Storybook

With @storybook/addon-mcp added, Storybook’s dev server answers at localhost:6006/mcp. The server has three sets of tools. The docs tools list the components and show one with its props, its first three stories and the docs you wrote for it. The development tools give the agent instructions for writing stories, preview what changed and open a review. The testing tool runs the tests, accessibility checks included. In the npm description’s words, it helps “agents automatically write and test stories for your UI components”.

All of it reads a components manifest: JSON that Storybook builds from your stories and the prop types it extracts from your code. The manifest is off until you switch it on in the config.

Storybook gives a design system agent access and readable docs for its components, and a test step that belongs with the acceptance checks. Storybook also publishes an llms.txt and an llms-full.txt of its own docs, and every docs page opens as Markdown when you add .md.

Among the 12 systems compared, Microsoft Fluent 2 publishes its React docs as a Storybook, and its llms.txt is built from that Storybook by a tool in Fluent’s repository.

• Your stack. The agent setup works only with React on Vite today; the manifest also comes from Angular and Vue on Vite (Vue with one more setting), and from no other framework.
• The version. Preview features can change in minor releases, and a beta of the addon’s next major version is already on npm.
• That the manifest is on, and that its props come from your types: the docs recommend react-docgen-typescript for that.