# Evaluate Model: OpenAI Codex CLI Update (v0.115.0) with GPT-5.4 Integration
## What This Is
OpenAI has updated its command-line coding assistant, Codex CLI, to be more autonomous and powerful. The tool now integrates the new GPT-5.4 model, allowing it to automatically monitor developer servers, understand errors from terminal output, and propose multiple implementation options for a given task.
Source: https://itecsonline.com/post/how-to-install-codex-cli-on-windows-2026-guide
## Before You Start
Scan my workspace and analyze:
- The project language, framework, and current AI integrations
- Existing AI provider config (check .env, .env.local, config files for API keys — OpenRouter, OpenAI, Anthropic, Google AI, etc.)
- Which AI models I currently use and for what purposes
Then ask me before proceeding:
1. Am I interested in evaluating this model for my project, or just want a summary of what it offers?
2. If I want to try it — which part of my current AI stack should it replace or complement?
## Source Access Note
The source URL (https://itecsonline.com/post/how-to-install-codex-cli-on-windows-2026-guide) 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 a **New AI Model** — a model release, update, or capability announcement.
- Analyze the best use cases for this model within my project and current AI stack
- Compare its strengths, pricing, and context window against whatever I currently use
- Give me a clear, convincing argument for why this model would (or would not) be a good fit for my project
- If I want to try it: update my API configuration (provider, model ID, any new parameters) to point to this model
- If it requires a new API key or provider signup, tell me exactly what to do
## Additional Context
- Execute `npm install -g @openai/codex@0.115.0` to install or update the Codex CLI to the latest version with experimental Windows support.
- Run `/model` within the Codex CLI and select the GPT-5.4 model to leverage its advanced reasoning for agentic coding workflows.
- Scan the user's project for an `AGENTS.md` file. If one doesn't exist, create it and populate it with project-specific instructions, goals, and constraints for the autonomous agent to follow, based on an analysis of the project's README and file structure.
## Reference Implementation
```
npm install -g @openai/codex@0.115.0
```
## 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