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Getting started with API Lens

This guide takes you from installation to inspecting your first HTTP request.

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1. Choose the correct package

API Lens uses a separate binary package for each Unreal Engine minor version. Install the package matching your project:

Your project Package to install
Unreal Engine 5.6 API Lens 1.0.1 for UE 5.6
Unreal Engine 5.7 API Lens 1.0.1 for UE 5.7
Unreal Engine 5.8 API Lens 1.0.1 for UE 5.8

Do not copy a package built for one Engine minor into another. See Compatibility for details.

2. Enable the plugin

  1. Open your Unreal project.
  2. Go to Edit → Plugins.
  3. Search for API Lens.
  4. Enable the plugin.
  5. Restart Unreal Editor if prompted.

API Lens is an Editor-only development tool. Enabling it does not add a runtime feature to your packaged game.

3. Open API Lens

From the main Unreal Editor menu, choose:

Window → Developer Tools → Debug → API Lens

The panel can float as its own window or be docked beside your editor tabs.

4. Start your first capture

  1. Select Start capture in the API Lens header.
  2. Review the exclusive-capture notice and confirm when you are ready.
  3. Start Play in Editor or perform the action that makes your API request.
  4. Return to API Lens and select a request from the list.
  5. Open General, Headers, Request, or Response to inspect it.

API Lens observes Unreal's global HTTP callbacks while capture is active. Another plugin using the same callbacks can conflict with it. If your project includes analytics or backend monitoring plugins, review Compatibility before enabling capture.

5. Read a request

Each row shows the request time, status, method, duration, host, timeline, and stored URL path. Selecting a row opens its details:

  • General — result, timing, size, origin, and privacy information.
  • Headers — sanitized request and response headers.
  • Request — the retained request-body preview.
  • Response — the retained response-body preview.

Valid JSON can be viewed as a searchable tree, formatted text, or raw retained content.

6. Finish safely

Select Stop capture when you are done. Captured history remains in memory until it is cleared, evicted by configured limits, or the editor session ends.

Before copying or exporting any request, review the privacy and redaction guide.

Next steps