Mock the Slack Events API challenge

A POST mock that answers Slack's url_verification handshake by echoing the challenge value back.

Accepts an incoming call and replies the way the service expects.

Response payload

{
  "challenge": "{{request.body.challenge}}"
}

Fields worth knowing

Field	What it means
challenge	Echoed straight from your request body via {{request.body.challenge}} — exactly what Slack's url_verification handshake checks for.

Create the mock

curl -X POST https://quickmock.dev/api/mocks \
  -H 'Content-Type: application/json' \
  -d '{
  "method": "POST",
  "response_status": 200,
  "content_type": "application/json",
  "response_body": "{\"challenge\":\"{{request.body.challenge}}\"}"
}'

Call it

curl -X POST -H 'Content-Type: application/json' -d '{"token":"verification-token-8f3a","challenge":"3eZbrw1aBm2rZSFEGRbdazZQb7aoEXsdMY19q6IcvKf","type":"url_verification"}' https://quickmock.dev/m/<slug>

What you get

POST the url_verification payload -> 200 echoes {"challenge":"..."} back
Slack requires this exact echo to verify the Events API endpoint

How this differs from the real thing

The request signature (the X-Slack-Signature header) isn't checked — this mock echoes the same challenge back to anyone who sends a matching body, not only to Slack itself.

Ready to use it?

Open it in the mock builder to tweak first

Pairs well with this guide: Echo the request back

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