LabscoMCP early access ↗
ShahramMebasharMCP SERVER · OFFICIAL PROJECT

Cairn

A task graph that lives as Markdown in your repository — agents claim ready work, run an observable session, and hand off for review, with the same gates the web UI enforces.

by ShahramMebashar ↗Project & Task Management✓ Official

LABSCO SUMMARY

The gates are the same for the agent and for you.

Both front-ends are thin adapters over one rule-set, so an agent cannot close a task by a route that skips the checks a human would have to pass. Closing deliberately blocks while the checks run — the latency is the point, since closing is when verification belongs. Because identity comes from --actor at startup rather than from the call, the provenance trail is something an agent cannot spoof by passing a different name.

What it is

A single Go binary that serves one task graph two ways: a web board for you and an MCP server for your agents. The tasks are Markdown files in the repository — YAML frontmatter for the machine, prose for people — so they branch, merge and review like code, and a task's history is its git history. No database.

What you get

  • Reads — identity for the bound actor, list filtered by status, assignee, ready or execution, and get for one task with its body, checks and provenance
  • create — the engine assigns the id; deps must already exist, so the graph never dangles, and checks can carry a shell command or be marked manual
  • claim to take a task, transition to move it, note to append an audit breadcrumb without changing state
  • Two gates enforced on every path: a task cannot leave its initial state until its dependencies close, and cannot enter a closed state until its checks pass — transition auto-runs the command checks and refuses on any failure
  • run_checks to run them without transitioning, with full output written to .cairn/runs/
  • Agent sessions — begin atomically claims the task and creates a durable attempt with an idempotency key, heartbeat reports progress, finish requires a review summary and moves to review, cancel releases the assignment and leaves the task open; get_session and list_sessions read them back
  • ready derived on read from whether dependencies are satisfied, never stored — so list(ready=true) is the agent's "what can I start now" query
  • Every write stamped with the actor that made it

Requirements

No account and no key. make build produces bin/cairn; there is also a desktop app for macOS, Windows and Linux on the releases page. ./bin/cairn web --repo . opens the board, and its Connect page detects installed agents and writes their MCP config for you — Claude Code, Cursor, Codex, Windsurf, OpenCode, Kilo Code and Pi in one click. By hand, register the binary by its full path: /path/to/repo/bin/cairn serve --actor agent:claude --repo <path>. Identity is fixed at startup by --actor and is not a tool argument, which is how each agent gets its own name in the provenance. Local and single-user by design, with no authentication. MIT.

Setup effort

Build from source

See installation options