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

# Rate Limits

> Understand API rate limits, concurrency limits, and how to handle throttling.

## Overview

Aifano enforces rate limits to ensure fair usage and platform stability. Limits are applied per organization and vary by plan.

## Rate Limits by Plan

| Plan           | Requests per Minute | Concurrent Jobs | Monthly Credits |
| -------------- | ------------------: | --------------: | --------------: |
| **Free**       |                  20 |               5 |           1,000 |
| **Pro**        |                 100 |              20 |          10,000 |
| **Enterprise** |              Custom |          Custom |          Custom |

<Note>
  Contact [support@aifano.com](mailto:support@aifano.com) for Enterprise plan details and custom rate limits.
</Note>

## Concurrency Limits

Concurrency limits control how many documents can be processed simultaneously. This applies to both sync and async endpoints.

| Endpoint Type                     | Free | Pro | Enterprise |
| --------------------------------- | ---: | --: | ---------: |
| Sync (`/parse`, `/extract`, etc.) |    5 |  20 |     Custom |
| Async (`/parse_async`, etc.)      |    5 |  20 |     Custom |
| Upload (`/upload`)                |   10 |  50 |     Custom |

## Rate Limit Headers

Rate limit information is included in API response headers:

| Header                  | Description                               |
| ----------------------- | ----------------------------------------- |
| `X-RateLimit-Limit`     | Maximum requests allowed per minute       |
| `X-RateLimit-Remaining` | Requests remaining in the current window  |
| `X-RateLimit-Reset`     | Unix timestamp when the rate limit resets |

## Handling Rate Limits

When you exceed the rate limit, the API returns a `429 Too Many Requests` response:

```json theme={null}
{
  "error": "Rate limit exceeded. Please retry after 30 seconds.",
  "retry_after": 30
}
```

### Retry Strategy

Implement exponential backoff when you receive a `429` response:

<CodeGroup>
  ```python Python theme={null}
  import time
  import requests

  def call_with_retry(url, headers, json_data, max_retries=5):
      for attempt in range(max_retries):
          response = requests.post(url, headers=headers, json=json_data)

          if response.status_code == 429:
              wait_time = min(2 ** attempt, 60)  # Max 60s
              print(f"Rate limited. Retrying in {wait_time}s...")
              time.sleep(wait_time)
              continue

          return response

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

  ```javascript JavaScript theme={null}
  async function callWithRetry(url, options, maxRetries = 5) {
    for (let attempt = 0; attempt < maxRetries; attempt++) {
      const response = await fetch(url, options);

      if (response.status === 429) {
        const waitTime = Math.min(2 ** attempt, 60) * 1000;
        console.log(`Rate limited. Retrying in ${waitTime / 1000}s...`);
        await new Promise(r => setTimeout(r, waitTime));
        continue;
      }

      return response;
    }

    throw new Error("Max retries exceeded");
  }
  ```
</CodeGroup>

## Best Practices

<AccordionGroup>
  <Accordion title="Use async endpoints for batch processing">
    Submit all jobs via async endpoints first, then poll for results. This is more efficient than sequential sync calls and avoids hitting rate limits.
  </Accordion>

  <Accordion title="Implement exponential backoff">
    When you receive a `429` response, wait before retrying. Double the wait time with each retry (1s, 2s, 4s, 8s...) up to a maximum of 60 seconds.
  </Accordion>

  <Accordion title="Monitor rate limit headers">
    Check `X-RateLimit-Remaining` in response headers to proactively slow down before hitting the limit.
  </Accordion>

  <Accordion title="Spread requests over time">
    Instead of sending 100 requests at once, spread them evenly across the minute to stay within rate limits.
  </Accordion>

  <Accordion title="Contact support for higher limits">
    If your use case requires higher rate limits, reach out to [support@aifano.com](mailto:support@aifano.com) to discuss Enterprise plans.
  </Accordion>
</AccordionGroup>

## Credit Limits vs. Rate Limits

| Type             | Scope               | Reset        | Error Code                         |
| ---------------- | ------------------- | ------------ | ---------------------------------- |
| **Rate Limit**   | Requests per minute | Every minute | `429`                              |
| **Credit Limit** | Credits per month   | Monthly      | `429` with `CREDIT_LIMIT_EXCEEDED` |

Rate limits restrict how fast you can make requests. Credit limits restrict how much processing you can do per month. Both return `429` status codes but with different error messages.