> ## Documentation Index
> Fetch the complete documentation index at: https://docs.nebius.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Nebius AI Cloud REST API reference

The Nebius AI Cloud REST API reference describes the available endpoints, request parameters, request bodies and responses. Endpoints are grouped by service, API version and resource.

You can try out requests on an endpoint page directly from the browser by specifying the required parameters and adding your access token to the `Authorization` header.

## Authentication

REST API requests require an access token. You can configure authentication for a user account or service account. For instructions, see [Authentication in the Nebius AI Cloud REST API](/rest-api/authentication).

## Error responses

When a request fails, the REST API returns a structured JSON error response. For example:

```json theme={null}
{
  "code": 7,
  "message": "you do not have permission to access the requested object"
}
```

The `code` value is the numeric canonical gRPC status code, and the `message` value contains a human-readable description of the error. In this example, code `7` is `PERMISSION_DENIED`.

Nebius APIs use only the canonical codes in the [full list of gRPC status codes](https://grpc.io/docs/guides/status-codes/#the-full-list-of-status-codes).