Run OpenAI Codex CLI on Claude, Gemini, or Llama (opens in new tab)

OpenAI's Codex CLI ships with a great editor-agent UX: shell tool, apply_patch, plan tracking, the lot. The catch — as of February 2026 it only speaks the OpenAI Responses API. Chat Completion support was dropped (codex-rs/model-provider-info/src/lib.rs: the WireApi enum has one variant, Responses). If you wanted to point it at a Chat-Completion-only endpoint — Ollama, LM Studio, your favorite Llama runner — you're out of luck. But Codex CLI is happy to talk to any server that speaks Response...