A context repository is a git repo of Markdown files where you store the documents your AI needs to operate with real understanding. Product vision, PRDs, feature specs, customer profiles, glossary — all versioned and reviewable, where both humans and agents can find it.

Why Markdown in git instead of Notion? Local files are instant (no MCP latency). Markdown is token-efficient — no rich-text metadata, just content. And git gives you versioning, branching, and reviewable PRs for free. When you update five documents as part of a product pivot, that's one PR you can roll back.

Then you add an AGENTS.md to the root of your project that links to the important documents. Think of it as a table of contents for your AI. When an agent picks up a task, it reads AGENTS.md first, then follows the links as needed.