Coordinating multiple AI coding agents on one repo or multiple in your own ecosystem — without git worktrees

If you have run more than one AI coding agent at once, you have met the failure

mode: agent A is editing src/auth.py while agent B rewrites the same file. One of them loses. The usual fixes are real, but they both dodge the actual problem.

The two usual answers, and what they dodge

Git worktrees. Give each agent its own checkout sharing one .git. They cannot collide on disk, and conflicts surface at merge time. This is isolation — it keeps agents apart so they never have to coordinate. Great until the merges fight.

Agent frameworks (LangGraph, CrewAI, AutoGen). You write the agents and their control flow in one process; one orchestrator spawns sub-agents. Powerful, but it assumes you are building the agents. If you are running off-the-shelf terminal assistants from different vendors, that is not your situation.