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

# How to conditionally fail requests based on request counts

Simulate a failed response on the first request and a successful one on subsequent attempts using [shared state](/http-interception/http-rules/advanced-usage/shared-state) in Requestly Interceptor.

<Warning>
  `$sharedState` is only available in extension versions > v24.8.13 and desktop app versions > v1.7.1.
</Warning>

### Steps to conditionally fail requests are:

<Steps>
  <Step title="Create a Modify Response Rule">
    Open Requestly Interceptor and create a new **Modify Response** rule.
  </Step>

  <Step title="Enable Dynamic JavaScript Modification">
    Choose the **Dynamic JavaScript** option to write custom logic for the response.
  </Step>

  <Step title="Add JavaScript to Control Response Based on Request Count">
    Use the following code to fail the first request and let others succeed:

    ```javascript theme={null}
    function modifyResponse(args) {
      const {
        method, url, response, responseType,
        requestHeaders, requestData, responseJSON
      } = args;

      // Get the current count or start from 0
      let count = $sharedState.count ?? 0;
      count++;
      $sharedState.count = count;

      // Succeed if it is not the first request
      if (count > 1) {
        return null;
      }

      // Allow all subsequent requests to succeed
      return response;
    }
    ```
  </Step>
</Steps>