Msw setup
Scaffold MSW and @msw-mcp/client in a web project for AI-driven dynamic mocks. Use when the user asks to set up MSW, add mocking to a new app, or migrate an existing MSW project.From its SKILL.md
npx -y skills add JasonBoy/msw-mcp --skill msw-setupAssembled from the repository path, not quoted from the project. Check it against their README if it does not work.
One thing to look at
- runs commandsInstructs the agent to run 4 commands, including `msw-cli setup` and 3 more.
SKILL.md
1.9 KB, 453 tokens by cl100k_base, as published. Nobody here has run it
msw-setup
Project scaffolding for MSW + the MCP client bridge. For runtime handler changes after setup, use the msw-cli skill.
Workflow
- Run
msw-cli setupin the project root (optional:--framework vite). - Follow the printed setup guide step by step (detect bundler, install deps, create
mocks/, env vars, entry point). - Run
msw-cli openand set the app's WebSocket URL to the URL from the output. - Run
msw-cli statusafter starting the dev server — confirmconnected: true(this only proves the WebSocket bridge, not that the first browser requests were intercepted). - Hard reload the app and confirm in DevTools → Network that initial API calls are mocked. This catches render-before-mock races that
msw-cli statusmisses. - Use
msw-cli add(and related commands) to manage mocks at runtime.
Do not duplicate the full setup guide in chat — execute from msw-cli setup output.
Notes
- Ask permission before
npm install/npx msw init(as the guide describes). - The WebSocket URL env var name depends on the framework:
NEXT_PUBLIC_MSW_WS_URL(Next.js),VITE_MSW_WS_URL(Vite), orMSW_WS_URL(Rspack/Rsbuild/Webpack) — must match the port frommsw-cli open. (MCP_SERVER_URLis accepted as a legacy fallback.) - Next.js App Router:
app/layout.tsxis a Server Component; the MSW bootstrap must be a'use client'gate so the app subtree does not mount (and fetch) beforeinitMocks()finishes. Follow the guide’s gatedMswProviderpattern — do not start MSW in a paralleluseEffectwhile rendering the full tree. - MCP users can still use
/msw-setupin an MCP client; the same guide backs both paths.
What ships with it
Read from the repository
Just SKILL.md. No reference files, no scripts.