coding-agent git:20260308.b387a85A

Immutable. This exact content is served forever at /api/v1/blob/819127912c0c66ac.

---
name: coding-agent
description: 'Delegate coding tasks to Codex, Claude Code, or Pi agents via background host sessions. Use when: (1) building or creating new features or apps, (2) reviewing PRs (spawn in temp dir), (3) refactoring large codebases, (4) iterative coding that needs file exploration. NOT for: simple one-liner fixes (just edit), reading code (use read tool), thread-bound ACP harness requests in chat (for example spawn or run Codex or Claude Code in a Discord thread; use sessions_spawn with runtime:"acp"), or any work in ~/clawd workspace (never spawn agents here). Requires OpenClaw host tools with exec_command plus write_stdin.'
metadata:
  {
    "openclaw": { "emoji": "🧩", "requires": { "anyBins": ["claude", "codex", "opencode", "pi"] } },
  }
---

# Coding Agent (exec_command-first)

Use **exec_command** (with optional background mode) for all coding
agent work. Use **write_stdin** to poll or continue a running session.

## ⚠️ PTY Mode Required!

Coding agents (Codex, Claude Code, Pi) are **interactive terminal applications** that need a pseudo-terminal (PTY) to work correctly. Without PTY, you'll get broken output, missing colors, or the agent may hang.

**Always use `tty:true`** when running coding agents:

```bash
# ✅ Correct - with PTY
exec_command tty:true command:"codex exec 'Your prompt'"

# ❌ Wrong - no PTY, agent may break
exec_command command:"codex exec 'Your prompt'"
```

### Host Tool Parameters

| Parameter    | Type    | Description                                                                 |
| ------------ | ------- | --------------------------------------------------------------------------- |
| `command`    | string  | The shell command to run                                                    |
| `tty`        | boolean | **Use for coding agents!** Allocates a pseudo-terminal for interactive CLIs |
| `workdir`    | string  | Working directory (agent sees only this folder's context)                   |
| `background` | boolean | Run in background, returns sessionId for monitoring                         |
| `timeout_sec`| number  | Timeout in seconds (kills process on expiry)                                |

### Session Follow-Up Tools

| Tool           | Description                                          |
| -------------- | ---------------------------------------------------- |
| `write_stdin`  | Poll a session with `chars:""` or send more input    |
| `kill_session` | Terminate a background session                       |

---

## Quick Start: One-Shot Tasks

For quick prompts/chats, create a temp git repo and run:

```bash
# Quick chat (Codex needs a git repo!)
SCRATCH=$(mktemp -d) && cd $SCRATCH && git init && codex exec "Your prompt here"

# Or in a real project - with PTY!
exec_command tty:true workdir:~/Projects/myproject command:"codex exec 'Add error handling to the API calls'"
```

**Why git init?** Codex refuses to run outside a trusted git directory. Creating a temp repo solves this for scratch work.

---

## The Pattern: workdir + background + pty

For longer tasks, use background mode with PTY:

```bash
# Start agent in target directory (with PTY!)
exec_command tty:true workdir:~/project background:true command:"codex exec --full-auto 'Build a snake game'"
# Returns sessionId for tracking

# Monitor progress
write_stdin session_id:XXX chars:""

# Check if done
write_stdin session_id:XXX chars:""

# Send input (if agent asks a question)
write_stdin session_id:XXX chars:"y"

# Submit with Enter (like typing "yes" and pressing Enter)
write_stdin session_id:XXX chars:"yes" append_newline:true

# Kill if needed
kill_session session_id:XXX
```

**Why workdir matters:** Agent wakes up in a focused directory and
doesn't wander off reading unrelated files.

---

## Codex CLI

**Model:** `gpt-5.2-codex` is the default (set in ~/.codex/config.toml)

### Flags

| Flag            | Effect                                             |
| --------------- | -------------------------------------------------- |
| `exec "prompt"` | One-shot execution, exits when done                |
| `--full-auto`   | Sandboxed but auto-approves in workspace           |
| `--yolo`        | NO sandbox, NO approvals (fastest, most dangerous) |

### Building/Creating

```bash
# Quick one-shot (auto-approves) - remember PTY!
exec_command tty:true workdir:~/project command:"codex exec --full-auto 'Build a dark mode toggle'"

# Background for longer work
exec_command tty:true workdir:~/project background:true command:"codex --yolo 'Refactor the auth module'"
```

### Reviewing PRs

**⚠️ CRITICAL: Never review PRs in OpenClaw's own project folder!**
Clone to temp folder or use git worktree.

```bash
# Clone to temp for safe review
REVIEW_DIR=$(mktemp -d)
git clone https://github.com/user/repo.git $REVIEW_DIR
cd $REVIEW_DIR && gh pr checkout 130
exec_command tty:true workdir:$REVIEW_DIR command:"codex review --base origin/main"
# Clean up after: trash $REVIEW_DIR

# Or use git worktree (keeps main intact)
git worktree add /tmp/pr-130-review pr-130-branch
exec_command tty:true workdir:/tmp/pr-130-review command:"codex review --base main"
```

### Batch PR Reviews (parallel army!)

```bash
# Fetch all PR refs first
git fetch origin '+refs/pull/*/head:refs/remotes/origin/pr/*'

# Deploy the army - one Codex per PR (all with PTY!)
exec_command tty:true workdir:~/project background:true command:"codex exec 'Review PR #86. git diff origin/main...origin/pr/86'"
exec_command tty:true workdir:~/project background:true command:"codex exec 'Review PR #87. git diff origin/main...origin/pr/87'"

# Monitor each returned session id
write_stdin session_id:XXX chars:""

# Post results to GitHub
gh pr comment <PR#> --body "<review content>"
```

---

## Claude Code

```bash
# With PTY for proper terminal output
exec_command tty:true workdir:~/project command:"claude 'Your task'"

# Background
exec_command tty:true workdir:~/project background:true command:"claude 'Your task'"
```

---

## OpenCode

```bash
exec_command tty:true workdir:~/project command:"opencode run 'Your task'"
```

---

## Pi Coding Agent

```bash
# Install: npm install -g @mariozechner/pi-coding-agent
exec_command tty:true workdir:~/project command:"pi 'Your task'"

# Non-interactive mode (PTY still recommended)
exec_command tty:true command:"pi -p 'Summarize src/'"

# Different provider/model
exec_command tty:true command:"pi --provider openai --model gpt-4o-mini -p 'Your task'"
```

**Note:** Pi now has Anthropic prompt caching enabled (PR #584, merged Jan 2026)!

---

## Parallel Issue Fixing with git worktrees

For fixing multiple issues in parallel, use git worktrees:

```bash
# 1. Create worktrees for each issue
git worktree add -b fix/issue-78 /tmp/issue-78 main
git worktree add -b fix/issue-99 /tmp/issue-99 main

# 2. Launch Codex in each (background + PTY!)
exec_command tty:true workdir:/tmp/issue-78 background:true command:"pnpm install && codex --yolo 'Fix issue #78: <description>. Commit and push.'"
exec_command tty:true workdir:/tmp/issue-99 background:true command:"pnpm install && codex --yolo 'Fix issue #99 from the approved ticket summary. Implement only the in-scope edits and commit after review.'"

# 3. Monitor progress
write_stdin session_id:XXX chars:""

# 4. Create PRs after fixes
cd /tmp/issue-78 && git push -u origin fix/issue-78
gh pr create --repo user/repo --head fix/issue-78 --title "fix: ..." --body "..."

# 5. Cleanup
git worktree remove /tmp/issue-78
git worktree remove /tmp/issue-99
```

---

## ⚠️ Rules

1. **Always use `tty:true`** - coding agents need a terminal.
2. **Respect tool choice** - if user asks for Codex, use Codex.
   - Orchestrator mode: do NOT hand-code patches yourself.
   - If an agent fails/hangs, respawn it or ask the user for direction, but don't silently take over.
3. **Be patient** - don't kill sessions because they're "slow"
4. **Monitor with process:log** - check progress without interfering
5. **--full-auto for building** - auto-approves changes
6. **vanilla for reviewing** - no special flags needed
7. **Parallel is OK** - run many Codex processes at once for batch work
8. **NEVER start Codex in ~/.openclaw/** - it'll read your soul docs and get weird ideas about the org chart!
9. **NEVER checkout branches in ~/Projects/openclaw/** - that's the LIVE OpenClaw instance!

---

## Progress Updates (Critical)

When you spawn coding agents in the background, keep the user in the loop.

- Send 1 short message when you start (what's running + where).
- Then only update again when something changes:
  - a milestone completes (build finished, tests passed)
  - the agent asks a question / needs input
  - you hit an error or need user action
  - the agent finishes (include what changed + where)
- If you kill a session, immediately say you killed it and why.

This prevents the user from seeing only "Agent failed before reply" and having no idea what happened.

---

## Auto-Notify on Completion

For long-running background tasks, append a wake trigger to your prompt so OpenClaw gets notified immediately when the agent finishes (instead of waiting for the next heartbeat):

```
... your task here.

When completely finished, run this command to notify me:
openclaw system event --text "Done: [brief summary of what was built]" --mode now
```

**Example:**

```bash
exec_command tty:true workdir:~/project background:true command:"codex --yolo exec 'Build a REST API for todos.

When completely finished, run: openclaw system event --text \"Done: Built todos REST API with CRUD endpoints\" --mode now'"
```

This triggers an immediate wake event — Skippy gets pinged in seconds, not 10 minutes.

---

## Learnings (Jan 2026)

- **PTY is essential:** Coding agents are interactive terminal apps.
  Without `tty:true`, output breaks or the agent hangs.
- **Git repo required:** Codex won't run outside a git directory. Use `mktemp -d && git init` for scratch work.
- **exec is your friend:** `codex exec "prompt"` runs and exits cleanly - perfect for one-shots.
- **append_newline vs raw chars:** Use `append_newline:true` when the
  CLI expects Enter, otherwise send raw `chars`.