Blueticked Webhooks API
Subscribe to and manage outbound event webhooks. Every delivery is a POST of a JSON envelope signed with the webhook's secret: x-blueticked-signature is sha256=, and x-blueticked-signature-v2 is t=,v1=, signed over .. Verify against the raw body before parsing, and refuse a v2 timestamp older than 300 seconds. During the 24h after a secret rotation, x-blueticked-signature-previous carries the signature made with the previous secret, and x-blueticked-signature-v2 carries a second v1 for it. Answer 2xx within 10 seconds; anything else is attempted up to 8 times in total with exponential backoff, starting at 10 seconds. Every attempt of one delivery carries the same delivery_id, which is the key to deduplicate on: the envelope's timestamp, and so the body and signature, change on each attempt. Redirects are not followed: a 3xx counts as a failed attempt.