Register webhook
Register a webhook endpoint to receive decision event notifications. The hmac_key is generated by Specter and returned once, in the creation response.
Authorizations
RS256-signed JWT bearer token, obtained via the OAuth2 client-credentials grant and verifiable against the issuer's JWKS (see Authentication).
Body
Webhook attributes
Event types this endpoint is subscribed to. Must contain at least one.
1decision.allow, decision.block, decision.review, decision.provisional, decision.async.allow, decision.async.block, decision.async.review Absolute http or https URL that Specter delivers event notifications to. Use a publicly reachable HTTPS URL; Specter does not deliver to private or reserved IP addresses.
255"https://merchant.example.com/webhooks/specter"
Response
Created webhook
Returned only on initial creation. Contains the plaintext hmac_key — store it securely, it will not be shown again.
"2f8d4b6c-9e1a-4c7f-b3d5-8a6e2c9f4b1d"
Plaintext HMAC key, 43 characters. Only returned once. Use it as a string exactly as returned; do not base64-decode it.
"q3Vt8hZ2mN0xYcLr5pW7sKfA1eJ9uDbG4oTnXiRvEyQ"
"2026-01-20T08:30:00Z"
"2026-01-20T08:30:00Z"
"https://merchant.com.example/webhooks/specter"