How to run several Claude Code sessions at once
Three ways. None of them needs anything configured on the Claude Code side.
Table of contents
Separate terminal windows
The cheapest option. Open two windows and run claude in each.
What bites is when both sessions touch the same file. One overwrites the other’s change and nobody is told. Give each session its own directory, or its own git worktree.
git worktree add ../work-auth -b fix-auth
cd ../work-auth && claude
tmux panes
Once windows stop being manageable, split with tmux. The sessions survive a closed terminal, so reconnecting over ssh picks up where you left off.
tmux new-session -d -s auth -c ../work-auth 'claude'
tmux attach -t auth
Past a handful of panes the screen runs out. Nine panes leaves text too small to read, and you still have to visit a pane to learn whether it is waiting for you.
More on that in what tmux does not solve.
A browser grid
MulmoTerminal keeps tmux underneath and puts the sessions in a browser grid.
npx mulmoterminal@latest
Each cell gets its own git worktree, so the first problem does not arise. The cell’s colour says whether the agent is working, waiting for you, or done, and the sound for waiting differs from the sound for finished.
Which to pick
| Sessions at once | What fits |
|---|---|
| up to 2 | separate windows |
| 3–4 | tmux |
| 5+ | something that shows state |
At two sessions, installing nothing is the fastest answer. Move on when “which one is stuck?” becomes the thing costing you time.
Related
日本語版: claude-code-parallel