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).
| HTTP | Status Code | Summary |
|---|---|---|
| 200 | OK | Everything worked as expected. |
| 400 | Bad Request | The request was unacceptable, often due to missing a required parameter |
| 401 | Unauthorized | No valid API key provided. |
| 402 | Request Failed | The parameters were valid but the request failed. |
| 403 | Forbidden | The API key doesn't have permissions to perform the request. |
| 404 | Not Found | The requested resource doesn't exist. |
| 429 | Too Many Requests | Too many requests hit the API too quickly. We recommend an exponential backoff of your requests. |
| 500, 502, 503, 504 | Server Errors | Something went wrong on our servers end. (These are rare.) |