OpenAI Codex

OpenAI's coding agent, in ChatGPT and the terminal. AI model and agent, with a free plan; runs on desktop, web. The stack builder picks it for AI coding.

Try OpenAI Codex Build a stack for AI coding

Plans and prices

PlanPriceWhat you get
ChatGPT FreeFreeCodex included, lowest limits
ChatGPT Plus$20/moCodex included; per-5-hour message limits by model
ChatGPT Pro$100/moFrom $100 ($200/$500 options); no five-hour limit
ChatGPT Business$25/moPer user, 2+ users; Plus-level Codex limits

Checked by hand against learn.chatgpt.com/docs/pricing on October 6, 2026; confidence high. Prices are monthly in US dollars unless the row says otherwise; the builder counts the plan it starts on, ChatGPT Plus.

When the stack builder picks it

The builder reads each job's rules from the top and takes the first step whose conditions hold and whose plan fits the money left. OpenAI Codex is named in these steps:

The rules are public in stack-rules.json, and how the stack builder scores explains the tie-break.

Works with

Godot, Unity and Unreal Engine.

Alternatives the same rules name

Signals and what people say

Change log

Logo: Nameryn monogram (no free mark on file), CC0 1.0.

Related