# Error codes

We use standard HTTP error codes to indicate success or failure of a request. Any request that returns HTTP 200 indicates success. Any HTTP 50x indicates that something failed server-side. If you see persistent HTTP 50x errors please contact us.

HTTP 40x errors indicate that something is wrong with your request. For instance:

| Code | Meaning                                             |
| ---- | --------------------------------------------------- |
| 400  | Your request is missing a required parameter        |
| 401  | Your API key is invalid                             |
| 403  | Your API key does not permit access to the resource |
| 404  | The resource (session, KM etc.) could not be found  |

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