# Paging over HTTP calls

> Use the Do While activity in Studio Web to implement API pagination by repeating HTTP calls until all data is retrieved, using cursors or response body indicators.

The following tutorial demonstrates how to use the **Do While** activity to handle API pagination by making repeated HTTP calls until all data is retrieved.

Pagination indicators, such as cursors, end-of-page flags, or limits, are typically included in the response headers, response body, or as query parameters.

This example retrieves a list of breweries using the **OpenBreweryDB** API. According to the OpenBreweryDB API specification, pagination is handled using **offset-based** (page-based) parameters. To paginate through the dataset, include **per_page=X&page=Y** as query parameters in the HTTP request.

1. [Create an API workflow](https://docs.uipath.com/studio-web/automation-suite/2.2510/user-guide/managing-api-workflows#creating-api-workflows).
2. Add a **HTTP** activity and configure it as follows:
   * **Method**—GET
   * **Request URL**—
     ```
     https://api.openbrewerydb.org/v1/breweries?per_page=10&page=1
     ```
3. **Debug** your API workflow to retrieve the first listing of breweries.
4. Add a **Script** activity and provide the following code:
   ```
   const url = new URL($input.request.url);
   const currentPage = Number(url.searchParams.get("page"));

   return { nextPage: currentPage + 1, 
   content: $input.content}
   ```

   Using **$input** instead of **$context** ensures you always reference the output of the last executed activity, especially inside a loop block. The JavaScript code returns a JSON object with **nextPage** and **content** properties. These properties allow you to control the loop, for example: continue while **nextPage < 10** or **content is not null**.

5. Add a **Loop > Do While** activity above the existing **HTTP** activity.
   1. Move both **HTTP** and **Script** activities inside the **Do While** activity body.
   2. Set the **Condition** for the **Do while** activity to `$input.nextPage < 5`.
   3. For the **HTTP** activity, open the Expression editor of the **Request URL** property and update the expression to:
      ```
      "https://api.openbrewerydb.org/v1/breweries?per_page=10&page=" + ($input.nextPage == null ? 1 : $input.nextPage)
      ```
6. Debug your workflow again and notice the result array in the **Output** tab of the **Run output** panel.
7. Outside of the **Do While** activity, add a **Response** activity and configure it as follows:
   * **Type**—Success
   * **Details**—Open the Expression editor and write the following:
     ```
     $context.outputs.Do_While_1.results.flatMap(result => result.content.map(brewery => brewery.name))
     ```This summarizes the response at step 6 and lists only the names of the breweries.
8. Copy the result from the **Output** tab of the **Run ouput** panel and configure it as an **Output** schema:
   1. Open the **Data manager** panel.
   2. In the **Output** tab, select **Generate From Payload**.
   3. Paste the copied result, and select **Generate Schema**.