---
title: "Errors"
sidebarTitle: "Errors"
description: "Error codes, error formats, mid-stream errors, and retry strategies for the Cline API."
---

The Cline API returns errors in a consistent JSON format. Understanding these errors helps you build reliable integrations.

## Error Format

All errors follow the OpenAI error format:

```json
{
  "error": {
    "code": 401,
    "message": "Invalid API key",
    "metadata": {}
  }
}
```

| Field | Type | Description |
|-------|------|-------------|
| `code` | number/string | HTTP status code or error identifier |
| `message` | string | Human-readable description of the error |
| `metadata` | object | Additional context (provider details, request IDs) |

## Error Codes

### HTTP Errors

These are returned as the HTTP response status code and in the error body:

| Code | Name | Cause | What to do |
|------|------|-------|------------|
| `400` | Bad Request | Malformed request body, missing required fields | Check your JSON syntax and required parameters |
| `401` | Unauthorized | Invalid or missing API key | Verify your API key in the `Authorization` header |
| `402` | Payment Required | Insufficient credits | Add credits at [app.cline.bot](https://app.cline.bot) |
| `403` | Forbidden | Key does not have access to this resource | Check key permissions |
| `404` | Not Found | Invalid endpoint or model ID | Verify the URL and model ID format |
| `429` | Too Many Requests | Rate limit exceeded | Wait and retry with exponential backoff |
| `500` | Internal Server Error | Server-side issue | Retry after a short delay |
| `502` | Bad Gateway | Upstream provider error | Retry after a short delay |
| `503` | Service Unavailable | Service temporarily down | Retry after a short delay |

### Mid-Stream Errors

When streaming, errors can occur after the response has started. These appear as a chunk with `finish_reason: "error"`:

```json
{
  "choices": [
    {
      "finish_reason": "error",
      "error": {
        "code": "context_length_exceeded",
        "message": "The input exceeds the model's maximum context length."
      }
    }
  ]
}
```

Common mid-stream error codes:

| Code | Meaning |
|------|---------|
| `context_length_exceeded` | Input tokens exceed the model's context window |
| `content_filter` | Content was blocked by a safety filter |
| `rate_limit` | Rate limit hit during generation |
| `server_error` | Upstream provider failed during generation |

<Warning>
  Mid-stream errors do not produce an HTTP error code (the connection was already 200 OK). Always check `finish_reason` in your streaming handler.
</Warning>

## Retry Strategies

### Exponential Backoff

For transient errors (429, 500, 502, 503), retry with exponential backoff:

```python
import time
import requests

def call_api_with_retry(payload, max_retries=3):
    for attempt in range(max_retries):
        response = requests.post(
            "https://api.cline.bot/api/v1/chat/completions",
            headers={
                "Authorization": "Bearer YOUR_API_KEY",
                "Content-Type": "application/json",
            },
            json=payload,
        )

        if response.status_code == 200:
            return response.json()

        if response.status_code in (429, 500, 502, 503):
            delay = (2 ** attempt) + 1
            print(f"Retrying in {delay}s (attempt {attempt + 1}/{max_retries})")
            time.sleep(delay)
            continue

        # Non-retryable error
        response.raise_for_status()

    raise Exception("Max retries exceeded")
```

### When to Retry

| Error | Retry? | Strategy |
|-------|--------|----------|
| `401 Unauthorized` | No | Fix your API key |
| `402 Payment Required` | No | Add credits |
| `429 Too Many Requests` | Yes | Exponential backoff (start at 1s) |
| `500 Internal Server Error` | Yes | Retry once after 1s |
| `502 Bad Gateway` | Yes | Retry up to 3 times with backoff |
| `503 Service Unavailable` | Yes | Retry up to 3 times with backoff |
| Mid-stream `error` | Depends | Retry the full request for transient errors |

### Rate Limits

If you hit rate limits frequently:

- Add delays between requests
- Reduce the number of concurrent requests
- Contact support if you need higher limits

## Debugging

When reporting issues, include:

1. The **error code and message** from the response
2. The **model ID** you were using
3. The **request ID** (from the `x-request-id` response header, if available)
4. Whether the error was **immediate** (HTTP error) or **mid-stream** (finish_reason error)

## Related

<CardGroup cols={2}>
  <Card title="Chat Completions" icon="message" href="/api/chat-completions">
    Endpoint reference with request and response schemas.
  </Card>
  <Card title="Authentication" icon="key" href="/api/authentication">
    Verify your API key is configured correctly.
  </Card>
</CardGroup>