Verify Nylas webhook signatures to trust your data

A webhook endpoint is a public URL sitting on the internet, and anything on the internet can send it a POST. If your app acts on whatever lands there, an attacker who guesses the URL can forge events: fake an inbound email, trigger a workflow, or feed your system garbage. The fix is to confirm two things before you trust a request, that you own the endpoint and that Nylas actually sent the payload, and both are built into how webhooks work.

This post covers verifying webhooks from two angles: the HTTP mechanics your endpoint implements, and the — the challenge handshake, the secret, and the signature header in full