResponse
 				err := json.Unmarshal(testResp.Body, &response)
 				assert.NoError(t, err)
 				assert.GreaterOrEqual(t, len(response.Backups), 1)
@@ -214,7 +217,7 @@ func Test_CreateBackup_PermissionsEnforced(t *testing.T) {
 				testUserToken = nonMember.Token
 			}
 
-			request := MakeBackupRequest{DatabaseID: database.ID}
+			request := backups_dto.MakeBackupRequest{DatabaseID: database.ID}
 			testResp := test_utils.MakePostRequest(
 				t,
 				router,
@@ -245,7 +248,7 @@ func Test_CreateBackup_AuditLogWritten(t *testing.T) {
 	database := createTestDatabase("Test Database", workspace.ID, owner.Token, router)
 	enableBackupForDatabase(database.ID)
 
-	request := MakeBackupRequest{DatabaseID: database.ID}
+	request := backups_dto.MakeBackupRequest{DatabaseID: database.ID}
 	test_utils.MakePostRequest(
 		t,
 		router,
@@ -373,7 +376,7 @@ func Test_DeleteBackup_PermissionsEnforced(t *testing.T) {
 				ownerUser, err := userService.GetUserFromToken(owner.Token)
 				assert.NoError(t, err)
 
-				response, err := GetBackupService().GetBackups(ownerUser, database.ID, 10, 0)
+				response, err := backups_services.GetBackupService().GetBackups(ownerUser, database.ID, 10, 0)
 				assert.NoError(t, err)
 				assert.Equal(t, 0, len(response.Backups))
 			}
@@ -999,7 +1002,7 @@ func Test_CancelBackup_InProgressBackup_SuccessfullyCancelled(t *testing.T) {
 	assert.NoError(t, err)
 
 	// Register a cancellable context for the backup
-	GetBackupService().taskCancelManager.RegisterTask(backup.ID, func() {})
+	task_cancellation.GetTaskCancelManager().RegisterTask(backup.ID, func() {})
 
 	resp := test_utils.MakePostRequest(
 		t,
@@ -1091,7 +1094,7 @@ func Test_ConcurrentDownloadPrevention(t *testing.T) {
 
 	time.Sleep(50 * time.Millisecond)
 
-	service := GetBackupService()
+	service := backups_services.GetBackupService()
 	if !service.IsDownloadInProgress(owner.UserID) {
 		t.Log("Warning: First download completed before we could test concurrency")
 		<-downloadComplete
@@ -1192,7 +1195,7 @@ func Test_GenerateDownloadToken_BlockedWhenDownloadInProgress(t *testing.T) {
 
 	time.Sleep(50 * time.Millisecond)
 
-	service := GetBackupService()
+	service := backups_services.GetBackupService()
 	if !service.IsDownloadInProgress(owner.UserID) {
 		t.Log("Warning: First download completed before we could test token generation blocking")
 		<-downloadComplete
@@ -1268,7 +1271,7 @@ func Test_MakeBackup_VerifyBackupAndMetadataFilesExistInStorage(t *testing.T) {
 	initialBackups, err := backupRepo.FindByDatabaseID(database.ID)
 	assert.NoError(t, err)
 
-	request := MakeBackupRequest{DatabaseID: database.ID}
+	request := backups_dto.MakeBackupRequest{DatabaseID: database.ID}
 	test_utils.MakePostRequest(
 		t,
 		router,
@@ -1502,7 +1505,7 @@ func createTestBackup(
 }
 
 func createExpiredDownloadToken(backupID, userID uuid.UUID) string {
-	tokenService := GetBackupService().downloadTokenService
+	tokenService := backups_download.GetDownloadTokenService()
 	token, err := tokenService.Generate(backupID, userID)
 	if err != nil {
 		panic(fmt.Sprintf("Failed to generate download token: %v", err))
@@ -1843,7 +1846,7 @@ func Test_DeleteBackup_RemovesBackupAndMetadataFilesFromDisk(t *testing.T) {
 	initialBackups, err := backupRepo.FindByDatabaseID(database.ID)
 	assert.NoError(t, err)
 
-	request := MakeBackupRequest{DatabaseID: database.ID}
+	request := backups_dto.MakeBackupRequest{DatabaseID: database.ID}
 	test_utils.MakePostRequest(
 		t,
 		router,

backend/internal/features/backups/backups/controllers/di.go

@@ -0,0 +1,23 @@
+package backups_controllers
+
+import (
+	backups_services "databasus-backend/internal/features/backups/backups/services"
+	"databasus-backend/internal/features/databases"
+)
+
+var backupController = &BackupController{
+	backups_services.GetBackupService(),
+}
+
+func GetBackupController() *BackupController {
+	return backupController
+}
+
+var postgresWalBackupController = &PostgreWalBackupController{
+	databases.GetDatabaseService(),
+	backups_services.GetWalService(),
+}
+
+func GetPostgresWalBackupController() *PostgreWalBackupController {
+	return postgresWalBackupController
+}

backend/internal/features/backups/backups/controllers/postgres_wal_controller.go

@@ -0,0 +1,339 @@
+package backups_controllers
+
+import (
+	"io"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+
+	backups_dto "databasus-backend/internal/features/backups/backups/dto"
+	backups_services "databasus-backend/internal/features/backups/backups/services"
+	"databasus-backend/internal/features/databases"
+)
+
+// PostgreWalBackupController handles WAL backup endpoints used by the databasus-cli agent.
+// Authentication is via a plain agent token in the Authorization header (no Bearer prefix).
+type PostgreWalBackupController struct {
+	databaseService *databases.DatabaseService
+	walService      *backups_services.PostgreWalBackupService
+}
+
+func (c *PostgreWalBackupController) RegisterRoutes(router *gin.RouterGroup) {
+	walRoutes := router.Group("/backups/postgres/wal")
+
+	walRoutes.GET("/next-full-backup-time", c.GetNextFullBackupTime)
+	walRoutes.GET("/is-wal-chain-valid-since-last-full-backup", c.IsWalChainValidSinceLastBackup)
+	walRoutes.POST("/error", c.ReportError)
+	walRoutes.POST("/upload/wal", c.UploadWalSegment)
+	walRoutes.POST("/upload/full-start", c.StartFullBackupUpload)
+	walRoutes.POST("/upload/full-complete", c.CompleteFullBackupUpload)
+	walRoutes.GET("/restore/plan", c.GetRestorePlan)
+	walRoutes.GET("/restore/download", c.DownloadBackupFile)
+}
+
+// GetNextFullBackupTime
+// @Summary Get next full backup time
+// @Description Returns the next scheduled full basebackup time for the authenticated database
+// @Tags backups-wal
+// @Produce json
+// @Security AgentToken
+// @Success 200 {object} backups_dto.GetNextFullBackupTimeResponse
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/next-full-backup-time [get]
+func (c *PostgreWalBackupController) GetNextFullBackupTime(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	response, err := c.walService.GetNextFullBackupTime(database)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, response)
+}
+
+// ReportError
+// @Summary Report agent error
+// @Description Records a fatal error from the agent against the database record and marks it as errored
+// @Tags backups-wal
+// @Accept json
+// @Security AgentToken
+// @Param request body backups_dto.ReportErrorRequest true "Error details"
+// @Success 200
+// @Failure 400 {object} map[string]string
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/error [post]
+func (c *PostgreWalBackupController) ReportError(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	var request backups_dto.ReportErrorRequest
+	if err := ctx.ShouldBindJSON(&request); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	if err := c.walService.ReportError(database, request.Error); err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	ctx.Status(http.StatusOK)
+}
+
+// IsWalChainValidSinceLastBackup
+// @Summary Check WAL chain validity since last full backup
+// @Description Checks whether the WAL chain is continuous since the last completed full backup.
+// Returns isValid=true if the chain is intact, or isValid=false with error details if not.
+// @Tags backups-wal
+// @Produce json
+// @Security AgentToken
+// @Success 200 {object} backups_dto.IsWalChainValidResponse
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/is-wal-chain-valid-since-last-full-backup [get]
+func (c *PostgreWalBackupController) IsWalChainValidSinceLastBackup(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	response, err := c.walService.IsWalChainValid(database)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, response)
+}
+
+// UploadWalSegment
+// @Summary Stream upload a WAL segment
+// @Description Accepts a zstd-compressed WAL segment binary stream and stores it in the database's configured storage.
+// WAL segments are accepted unconditionally.
+// @Tags backups-wal
+// @Accept application/octet-stream
+// @Security AgentToken
+// @Param X-Wal-Segment-Name header string true "24-hex WAL segment identifier (e.g. 0000000100000001000000AB)"
+// @Success 204
+// @Failure 400 {object} map[string]string
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/upload/wal [post]
+func (c *PostgreWalBackupController) UploadWalSegment(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	walSegmentName := ctx.GetHeader("X-Wal-Segment-Name")
+	if walSegmentName == "" {
+		ctx.JSON(
+			http.StatusBadRequest,
+			gin.H{"error": "X-Wal-Segment-Name is required for wal uploads"},
+		)
+		return
+	}
+
+	uploadErr := c.walService.UploadWalSegment(
+		ctx.Request.Context(),
+		database,
+		walSegmentName,
+		ctx.Request.Body,
+	)
+
+	if uploadErr != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": uploadErr.Error()})
+		return
+	}
+
+	ctx.Status(http.StatusNoContent)
+}
+
+// StartFullBackupUpload
+// @Summary Stream upload a full basebackup (Phase 1)
+// @Description Accepts a zstd-compressed basebackup binary stream and stores it in the database's configured storage.
+// Returns a backupId that must be completed via /upload/full-complete with WAL segment names.
+// @Tags backups-wal
+// @Accept application/octet-stream
+// @Produce json
+// @Security AgentToken
+// @Success 200 {object} backups_dto.UploadBasebackupResponse
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/upload/full-start [post]
+func (c *PostgreWalBackupController) StartFullBackupUpload(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	backupID, uploadErr := c.walService.UploadBasebackup(
+		ctx.Request.Context(),
+		database,
+		ctx.Request.Body,
+	)
+
+	if uploadErr != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": uploadErr.Error()})
+		return
+	}
+
+	ctx.JSON(http.StatusOK, backups_dto.UploadBasebackupResponse{
+		BackupID: backupID,
+	})
+}
+
+// CompleteFullBackupUpload
+// @Summary Complete a previously uploaded basebackup (Phase 2)
+// @Description Sets WAL segment names and marks the basebackup as completed, or marks it as failed if an error is provided.
+// @Tags backups-wal
+// @Accept json
+// @Security AgentToken
+// @Param request body backups_dto.FinalizeBasebackupRequest true "Completion details"
+// @Success 200
+// @Failure 400 {object} map[string]string
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/upload/full-complete [post]
+func (c *PostgreWalBackupController) CompleteFullBackupUpload(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	var request backups_dto.FinalizeBasebackupRequest
+	if err := ctx.ShouldBindJSON(&request); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	if request.Error == nil && (request.StartSegment == "" || request.StopSegment == "") {
+		ctx.JSON(
+			http.StatusBadRequest,
+			gin.H{"error": "startSegment and stopSegment are required when no error is provided"},
+		)
+		return
+	}
+
+	if err := c.walService.FinalizeBasebackup(
+		database,
+		request.BackupID,
+		request.StartSegment,
+		request.StopSegment,
+		request.Error,
+	); err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	ctx.Status(http.StatusOK)
+}
+
+// GetRestorePlan
+// @Summary Get restore plan
+// @Description Resolves the full backup and all required WAL segments needed for recovery. Validates the WAL chain is continuous.
+// @Tags backups-wal
+// @Produce json
+// @Security AgentToken
+// @Param backupId query string false "UUID of a specific full backup to restore from; defaults to the most recent"
+// @Success 200 {object} backups_dto.GetRestorePlanResponse
+// @Failure 400 {object} map[string]string "Broken WAL chain or no backups available"
+// @Failure 401 {object} map[string]string
+// @Failure 500 {object} map[string]string
+// @Router /backups/postgres/wal/restore/plan [get]
+func (c *PostgreWalBackupController) GetRestorePlan(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	var backupID *uuid.UUID
+	if raw := ctx.Query("backupId"); raw != "" {
+		parsed, parseErr := uuid.Parse(raw)
+		if parseErr != nil {
+			ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid backupId format"})
+			return
+		}
+
+		backupID = &parsed
+	}
+
+	response, planErr, err := c.walService.GetRestorePlan(database, backupID)
+	if err != nil {
+		ctx.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+
+	if planErr != nil {
+		ctx.JSON(http.StatusBadRequest, planErr)
+		return
+	}
+
+	ctx.JSON(http.StatusOK, response)
+}
+
+// DownloadBackupFile
+// @Summary Download a backup or WAL segment file for restore
+// @Description Retrieves the backup file by ID (validated against the authenticated database), decrypts it server-side if encrypted, and streams the zstd-compressed result to the agent
+// @Tags backups-wal
+// @Produce application/octet-stream
+// @Security AgentToken
+// @Param backupId query string true "Backup ID from the restore plan response"
+// @Success 200 {file} file
+// @Failure 400 {object} map[string]string
+// @Failure 401 {object} map[string]string
+// @Router /backups/postgres/wal/restore/download [get]
+func (c *PostgreWalBackupController) DownloadBackupFile(ctx *gin.Context) {
+	database, err := c.getDatabase(ctx)
+	if err != nil {
+		ctx.JSON(http.StatusUnauthorized, gin.H{"error": "invalid agent token"})
+		return
+	}
+
+	backupIDRaw := ctx.Query("backupId")
+	if backupIDRaw == "" {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "backupId is required"})
+		return
+	}
+
+	backupID, err := uuid.Parse(backupIDRaw)
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": "invalid backupId format"})
+		return
+	}
+
+	reader, err := c.walService.DownloadBackupFile(database, backupID)
+	if err != nil {
+		ctx.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	defer func() { _ = reader.Close() }()
+
+	ctx.Header("Content-Type", "application/octet-stream")
+	ctx.Status(http.StatusOK)
+
+	_, _ = io.Copy(ctx.Writer, reader)
+}
+
+func (c *PostgreWalBackupController) getDatabase(
+	ctx *gin.Context,
+) (*databases.Database, error) {
+	token := ctx.GetHeader("Authorization")
+	return c.databaseService.GetDatabaseByAgentToken(token)
+}

backend/internal/features/backups/backups/controllers/testing.go

@@ -1,17 +1,17 @@
-package backups
+package backups_controllers
 
 import (
 	"testing"
 	"time"
 
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+
 	backups_core "databasus-backend/internal/features/backups/backups/core"
 	backups_config "databasus-backend/internal/features/backups/config"
 	"databasus-backend/internal/features/databases"
 	workspaces_controllers "databasus-backend/internal/features/workspaces/controllers"
 	workspaces_testing "databasus-backend/internal/features/workspaces/testing"
-
-	"github.com/gin-gonic/gin"
-	"github.com/google/uuid"
 )
 
 func CreateTestRouter() *gin.Engine {
@@ -41,7 +41,7 @@ func WaitForBackupCompletion(
 	deadline := time.Now().UTC().Add(timeout)
 
 	for time.Now().UTC().Before(deadline) {
-		backups, err := backupRepository.FindByDatabaseID(databaseID)
+		backups, err := backups_core.GetBackupRepository().FindByDatabaseID(databaseID)
 		if err != nil {
 			t.Logf("WaitForBackupCompletion: error finding backups: %v", err)
 			time.Sleep(50 * time.Millisecond)

backend/internal/features/backups/backups/core/di.go

@@ -0,0 +1,7 @@
+package backups_core
+
+var backupRepository = &BackupRepository{}
+
+func GetBackupRepository() *BackupRepository {
+	return backupRepository
+}

backend/internal/features/backups/backups/core/enums.go

@@ -8,3 +8,10 @@ const (
 	BackupStatusFailed     BackupStatus = "FAILED"
 	BackupStatusCanceled   BackupStatus = "CANCELED"
 )
+
+type PgWalUploadType string
+
+const (
+	PgWalUploadTypeBasebackup PgWalUploadType = "basebackup"
+	PgWalUploadTypeWal        PgWalUploadType = "wal"
+)

backend/internal/features/backups/backups/core/model.go

@@ -1,10 +1,20 @@
 package backups_core
 
 import (
-	backups_config "databasus-backend/internal/features/backups/config"
+	"fmt"
 	"time"
 
 	"github.com/google/uuid"
+
+	backups_config "databasus-backend/internal/features/backups/config"
+	files_utils "databasus-backend/internal/util/files"
+)
+
+type PgWalBackupType string
+
+const (
+	PgWalBackupTypeFullBackup PgWalBackupType = "PG_FULL_BACKUP"
+	PgWalBackupTypeWalSegment PgWalBackupType = "PG_WAL_SEGMENT"
 )
 
 type Backup struct {
@@ -26,5 +36,24 @@ type Backup struct {
 	EncryptionIV   *string                         `json:"-"          gorm:"column:encryption_iv"`
 	Encryption     backups_config.BackupEncryption `json:"encryption" gorm:"column:encryption;type:text;not null;default:'NONE'"`
 
-	CreatedAt time.Time `json:"createdAt" gorm:"column:created_at"`
+	// Postgres WAL backup specific fields
+	PgWalBackupType                 *PgWalBackupType `json:"pgWalBackupType"                 gorm:"column:pg_wal_backup_type;type:text"`
+	PgFullBackupWalStartSegmentName *string          `json:"pgFullBackupWalStartSegmentName" gorm:"column:pg_wal_start_segment;type:text"`
+	PgFullBackupWalStopSegmentName  *string          `json:"pgFullBackupWalStopSegmentName"  gorm:"column:pg_wal_stop_segment;type:text"`
+	PgVersion                       *string          `json:"pgVersion"                       gorm:"column:pg_version;type:text"`
+	PgWalSegmentName                *string          `json:"pgWalSegmentName"                gorm:"column:pg_wal_segment_name;type:text"`
+
+	UploadCompletedAt *time.Time `json:"uploadCompletedAt" gorm:"column:upload_completed_at"`
+	CreatedAt         time.Time  `json:"createdAt"         gorm:"column:created_at"`
+}
+
+func (b *Backup) GenerateFilename(dbName string) {
+	timestamp := time.Now().UTC()
+
+	b.FileName = fmt.Sprintf(
+		"%s-%s-%s",
+		files_utils.SanitizeFilename(dbName),
+		timestamp.Format("20060102-150405"),
+		b.ID.String(),
+	)
 }

backend/internal/features/backups/backups/core/repository.go

@@ -1,13 +1,13 @@
 package backups_core
 
 import (
-	"databasus-backend/internal/storage"
 	"errors"
-
 	"time"
 
 	"github.com/google/uuid"
 	"gorm.io/gorm"
+
+	"databasus-backend/internal/storage"
 )
 
 type BackupRepository struct{}
@@ -88,7 +88,7 @@ func (r *BackupRepository) FindLastByDatabaseID(databaseID uuid.UUID) (*Backup,
 		Where("database_id = ?", databaseID).
 		Order("created_at DESC").
 		First(&backup).Error; err != nil {
-		if err == gorm.ErrRecordNotFound {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return nil, nil
 		}
 
@@ -245,3 +245,180 @@ func (r *BackupRepository) FindOldestByDatabaseExcludingInProgress(
 
 	return backups, nil
 }
+
+func (r *BackupRepository) FindCompletedFullWalBackupByID(
+	databaseID uuid.UUID,
+	backupID uuid.UUID,
+) (*Backup, error) {
+	var backup Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND id = ? AND pg_wal_backup_type = ? AND status = ?",
+			databaseID,
+			backupID,
+			PgWalBackupTypeFullBackup,
+			BackupStatusCompleted,
+		).
+		First(&backup).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return &backup, nil
+}
+
+func (r *BackupRepository) FindCompletedWalSegmentsAfter(
+	databaseID uuid.UUID,
+	afterSegmentName string,
+) ([]*Backup, error) {
+	var backups []*Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND pg_wal_backup_type = ? AND pg_wal_segment_name >= ? AND status = ?",
+			databaseID,
+			PgWalBackupTypeWalSegment,
+			afterSegmentName,
+			BackupStatusCompleted,
+		).
+		Order("pg_wal_segment_name ASC").
+		Find(&backups).Error
+	if err != nil {
+		return nil, err
+	}
+
+	return backups, nil
+}
+
+func (r *BackupRepository) FindLastCompletedFullWalBackupByDatabaseID(
+	databaseID uuid.UUID,
+) (*Backup, error) {
+	var backup Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND pg_wal_backup_type = ? AND status = ?",
+			databaseID,
+			PgWalBackupTypeFullBackup,
+			BackupStatusCompleted,
+		).
+		Order("created_at DESC").
+		First(&backup).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return &backup, nil
+}
+
+func (r *BackupRepository) FindWalSegmentByName(
+	databaseID uuid.UUID,
+	segmentName string,
+) (*Backup, error) {
+	var backup Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND pg_wal_backup_type = ? AND pg_wal_segment_name = ?",
+			databaseID,
+			PgWalBackupTypeWalSegment,
+			segmentName,
+		).
+		First(&backup).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return &backup, nil
+}
+
+func (r *BackupRepository) FindLatestCompletedFullWalBackupBefore(
+	databaseID uuid.UUID,
+	before time.Time,
+) (*Backup, error) {
+	var backup Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND pg_wal_backup_type = ? AND status = ? AND created_at <= ?",
+			databaseID,
+			PgWalBackupTypeFullBackup,
+			BackupStatusCompleted,
+			before,
+		).
+		Order("created_at DESC").
+		First(&backup).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return &backup, nil
+}
+
+func (r *BackupRepository) FindStaleUploadedBasebackups(olderThan time.Time) ([]*Backup, error) {
+	var backups []*Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"status = ? AND upload_completed_at IS NOT NULL AND upload_completed_at < ?",
+			BackupStatusInProgress,
+			olderThan,
+		).
+		Find(&backups).Error
+	if err != nil {
+		return nil, err
+	}
+
+	return backups, nil
+}
+
+func (r *BackupRepository) FindLastWalSegmentAfter(
+	databaseID uuid.UUID,
+	afterSegmentName string,
+) (*Backup, error) {
+	var backup Backup
+
+	err := storage.
+		GetDb().
+		Where(
+			"database_id = ? AND pg_wal_backup_type = ? AND pg_wal_segment_name > ? AND status = ?",
+			databaseID,
+			PgWalBackupTypeWalSegment,
+			afterSegmentName,
+			BackupStatusCompleted,
+		).
+		Order("pg_wal_segment_name DESC").
+		First(&backup).Error
+	if err != nil {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
+			return nil, nil
+		}
+
+		return nil, err
+	}
+
+	return &backup, nil
+}

backend/internal/features/backups/backups/download/di.go

@@ -13,9 +13,11 @@ var downloadTokenRepository = &DownloadTokenRepository{}
 
 var downloadTracker = NewDownloadTracker(cache_utils.GetValkeyClient())
 
-var bandwidthManager *BandwidthManager
-var downloadTokenService *DownloadTokenService
-var downloadTokenBackgroundService *DownloadTokenBackgroundService
+var (
+	bandwidthManager               *BandwidthManager
+	downloadTokenService           *DownloadTokenService
+	downloadTokenBackgroundService *DownloadTokenBackgroundService
+)
 
 func init() {
 	env := config.GetEnv()

backend/internal/features/backups/backups/download/rate_limiter.go

@@ -66,9 +66,7 @@ func (rl *RateLimiter) Wait(bytes int64) {
 		tokensNeeded := float64(bytes) - rl.availableTokens
 		waitTime := time.Duration(tokensNeeded/float64(rl.bytesPerSecond)*1000) * time.Millisecond
 
-		if waitTime < time.Millisecond {
-			waitTime = time.Millisecond
-		}
+		waitTime = max(waitTime, time.Millisecond)
 
 		rl.mu.Unlock()
 		time.Sleep(waitTime)

backend/internal/features/backups/backups/download/repository.go

@@ -2,12 +2,14 @@ package backups_download
 
 import (
 	"crypto/rand"
-	"databasus-backend/internal/storage"
 	"encoding/base64"
+	"errors"
 	"time"
 
 	"github.com/google/uuid"
 	"gorm.io/gorm"
+
+	"databasus-backend/internal/storage"
 )
 
 type DownloadTokenRepository struct{}
@@ -28,9 +30,8 @@ func (r *DownloadTokenRepository) FindByToken(token string) (*DownloadToken, err
 	err := storage.GetDb().
 		Where("token = ?", token).
 		First(&downloadToken).Error
-
 	if err != nil {
-		if err == gorm.ErrRecordNotFound {
+		if errors.Is(err, gorm.ErrRecordNotFound) {
 			return nil, nil
 		}
 		return nil, err

backend/internal/features/backups/backups/download/tracking.go

@@ -1,12 +1,13 @@
 package backups_download
 
 import (
-	cache_utils "databasus-backend/internal/util/cache"
 	"errors"
 	"time"
 
 	"github.com/google/uuid"
 	"github.com/valkey-io/valkey-go"
+
+	cache_utils "databasus-backend/internal/util/cache"
 )
 
 const (
@@ -16,9 +17,7 @@ const (
 	downloadHeartbeatDelay = 3 * time.Second
 )
 
-var (
-	ErrDownloadAlreadyInProgress = errors.New("download already in progress for this user")
-)
+var ErrDownloadAlreadyInProgress = errors.New("download already in progress for this user")
 
 type DownloadTracker struct {
 	cache *cache_utils.CacheUtil[string]

backend/internal/features/backups/backups/dto.go

@@ -1,29 +0,0 @@
-package backups
-
-import (
-	backups_core "databasus-backend/internal/features/backups/backups/core"
-	"databasus-backend/internal/features/backups/backups/encryption"
-	"io"
-)
-
-type GetBackupsRequest struct {
-	DatabaseID string `form:"database_id" binding:"required"`
-	Limit      int    `form:"limit"`
-	Offset     int    `form:"offset"`
-}
-
-type GetBackupsResponse struct {
-	Backups []*backups_core.Backup `json:"backups"`
-	Total   int64                  `json:"total"`
-	Limit   int                    `json:"limit"`
-	Offset  int                    `json:"offset"`
-}
-
-type DecryptionReaderCloser struct {
-	*encryption.DecryptionReader
-	BaseReader io.ReadCloser
-}
-
-func (r *DecryptionReaderCloser) Close() error {
-	return r.BaseReader.Close()
-}