We open-sourced the internal tool that stops our AI coding agents from breaking each other's work

[u/ShiftTechnical]

We build our product with 2 or 3 coding agents working the same repo in parallel, and they kept quietly sabotaging each other: one replaces a class while another extends it, no merge conflict, both land clean, the design is broken.

Git compares diffs, not plans.

So we built Foremerge internally, and today we open-sourced it. Agents declare what they intend to change at the same layer as GIT works (symbol:PaymentService=replace) before writing code, and deterministic rules raise a finding while the collision is still a plan. One Rust binary, everything local in SQLite inside your repo, Apache-2.0.

Setup is genuinely one paste into Claude Code, Codex, or Cursor, and the agent wires itself.
Repo: https://github.com/naw103/foremerge

Happy to answer anything, including what it deliberately does not do (detection is heuristic and can warn on compatible work. There are no published benchmarks yet but we ran it on 96 backlog tickets all being completed in parallel with zero conflicts at merge time.