Errors

Failed /v1 requests return:

{
  "error": {
    "type": "authentication_error",
    "code": "invalid_api_key",
    "message": "Invalid API key provided."
  }
}

Session app routes still use { "error": { "kind", "message" } } — only the public API uses type / code.

Types

Optional param names the field that failed validation (for example expiresAt).