Why Github Copilot network request not appeared in Visual Studio Code Developer Tools?

I am working on a confidential project, so I ensure that only specific parts of the code are sent to Copilot Chat. To achieve this, I have disabled Copilot Completion and primarily use Copilot Chat. At the file level, I have disabled it entirely and only enable it for the specific range of code I select when necessary. In some cases, I include entire files, but only if I am certain they contain no confidential data. Otherwise, I use the traditional method of copying the code and pasting it into the chat.

The method I used to inspect network requests was to press Ctrl+Shift+P, type Developer: Toggle Developer Tools, and press Enter. A new window, similar to the Chromium browser, then opened. I inspected the network requests in the Network tab, started the Copilot conversation, and checked the Network DevTools again. However, no network requests related to GitHub or Copilot appeared.

Another method I tried was opening Copilot Chat in a new window. Then, I pressed Ctrl+Shift+P, typed Developer: Open Webview Developer Tools, and pressed Enter. However, no new window appeared.

It's true that VSCode Developer Tool cannot inspect extension network because it's running under separate process called the Extension Host. You can take a look here but it seems complicated to setup https://stackoverflow.com/a/67099176/3789481

A simpler approach is to use Fiddler Classic as a forward proxy. By doing this, all API requests from VSCode will go through Fiddler, allowing you to inspect them, including HTTPS requests through TLS Inspection.

Fiddler setup:

VSCode setup:

After that, you can inspect for any *.githubcopilot.com directly, e.g. inline suggestion

VSCode will send prompt and get response back as Content-Type: text/event-stream

You can also inspect GHCP Chat with that same endpoint