How Codex Happened: inside OpenAI's coding comeback from failed launch to 40M weekly users
danshipper · x · 2026-10-16
Every's Dan Shipper publishes "How Codex Happened," a behind-closed-doors story of OpenAI's coding pivot.
- Summer 2025: early GPT-5 testing left Every's team underwhelmed by Codex; the cloud version had missed PMF and the team was pivoting to a local terminal agent.
- Less than 12 months later, Codex swallowed the ChatGPT desktop app from the inside (running as com.openai.codex on Mac), Codex + ChatGPT for Work hit 40M+ weekly users, and leader Thibault Sottiaux now runs all of OpenAI's core products.
- Key move: Codex trained its own dedicated model line, separate from ChatGPT, with researchers and product working tightly together.
Related event: Every's "How Codex Happened" Chronicles Codex's Comeback(13 posts)→
More from coding & agent
- NimbusImage opens an API for agentic control via Claude Code: clean up images by prompt — arjunrajlab · 2026-10-16
- NimbusImage adds an agentic API drivable via Claude Code for bioimage analysis — arjunrajlab · 2026-10-16
- a16z's call for startups: computer use agents that actually finish the job — andrewchen · 2026-10-16
- REAX SN92 targets the AI decision economy: small models making millions of micro-decisions daily — markjeffrey · 2026-10-16
- Design studio MCPs clients' slop AI websites straight into Sketch for a fast redesign — michalmalewicz · 2026-10-16
- Dev Builds Haunted Escape Room to Test Reflection AI's Beam, Solves It in 30 Seconds — wandb · 2026-10-16