---
title: "Update a system topic."
method: PATCH
path: "/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.EventGrid/systemTopics/{systemTopicName}"
tags: ["SystemTopics"]
---

# Update a system topic.

`PATCH /subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.EventGrid/systemTopics/{systemTopicName}`

Asynchronously updates a system topic with the specified parameters.

## Path parameters

- `systemTopicName` string, required

## Parameters

- `../../../../../../common-types/resource-management/v3/types.json#/components/parameters/SubscriptionIdParameter` — unresolved $ref
- `../../../../../../common-types/resource-management/v6/types.json#/components/parameters/ResourceGroupNameParameter` — unresolved $ref
- `../../../../../../common-types/resource-management/v6/types.json#/components/parameters/ApiVersionParameter` — unresolved $ref

## Request body

- SystemTopicUpdateParameters — Properties of the System Topic update.
  - `tags` object — Tags of the system topic.
  - `identity` IdentityInfo — The identity information for the resource.
    - `type` 'None' | 'SystemAssigned' | 'UserAssigned' | 'SystemAssigned, UserAssigned' — The type of managed identity used. The type 'SystemAssigned, UserAssigned' includes both an implicitly created identity and a set of user-assigned identities. The type 'None' will remove any identity.
    - `principalId` string — The principal ID of resource identity.
    - `tenantId` string — The tenant ID of resource.
    - `userAssignedIdentities` object — The list of user identities associated with the resource. The user identity dictionary key references will be ARM resource ids in the form: '/subscriptions/{subscriptionId}/resourceGroups/{resourceGroupName}/providers/Microsoft.ManagedIdentity/userAssignedIdentities/{identityName}'. This property is currently not used and reserved for future usage.

## Response `200`

System Topic update request accepted.

- SystemTopic — Definition of a Resource.
  - `id` string — Fully qualified identifier of the resource.
  - `name` string — Name of the resource.
  - `type` string — Type of the resource.

## Other responses

- `201` — System Topic update request accepted.
- `default` — *** Error Responses: *** * 400 Bad Request. * 500 Internal Server Error.

## Changes

- **2026-07-13** (2017-06-15-preview) `285f714f3339` — 2 warning
  - the optional response header `Location` removed for the status `201`
  - the optional response header `Retry-After` removed for the status `201`
- **2026-07-13** (2017-06-15-preview) `6114a105ef69` — 3 warning
  - deleted the `path` request parameter `resourceGroupName`
  - deleted the `path` request parameter `subscriptionId`
  - deleted the `query` request parameter `api-version`
- **2026-07-13** (2017-06-15-preview) `04232a2819a1` — 1 info
  - endpoint added
- **2026-07-13** (2017-06-15-preview) `622990cd7696` — 1 breaking
  - api path removed without deprecation
- **2026-07-13** (2017-06-15-preview) `93474e2eb953` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/azure/apis/eventgrid-microsoft-eventgrid-eventgrid/changes/subscriptions/:subscriptionId/resourceGroups/:resourceGroupName/providers/Microsoft.EventGrid/systemTopics/:systemTopicName/patch.md)

---

[API](https://skmtc.dev/azure/apis/eventgrid-microsoft-eventgrid-eventgrid.md) · [All operations](https://skmtc.dev/azure/apis/eventgrid-microsoft-eventgrid-eventgrid/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/azure/eventgrid-microsoft-eventgrid-eventgrid/revisions/285f714f3339/schema)