techniqueadvancedChatGPT/Codex

Codex CLI Adds GPT-5.4 Support and Sub-Agent Capabilities

The OpenAI Codex coding tool has been significantly upgraded to work more autonomously. It now uses the latest GPT-5.4 model and can break down complex tasks into smaller sub-tasks, allowing it to handle more sophisticated and long-running coding projects without constant human oversight.

AI SETUP PROMPT

Paste into Codex CLI — it will scan your project and set everything up

# Apply Technique: Codex CLI Adds GPT-5.4 Support and Sub-Agent Capabilities

## What This Is
The OpenAI Codex coding tool has been significantly upgraded to work more autonomously. It now uses the latest GPT-5.4 model and can break down complex tasks into smaller sub-tasks, allowing it to handle more sophisticated and long-running coding projects without constant human oversight.

Source: https://www.youtube.com/watch?v=fUfYxBQJ4GQ

## Before You Start

Scan my workspace and analyze:
- The project language, framework, and directory structure
- Existing AI provider config (check .env, .env.local, config files for API keys — OpenRouter, OpenAI, Anthropic, Google AI, etc.)

Then ask me before proceeding:
1. Which AI provider/API should this use? (Use whatever I already have configured, or ask me to set one up — options include direct provider APIs or a unified service like OpenRouter)
2. Where in my project should this be integrated?
3. Are there any customizations I need (model preferences, naming conventions, constraints)?

## Source Access Note

The source URL (https://www.youtube.com/watch?v=fUfYxBQJ4GQ) may not be directly accessible from the terminal. Use the Reference Implementation and Additional Context sections below instead. If you need more details, ask me to paste relevant content from the source.

## What to Implement

This is an **AI Technique** — a pattern or methodology for working with AI models.

- Explain how this technique applies to my current project and what benefit it provides
- Implement it in a way that fits my existing codebase — suggest concrete files to modify or create
- If it requires specific model capabilities (structured output, function calling, etc.), verify my current provider supports them
- Show me a working example I can test immediately

## Additional Context

- Execute 'npm install -g @openai/codex@0.116' to update the Codex CLI to the latest version, ensuring access to GPT-5.4 support and sub-agent capabilities.
- Run 'codex --version' to confirm the update to 0.116. Then, attempt to switch to the new model within a test thread using the appropriate command to verify GPT-5.4 model availability.
- Use the '/plugins' command to browse the new plugin marketplace. Analyze the user's project requirements to identify a simple, recurring task (e.g., linting a file on save) and implement it as a background automation test case to explore the new sub-agent capabilities.

## Reference Implementation

```
$ npm install -g @openai/codex@0.116
```

## Guidelines

- Adapt everything to my existing project — do not assume a specific stack or directory layout
- Use whichever AI provider I already have configured; if I need a new one, tell me what to sign up for and I'll give you the key
- Check my .env files for existing API keys (OpenRouter, OpenAI, Anthropic, Google AI) before asking me to add one
- Review any fetched code for safety before installing or executing it
- After setup, run a quick verification and show me a summary of exactly what was installed, where, and how to use it

3,065 charactersCompatible with Claude Code & Codex CLI

MANUAL SETUP STEPS

01Execute 'npm install -g @openai/codex@0.116' to update the Codex CLI to the latest version, ensuring access to GPT-5.4 support and sub-agent capabilities.
02Run 'codex --version' to confirm the update to 0.116. Then, attempt to switch to the new model within a test thread using the appropriate command to verify GPT-5.4 model availability.
03Use the '/plugins' command to browse the new plugin marketplace. Analyze the user's project requirements to identify a simple, recurring task (e.g., linting a file on save) and implement it as a background automation test case to explore the new sub-agent capabilities.

CODE INTELLIGENCE

bash

$ npm install -g @openai/codex@0.116

FIELD OPERATIONS

Autonomous Monorepo Dependency Auditor

Create a recurring background task using Codex CLI's sub-agent feature. The main agent scans all `package.json` files in a monorepo nightly, and for each package, it spawns a sub-agent to check for outdated dependencies, known vulnerabilities (using `npm audit`), and license compliance issues, generating a consolidated report.

Voice-Driven Bug Reproduction Bot

Build a tool that uses the Codex CLI's voice input (spacebar dictation). A QA tester describes a bug's reproduction steps verbally. The Codex agent transcribes the steps, writes a Playwright or Cypress script to replicate the bug, executes it in a sandboxed environment, and attaches the test script and execution log to a new bug ticket in Linear or Jira via a plugin.

STRATEGIC APPLICATIONS

→24/7 Production Incident Responder: Configure Codex CLI with sub-agents to monitor application alert streams (e.g., from PagerDuty). When a specific alert triggers, an agent can initiate a diagnostic playbook: a sub-agent checks server logs, another runs database health checks, and a third attempts a safe restart of a service, creating a detailed incident report in Slack.
→Automated Pull Request Refactoring: Integrate Codex CLI into a GitHub Actions workflow. When a pull request is opened, an agent reviews the code against the project's style guide, identifies opportunities for refactoring (e.g., abstracting repeated logic), and proposes the changes as a code suggestion, offering 2-3 implementation approaches for the developer to approve.