agentmash

When multiple team members each run their own AI coding agent, the agents don't know what the others are changing until the work collides, often at merge time. The page frames this as a growing problem as more of a codebase's edits come from agents working in parallel: without coordination, only about 55% of overlaps are caught before a conflicting write, and teams spend hours on manual fixes, reruns, and merge conflicts. It cites per-task costs like 2.70 human hours, $182 in combined cost, and 540 minutes of human conflict-resolution time per 100 tasks when agents work without any shared awareness.

agentmash is a desktop app (download for Mac or Windows) that sits alongside each teammate's existing coding agent (Claude Code, Cursor, Codex, Gemini CLI, and others) and gives it a heads-up before an edit lands: if another agent has uncommitted or in-progress changes to the same file, the acting agent is told to keep its change additive and to say so in its reply. It includes a shared chat where the last messages reach every agent before its next prompt, an '@' mention system, and a lobby mechanism where one teammate can ask a prompt against a teammate's agent, with that teammate approving, narrowing, or declining the request before anything runs on their own machine and account. The page reports the system catching 98.6% of overlaps before a conflicting write, settling 98.5% of overlaps without a human arbiter, and cutting cost per task by about 33% and merge time by about 52% across tested model pairs.