Summary
The assistant reaches for pc_* components instead of inventing Tailwind.
Without the schemas, an agent writing HEEx guesses at markup. With them it gets attrs, slots, allowed values and an example on demand — and because the schemas are generated by introspecting the library, they do not drift away from it.
What it is
A hosted MCP server serving schemas for petal_components, the Shadcn-style component library for Phoenix LiveView. The schemas are extracted from the library itself by a Mix task that introspects Phoenix.Component.__components__/0, so they track the real library rather than a hand-written copy.
What you get
- Every component in the library listed with a one-line summary
- The full schema for one component — attrs, slots, defaults, allowed values and docs
- A HEEx usage example alongside the schema
Requirements
Nothing to install — add https://mcp.petal.build to your client as an HTTP server, then work inside a Phoenix project. No account, no key.
Setup effort
One command — claude mcp add petal --transport http https://mcp.petal.build