Express

You can host Inngest functions directly as an Express route. In order to deploy with express, you need to:

1. Serve your functions in a new route via middleware
2. Register your functions with Inngest after deploying to your hosting service

Serving functions in Express

Import serve from the inngest/express package to create middleware for Express:

ts
import express from "express";
// Import serve from inngest
import { createFunction } from "inngest";
import { serve } from "inngest/express";
const app = express();
// Ensure your express app parses JSON requests properly.  This MUST
// be added to your app.
app.use(express.json())
// You'd usually have your functions defined in a separate file and imported here.
const exampleFn = createFunction(
  "The name of my function",
  "app/user.created",
  ({ event }) => { return { body: "hello!" }; }
);
// Create an endpoint for Inngest functions by calling serve() with
// an app name and the given functions to put live.
//
// This reads a process.env.INNGEST_SIGNING_KEY variable during setup,
// which is available within your account.
const inngestMiddleware = serve("My app/service name", [exampleFn]);
// Use the middleware from Inngest to host at /api/inngest.
app.use("/api/inngest", inngestMiddleware);
app.listen(3006, () => { console.log("running"); });

This hosts an API endpoint at ${your-url}/api/inngest, which we'll use to call your functions.

serve syntax

serve(appName, [functions]);
serve(appName, [functions], options);

serve arguments

• appName: The name of your app or microservice, used to group all functions together
• [functions]: An array of all functions to enable
• options: An optional object of options, with the type:

ts
type Options = {
  /**
   * A key used to sign requests to and from Inngest in order to prove that the
   * source is legitimate.
   *
   * You must provide a signing key to communicate securely with Inngest. If
   * your key is not provided here, we'll try to retrieve it from the
   * `INNGEST_SIGNING_KEY` environment variable.
   *
   * You can retrieve your signing key from the Inngest UI inside the "Secrets"
   * section at {@link https://app.inngest.com/secrets}. We highly recommend
   * that you add this to your platform's available environment variables as
   * `INNGEST_SIGNING_KEY`.
   *
   * If no key can be found, you will not be able to register your functions or
   * receive events from Inngest.
   */
  signingKey?: string;
  /**
   * Controls whether a landing page with introspection capabilities is shown
   * when a `GET` request is performed to this handler.
   *
   * Defaults to true if NODE_ENV !== production.
   *
   * This page is highly recommended when getting started in development,
   * testing, or staging environments.
   */
  landingPage?: boolean;
  /**
   * The URL used to register functions with Inngest.
   * Defaults to https://api.inngest.com/fn/register
   */
  inngestRegisterUrl?: string;
  /**
   * If provided, will override the used `fetch` implementation. Useful for
   * giving the library a particular implementation if accessing it is not done
   * via globals.
   *
   * By default the library will try to use the native Web API fetch, falling
   * back to a Node implementation if no global fetch can be found.
   */
  fetch?: typeof fetch;
}

Checking function configuration

To make sure everything is set up as you expect it to be, Inngest provides a local dashboard to introspect your served handler, show any found functions, and raise any errors before you get to production.

Visit ${your-url}/api/inngest to see the dashboard. If there are any problems detected, they'll show up here.

Registering your functions with Inngest

By default, Inngest doesn't know which functions you're serving or the URL of your app. Once you deploy your site to production, you'll need to reigster your functions with Inngest. You can do this via the UI or via an API call.

Registering via the UI

You can add your endpoint’s URL to Inngest via the dashboard:

Registering via the API

You can register your function’s endpoints with a single PUT call to your function endpoint:

bash
curl -X PUT https://www.example.com/api/inngest

Remember to swap www.example.com with your own domain name.

You can read more about registering functions here.