CodebaseOS — Origin Story for Any Line of Code

Every line of code has a story — why it was written, what PR introduced it, what issue it fixed, what decision shaped it. That story is normally scattered across git history, closed PRs, and stale issues. CodebaseOS reconstructs it on demand: right-click any line, ask "why," and get a graph-grounded answer with clickable links to the real PR, commit, or issue — in about 200ms.

**How it works**: CodebaseOS ingests a repository's history into a HydraDB temporal context graph — commits, PRs, issues, and the relationships between them. Ingestion is Merkle-chain verified, so you can prove the graph matches the source history (`make verify` → ✓ Merkle chain intact). Small repos are ingested completely (and report coverage, e.g. "✓ complete: 38/38 commits"); large repos are sampled (latest N) and flagged honestly.

**In the editor**: hover a line or click the 🧬 Why? / 📜 Origin story CodeLens to get a graph-grounded answer. Other commands — "Explain this file" (what it does, who owns it, key decisions), "What changed" (everything touching a file in a date range), and "Bus factor" (who holds the knowledge and the risk if they leave). Any answer can be copied as Markdown to paste into a PR or doc. No graph database to operate, no query language to learn — just ask.

**Architecture**: a VS Code extension (hover, CodeLens, webviews), a FastAPI backend, and a dashboard with a force-directed graph, chaos view, and time-travel. Built for the "Agents Under Pressure — Build your own OS" 48-hour hackathon at AI Valley. Published to the VS Code Marketplace.