// use case

Expose your FastAPI dev server to Slack for Slack events

1. 1

   Reserve a stable subdomain

   On the lrok free plan you keep one reserved subdomain forever. Pick a name your Slack dashboard can hold onto — webhook URLs that survive laptop restarts mean fewer dashboard re-pastes.

   $ lrok reserve fas-slack
     Reserved https://fas-slack.lrok.io

2. 2

   Run your FastAPI app

   Start the dev server on port 8000 (the FastAPI default).

   $ uvicorn main:app --reload

3. 3

   Tunnel localhost to the public URL

   lrok forwards https://fas-slack.lrok.io/webhook → http://127.0.0.1:8000/webhook. The flag --hint binds your reserved subdomain to this tunnel.

   $ lrok http 8000 --hint fas-slack
     Forwarding https://fas-slack.lrok.io  ->  http://127.0.0.1:8000

4. 4

   Paste the URL into Slack

   Slack app → Event Subscriptions → Request URL. Paste https://fas-slack.lrok.io/webhook as the destination.

5. 5

   Watch deliveries land in the request inspector

   Every webhook Slack sends shows up at lrok.io/dashboard with full body, headers, status, and latency. Re-deliver any request to your FastAPI handler with one click. On the first paste of your URL into Slack, the app sends a {"type":"url_verification","challenge":"..."} POST. Echo back the challenge as JSON and you're live.