Function handler reference

Reference documentation for the shape of the function wrapper.

Every Function must export a handler. Handlers contain the logic that the Function infrastructure runs when your document changes trigger the function.

Create a function handler with the sanity blueprints add function command. Every handler receives an object containing context and event parameters.

• clientOptionsobject

  Coming soon

• projectIdstring

  The ID of the project that triggered this function.

• datasetstring

  The dataset name of the project that triggered this function.

• apiHoststring

  Defaults to https://api.sanity.io.

• tokenstring

  A token provided by the function with access to your Sanity project. Note: the token is obfuscated in logs for security. You can directly use it to configure the Sanity client or to make API calls.

{
  clientOptions: {
    apiHost: 'https://api.sanity.io',
    projectId: 'abc123',
    dataset: 'production',
    token: '***************'
  }
}

• dataobject

  A Sanity Document containing the default document shape and available values, or the shape defined in the Blueprints configuration function's event.projection.

{
  data: {
    _id: '1234',
    _type: 'article',
    title: 'Functions quick start',
    _createdAt: "2025-04-24T16:26:58.901Z",
    _publishedAt: "2025-04-24T16:26:58.901Z",
    
  }
}

import { documentEventHandler } from '@sanity/functions'

export const handler = documentEventHandler(async ({ context, event }) => {
  console.log("Context: ", context)
  console.log("Event: ", event)
})

export async function handler({context, event}) {
  console.log("Context: ", context)
  console.log("Event: ", event)
}

When you create a new TypeScript function with sanity blueprint add, you'll be prompted to add types.

If you did not add types as part of the init process, they are available in the @sanity/functions package:

npm install -D @sanity/functions

You can then import and use the documentEventHandler helper to provide type support. See the example TS handler above for implementation details.