collision-guard
Warns when another open Claude chat recently edited the same file.
Source and capability notes checked · By Nate Herk · Updated Oct 3, 2026
What collision-guard looks like in use
No recording yet for collision-guard. The repository README has the details.
Before you install
A mod is not sandboxed. It runs inside Claude Code with your permissions. This one:
- can read Edit paths
- can read first-prompt chat labels and other local edit ledgers
- can write Per-chat JSON edit ledgers
Check it yourself before running it: git clone https://github.com/nateherkai/claude-code-mods && claude plugin validate ./ · MIT licensed
Install
claude plugin marketplace add nateherkai/claude-code-mods
claude plugin install collision-guard@nateherk-mods
Then run /guard inside the session.
Needs Claude Code 2.1.287 or later. After installing, run
/reload-plugins if the session was already open.
Full install guide
What changes after installation
Before a supported edit, the mod checks other local chats for recent changes to the same path. A collision opens a dialog where you can proceed, cancel or move tracked-file work into a git worktree.
/guard lists recent chat activity. The detection window and enabled state can be changed through the same command.
Good to know
All participating chats need the mod loaded, so start new chats after installation. Ledgers are local to one machine and user account. The short first-prompt label can appear in another chat’s collision question unless recording mode masks it.
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