---
title: "Changes to Retrieve a custom action definition"
method: GET
path: "/automation/actions/2026-09/{appId}/{definitionId}"
---

# Changes to Retrieve a custom action definition

`GET /automation/actions/2026-09/{appId}/{definitionId}`

> Every recorded change to this operation, newest first.

## Timeline

Changed in 4 of 11 revisions.

- **2026-10-10** (2026-09) `5b95e5eb45d5`: 2 warning
- **2026-09-28** (2026-09) `5b95e5eb45d5`: 2 warning
- **2026-09-11** (2026-09) `a516396e0463`: 2 info
- **2026-09-03** (2026-09) `c6eb28324e2a`: 2 breaking, 3 warning, 4 info

## Changes

- **2026-10-10** (2026-09) `5b95e5eb45d5`: 2 warning
  - added the new `OBJECT_TYPE` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #4: STRING]/format` response property for the response status `200`
  - added the new `OBJECT_TYPE` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #6: ARRAY]/items/oneOf[subschema #4: STRING]/format` response property for the response status `200`
- **2026-09-28** (2026-09) `5b95e5eb45d5`: 2 warning
  - added the new `OBJECT_TYPE` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #4: STRING]/format` response property for the response status `200`
  - added the new `OBJECT_TYPE` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #6: ARRAY]/items/oneOf[subschema #4: STRING]/format` response property for the response status `200`
- **2026-09-11** (2026-09) `a516396e0463`: 2 info
  - the endpoint scheme security `developer_hapikey` was added to the API
  - the endpoint scheme security `oauth2` was removed from the API
- **2026-09-03** (2026-09) `c6eb28324e2a`: 2 breaking, 3 warning, 4 info
  - added `#/components/schemas/UnknownFieldSchema` to the `outputFields/items/typeDefinition/schema` response property `oneOf` list for the response status `200`
  - added `#/components/schemas/UnknownFieldSchema` to the `outputFields/items/typeDefinition/schema/oneOf[subschema #6: ARRAY]/items` response property `oneOf` list for the response status `200`
  - added the new `MONTH_AND_DAY` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #4: STRING]/format` response property for the response status `200`
  - added the new `MONTH_AND_DAY` enum value to the `outputFields/items/typeDefinition/schema/oneOf[subschema #6: ARRAY]/items/oneOf[subschema #4: STRING]/format` response property for the response status `200`
  - added the new `time_range` enum value to the `outputFields/items/typeDefinition/type` response property for the response status `200`
  - the endpoint scheme security `oauth2` was added to the API
  - the endpoint scheme security `developer_hapikey` was removed from the API
  - api tag `Definitions` added
  - api tag `Basic` removed

---

[Operation](https://skmtc.dev/hubspot/apis/automation-actions-v4/docs/automation/actions/2026-09/:appId/:definitionId/get.md) - [API](https://skmtc.dev/hubspot/apis/automation-actions-v4.md) - [Page](https://skmtc.dev/hubspot/apis/automation-actions-v4/changes/automation/actions/2026-09/:appId/:definitionId/get)