- name
- codex-worker
- description
- Spawn and manage multiple Codex CLI agents via tmux to work on tasks in parallel. Use whenever a task can be decomposed into independent subtasks (e.g. batch triage, parallel fixes, multi-file refactors). When codex and tmux are available, prefer this over the built-in Task tool for parallelism.
# 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
```bash
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:
| | Format | Example |
|---|---|---|
| Task name | `<type>-<number>-<desc>` | `issue-836-prompt-dollar-sign` |
| Git branch | same as task name | `issue-836-prompt-dollar-sign` |
| Worktree dir | `<project>.worktrees/<task>` | `kimi-cli.worktrees/issue-836-prompt-dollar-sign` |
| tmux session | `codex-worker-<task>` | `codex-worker-issue-836-prompt-dollar-sign` |
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
```bash
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`.
```bash
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
```bash
tmux capture-pane -t "$SESSION" -p | tail -30
```
### Attach for hands-on interaction
```bash
tmux attach -t "$SESSION"
```
### Parallel fan-out
```bash
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.
```bash
codex exec --dangerously-bypass-approvals-and-sandbox \
-o "/tmp/$NAME-result.md" \
"Your prompt here"
```
## Lifecycle management
List active workers:
```bash
tmux ls | grep ^codex-worker-
```
Kill a finished worker:
```bash
tmux kill-session -t "codex-worker-$NAME"
```
Clean up worktree after merging:
```bash
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:
```bash
tmux list-sessions -F '#{session_name}:#{pane_dead}' \
| grep ':1$' \
| cut -d: -f1 \
| xargs -I{} tmux kill-session -t {}
```
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