Linear Webhooks Reference: https://linear.app/developers/webhooks Signature verification Linear signs every delivery with HMAC-SHA256: Verify in constant time: Always read the raw body bytes, not the parsed JSON. Express: Replay protection Each delivery has a field in the JSON body (Unix ms). Reject events older than 5 minutes: Idempotency Linear may re-deliver. Each event has: - — unique per delivery (use this!) - — entity ID Store seen in Redis with 7-day TTL; ignore duplicates. Resource types , , , , , , , , , , , , . Subscribe selectively — fewer types means smaller event volume. Action t…