repolith
The coordination layer for parallel AI coding agents.
File-level locks, plan-conflict detection, and auto-resume for multiple Claude Code sessions on the same repos. Worktree isolation defers the conflict to merge time — after every session already did the work. Coordination prevents it at plan time and edit time.
Real repolith from npm, nothing mocked — two sessions collide, the second is denied, waits, and auto-resumes.
9 weeks of dogfooding on the author's own two-repo workspace (Jun 29 – Aug 30, 2026). Exact counts from the coordination journal.
How it works
Plan-time catch
A hook on ExitPlanMode captures each session's plan. Two plans overlapping on the same files? The second session finds out before writing a line.
Edit gate + auto-resume
First touch claims the file. A second live session is denied with the holder named, can queue, and resumes FIFO the moment the file frees up. Deadlocks are surfaced, not hung.
Journal + drift control
Every file has a journal. Sessions read what the last session did there before editing, and get a catch-up brief on start. Heartbeats + git-verified staleness keep crashed sessions from wedging the store.
Honest limits: same-machine only (shared JSON store), cooperative — it coordinates sessions that run the hooks. Claude Code today; other agents via the CLI. Advisory by design: every hook exits 0 on internal failure, so coordination can never break your edit flow. Also does multi-repo: TOML manifest, lockfile with an atomic workspace hash, parallel dispatch, VS Code extension.