#Fixture app

A small React app for manually exercising the react-devtools-cdt-mcp tools with chrome-devtools-mcp. Not part of the published package.

It renders a variety of components so every tool has something to inspect: function/host/context/memo/forwardRef nodes, a custom hook (nested subHooks), keyed list items, and timer/button components that re-render (for profiling).

Like react-devtools-shell, React (and the DevTools backend dependencies the facade uses) are resolved from the monorepo build output via webpack aliases, so the fixture runs against React from source — no CDN copy, and react_get_component_by_uid hooks inspection matches the build exactly.

#Run

1. Build React for DevTools from the repo root (populates build/oss-experimental/):

   yarn build-for-devtools

1. Start the fixture dev server (bundles the package source + this app):

   cd packages/react-devtools-cdt-mcp/fixtures/app
   yarn start

This opens http://localhost:8080/.

1. Point chrome-devtools-mcp at the page. The React tool group is discovered automatically — list it with list_3p_developer_tools and call the tools with execute_3p_developer_tool({toolName, params}).

#Test with the chrome-devtools-mcp CLI

With the dev server running, drive the tools end-to-end from the CLI:

1. Start chrome-devtools-mcp with experimental third-party tools enabled:

   chrome-devtools start --categoryExperimentalThirdParty=true

1. Navigate to the fixture page:

   chrome-devtools navigate_page --url http://localhost:8080

1. Run a React tool by name:

   chrome-devtools execute_3p_developer_tool <react-tool-name>