AI Potluck
Product / UX / Orchestration & agents

Codex CLI

OpenAI

Lightweight open source coding agent from OpenAI that runs in your terminal. Built in Rust for speed, it reads your codebase, proposes a plan, and executes multi-file changes with sandboxed command execution. Differentiates as OpenAI's official open source agent offering (Apache-2.0) with tight integration to OpenAI models. 84.6K GitHub stars with an extraordinary 2,893 commits in 90 days and 454 contributors, the most rapidly developed OSS agent as of May 2026.

OpenAI Codex CLI v0.137.0 (Jun 4 2026); GitHub openai/codex 88.6k stars, built in Rust. Open-source terminal coding agent (the agent itself is OSS; it calls OpenAI models). Confirmed live June 2026.

Openness

5 high confidence
5.0
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)

Verified Apache-2.0 OSI with public Rust source (96.1% Rust); OpenAI's own docs call it open source. Backing models are proprietary, but the orchestration agent scored here is fully open. License/version/stars confirmed via primary GitHub source.

Adoption

4 high confidence
4.0

OpenAI confirmed Codex surpassed 4M weekly developers (Apr 21 2026 announcement; 5M+ reported more recently). Firmly in the 1-10M+ reach band on disclosed developer count. Primary OpenAI announcement now cited as the basis (was previously sourced only to a distribution page).

Capability

4 medium confidence
4.0

Capable, heavily-used coding agent backed by frontier OpenAI models, but no standalone agent SWE-bench placement published. Scored on feature matrix; high but not the open-agent benchmark frontier-definer (OpenHands 68.4%).

Unchanged since 2026-06-09 (last edited, not re-checked)