Is OpenAI Codex CLI the Game-Changer or a Disappointing AI Terminal Assistant?

Should Developers Trust OpenAI Codex CLI? Unveiling the Surprising Truth About This AI Tool

OpenAI Codex CLI is an open-source command-line tool designed to bring advanced AI coding assistance directly into your terminal. By leveraging powerful AI models, it allows you to generate, edit, and execute code using natural language, aiming to streamline workflows for developers and DevOps professionals. However, despite its promise, Codex CLI currently faces limitations compared to more mature AI CLIs like Warp, Cline, and Roo Code.

What Makes OpenAI Codex CLI Stand Out?

• Open Source & Local Integration: Codex CLI runs locally and is fully open-source, giving developers transparency, control, and the ability to contribute to its evolution.
• Natural Language Coding: You can instruct the AI to write, edit, or explain code and automate tasks using simple language commands-no need to remember complex syntax.
• Multimodal Inputs: Unique among some competitors, Codex CLI can accept screenshots or sketches as input, enabling visual-to-code workflows.
• Model Flexibility: It supports integration with OpenAI’s latest models, such as o3 and o4-mini, for various coding tasks.
• DevOps Automation: Codex CLI can automate repetitive DevOps tasks, generate scripts, refactor code, and integrate with CI/CD pipelines, making it a valuable tool for operations teams.

Installation & Setup Simplified

Prerequisite

Node.js must be installed.

Installation

• Windows: Download the installer.
• Mac: Use Homebrew (brew install node), then install Codex CLI via npm install -g @openai/codex.

API Key Setup

• Windows: Set with $env:OPENAI_API_KEY = “your-api-key-here”.
• Mac: Use export OPENAI_API_KEY=”your-api-key-here”, and add it to your bash profile for persistence.

Type codex in your terminal to start Codex CLI.

How Codex CLI Works in Practice

Model Selection

Choose your preferred OpenAI model with /model. Note: Not all listed models are supported; some may result in errors or are unavailable.

Approval Modes

Control the AI’s autonomy with three modes:

• Suggest: AI proposes changes, you approve.
• Auto Edit: AI edits files, but you approve executions.
• Full Auto: AI acts autonomously within a sandboxed environment.

Session Limitations

Approval modes and session context are not retained after exit; you must reconfigure each time.

Key Limitations and Drawbacks

• Session Persistence: Codex CLI does not retain session history or approvals after restart, unlike some competitors.
• Model Compatibility Issues: Some advanced models (e.g., gpt-4o-search-preview) are not supported, and attempts to use them may result in errors.
• No Traditional CLI Commands: You must exit Codex CLI to run standard terminal commands, which disrupts workflow.
• Feature Gaps: Compared to tools like Warp or Cline, Codex CLI lacks seamless integration and session awareness, making it less efficient for power users.

Conclusion: Promising, But Not Yet Essential

OpenAI Codex CLI is an innovative step toward agentic, AI-powered software development. Its open-source approach and multimodal capabilities are impressive, but current limitations in usability, session management, and model support mean it lags behind established tools like Warp and Cline. As OpenAI continues to refine Codex CLI and the developer community contributes, its potential may be unlocked in future releases.