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

# Error Handling

> Understanding API error responses and codes

# Error Handling

All errors return JSON with consistent structure and appropriate HTTP status codes.

## Error Response Format

```json theme={null}
{
  "error": {
    "code": "INSUFFICIENT_BALANCE",
    "message": "Insufficient balance for transaction",
    "details": {
      "required": "1.5 SOL",
      "available": "1.2 SOL"
    }
  }
}
```

## HTTP Status Codes

| Code    | Description                             |
| ------- | --------------------------------------- |
| **200** | Success                                 |
| **400** | Bad Request - Invalid parameters        |
| **401** | Unauthorized - Invalid API key          |
| **404** | Not Found - Resource doesn't exist      |
| **429** | Too Many Requests - Rate limit exceeded |
| **500** | Internal Server Error                   |

## Common Error Codes

### Quote Errors

| Code                     | Description              |
| ------------------------ | ------------------------ |
| `INVALID_ASSET`          | Unsupported asset symbol |
| `AMOUNT_TOO_SMALL`       | Below minimum amount     |
| `INSUFFICIENT_LIQUIDITY` | Not enough liquidity     |

### Transaction Errors

| Code                   | Description                  |
| ---------------------- | ---------------------------- |
| `INVALID_QUOTE`        | Quote expired or not found   |
| `INVALID_SIGNATURE`    | Malformed signed transaction |
| `INSUFFICIENT_BALANCE` | Not enough tokens            |
| `ROUTING_UNAVAILABLE`  | Private mode unavailable     |

### Authentication Errors

| Code                  | Description         |
| --------------------- | ------------------- |
| `INVALID_API_KEY`     | API key is invalid  |
| `EXPIRED_API_KEY`     | API key has expired |
| `RATE_LIMIT_EXCEEDED` | Too many requests   |

## Retry Logic

Implement exponential backoff for retries:

```javascript theme={null}
async function retryRequest(fn, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      return await fn();
    } catch (error) {
      if (i === maxRetries - 1) throw error;
      await new Promise(r => setTimeout(r, 1000 * Math.pow(2, i)));
    }
  }
}
```