@alex_prompter: Two AI agents editing the same codebase will wreck each other's work unless you give them this instruction. Run two age…

Two AI agents editing the same codebase will wreck each other's work unless you give them this instruction. Run two agents in the same repo at once, and they start undoing each other's changes. One refactors a file, the other decides it looks broken and reverts it. You end up debugging your agents instead of your code. You don't need worktrees or an orchestration framework for this. The fix is one shared markdown file that both agents can write to. Add this line to each agent's prompt. "You're not the only agent working on this project. If something changes that you didn't touch, it was probably another agent. Use notes.md to leave messages for each other. Never block each other's work, resolve conflicts together, and delete your messages from the file when you're done." Now they coordinate instead of colliding. One agent drops a note saying it's rewriting the auth module, the other reads it and stays out of that folder until the note clears. It works across different models, too. The file is the protocol, so it doesn't matter whose agent is reading it. Try it next time you run agents in parallel.