# Response Models

Each operation may return one of the following HTTP responses, depending on the operation and action performed.

### 200 Successful

Successful response models vary per operation and are detailed in the sections that follow.

### 400 Bad Request

A bad request response will be returned for any operations that fail validation, e.g. uniqueness, malformed type, etc.

An error message is returned in the body of the response.

### 404 Not Found

A not found response will be returned when referencing an entity that does not exist, e.g. fetching a Batch with an `id` that does not exist.

### 401 Unauthorised

A 401 HTTP status code will be returned should an invalid Bearer token be supplied as part of a request’s Header, or if the Bearer token supplied has expired.

### 500 Server Error

A server errors when an unhandled exception is thrown by the Redemptions API. The exception will be returned within the response body.

Please contact 6DOT50 [Support](https://6dot50.gitbook.io/6dot50-apis/support-1) with the error.