OpenAI Codex CLI Skill

Use OpenAI Codex CLI (

codex

When to Use

• User asks for code changes, refactoring, or implementation
• CI/build failures need fixing
• Code review before commit/push
• Large codebase exploration or explanation
• Tasks requiring file editing + command execution
• When GPT-5-Codex model strengths are needed (code generation, tool use)

Installation & Auth

Codex CLI requires ChatGPT Plus/Pro/Business/Enterprise subscription.

# Install
npm i -g @openai/codex

# Authenticate (opens browser for OAuth)
codex login

# Or use API key
printenv OPENAI_API_KEY | codex login --with-api-key

# Verify auth
codex login status

Core Commands

Interactive Mode (TUI)

codex                           # Launch interactive terminal UI
codex "explain this codebase"   # Start with a prompt
codex --cd ~/projects/myapp     # Set working directory

Non-Interactive (Scripting)

codex exec "fix the CI failure"                    # Run and exit
codex exec --full-auto "add input validation"      # Auto-approve workspace writes
codex exec --json "list all API endpoints"         # JSON output for parsing
codex exec -i screenshot.png "match this design"   # With image input

Session Management

codex resume               # Pick from recent sessions
codex resume --last        # Continue most recent
codex resume <SESSION_ID>  # Resume specific session

Slash Commands (In TUI)

/model

/approvals

/review

/diff

/compact

/init

/status

/undo

/new

/mcp

/mention <path>

Approval Modes

Key Flags

--model, -m <model>

--cd, -C <path>

--add-dir <path>

--image, -i <path>

--full-auto

--sandbox <mode>

--json

--search

Clawdbot Integration Patterns

Pattern 1: Direct exec Tool

Call Codex from Clawdbot's exec tool for coding tasks:

# In Clawdbot session
exec codex exec --full-auto --cd ~/projects/medreport "fix the TypeScript errors in src/components"

Pattern 2: Subagent Delegation

Spawn a coding subagent that uses Codex:

// In agents.defaults or per-agent config
{
  agents: {
    list: [
      {
        id: "coder",
        workspace: "~/clawd-coder",
        model: "openai-codex/gpt-5.2",  // Uses Codex auth
        tools: {
          allow: ["exec", "read", "write", "edit", "apply_patch", "process"]
        }
      }
    ]
  }
}

Pattern 3: CLI Backend Fallback

Configure Codex as a text-only fallback:

{
  agents: {
    defaults: {
      cliBackends: {
        "codex-cli": {
          command: "codex",
          args: ["exec", "--full-auto"],
          output: "text",
          sessionArg: null  // Codex manages its own sessions
        }
      }
    }
  }
}

Pattern 4: MCP Server Mode

Run Codex as an MCP server for other agents:

codex mcp-server  # Exposes Codex tools via stdio MCP

Clawdbot Config: OpenAI Codex Provider

Use your ChatGPT Pro subscription via the

openai-codex

{
  agents: {
    defaults: {
      model: { primary: "openai-codex/gpt-5.2" },
      models: {
        "openai-codex/gpt-5.2": { alias: "Codex" },
        "anthropic/claude-opus-4-5": { alias: "Opus" }
      }
    }
  }
}

Auth syncs automatically from

~/.codex/auth.json

Code Review Workflow

# Interactive review
codex
/review  # Choose: branch, uncommitted, or specific commit

# Non-interactive
codex exec "review the changes in this PR against main branch"

Multi-Directory Projects

# Work across monorepo packages
codex --cd apps/frontend --add-dir ../backend --add-dir ../shared

# Or in TUI
codex --cd ~/projects/myapp --add-dir ~/projects/shared-lib

Custom Slash Commands

Create reusable prompts in

~/.codex/prompts/

<!-- ~/.codex/prompts/pr.md -->
---
description: Prepare and open a draft PR
argument-hint: [BRANCH=<name>] [TITLE="<title>"]
---

Create branch `dev/$BRANCH` if specified.
Stage and commit changes with a clear message.
Open a draft PR with title $TITLE or auto-generate one.

Invoke:

/prompts:pr BRANCH=feature-auth TITLE="Add OAuth flow"

MCP Integration

Add MCP servers to extend Codex:

# Add stdio server
codex mcp add github -- npx @anthropic/mcp-server-github

# Add HTTP server
codex mcp add docs --url https://mcp.deepwiki.com/mcp

# List configured
codex mcp list

Web Search

Enable in

~/.codex/config.toml

[features]
web_search_request = true

[sandbox_workspace_write]
network_access = true

Then Codex can search for current docs, APIs, etc.

Best Practices

1. Start with

   /init

   to create AGENTS.md with repo-specific instructions
2. Use

   /review

   before commits for AI code review
3. Set

   /approvals

   appropriately — Auto for trusted repos, Read Only for exploration
4. Use

   --add-dir

   for monorepos instead of

   danger-full-access

5. Resume sessions to maintain context across coding sessions
6. Attach images for UI work, design specs, error screenshots

Example Workflows

Fix CI Failure

codex exec --full-auto "The CI is failing on the lint step. Fix all ESLint errors."

Refactor Component

codex exec --cd src/components "Refactor UserProfile.tsx to use React Query instead of useEffect for data fetching"

Implement Feature from Spec

codex exec -i spec.png --cd ~/projects/app "Implement this feature based on the design spec"

Code Review PR

codex exec "Review the diff between main and feature/auth branch. Focus on security issues."

Troubleshooting

codex logout

codex login

/approvals

--full-auto

/compact

--cd

/status

References

• Codex CLI Overview
• Codex CLI Features
• Codex CLI Reference
• Slash Commands Guide
• AGENTS.md Spec
• Codex GitHub