Codex Release Notes

GPT-5.1 Codex options

Along with the GPT-5.1 launch in the API, we are introducing new gpt-5.1-codex-mini and gpt-5.1-codex model options in Codex, a version of GPT-5.1 optimized for long-running, agentic coding tasks and use in coding agent harnesses in Codex or Codex-like harnesses.

Starting today, the CLI and IDE Extension will default to gpt-5.1-codex on macOS and Linux and gpt-5.1 on Windows.

If you have a model specified in your config.toml configuration file, you can instead try out gpt-5.1-codex for a new Codex CLI session using:

codex --model gpt-5.1-codex

You can also use the /model slash command in the CLI. In the Codex IDE Extension you can select GPT-5.1-Codex from the dropdown menu.

If you want to switch for all sessions, you can change your default model to gpt-5.1-codex by updating your config.toml configuration file:

model = "gpt-5.1-codex"

New gpt-5-codex-mini model option

Today we are introducing a new gpt-5-codex-mini model option to Codex CLI and the IDE Extension. The model is a smaller, more cost-effective, but less capable version of gpt-5-codex that provides approximately 4x more usage as part of your ChatGPT subscription.

Starting today, the CLI and IDE Extension will automatically suggest switching to gpt-5-codex-mini when you reach 90% of your 5-hour usage limit, to help you work longer without interruptions.

You can try the model for a new Codex CLI session using:

codex --model gpt-5-codex-mini

You can also use the /model slash command in the CLI. In the Codex IDE Extension you can select GPT-5-Codex-Mini from the dropdown menu.

Alternatively, you can change your default model to gpt-5-codex-mini by updating your config.toml configuration file:

model = "gpt-5-codex-mini”

@Codex in Slack

You can now questions and assign tasks to Codex directly from Slack. See the Slack guide to get started.

Codex SDK

Integrate the same agent that powers the Codex CLI inside your own tools and workflows with the Codex SDK in Typescript. With the new Codex GitHub Action, you can easily add Codex to CI/CD workflows. See the Codex SDK guide to get started.

import { Codex } from "@openai/codex-sdk" ;

const agent = new Codex ();

const thread = await agent.startThread ();

const result = await thread.run ("Explore this repo" );
console.log (result);

const result2 = await thread.run ("Propose changes" );
console.log (result2);

New admin controls and analytics

ChatGPT workspace admins can now edit or delete Codex Cloud environments. With managed config files, they can set safe defaults for CLI and IDE usage and monitor how Codex uses commands locally. New analytics dashboards help you track Codex usage and code review feedback. Learn more in the enterprise admin guide.

Availability and pricing updates

The Slack integration and Codex SDK are available to developers on ChatGPT Plus, Pro, Business, Edu, and Enterprise plans starting today, while the new admin features will be available to Business, Edu, and Enterprise. Beginning October 20, Codex Cloud tasks will count toward your Codex usage. Review the Codex pricing guide for plan-specific details.