Handle message.created Webhooks in Next.js

What actually happens in the first ten seconds after someone emails your AI agent? If you've built the agent on a covers the full handler lifecycle, including all the delivery variants.

Prove it works

Deploy, create the webhook against your production URL, then send a message from your phone to the agent's address. Watch the route logs: GET challenge, then a POST within seconds of the message landing. Once that round-trip works, the rest of the agent — classification, drafting, sending the reply from the same grant — is regular application code.

What's your dedupe store of choice for webhook handlers — database constraint, Redis, or something else?