name: codexforclaude description: "OpenAI Codex CLI configuration guide for Claude. Use when users ask about: codex config, ~/.codex/config.toml, codex sandbox policies, codex approval modes, creating codex skills, codex mcp servers, codex model settings, local LLM providers, or integrating tools with Codex."

Codex CLI Configuration Guide

Configure and extend OpenAI Codex CLI for optimal development workflows.

Quick Reference

Core Configuration

Edit ~/.codex/config.toml for all settings:

# Model settings
model = "gpt-5-codex"
model_reasoning_effort = "medium"  # minimal|low|medium|high|xhigh

# Security
sandbox_mode = "workspace-write"   # read-only|workspace-write|danger-full-access
approval_policy = "on-failure"     # untrusted|on-failure|on-request|never

# Trust specific projects
[projects."/path/to/project"]
trust_level = "trusted"

For detailed config options: See references/config-toml.md

Sandbox and Approval Policies

Sandbox modes control file system access:

• read-only - Can only read files, no writes
• workspace-write - Write within project directory only
• danger-full-access - Full system access (use carefully)

Approval policies control command execution:

• untrusted - Only trusted commands run without approval
• on-failure - Auto-run, ask approval only on failures
• on-request - Model decides when to ask
• never - Never ask (dangerous)

For security deep dive: See references/sandbox-approval.md

Adding MCP Servers

Via CLI (Recommended)

codex mcp add context7 -- npx -y @upstash/context7-mcp
codex mcp add myserver --env API_KEY=xxx -- node server.js

Via config.toml

[mcp_servers.context7]
command = "npx"
args = ["-y", "@upstash/context7-mcp"]

[mcp_servers.figma]
url = "https://mcp.figma.com/mcp"
bearer_token_env_var = "FIGMA_OAUTH_TOKEN"

For full MCP options: See references/mcp-servers.md

Creating Codex Skills

Skills extend Codex with specialized knowledge. Structure:

~/.codex/skills/my-skill/
├── SKILL.md          # Required: instructions + metadata
├── scripts/          # Optional: executable code
├── references/       # Optional: detailed docs
└── assets/           # Optional: templates

Minimal SKILL.md:

---
name: my-skill
description: When to trigger this skill
---

Instructions for Codex when using this skill.

Quick start: Ask Codex to use $skill-creator to bootstrap a new skill.

For skill development guide: See references/creating-skills.md

Model and Provider Settings

# Use specific model
model = "gpt-5-codex"

# Reasoning effort (Responses API)
model_reasoning_effort = "high"  # minimal|low|medium|high|xhigh

# Verbosity (GPT-5)
model_verbosity = "medium"  # low|medium|high

# Use local provider (LM Studio/Ollama)
model_provider = "oss"

For local LLM setup: See references/model-providers.md

Feature Flags

Enable experimental features in [features]:

[features]
# Stable
shell_tool = true
parallel = true
view_image_tool = true

# Beta
unified_exec = true
shell_snapshot = true

# Experimental
skills = true
tui2 = true

Common Workflows

Full Autonomous Mode

codex --full-auto "implement feature X"
# Equivalent to: -a on-request --sandbox workspace-write

Dangerous Bypass (CI/sandboxed environments only)

codex --dangerously-bypass-approvals-and-sandbox "run tests"

Project-Specific Trust

[projects."/home/user/trusted-project"]
trust_level = "trusted"

Codex vs Claude Code

Reference Files

• references/config-toml.md - Complete config.toml reference
• references/sandbox-approval.md - Security policies deep dive
• references/mcp-servers.md - MCP server configuration
• references/creating-skills.md - Skill development guide
• references/model-providers.md - Model and provider settings