# Harnery > Multi-agent coordination for AI coding agents: Claude Code, Cursor, and Codex. [](https://github.com/ryanjkelly/harnery/actions/workflows/ci.yml) [](https://www.npmjs.com/package/harnery) [](LICENSE) > ⚠️ **Pre-1.0.** API surface is still settling. Pin a specific minor version (`harnery@^0.31.0`) and read the [CHANGELOG](CHANGELOG.md) before each upgrade. ## What it is `harnery` keeps multiple AI coding agents from stepping on each other in a shared checkout. It came out of years of running several Claude Code / Cursor / Codex sessions at once against the same monorepo. - **Multi-agent coordination.** Per-agent heartbeats in `.harnery/active/`, claim-time and commit-time guards, the canonical event stream, councils, a decision docket, per-agent journals, and adapter adapters for Claude Code / Cursor / Codex. - **Cross-machine presence.** Sessions on every machine that shares a repo see each other, labeled by machine. Zero-config over the repo's own git remote (presence refs), with an optional live-socket upgrade via an end-to-end-encrypted relay: the public `relay.harnery.com`, or self-host with `harn relay serve` / the bundled Cloudflare Worker (`relay/worker/`). The relay sees only ciphertext in opaquely-named rooms. - **Coordination-aware workflows.** `harn workflow run