Cal.com uses conventional HTTP response codes to indicate the success or failure of an API request. In general: Codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, or something else failed, etc.). Codes in the 5xx range indicate an error with Cal.com’s servers (these are rare).
HTTPStatus CodeSummary
200OKEverything worked as expected
400Bad RequestThe request was unacceptable, often due to missing a required parameter
401UnauthorizedNo valid API key provided.
402Request FailedThe parameters were valid but the request failed.
403ForbiddenThe API key doesn’t have permissions to perform the request.
404Not FoundThe requested resource doesn’t exist.
429Too Many RequestsToo many requests hit the API too quickly. We recommend an exponential backoff of your requests.
500, 502, 503, 504erver ErrorsSomething went wrong on our servers end. (These are rare.)