Codex CLI

license

Apache-2.0(OSI, the CLI agent)

source

public(GitHub)

note

agent is OSS but optimized for/defaults to OpenAI models (provider-leaning, not license-restricted)

core features withheld

no — one Apache-2.0 LICENSE at the root governs the whole tree

Codex CLI is released under Apache-2.0, and the published Rust source is the whole of the CLI agent. Signing in with a ChatGPT plan or an API key pays for model access rather than for any CLI feature withheld from the source, so nothing about the agent itself is gated.

• https://github.com/openai/codex recorded 2026-06-04

  Apache-2.0 license, public Rust source, v0.137.0 Jun 4 2026, 88.6k stars (verified)

• https://raw.githubusercontent.com/openai/codex/main/docs/license.md recorded 2026-09-29

  The repository license page states "This repository is licensed under the [Apache-2.0 License](../LICENSE)." with no other license for the tree.

• https://raw.githubusercontent.com/openai/codex/main/LICENSE recorded 2026-09-29

  The root LICENSE file is the standard text of the Apache License and opens with "Apache License" and "Version 2.0, January 2004", with the grant clause "Licensed under the Apache License, Version 2.0".

• https://raw.githubusercontent.com/openai/codex/main/README.md recorded 2026-09-29

  The README describes a locally run agent that is "a coding agent from OpenAI that runs locally on your computer", installed from npm or Homebrew.

• https://raw.githubusercontent.com/openai/codex/main/README.md recorded 2026-09-29

  The README says paid plans and keys buy model access, not CLI features: "We recommend signing into your ChatGPT account to use Codex as part of your Plus, Pro, Business, Edu, or Enterprise" and "You can also use Codex with an API key".

OpenAI and independent tracking both report a weekly active developer count for Codex CLI, corroborated by stars on the same GitHub repository. That figure is measured weekly rather than the monthly count this scale is written in, so it likely understates the number a monthly measure would show.

• https://en.wikipedia.org/wiki/OpenAI_Codex_(AI_agent) recorded 2026-10-08

  Codex "had grown to more than 2 million weekly active users" by March 2026, after Fortune reported 1.6 million, with Cisco, Nvidia, Ramp, Rakuten and Harvey named as deployments. The article no longer carries a 6 million figure.

• https://github.com/openai/codex recorded 2026-08-13

  105.7k stars, 16.0k forks, broad active install base (corroborating)

• https://openai.com/index/scaling-codex-to-enterprises-worldwide/ recorded 2026-06-04

  OpenAI: Codex surpassed 4M weekly developers (Apr 2026). Not re-fetchable - openai.com answers 403 to a non-browser request.

Capable, heavily-used coding agent backed by frontier OpenAI models, but no standalone agent SWE-bench placement is published, so this reads from its feature set: high, but not the open-agent benchmark frontier-definer (OpenHands 68.4%).

• https://developers.openai.com/codex/cli recorded 2026-09-29

  The docs page lists Sandboxing, Auto-review and a "subagents" section: "Ask Codex to delegate focused work to specialized agents". Searched for a benchmark figure: none.