Request bin.
A throwaway URL that catches whatever is sent to it and shows each request the moment it arrives. Point a webhook at it, watch it land.
About this tool
Creating a bin gives you two URLs: a short capture address of the form /b/<id> that you hand to whatever you are testing, and a viewer page that streams every request it receives over a server-sent events connection. Each request shows the method, path, query string, headers, body (pretty-printed when it is JSON) and the sender's address, with one-click copy of the body or of an equivalent curl command so you can replay it against your real endpoint.
Anything appended to the capture URL is recorded too, so /b/<id>/orders/123?dry=1 works and the sub-path shows up in the viewer. That makes it easy to see exactly which paths and parameters a third party is calling.
Typical uses: checking what a payment provider, Git host or chat platform actually posts before you write the handler; confirming a retry policy and its backoff timings; capturing a mobile app's requests by pointing it at the bin; or just getting a fast answer to "did the request even leave the building".
Bins are held in memory on a single server. They vanish after 15 minutes without traffic, or 90 minutes regardless, and if the process restarts. Do not send anything here you would not be happy to have on a shared screen; the URL is unguessable but not a secret you should rely on.