• Install mitmproxy as described in ../CONTRIBUTING.md
• Run node --version to make sure that you have at least Node.js 24 or above.
• Run cd ./web to change to the directory with package.json.
• Run npm install to install dependencies.
• Run uv run mitmweb
• Run npm start in a separate window to start the Vite development server for the web interface.

• Run npm test to run the test suite.

• Run npm run prettier to format your code. You can also integrate prettier into your editor, see https://prettier.io/docs/en/editors.html

There are two components:

• Server: mitmproxy/tools/web

• Client: web

We very much appreciate any (small) improvements to mitmweb. Please do not include the compiled assets in mitmproxy/tools/web/static in your pull request. Refreshing them on every commit would massively increase repository size. We will update these files before every release.

• You can debug application state using the React DevTools and Redux DevTools browser extensions.