PQM.guide

A community-driven Power Query M language reference, hosted at pqm.guide.

PQM.guide documents 661 Power Query M functions across 26 categories with clear syntax references, visual output examples, and practical best practices. It also includes concept guides, practical patterns, and an MCP server so AI assistants can query M documentation directly. Think of it as DAX.guide for the M language.

What's on the Site

Section	URL	Description
Functions	/functions/[slug]	661 functions across 26 categories with syntax, parameters, examples, and best practices
Concepts	/concepts/[slug]	22 concept guides covering M fundamentals (lazy evaluation, query folding, type system, etc.)
Patterns	/patterns/[slug]	18 practical M recipes grouped by difficulty (beginner → advanced)
Start Here	/learn	A curated 8-step learning path for developers new to M
Sample Tables	/sample-tables	Reference data used in function examples (Sales, Customers, Products, Employees, OrderLog)
Resources	/resources	Curated tools, books, YouTube channels, blogs, and community links
MCP Server	/mcp	Connect AI assistants like Claude and Cursor to PQM.guide via the Model Context Protocol
Format M	/format-m	Interactive formatter and validator for Power Query M snippets

API & LLM Access

PQM.guide exposes several machine-readable endpoints:

Endpoint	Description
GET /api/functions	All 661 functions (metadata)
GET /api/functions/[slug]	Single function with full content, remarks, and parsed examples
GET /api/concepts	All concept guides
GET /api/concepts/[slug]	Single concept with full content
GET /api/patterns	All patterns
GET /api/patterns/[slug]	Single pattern with full content
GET /api/search?q=	Fuzzy search across all functions
GET /api/tables/[id]	Sample table data as JSON (Sales, Customers, Products, Employees, OrderLog)
GET /llms.txt	Plain-text index (llmstxt.org format) for LLM crawlers
POST /api/mcp	MCP JSON-RPC 2.0 endpoint (Streamable HTTP transport)
POST /api/format-m	Format or validate M code — body { code, action: "format" | "validate" }

MCP Server

Connect Claude Desktop by adding this to claude_desktop_config.json:

{
  "mcpServers": {
    "pqm-guide": {
      "command": "npx",
      "args": ["mcp-remote", "https://pqm.guide/api/mcp"]
    }
  }
}

Any client supporting Streamable HTTP can also connect directly to https://pqm.guide/api/mcp.

Contributing

PQM.guide is open to contributions from the Power Query community. Most content is MDX (Markdown + YAML frontmatter) — no React, TypeScript, or Next.js knowledge required for typical edits.

See CONTRIBUTING.md for full details: frontmatter schemas, example output format, slug rules, sample table usage, and PR guidelines.

Quick ways to help:

• Fix a typo or improve a function's remarks
• Improve a function's remarks or examples
• Write a new concept guide or pattern recipe
• Open an issue or start a discussion if you'd rather suggest changes without code

Claude Code commands

If you use Claude Code, the repo includes slash commands that automate content scaffolding and publishing:

Command	What it does
/add-function	Scaffold a new function page — prompts for the function name, researches the official spec, generates the MDX file with correct frontmatter, and runs tests
/add-concept	Scaffold a new concept guide
/add-pattern	Scaffold a new pattern recipe
/edit-page	Edit an existing page — accepts a URL, slug, or M function name (e.g. Table.AddColumn), reads the current content, and walks you through the change
/publish	Package uncommitted changes into a pull request
/refresh-site	Full content freshness review — scans Microsoft blogs, checks for new M functions, verifies compatibility flags, and updates stale content

These commands live in .claude/commands/ and are loaded automatically when you open the project in Claude Code.

Running Locally

git clone https://github.com/kyleamueller/PQM.guide.git
cd PQM.guide
npm install
cp .env.example .env.local   # optional — enables Google Analytics locally
npm run dev

Open http://localhost:3000 to preview the site. npm install also sets up a pre-push hook that runs type checking and tests automatically. Google Analytics is optional — the site works fully without setting NEXT_PUBLIC_GA_MEASUREMENT_ID.

Other useful commands:

npm run typecheck   # TypeScript type check
npm run test        # Vitest test suite (45 tests)
npm run build       # Full production build (1,447 pages)

License

• Code (the Next.js app, components, API routes): MIT
• Content (function references, concept guides, patterns in src/content/): CC BY 4.0

If you republish or build on the documentation content, attribution to pqm.guide is required.

Tech Stack

• Next.js 16 with App Router
• React 19
• Tailwind CSS 4
• TypeScript, MDX, gray-matter, PrismJS, Fuse.js, next-themes
• @fluentui/react-icons for sidebar category icons
• @microsoft/powerquery-formatter and @microsoft/powerquery-parser (MIT) power the /format-m page and the format_m_code / validate_m_code MCP tools — the same engines behind VS Code's Power Query extension
• MCP: JSON-RPC 2.0 over Streamable HTTP (no external SDK)
• Deployed on Vercel