OpenAI Codex CLI
Open-source terminal coding agent from OpenAI with 67K GitHub stars
Our Take
OpenAI's Codex CLI, open-sourced in April 2025 under Apache 2.0, has accumulated 67K GitHub stars and 400+ contributors. Written in Rust, it features a full-screen terminal UI, subagent coordination via /fleet, and sandboxed execution. It's included free with ChatGPT Plus ($20/month) and uses GPT-5.4 as its default model. For developers already paying for ChatGPT Plus, Codex CLI is essentially a free bonus. The open-source nature and Rust implementation make it fast and extensible. However, it trails Claude Code in agentic reliability on complex tasks, and the ecosystem is still maturing compared to more established terminal agents like Aider.
Pros
- + Open-source under Apache 2.0 with 67K GitHub stars
- + Free for ChatGPT Plus subscribers
- + Fast Rust implementation with full-screen terminal UI
- + Subagent coordination via /fleet for parallel tasks
Cons
- - Trails Claude Code in reliability on complex agentic tasks
- - Ecosystem still maturing compared to established alternatives
- - Requires ChatGPT Plus subscription for best experience
Details
- Pricing Model
- freemium
- Starting Price
- $20/mo (via ChatGPT Plus)
- Self-Hosted
- Yes
- Cloud Hosted
- Yes
- Founded
- 2025
- Repository
- GitHub →
Best For
- • Developers wanting an open-source terminal agent
- • ChatGPT Plus subscribers looking for CLI coding
- • Multi-agent coordination via /fleet
Integrations
Terminal/CLI GitHub ChatGPT Plus
Articles featuring OpenAI Codex CLI
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