Error responses

All Flexprice API errors follow a consistent structure. Each error response includes:

success: Boolean flag indicating whether the request was successful (always false for errors)
error: Object containing error details with:
- message: Human-readable description of the error
- internal_error: Internal error details (may be empty for client errors)

Error responses may also include additional fields specific to the error type.

{
  "success": false,
  "error": {
    "message": "Could not find a resource of type Plan with identifier: DBhwNcMNfYgeBpn.",
    "internal_error": ""
  }
}

Common error types

The table below lists common error types. When processing errors programmatically, use the HTTP status code along with the error message.

Title	Status code	Description
Authentication failure	401	Your request did not provide a valid or well-formatted API key. Ensure you’re including the `x-api-key` header with a valid API key.
Request validation error	400	A request that fails validation will return human-readable information about what went wrong. The error response includes a `message` field describing the validation issues.
Duplicate resource creation	400	Returned when attempting to create a resource that already exists.
Resource not found	404	This is returned when a provided identifier does not map to a resource that is accessible by the current account.
Feature not available	404	Returned when the endpoint or feature is behind a feature flag on the server-side and is unavailable for current use.
URL not found	404	Returned when the requested URL was not found on the server.
Resource conflict	409	Returned when the request conflicts with another concurrent request. This may occur when multiple requests attempt to modify the same resource simultaneously (e.g., the credits ledger). You can safely retry these requests.
Too many requests	429	Returned when the request rate exceeds the limit.
Internal Server error	500	This is an internal server error. The Flexprice team has been notified!

​Error responses

​Common error types

Error responses

Common error types