The Ultimate Guide to Webhook Security Signatures

HMAC (Hash-Based Message Authentication Code) is the industry standard for verifying that a webhook actually came from the sender it claims to be from.

How It Works

The sender takes the payload content, adds a timestamp, and hashes it using a secret key only known to you and them. They send this hash in a header (e.g., `X-Hub-Signature`). Your server repeats the process. If the hashes match, the request is authentic.

Why Documentation is Key

When a security incident occurs, being able to produce a certificate showing "This request had a valid signature at 10:00 AM" is invaluable. It proves that you performed due diligence in accepting incoming data streams.