Codex Worker

codex-worker

Orchestrate multiple Codex CLI (codex) agents running in parallel, each in its own git worktree and tmux session.

When to use: Whenever you identify that a task can be split into independent subtasks — don't wait for the user to ask for parallelism. Examples:

• User says "triage all open issues updated in the last 7 days" → fetch the issue list, then spawn one codex worker per issue.
• User says "refactor these 5 modules" → one worker per module.
• User says "fix lint errors across packages" → one worker per package.

Replaces Task tool: When codex and tmux are available in the environment, use codex workers instead of the built-in Task (subagent) tool. Codex workers are full-featured agents with their own file system access, shell, and isolated worktree — far more capable than subagents.

Preflight check

command -v codex && codex login status && command -v tmux

All three must succeed. The project must be a git repository.

Naming convention

Git branch and worktree directory share a task name:

<type>-<issue number (optional)>-<short description>

The tmux session adds a codex-worker- prefix so workers are easy to filter:

More examples:

• issue-518-mcp-config-isolation
• fix-share-dir-skills-path
• feat-ask-user-tool
• refactor-jinja-templates

List only codex workers: tmux ls | grep ^codex-worker-

Usage

Prefer tmux + interactive codex for all tasks. It supports multi-turn dialogue, the user can tmux attach to inspect or intervene, and you can send follow-up prompts from outside.

Spawn a worker

NAME="issue-836-prompt-dollar-sign"        # task name
SESSION="codex-worker-$NAME"               # tmux session name
PROJECT_DIR="$(pwd)"
WORKTREE_DIR="$PROJECT_DIR.worktrees"

# 1. Create worktree (skip if exists)
git worktree add "$WORKTREE_DIR/$NAME" -b "$NAME" main 2>/dev/null

# 2. Launch interactive codex inside tmux
tmux new-session -d -s "$SESSION" -x 200 -y 50 \
  "cd $WORKTREE_DIR/$NAME && codex --dangerously-bypass-approvals-and-sandbox"

Send a prompt

The Codex TUI needs time to initialize before it accepts input. After launching a session, wait at least 5 seconds before sending a prompt. Then send the text followed by Enter. If the prompt stays in the input field without being submitted, send an additional Enter.

sleep 5  # wait for Codex TUI to initialize
tmux send-keys -t "$SESSION" "Your prompt here" Enter
# If it doesn't submit, send another Enter:
# tmux send-keys -t "$SESSION" Enter

Peek at output

tmux capture-pane -t "$SESSION" -p | tail -30

Attach for hands-on interaction

tmux attach -t "$SESSION"

Parallel fan-out

TASKS=(
  "issue-518-mcp-config-isolation|Triage #518: MCP config 被子 agent 继承的隔离问题。分析根因，给出修复方案。"
  "issue-836-prompt-dollar-sign|Triage #836: prompt 包含 $ 时启动静默失败。分析根因，给出修复方案。"
)

PROJECT_DIR="$(pwd)"
WORKTREE_DIR="$PROJECT_DIR.worktrees"

for entry in "${TASKS[@]}"; do
  NAME="${entry%%|*}"
  PROMPT="${entry#*|}"
  SESSION="codex-worker-$NAME"
  git worktree add "$WORKTREE_DIR/$NAME" -b "$NAME" main 2>/dev/null
  tmux new-session -d -s "$SESSION" -x 200 -y 50 \
    "cd $WORKTREE_DIR/$NAME && codex --dangerously-bypass-approvals-and-sandbox"
  sleep 5  # wait for Codex TUI to fully initialize
  tmux send-keys -t "$SESSION" "$PROMPT" Enter
done

Fallback: codex exec

Only use codex exec when you explicitly don't need follow-up (e.g. CI, pure analysis with -o output). It does not support multi-turn dialogue.

codex exec --dangerously-bypass-approvals-and-sandbox \
  -o "/tmp/$NAME-result.md" \
  "Your prompt here"

Lifecycle management

List active workers:

tmux ls | grep ^codex-worker-

Kill a finished worker:

tmux kill-session -t "codex-worker-$NAME"

Clean up worktree after merging:

tmux kill-session -t "codex-worker-$NAME" 2>/dev/null
git worktree remove "$WORKTREE_DIR/$NAME"
git branch -d "$NAME"

Batch cleanup of dead sessions:

tmux list-sessions -F '#{session_name}:#{pane_dead}' \
  | grep ':1$' \
  | cut -d: -f1 \
  | xargs -I{} tmux kill-session -t {}