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Testing functions

You can test functions locally, across any framework, by using our CLI. The CLI provides everything you need to receive events and run functions on your machine.

Follow along to learn how to:

  • View the SDK dashboard
  • Run the CLI
  • Test functions using the SDK and CLI together

View the SDK dashboard

The SDK provides a built-in UI via the serve handler for your framework (read the docs here), which shows you all of your registered functions and allows you to send test events to trigger your functions. Follow these steps to see the SDK UI:

  1. Ensure you're serving the Inngest SDK for your framework
  2. Run your project, eg. via yarn dev for NextJS
  3. Browse to your site's URL at /api/inngest, eg. http://localhost:3000/api/inngest.

You will see the following UI:


Run the CLI

The CLI runs Inngest locally, allowing you to process events and run functions on your own machine.

To run the CLI, copy the command from the header of your SDK UI. The command looks similar to the following, using your own URL/port:

npx inngest-cli@latest dev -u http://localhost:3000/api/inngest

The CLI will automatically connect to your project, initialize your functions, and start an HTTP server which accepts events from your project. When events are received, the CLI will run your functions automatically, and show output in the CLI's logs.

Once you've started the dev server, you should see your functions registered and ready to go in the output! In addition, our SDK debug page will now show that we're connected to the dev server.


Check dev server logs
12:10PM INF overriding config to log step output within dev server
12:10PM INF executor > starting queue backend=inmemory
12:10PM INF runner > starting event stream backend=inmemory
12:10PM INF runner > starting queue backend=inmemory
12:10PM INF runner > initializing scheduled messages len=0
12:10PM INF executor > service starting
12:10PM INF devserver > service starting
12:10PM INF executor > subscribing to function queue
12:10PM INF api > starting server addr=
12:10PM INF runner > service starting
12:10PM INF runner > subscribing to events topic=events
12:11PM INF devserver > registered functions app="My Next.js App" framework=nextjs len=1 sdk=js:v0.6.0 url=http://localhost:3001/api/inngest

Testing functions

With the CLI running, your SDK UI page should show that you're connected to the dev server.

You can use the SDK UI to send test events to the CLI. Enter your event into the input box and hit send to send the event to Inngest. Any functions that subscribe to your event will run in the background!

Here's an example:

Send an event

Check dev server logs
12:18PM INF api > publishing event event={"data":{"name":"Inngest"},"id":"01GFX481B6482Y32VSQFB6BJJY","name":"demo/event.sent"} event_name=demo/event.sent id=01GFX481B6482Y32VSQFB6BJJY
12:18PM INF runner > received message event=demo/event.sent id=01GFX481B6482Y32VSQFB6BJJY
12:18PM INF runner > initializing fn event=demo/event.sent function=my-next-js-app-hello-world id=01GFX481B6482Y32VSQFB6BJJY
12:18PM INF executor > executing action run_id=01GFX481H2KSDE7JNHR1Y0XT1J scopes=null step=step version=null
12:18PM INF output > step output attempt=0 fn_id=my-next-js-app-hello-world fn_name="Hello World" output={"body":{"message":"Hello, Inngest!"},"status":200} run_id=01GFX481H2KSDE7JNHR1Y0XT1J step=step

From here, learn how to send events to Inngest using the SDK. In development, with the dev server running, events will automatically be sent to your local CLI and will trigger functions locally.