Sometimes you want to subscribe to changes from an API, and we don’t have an Integration for it yet. That’s when you can use defineHttpEndpoint to receive webhooks, verify them, and create an HTTP Trigger.

Defining an HTTP endpoint

We’ll use as an example:

const caldotcom = client.defineHttpEndpoint({
  //this should be unique inside your project
  id: "",
  //usually you'd use the domain name of the service
  source: "",
  //the icon is optional, it displays in the dashboard
  icon: "caldotcom",
  //this function is called when a webhook is received
  verify: async (request) => {
    //this is a useful helper function that can verify sha256 signatures
    //each API has a different header name
    return await verifyRequestSignature({
      //you can find the header name in the API's documentation
      headerName: "X-Cal-Signature-256",
      //you can find the secret in the dashboard, on the HTTP endpoint page
      secret: process.env.CALDOTCOM_SECRET!,
      algorithm: "sha256",

When this code runs (and you’re running the CLI dev command) the HTTP endpoint will be created and be visible in the dashboard.

The verify function is compulsory and is automatically called when a webhook is received. It’s required to return a result from this function – 90% of the time you can use our verifyRequestSignature helper function.

Getting the URL and secret

In our dashboard, you can navigate to the HTTP endpoints page. From there you can select your endpoint and copy the URL (1) and secret (2) for the appropriate Environment.

HTTP endpoint page

You then need to input these values into the developer section of the API you want to subscribe to. Some APIs, like Stripe’s, don’t require a secret to be entered. Instead they will generate one for you to use.

Saving the secret

You should save the secret and add it to your environment variables. Locally this usually means adding it to your .env file. When you deploy you’ll need to put it in relevant section of your cloud provider’s dashboard. In the code above we’re using CALDOTCOM_SECRET as the environment variable name.

Creating a Trigger

//... the code from above that created the caldotcom endpoint

  id: "http-caldotcom",
  name: "HTTP",
  version: "1.0.0",
  enabled: true,
  //this create a Trigger using the caldotcom endpoint
  trigger: caldotcom.onRequest(),
  run: async (request, io, ctx) => {
    //note that when using HTTP endpoints, the first parameter is the request
    //you need to get the body, usually it will be json so you do:
    const body = await request.json();
    await`Body`, body);

You can create multiple Triggers from the same endpoint. You can also add filters to the Trigger so it only runs when the request matches certain criteria. View the SDK reference.

More information