JSON custom field with default value {} is set as null #1359

New Issue

MrUnknownDE · 2026-04-06T00:00:15+02:00

MrUnknownDE commented

2026-04-06 00:00:15 +02:00

Originally created by @lucagubler on 9/2/2025

Deployment Type

Self-hosted

NetBox Version

v4.3.7

Python Version

3.12

Steps to Reproduce

Create a new custom field test_config of type JSON with default value {} (empty dict) and assign it to virtual machines.
Create a new virtual machine but leave the test_config custom field blank.
Virtual machine is created, but test_config is set to null instead of empty dict {}

Expected Behavior

The default value should be set to an empty dict {} instead of null

Observed Behavior

The default value was set to null

*Originally created by @lucagubler on 9/2/2025* ### Deployment Type Self-hosted ### NetBox Version v4.3.7 ### Python Version 3.12 ### Steps to Reproduce 1. Create a new custom field `test_config` of type `JSON` with default value `{}` (empty dict) and assign it to virtual machines. 2. Create a new virtual machine but leave the `test_config` custom field blank. 3. Virtual machine is created, but `test_config` is set to `null` instead of empty dict `{}` ### Expected Behavior The default value should be set to an empty dict `{}` instead of `null` ### Observed Behavior The default value was set to `null`

MrUnknownDE closed this issue

2026-04-06 00:00:15 +02:00

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21455-sql-indexes-audit

21357-register-model-actions

feature

20924-plugin-ui-components

21766-improve-test-coverage-for-sortable-table-columns

21157-export-template-public-models

21025-pre-render-config-contexts

21364-swagger

feature-ip-prefix-link

20911-dropdown-3

fix_module_substitution

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20044-elevation-stuck-lightmode

7604-filter-modifiers-v3

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19724-graphql

14884-script

19720-macaddress-interface-generic-relation

fix-19669-api-image-download

7604-filter-modifiers

19275-fixes-interface-bulk-edit

fix-17794-get_field_value_return_list

11507-show-aggregate-and-rir-on-api

9583-add_column_specific_search_field_to_tables

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Reference: github/netbox#1359

JSON custom field with default value {} is set as null #1359