codex
Lightweight coding agent that runs in your terminal
The Lens
By Erik Loyd, SaaS CEO and former COO/CFO of an AWS Premier Partner.
Updated Sep 2026
Codex CLI is OpenAI's coding agent for the terminal. Point it at a repo and it reads files, writes code, and runs commands while you approve each step or let it run. The client is Rust, Apache 2.0, and free to install with a single command.
There is nothing to host. The sandboxing is real rather than decorative: Seatbelt on macOS, bubblewrap on Linux and WSL2, with an approval mode that asks before the agent reaches the internet. The escape hatch is the part worth knowing about. Run codex with the --oss flag and it drives Ollama or LM Studio on your own machine, and the provider config accepts any OpenAI-compatible base URL.
Anyone already paying for ChatGPT gets this at no extra cost. Teams weighing it against Copilot or Cursor should know it does no inline completion. It is a terminal agent plus an IDE extension, not an autocomplete engine.
The catch is what Apache 2.0 actually covers. The license is on the wrapper, not the model. Codex runs on every ChatGPT tier including Free, but free buys you quick tasks and little else, and real work pushes you up through Go at $8 a month, Plus at $20, and Pro from $100. What the tiers sell is volume, not access. You can read and fork the client all you like; the intelligence behind it stays metered.
Free vs Self-Hosted vs Paid
fully freeFree tier
The CLI is Apache 2.0 and free to install. ChatGPT Free includes Codex for quick coding tasks, so you can try it without paying anything. Running it against local models costs nothing at any volume: the --oss flag targets Ollama or LM Studio on your own hardware, and the model_providers config accepts any OpenAI-compatible base URL.
Self-hosted There is no server to run, so self-hosting here means supplying your own inference. A local runtime or any third-party OpenAI-compatible endpoint works.
Paid Codex is on every ChatGPT tier, so the tiers buy volume rather than access. Go is $8/mo for lightweight tasks. Plus is $20/mo with access across web, CLI, IDE, and iOS. Pro starts at $100/mo, which OpenAI markets as 5x or 20x the Codex usage of Plus. Business is $20/user/mo billed annually, and Enterprise and Edu are custom. The separate path is an OpenAI API key billed at standard per-token rates, which covers local workflows but leaves some workspace and cloud features unavailable.
Free, open source client. Codex runs on every ChatGPT tier including Free, but usable volume means Go at $8/mo, Plus at $20/mo, or Pro from $100/mo. Local models keep it free at any volume.
What to do by team size
- Solo
- free on ChatGPT Free for light use or with a local model; $8/mo Go or $20/mo Plus once you lean on it
- Small team
- Plus seats at $20/mo each, or run it against an existing API key budget
- Medium team
- Business at $20/user/mo annually, plus managed hook policy so agent config stays consistent
- Large team
- Business or Enterprise seats for admin controls, workspace policy, and credit-based scaling
Get tools like this every Wednesday
One featured tool, three on the radar. No fluff.
Similar Tools
The open source coding agent.
An open-source AI coding agent that lives in your terminal.
⌥ AI Coding agent for the terminal: hash-anchored edits, optimized tool harness, LSP, Python, browser, subagents, and more
Autonomous coding agent right in your IDE, capable of creating/editing files, executing commands, using the browser, and more with your permission every step of the way.
DeepSeek + MiMo coding agent in terminal
The free coding agent
A low score is not a verdict on quality. Young and niche tools start low by design. How we calculate scores
Trust Signals
License: Apache License 2.0
Use freely. Patent grant included.
Commercial use: ✓ Yes
About
- Owner
- OpenAI (Organization)
- Backed by
- Microsoft
- Stars
- 130,524
- Forks
- 20,578
Also by OpenAI
Lean certificates accompanying Navier-Stokes and Euler results
Conditional Lean formalization and numerical certificate for prime gaps at most 186.
Lean certificates accompanying ten proofs in mathematics and theoretical computer science
Explore Further
More tools in the directory
openclaw
Your own personal AI assistant. Any OS. Any Platform. The lobster way. 🦞
392.8k ★everything-claude-code
The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond.
288.3k ★DeepSeek Harness
DeepSeek Harness: Everything is a Plugin.
260.8k ★