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

# MCP Error Codes

The Bigdata MCP server reports failures in two different ways, depending on where the failure happens. Authentication, access, and generic server problems come back as HTTP error responses. Problems that occur while a tool is validating or running its request come back as HTTP 200 with an error flag inside the response.

## HTTP error codes

If there is an issue with authentication, access, or a generic server error, the MCP server returns one of the following:

| HTTP status | Details                                    | Suggested action                                                                                                                              |
| ----------- | ------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------- |
| `401`       | Re-authentication required.                | The client should automatically try the OAuth flow to authenticate.                                                                           |
| `403`       | Forbidden access to a service or resource. | Verify your credentials. If they are correctly provided, email [support@bigdata.com](mailto:support@bigdata.com) to revise your entitlements. |
| `500`       | An unexpected error occurred.              | Please try again later.                                                                                                                       |

## Tool errors

If a tool responds but there was an error during validation or execution, the server returns **HTTP 200 Success** with the response parameter `isError` set to `true`. The explanation for the user is in the text content block.

The following example shows a user who has run out of credits, so the tool could not return data:

```json theme={null}
event: message
data: {
  "jsonrpc": "2.0",
  "id": 5,
  "result": {
    "content": [
      {
        "type": "text",
        "text": "request_id: af5b4056-11c4-4ffb-9fa5-dc23414c017b\n\nYou've used up your credits.\n\nIndividual: [Top up](https://app.bigdata.com/billing?utm_source=claude.ai) with credits and resume instantly — pay only for what you use.\n\nTeams & organizations: [Request enterprise access](https://bigdata.com/get-mcp) to expand your quota.\n\n"
      }
    ],
    "isError": true
  }
}
```

Once the `\n` escapes are resolved, the `text` field reads as follows:

```text theme={null}
request_id: af5b4056-11c4-4ffb-9fa5-dc23414c017b

You've used up your credits.

Individual: [Top up](https://app.bigdata.com/billing?utm_source=claude.ai) with credits and resume instantly — pay only for what you use.

Teams & organizations: [Request enterprise access](https://bigdata.com/get-mcp) to expand your quota.
```

<Note>
  At the moment we do not support error codes in tool responses. Please email [support@bigdata.com](mailto:support@bigdata.com) if you require it for your use case and we will start providing errors to satisfy them.
</Note>