AddEvent 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, an object was not found, etc.).
  • Codes in the 5xx range indicate an error with AddEvent's servers (these are rare).

HTTP status code summary

Response codeMeaning
200 OkEverything worked as expected. Covers the following cases:
- Object was retrieved or updated successfully
- Searches will always return 200 responses, even if there are no results
201 CreatedEverything worked as expected: object created successfully.
204 No contentEverything worked as expected: object deleted successfully.
400 Bad requestThe request was unacceptable, oftern due to a missing required parameter.
401 UnauthorizedNo valid API key provided.
403 ForbiddenThe API key doesn't have the permission to perform the request. Usually one of the following cases:
- The account's plan does not support API access (e.g. the free Hobby plan)
- The account has exceeded a specific usage limit that prevents them from performing this action
404 Not foundThe requested resource does not exist, has been deleted, or does not belong to the account which made the API request.
405 Not allowedThe endpoint does not support this method (verb).
500 Server errorSomething went wrong on AddEvent's end.


For most 4xx errors, we include an error_id and a message that can be used to troubleshoot the error.