Delete topic SMTs

This document explains how to delete Single Message Transforms (SMTs) from an existing Pub/Sub topic, by updating the topic,

To delete topic SMTs, you can use the Google Cloud console, the Google Cloud CLI, the client library, or the Pub/Sub API.

Required roles and permissions

To get the permission that you need to delete topic SMTs, ask your administrator to grant you the Pub/Sub Editor (roles/pubsub.editor) IAM role on your project. For more information about granting roles, see Manage access to projects, folders, and organizations.

This predefined role contains the pubsub.topics.update permission, which is required to delete topic SMTs.

You might also be able to get this permission with custom roles or other predefined roles.

You can configure access control at the project level and at the individual resource level.

To delete topic SMTs, follow these steps:

In the Google Cloud console, go to the Pub/Sub Topics page.

Go to Topics
Click the topic for which you want to delete an SMT.
In the topic details page, click Edit.

The Transforms tab lists all the SMTs that are attached to the topic.
Click the delete button for the SMT you would like to delete.
Click Update.

In the Google Cloud console, activate Cloud Shell.

Activate Cloud Shell

At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.
This command deletes all SMTs associated with the specified topic.

Run the gcloud pubsub topics update command with the --clear-message-transforms flag:
```
gcloud pubsub topics update TOPIC_ID --clear-message-transforms
```
Replace the following:
- TOPIC_ID: The ID or name of the topic you want to update.
To instead remove a single SMT, refer to Update topic SMTs and create a new message-transforms-file that excludes the SMT you wish to delete.