The OOXML spec, explained by people who actually implemented it.

What is this?

An interactive reference for ECMA-376 (Office Open XML) with:

• Live previews - See XML rendered in real-time with SuperDoc
• Implementation notes - Real-world gotchas from building document processors
• Practical examples - Working code, not just spec excerpts

Why?

The official ECMA-376 spec is 5,000+ pages. Most of it you'll never need. This reference focuses on what matters for building document tools, with insights from implementing SuperDoc.

MCP Server

The world's first ECMA-376 MCP server. Ask Claude about OOXML and get answers grounded in the actual spec.

claude mcp add --transport http ecma-spec https://api.ooxml.dev/mcp

Example: "How do I set paragraph spacing in WordprocessingML?" - Claude searches 18,000+ spec chunks and returns the relevant sections.

Development

# Install dependencies
bun install

# Start dev server
bun dev

# Build for production
bun run build

Contributing

Contributions welcome! Add implementation notes, fix examples, or improve docs.

License

MIT

---

Built by 🦋SuperDoc