Rotate the signing secret
Mints a new webhook signing secret, returns it, persists it as the current secret, and demotes the previous secret with a 24-hour overlap during which both remain valid for verification. Delivery signs with the current secret. A subscription with no signing secret at rest (a pull sink) returns 422 no_secret_to_rotate.
Authorizations
A bearer JWT issued by Access Manager. The /v1 surface never reads a tenant from the body, path, or query. Machine callers obtain a token with the Access Manager client-credentials flow. The /admin surface authorizes against an operator scope and carries no tenant context.
Headers
A client-chosen unique key that makes this mutation at-most-once. A mutation sent without it is rejected before any write with 400 missing_idempotency_key. Reusing the same key with an identical request replays the original response byte-for-byte (with X-Idempotency-Replayed: true); reusing it with a different request body returns 409 idempotency_conflict. To re-drive a corrected request, mint a new key.
Path Parameters
The unique identifier of the subscription (UUIDv7).
Response
A new signing secret was minted. No read route returns it; a replay of the same X-Idempotency key returns this same response.

