tmux-long-tasks - SKILL.md Agent Skill

name: tmux-long-tasks description: Use tmux to launch and manage long-running jobs that must survive beyond the bash tool timeout. Use this skill when the user mentions long-running commands, background tasks, training jobs, large builds, or any command expected to exceed the bash tool timeout. license: MIT metadata: tmux: long-running jobs bash: background tasks

Run Long Tasks with tmux

The bash tool kills all processes (including & and nohup) when it times out. Use tmux for any job that may exceed the timeout.

Do NOT use &, nohup, or shell backgrounding for long-running jobs.

Required Inputs

Before launching, you need:

tmux session name
Job/window name
Working directory
Command to run

If any are missing, ask the user and stop.

Instructions

Step 1: Check tmux sessions

tmux list-sessions 2>/dev/null || echo "NO_TMUX_SESSIONS"

If tmux is not installed, stop and report.

If the target session does not exist, create it:

tmux new-session -d -s <session>

Step 2: Create a window and launch the job

tmux new-window -d -n <job_name> -t <session>
tmux send-keys -t <session>:<job_name> 'cd /work/dir || exit 1; CMD 2>&1 | tee run.log' Enter

Use cd <dir> || exit 1 (not &&) so failures are visible in pane output.

If a window with the same name already exists, append a suffix (e.g., _2).

Step 3: Verify the job started

sleep 2
tmux capture-pane -p -t <session>:<job_name> | tail -5

If the shell prompt reappeared or an error is visible, the job failed immediately. Report to user.

Step 4: Check progress

tmux capture-pane -p -t <session>:<job_name> | tail -20

For full history, use the log file:

tail -20 /work/dir/run.log

Step 5: Stop the job

tmux send-keys -t <session>:<job_name> C-c

Step 6: Report to user

After launching, report:

Job launched in tmux.
Session: <session> | Window: <job_name>
Log: <log_file>
Check: tmux capture-pane -p -t <session>:<job_name> | tail -20
Stop:  tmux send-keys -t <session>:<job_name> C-c