# Project rules: my first MCP server

## What we are building
A small MCP server in TypeScript that gives an AI assistant three tools over a local notes folder:
list_notes, read_note and search_notes. It runs over stdio and is used from Claude Code or Claude Desktop.

## Stack
- Node.js 20+, TypeScript, ES modules
- @modelcontextprotocol/sdk (official TypeScript SDK)
- zod for tool input schemas

## Rules
- Never write to stdout except through the MCP transport. Use console.error for logs (stdout is the protocol channel).
- Every tool validates input with zod and returns a clear text error instead of throwing.
- Read-only: no tool may create, change or delete files.
- Only files inside NOTES_DIR can be read. Resolve paths and reject anything outside it (no ../ escapes, no symlinks out).
- Keep tool descriptions short and specific: the model chooses tools by reading them.
- After each change run: npm run build. Fix type errors before moving on.