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.
[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],["最后更新时间 (UTC)：2025-08-17。"],[],[],null,["# Delete topic SMTs\n\nThis document explains how to delete Single Message Transforms (SMTs) from\nan existing Pub/Sub topic.\n\nTo delete topic SMTs, you can use the Google Cloud console, the Google Cloud CLI,\nthe client library, or the Pub/Sub API.\n\nRequired roles and permissions\n------------------------------\n\n\nTo get the permissions that\nyou need to delete topic SMTs,\n\nask your administrator to grant you the\n\n\n[Pub/Sub Editor](/iam/docs/roles-permissions/pubsub#pubsub.editor) (`roles/pubsub.editor`)\nIAM role on your project.\n\n\nFor more information about granting roles, see [Manage access to projects, folders, and organizations](/iam/docs/granting-changing-revoking-access).\n\n\nThis predefined role contains\n\nthe permissions required to delete topic SMTs. To see the exact permissions that are\nrequired, expand the **Required permissions** section:\n\n\n#### Required permissions\n\nThe following permissions are required to delete topic SMTs:\n\n- Grant the update a topic permission on the topic: ` ``projects.topics.patch`\n- Grant the view a topic permission on the project. This permission is only required if you are using the Google Cloud console: ` ``pubsub.topics.view`\n\n\nYou might also be able to get\nthese permissions\nwith [custom roles](/iam/docs/creating-custom-roles) or\nother [predefined roles](/iam/docs/roles-overview#predefined).\n\nYou can configure access control at the project level and at the individual\nresource level.\n\nDelete topic SMTs\n-----------------\n\nTo delete topic SMTs, follow these steps: \n\n### Console\n\n1. In the Google Cloud console, go to the Pub/Sub **Topics** page.\n\n [Go to Topics](https://console.cloud.google.com/cloudpubsub/topic)\n2. Click the topic for which you want to delete an SMT.\n\n3. In the topic details page, click **Edit**.\n\n The **Transforms** tab lists all the SMTs that are attached to the topic.\n4. Click the delete button for the SMT you would like to delete.\n\n5. Click **Update**.\n\n### gcloud\n\n1. In the Google Cloud console, activate Cloud Shell.\n\n [Activate Cloud Shell](https://console.cloud.google.com/?cloudshell=true)\n\n\n At the bottom of the Google Cloud console, a\n [Cloud Shell](/shell/docs/how-cloud-shell-works)\n session starts and displays a command-line prompt. Cloud Shell is a shell environment\n with the Google Cloud CLI\n already installed and with values already set for\n your current project. It can take a few seconds for the session to initialize.\n2. This command deletes all SMTs associated with the specified topic.\n\n Run the\n [`gcloud pubsub topics update`](/sdk/gcloud/reference/pubsub/topics/update) command with the `--clear-message-transforms` flag:\n\n \u003cbr /\u003e\n\n ```bash\n gcloud pubsub topics update TOPIC_ID --clear-message-transforms\n ```\n\n Replace the following:\n - \u003cvar translate=\"no\"\u003eTOPIC_ID\u003c/var\u003e: The ID or name of the topic you want to update.\n\n To instead remove a single SMT, refer to [Update topic SMTs](/pubsub/docs/smts/update-topic-smt) and create a new `message-transforms-file` that excludes the SMT you wish to delete.\n\n \u003cbr /\u003e\n\n\u003cbr /\u003e\n\nWhat's next\n-----------\n\n- [Create a topic with SMTs](/pubsub/docs/smts/create-topic-smt)\n\n- [Update topic SMTs](/pubsub/docs/smts/update-topic-smt)"]]
