Topic

O3

Topic

O3

OpenAI's Codex Agent Runs on codex-1, a Tuned o3 for Coding

OpenAI's system card addendum details Codex, a cloud coding agent built on codex-1 — an o3 variant RL-tuned to run tests until they pass and cite terminal logs as proof.

September 24, 2026

OpenAI swaps GPT-4o for o3 inside Operator, leaves API unchanged
September 24, 2026
OpenAI Adds Remote MCP Support and New Built-In Tools to Responses API
September 24, 2026
OpenAI details codex-1: an o3 variant tuned for real coding work
September 24, 2026
OpenAI Cuts Model Scheming 30-Fold With Deliberative Alignment
September 24, 2026
OpenAI Launches o3 and o4-mini, Its Smartest Models Yet
September 24, 2026