subcodex

name	subcodex
description	Collaborate with Codex (GPT-5.2) via named sessions. Trigger: user asks to work with Codex, use Codex, ask Codex, involve Codex, etc. CRITICAL: Use subcodex CLI via Bash, NOT the Task subagent tool.

subcodex

Named Codex sessions that persist across conversation compacts.

Quick Reference

# New session
./skills/subcodex/subcodex new <name> "prompt"

# Resume session
./skills/subcodex/subcodex resume <session-name> "prompt"

# List sessions (shows last 25, use --all for all)
./skills/subcodex/subcodex list

# Code review
./skills/subcodex/subcodex review --uncommitted <name>
./skills/subcodex/subcodex review --base main <name> "focus on security..."

Critical: Background Execution

ALWAYS use run_in_background: true — Codex takes 1-30+ minutes.

After starting a background command:

1. Tell the user you're waiting for Codex
2. Stop immediately — don't poll or check
3. You'll be notified via <task-notification> when Codex is done

Codex Capabilities

Codex can read, write, and execute — just like you. Tell it to make changes directly, not to provide diffs or suggestions.

Options:

• --reasoning low|medium|high|xhigh (default: high)
• --read-only — read-only sandbox
• --dangerous — full system access

Sessions

Session names get a random suffix: my-task becomes my-task-x7k2.

Use the full name (with suffix) when resuming:

./skills/subcodex/subcodex resume my-task-x7k2 "continue with..."

subcodex list shows: status (running/stopped), tool_calls, cwd, duration.

Code Reviews

# Review uncommitted changes
./skills/subcodex/subcodex review --uncommitted my-review

# Review against branch
./skills/subcodex/subcodex review --base main my-review

# Review specific commit
./skills/subcodex/subcodex review --commit HEAD my-review

# Add instructions
./skills/subcodex/subcodex review --uncommitted my-review "read these relevant docs first, focus on security, suggest simplifications, .."

Reviews use --reasoning xhigh and read-only mode by default.

Collaboration

Claude leads, Codex executes. Use Codex to review designs and implement complex tasks. Push back on over-engineering.

Typical flow:

1. Claude proposes approach
2. Codex reviews/critiques
3. Claude decides
4. Codex implements
5. Claude reviews result

Push for simple code: less abstraction, fail-fast, no "just in case" code.