Send a webhook.test event to an endpoint

A parameter is missing or malformed, or the link is not one this endpoint takes.

Fix the parameter named in param as the message says. For a link of the wrong kind, call an endpoint listed in details.endpoints, when there is one.

The x-api-key header is missing, or its key is unknown or revoked. On the dashboard's routes: the session cookie is missing or expired.

Send a valid API key in the x-api-key header. No key yet? A person gets one at details.signup_url; an AI agent follows details.agent_auth_url.

The API key is valid but may not make this request, and details.reason says why: the account is suspended, the key lacks the route's scope, waits for its owner to confirm it by email, has expired, or was used from an IP outside its allowlist, or a rotated key's previous secret was used for a call that needs the admin scope. A running job stops with it too when its account is suspended or the key that created it is revoked or expires. It is about the key, never the item: a private item is private_or_unavailable, also 403, so branch on the code.

Act on details.reason. suspended: contact support. scope: use a key with details.required_scope. previous_secret: use the new secret. key_pending: have the owner open the emailed link. key_expired or key_revoked: create a new key. ip_not_allowed: call from an allowed IP.

The item does not exist or was deleted. On GET /v1/requests/{id}/response: the response was not kept (details.reason says why).

Check the link or ID. Do not retry.

A request with this Idempotency-Key is still running.

Retry after the seconds in the retry-after header to get that request's result.

This Idempotency-Key was already used for a different request (another route or body). Or it was used for this same request, which ran and returned a secret we no longer keep (details.reason answer_expired): running it again would create another.

Use a new Idempotency-Key for a different request, and reuse a key only to retry the identical request. With reason answer_expired, check what the first request created (GET /v1/api_keys, GET /v1/webhook_endpoints) before sending it again under a new key.

The account passed its runaway-protection ceiling: a high per-account limit that stops a broken client loop (plans have no rate limit). Requests without an API key (signup, the MCP server's tool listing and find_endpoint) are limited per IP address instead. It also stops an account whose failed requests in the last hour cost far more than its successful ones paid for: failures are free within a limit (the message says so), and successes raise it.

Wait the seconds in the retry-after header, then retry. If your steady traffic needs more, ask support to raise the ceiling; without an API key, send one.