Openai Codex Reference

OpenAI Codex Reference Skill

Core Principle

Always prefer fetching from official documentation over relying on training data. When working with Codex features, use the official docs at https://developers.openai.com/codex as the authoritative source. This applies both when users ask AND when the Agent needs accurate information about how Codex works internally.

When to Use This Skill

Trigger in all these contexts:

• User asks about Codex features, configuration, or commands
• Agent needs to implement hooks, skills, MCP servers, or plugins for Codex
• Agent needs to configure Codex settings (config files, rules, AGENTS.md)
• Agent encounters an unfamiliar Codex feature or command
• Agent needs to write Codex scripts (hooks, slash commands)
• Agent needs to understand sandboxing, subagents, or workflows
• Agent needs to integrate with GitHub, Slack, Linear, or other platforms
• Agent needs to use Codex CLI, IDE extension, or cloud features
• Agent needs to troubleshoot Codex issues
• Agent needs accurate API reference, SDK usage, or configuration syntax

Official Documentation Index

Base URL: https://developers.openai.com/codex

Getting Started

• Overview: /codex
• Quickstart: /codex/quickstart
• Use cases: /codex/use-cases
• Migration guide: /codex/migrate
• Pricing: /codex/pricing

Concepts

• Prompting: /codex/prompting
• Customization: /codex/concepts/customization
• Memories: /codex/concepts/memories
• Chronicle: /codex/concepts/memories/chronicle
• Sandboxing: /codex/concepts/sandboxing
• Auto-review: /codex/concepts/sandboxing/auto-review
• Subagents: /codex/concepts/subagents
• Workflows: /codex/workflows
• Models: /codex/models
• Cyber Safety: /codex/concepts/cyber-safety

Using Codex - App

• App overview: /codex/app
• App features: /codex/app/features
• App settings: /codex/app/settings
• App review: /codex/app/review
• App automations: /codex/app/automations
• Worktrees: /codex/app/worktrees
• Local environments: /codex/app/local-environments
• Browser: /codex/app/browser
• Chrome extension: /codex/app/chrome-extension
• Computer use: /codex/app/computer-use
• Commands: /codex/app/commands
• Windows: /codex/app/windows
• Troubleshooting: /codex/app/troubleshooting

Using Codex - IDE Extension

• IDE overview: /codex/ide
• IDE features: /codex/ide/features
• IDE settings: /codex/ide/settings
• IDE commands: /codex/ide/commands
• Slash commands: /codex/ide/slash-commands

Using Codex - CLI

• CLI overview: /codex/cli
• CLI features: /codex/cli/features
• CLI reference: /codex/cli/reference
• Slash commands: /codex/cli/slash-commands

Using Codex - Cloud

• Cloud overview: /codex/cloud
• Environments: /codex/cloud/environments
• Internet access: /codex/cloud/internet-access

Integrations

• GitHub: /codex/integrations/github
• Slack: /codex/integrations/slack
• Linear: /codex/integrations/linear

Security

• Security overview: /codex/security
• Security setup: /codex/security/setup
• Threat model: /codex/security/threat-model
• Security FAQ: /codex/security/faq

Configuration

• Basic config: /codex/config-basic
• Advanced config: /codex/config-advanced
• Config reference: /codex/config-reference
• Config samples: /codex/config-sample
• Speed settings: /codex/speed
• Rules: /codex/rules
• Hooks: /codex/hooks
• AGENTS.md: /codex/guides/agents-md
• MCP: /codex/mcp
• Plugins: /codex/plugins
• Build plugins: /codex/plugins/build
• Skills: /codex/skills
• Subagents: /codex/subagents

Administration

• Authentication: /codex/auth
• Agent approvals & security: /codex/agent-approvals-security
• Remote connections: /codex/remote-connections
• Enterprise admin: /codex/enterprise/admin-setup
• Enterprise governance: /codex/enterprise/governance
• Managed configuration: /codex/enterprise/managed-configuration
• Windows: /codex/windows

Automation

• Non-interactive mode: /codex/noninteractive
• Codex SDK: /codex/sdk
• App Server: /codex/app-server
• Agents SDK guide: /codex/guides/agents-sdk
• GitHub Action: /codex/github-action

Learn

• Best practices: /codex/learn/best-practices
• Videos: /codex/videos
• Build AI-native team: /codex/guides/build-ai-native-engineering-team

Releases

• Changelog: /codex/changelog
• Feature maturity: /codex/feature-maturity
• Open source: /codex/open-source

Workflow

Step 1: Identify the Topic

Map the question to the most relevant documentation page(s). Use the index above for guidance.

Step 2: Fetch from Official Docs

Use WebFetch to retrieve the relevant page(s):

WebFetch(url="https://developers.openai.com/codex/[topic]", prompt="Extract all relevant information about [specific topic]")

For unknown topics, start with the main Codex page:

WebFetch(url="https://developers.openai.com/codex", prompt="Find documentation related to [topic]")

Step 3: Synthesize and Answer

Combine information from official docs with your own knowledge. When citing specific features, configuration options, or command syntax, always reference the official documentation as the source.

Step 4: Provide Actionable Guidance

Don't just quote docs — provide concrete examples, configuration snippets, or step-by-step instructions based on what the official docs say.

Examples

User asks about hooks: → Fetch /codex/hooks, explain hook types, configuration, and provide examples.

Agent needs to create a skill: → Fetch /codex/skills, explain skill structure, SKILL.md format, and how to trigger skills.

Agent needs to configure MCP: → Fetch /codex/mcp, explain MCP server setup, configuration, and provide examples.

User asks about AGENTS.md: → Fetch /codex/guides/agents-md, explain the purpose and format of AGENTS.md files.

User asks about CLI commands: → Fetch /codex/cli/reference, list relevant commands with flags and examples.

User asks about sandboxing: → Fetch /codex/concepts/sandboxing, explain how Codex sandboxing works and its security implications.

Important Notes

• The documentation is comprehensive. You don't need to fetch all pages — only the ones relevant to the question.
• When users ask about "how Codex works" or "what can Codex do", start with the overview page /codex.
• Codex has many similarities to Claude Code but also differences — always fetch the specific Codex documentation rather than assuming features work the same way.
• Codex documentation is actively maintained — prefer real-time fetch over cached knowledge.
• If a page doesn't exist or can't be fetched, fall back to your training knowledge but clearly note when the information may be outdated.

Source: platootalp/claude-harness — distributed by TomeVault.