Functions

Create a Sync Tag Invalidate Function

Build and deploy a new Sync Tag Invalidate function to Sanity's infrastructure.

Sync Tag Invalidate Functions allow you to run small, single-purpose code whenever your Live Content in Sanity changes. This guide explains how to set up your project, initialize your first blueprint, add a function, and deploy it to Sanity's infrastructure.

Experimental feature

Only one sync-tag-invalidate function per dataset allowed

Prerequisites:

  • The latest version of sanity CLI (sanity@latest) is recommended to interact with Blueprints and Functions as shown in this guide. You can always run the latest CLI commands with npx sanity@latest.
  • Node.js v24.x. We highly suggest working on this version as it is the same version that your functions will run when deployed to Sanity.
  • An existing project and a role with Deploy Studio permissions (the deployStudio grant).

Avoid recursive loops

If you’ve previously created a project, you can skip ahead to Add a Sync Tag Invalidate function.

Set up your project

To create a function, you need to initialize a blueprint. Blueprints are templates that describe Sanity resources. In this case, a blueprint describes how your function will respond to updates in your Sanity project. We recommend keeping functions and blueprints a level above your Studio directory.

For example, if you have a Marketing Website that uses Sanity, you may have a structure like this:

marketing-site/
├─ studio/
├─ next-app/

If you initialize the blueprint in the marketing-site directory, functions and future resources will live alongside the studio and next-app directory.

Functions and Blueprints match your workflow

Create a blueprint

Initialize your first blueprint with the init command. Replace <project-id> with your project ID, found in manage or your sanity.config.ts file.

This configures a new blueprint for your project, adds a sanity.blueprint.ts config file to the current directory (.), and creates a new stack named production.

Follow the prompt and run your package manager’s install command to add the dependencies.

Add a Sync Tag Invalidate function

Use the sanity functions add command to add a new function. You can also run it without any flags for interactive mode.

After running the command, follow the prompt and add the function declaration to your sanity.blueprint.ts configuration. Your file should look like this:

By default, your new function will receive Live Content sync tag invalidation events for all datasets in your project. We recommend you add an event to your function definition with a resource scoping your function to a particular dataset.

You can see all available options in the Function section of the Blueprints configuration reference documentation.

If you've followed the directory structure mentioned earlier, you'll see it grow to something like this:

marketing-site/
├─ studio/
├─ next-app/
├─ sanity.blueprint.ts
├─ package.json
├─ node_modules/
├─ functions/
│  ├─ invalidate-tags/
│  │  ├─ index.ts

After updating the sanity.blueprint.ts file, open functions/invalidate-tags/index.ts in your editor.

The syncTagInvalidateEventHandler function

Every function exports a handler from the index file.

The handler receives a context, an event and a done callback.

The event contains the Live Content sync tags that were invalidated, available at event.data.syncTags. You can learn more in the Function handler reference.

The done callback is an asynchronous method issuing an HTTP request back to Sanity, notifying us that you have completed your invalidation routine. It is a thin wrapper around native node.js fetch, returning a fetch Response.

Test the function locally

You can test functions locally with the functions development playground. Local testing is a great way to experiment without affecting your usage quota.

To launch the development playground, run the following:

If you run this on the starter function from earlier, you'll see the default output message in the console pane.

Loading...

Select your new Sync Tag Invalidate function from the list on the left. Note that the Sync Tag Payload panel is populated with a dummy sync tag invalidate event shape that your function can use as a test payload.

Click the Run button at the bottom, and you should see the starter Sync Tag Invalidate function template code output its logs to the Console panel:

Development playground

Deploy a function

Once you're satisfied that the function works as expected, deploy it by deploying the blueprint stack.

You can begin using your function when the deployment finishes. Edit a document in a dataset and publish the changes to trigger the function.

If you need to change the function, update your code and re-run the deploy command to push the new changes live.

Check the logs

When you tested the function locally, you saw the logs directly in your console. Once deployed, the function and its logs are in the cloud.

View the logs with the functions logs command. Replace invalidate-tags with your function name.

This command outputs the function's logs. Try updating your document, publishing the change, and running the command again to see new logs.

Destroy a deployed blueprint

Sometimes you want to remove a deployed resource so it won't run anymore or affect any future usage quotas.

To remove a resources created with a blueprint, you need to either:

  • Remove the definition from the blueprint, and run the deploy command again.
  • Destroy the blueprint with the destroy command.

The blueprints destroy command removes, or undeploys, the blueprint and all of its resources from Sanity's infrastructure. It does not remove your local files.

To remove the resource from the blueprint locally, you can remove it from the resources array in the sanity.blueprint.ts file, then delete any associated files.

Redeploying a destroyed blueprint

When you run blueprints destroy, it's as if you never used blueprints init during setup. The only difference is you still have all the files in your directory. To use this blueprint again and redeploy it, you'll need to let Sanity know about it. You can do this by running init again:

This launches an editing interface that lets you reconfigure the blueprint, if needed, and it reconnects the blueprint to Sanity. Now you can add more functions or redeploy. Keep in mind that any environment variables added before destroying the blueprint will not carry over.

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