How to test Slack webhooks locally

Slack sends webhooks for slash commands, interactive components, and event subscriptions. Test your Slack app's event handling locally with RelayFox — no ngrok required.

1. 1
   Create a free RelayFox URL on the homepage (no signup needed).
2. 2
   Paste it as your webhook endpoint: Slack API Dashboard → Your App → Event Subscriptions / Interactivity → Request URL.
3. 3
   Trigger an event (e.g. message) and watch it arrive live in RelayFox.
4. 4
   Run the CLI to forward captured events to your local server:

   npx relayfox forward <endpoint-id> --to http://localhost:3000 --token rfx_...

5. 5
   Inspect headers, body and replay any event as many times as you need.

RelayFox preserves the X-Slack-Signature header when forwarding, so Slack's signature verification works against your local server unchanged.