Version: Current – v2.x

In the event of an error, the response will often have a type of `application/json` and there will be a `error` key with a description of the error.

These HTTP Status codes could be returned from the API if there is an error:

| Error Code | Name                  | Description                                                     |
|------------|-----------------------|-----------------------------------------------------------------|
| 400        | Bad Request           | Your request is invalid.                                        |
| 401        | Unauthorized          | Your API credentials are not recognized (your client/secret or token is wrong). |
| 403        | Forbidden             | Your credentials are recognized, but you don't have permissions to do what you're trying to do. |
| 404        | Not Found             | The specified object could not be found.                       |
| 405        | Method Not Allowed     | You tried to access with an invalid method.                    |
| 406        | Not Acceptable        | You requested a format that isn't json.                        |
| 429        | Too Many Requests     | You have sent more requests than are allowed (see [Rate Limits](https://developer.parallelmarkets.com/docs/server/errors/#rate-limits) below) |
| 500        | Internal Server Error | We had a problem with our server. Try again later.           |
| 503        | Service Unavailable   | We're temporarily offline for maintenance. Please try again later.

Example of an error response:

```json
{ "error": "The client_id and client_secret provided are invalid." }
```

## Rate Limits  
The Parallel API employs a number of safeguards to prevent bursts of incoming requests from negatively impacting the experience of our users and partners. If you send more requests than are permitted within a certain time period, our API will respond with a `429` status code. You should not make more than 100 requests per second to any of the Parallel endpoints.