Request Inspector

Request Inspector helps developers inspect outgoing HTTP requests while running and debugging code in VS Code. It starts the system mitmproxy command in a managed VS Code Terminal and automatically injects proxy environment variables into VS Code debug sessions while the proxy is active.

Once mitmproxy is installed, the goal is zero configuration for day-to-day development: start the proxy, run your code, and check whether the requests your program sends are correct.

Features

• System mitmproxy runtime: uses the mitmproxy command available on your PATH.
• One-click proxy control: start, stop, restart, toggle, or focus the managed proxy from the command palette and Status Bar.
• Default proxy port: uses 8888 when available and falls back to another available local port when needed.
• Native terminal experience: runs mitmproxy in a regular VS Code Terminal so captured traffic stays visible and interactive.
• Debug-session proxy injection: adds HTTP_PROXY, HTTPS_PROXY, and ALL_PROXY while the proxy is running, without modifying .vscode/launch.json.

Requirements

Install mitmproxy on your system before starting the proxy. Request Inspector runs the mitmproxy command from your PATH and does not download or install a runtime automatically.

Typical Workflow

flowchart TD
    command[Run mitmproxy: Start mitmproxy]
    port[Use port 8888 or choose another available local port]
    terminal[Start mitmproxy in a managed VS Code Terminal]
    inject[Enable proxy environment injection]
    debug[Start a VS Code debug session]
    app[Application sends HTTP requests]
    proxy[Requests pass through local mitmproxy]
    inspect[Inspect requests in the managed terminal]
    stop[Run mitmproxy: Stop mitmproxy]
    cleanup[Terminate the terminal and stop injecting proxy variables]

    command --> port
    port --> terminal --> inject --> debug
    debug --> app --> proxy --> inspect
    inspect --> stop --> cleanup

In practice, start mitmproxy before launching your application debug session. Request Inspector uses port 8888 when available and opens a managed VS Code Terminal for the proxy. If 8888 is already in use, it falls back to another available local port. While the proxy is running, new debug sessions receive standard proxy environment variables so supported HTTP clients send traffic through local mitmproxy. When inspection is finished, stop mitmproxy to close the managed terminal and disable proxy injection for future debug sessions.

Limitations

Request Inspector depends on applications respecting standard proxy environment variables. Some runtimes, SDKs, or HTTP clients may need their own proxy configuration.

To inspect HTTPS traffic, the application or system trust store must trust the mitmproxy certificate authority. See the official mitmproxy certificate documentation for setup details.