Codex Agent (wrapper)

IMPORTANT: Execution Instructions

This script runs synchronously and returns output directly. Do NOT run it in the background.

When invoking via Bash, you MUST:

1. Use timeout: 600000 (10 minutes) — codex runs can take several minutes
2. Run it as a foreground command (do NOT use run_in_background)
3. Read the output directly from the Bash result — no need to poll or check later

Example Bash invocation:

Bash(command: "~/.claude/skills/codex-agent/scripts/codex-agent Your prompt here", timeout: 600000)

---

Thin wrapper around codex CLI (OpenAI Codex) for non-interactive use:

• Provide prompt via arguments, PROMPT_FILE, or stdin
• Model selection via --model or CODEX_MODEL env var
• Session resume via --resume or CODEX_SESSION env var
• Auto-detects OAuth login (~/.codex/auth.json) or API keys
• Clear error messages with diagnostics on failure

Prerequisites

Codex CLI v0.80.0+ required:

npm install -g @openai/codex@latest
codex --version  # should be 0.80.0 or higher

Authentication (one of these):

1. Run codex login for ChatGPT OAuth (creates ~/.codex/auth.json)
2. Set OPENAI_API_KEY environment variable
3. Set CODEX_API_KEY environment variable (exec mode only)

Usage

# Arguments
~/.claude/skills/codex-agent/scripts/codex-agent Your prompt here

# File via env var
PROMPT_FILE=task.md ~/.claude/skills/codex-agent/scripts/codex-agent

# Stdin
cat task.md | ~/.claude/skills/codex-agent/scripts/codex-agent

Session Resume

# Resume most recent session
~/.claude/skills/codex-agent/scripts/codex-agent --resume latest "Follow-up question"

# Resume by UUID (find in ~/.codex/sessions/)
~/.claude/skills/codex-agent/scripts/codex-agent --resume 019bf3a2-40ce-7923-b501-3d4ebd00aed3 "Continue"

# Via environment variable
CODEX_SESSION=latest ~/.claude/skills/codex-agent/scripts/codex-agent "Follow-up"

Model Selection

# Via flag
~/.claude/skills/codex-agent/scripts/codex-agent --model gpt-5.2-codex "Your prompt"

# Via environment variable
CODEX_MODEL=gpt-5.2-codex ~/.claude/skills/codex-agent/scripts/codex-agent "Your prompt"

Environment Variables

Variable	Description
PROMPT_FILE	Read prompt from this file
CODEX_MODEL	Model to use (passed as --model)
CODEX_SESSION	Session to resume (latest or UUID)
OPENAI_API_KEY	API key authentication
CODEX_API_KEY	API key for exec mode

Output

Returns plain text response followed by the session ID:

<response text>

[session_id: <uuid>]

Capture the session ID to continue the conversation with --resume <uuid>.

Troubleshooting

Diagnostics are shown automatically on any failure. You can also run:

~/.claude/skills/codex-agent/scripts/codex-agent --version

Common issues:

1. No auth configured: Run codex login to set up OAuth, or set OPENAI_API_KEY
2. codex not found: Install with npm install -g @openai/codex
3. Session not found: Check ~/.codex/sessions/ for valid UUIDs
4. Connection errors: Check network connectivity and auth token expiry

Notes

• Runs codex exec --dangerously-bypass-approvals-and-sandbox (YOLO mode)
• Uses --skip-git-repo-check to allow running outside git repos
• Sessions stored in ~/.codex/sessions/YYYY/MM/DD/rollout-*.jsonl
• For bidirectional streaming, use codex app-server directly (JSON-RPC)