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

# Error Codes & Handling

> Understand and handle API errors

## HTTP Status Codes

| Status | Meaning               | Common Causes                           |
| ------ | --------------------- | --------------------------------------- |
| 200    | Success               | Request completed successfully          |
| 400    | Bad Request           | Invalid parameters or malformed request |
| 401    | Unauthorized          | Missing or invalid API key              |
| 402    | Payment Required      | Insufficient quota for this operation   |
| 403    | Forbidden             | Valid auth but insufficient permissions |
| 404    | Not Found             | Resource doesn't exist                  |
| 429    | Too Many Requests     | Rate limit exceeded                     |
| 500    | Internal Server Error | Server-side error                       |

## Error Response

When a request fails, the API returns a structured error body alongside the HTTP status code. The `error_code` field identifies the specific error for programmatic handling:

```json theme={null}
{
  "success": false,
  "message": "Human-readable error description",
  "error_code": "ERROR_CODE"
}
```

## Error Codes

| Error Code                     | Description                                                                     |
| ------------------------------ | ------------------------------------------------------------------------------- |
| `NOT_FOUND`                    | Resource not found                                                              |
| `DRIVE_ITEM_CONFLICT`          | Drive item name conflict, e.g. file or folder with the same name already exists |
| `INVALID_ARGUMENT`             | Invalid input: parameter validation, type mismatch, or malformed body           |
| `CONNECTOR_NOT_LINKED`         | Third-party connector (WPS, Lark, etc.) not yet authorized                      |
| `STATE_NOT_READY`              | Resource exists but its current state does not allow the operation              |
| `ACCESS_DENIED`                | Caller lacks permission to access the resource                                  |
| `QUOTA_EXCEEDED`               | Quota or usage limit exceeded                                                   |
| `DATASET_TABLE_LIMIT_EXCEEDED` | Number of tables in the NL2SQL dataset exceeds the allowed limit                |
| `DOWNLOAD_NOT_SUPPORTED`       | The requested resource does not support download                                |
| `UNAUTHORIZE`                  | Authentication required                                                         |
| `CONNECTOR_UNAUTHORIZE`        | Connector unauthorized                                                          |
| `CUSTOM_ID_CONFLICT`           | A resource with the given `custom_id` already exists                            |
| `BINDING_ALREADY_EXISTS`       | The binding relationship already exists                                         |
| `INTERNAL_ERROR`               | Unexpected server-side error                                                    |

## Error Handling Best Practices

### Retry Logic

```javascript theme={null}
async function apiRequest(url, options, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      const response = await fetch(url, options);
      
      if (response.ok) {
        return await response.json();
      }
      
      // Don't retry 4xx errors (except 429)
      if (response.status >= 400 && response.status < 500 && response.status !== 429) {
        throw new Error(`Client error: ${response.status}`);
      }
      
      // Exponential backoff for 5xx and 429
      if (i < maxRetries - 1) {
        await sleep(Math.pow(2, i) * 1000);
        continue;
      }
    } catch (error) {
      if (i === maxRetries - 1) throw error;
      await sleep(Math.pow(2, i) * 1000);
    }
  }
}
```

### Error Logging

```javascript theme={null}
try {
  const data = await apiRequest(url, options);
  return data;
} catch (error) {
  console.error('API Error:', {
    url,
    status: error.status,
    message: error.message,
    timestamp: new Date().toISOString()
  });
  throw error;
}
```

## Next Steps

<CardGroup cols={2}>
  <Card title="Authentication" icon="key" href="/features/memorylake/api-reference/authentication">
    Learn about authentication
  </Card>

  <Card title="Rate Limits" icon="gauge" href="/features/memorylake/api-reference/rate-limits">
    Understand rate limiting
  </Card>
</CardGroup>