Codex Changelog

Codex now supports agent skills: reusable bundles of instructions (plus optional scripts and resources) that help Codex reliably complete specific tasks.

Skills are available in both the Codex CLI and IDE extensions.

You can invoke a skill explicitly by typing $skill-name (for example, $skill-installer or the experimental $create-plan skill after installing it), or let Codex select a skill automatically based on your prompt.

Learn more in the skills documentation.

![](/images/codex/skills/skills-selector-cli-light.webp)
![](/images/codex/skills/skills-selector-cli-dark.webp)




![](/images/codex/skills/skills-selector-ide-light.webp)
![](/images/codex/skills/skills-selector-ide-dark.webp)

Folder-based standard (agentskills.io)

Following the open agent skills specification, a skill is a folder with a required SKILL.md and optional supporting files:

my-skill/
  SKILL.md       # Required: instructions + metadata
  scripts/       # Optional: executable code
  references/    # Optional: documentation
  assets/        # Optional: templates, resources

Install skills per-user or per-repo

You can install skills for just yourself in ~/.codex/skills, or for everyone on a project by checking them into .codex/skills in the repository.

Codex also ships with a few built-in system skills to get started, including $skill-creator and $skill-installer. The $create-plan skill is experimental and needs to be installed (for example: $skill-installer install the create-plan skill from the .experimental folder).

Curated skills directory

Codex ships with a small curated set of skills inspired by popular workflows at OpenAI. Install them with $skill-installer, and expect more over time.

Today we are releasing GPT-5.2-Codex, the most advanced agentic coding model yet for complex, real-world software engineering.

GPT-5.2-Codex is a version of GPT-5.2 further optimized for agentic coding in Codex, including improvements on long-horizon work through context compaction, stronger performance on large code changes like refactors and migrations, improved performance in Windows environments, and significantly stronger cybersecurity capabilities.

Starting today, the CLI and IDE Extension will default to gpt-5.2-codex for users who are signed in with ChatGPT. API access for the model will come soon.

If you have a model specified in your config.toml configuration file, you can instead try out gpt-5.2-codex for a new Codex CLI session using:

codex --model gpt-5.2-codex

You can also use the /model slash command in the CLI. In the Codex IDE Extension you can select GPT-5.2-Codex from the dropdown menu.

If you want to switch for all sessions, you can change your default model to gpt-5.2-codex by updating your config.toml configuration file:

model = "gpt-5.2-codex”

Assign or mention @Codex in an issue to kick-off a Codex cloud task. As Codex works, it posts updates back to Linear, providing a link to the completed task so you can review, open a PR, or keep working.

To learn more about how to connect Codex to Linear both locally through MCP and through the new integration, check out the Codex for Linear documentation.

Minor updates to address a few issues with Codex usage and credits:

• Adjusted all usage dashboards to show "limits remaining" for consistency. The CLI previously displayed "limits used."
• Fixed an issue preventing users from buying credits if their ChatGPT subscription was purchased via iOS or Google Play.
• Fixed an issue where the CLI could display stale usage information; it now refreshes without needing to send a message first.
• Optimized the backend to help smooth out usage throughout the day, irrespective of overall Codex load or how traffic is routed. Before, users could get unlucky and hit a few cache misses in a row, leading to much less usage.

Today we are releasing GPT-5.1-Codex-Max, our new frontier agentic coding model.

GPT‑5.1-Codex-Max is built on an update to our foundational reasoning model, which is trained on agentic tasks across software engineering, math, research, and more. GPT‑5.1-Codex-Max is faster, more intelligent, and more token-efficient at every stage of the development cycle–and a new step towards becoming a reliable coding partner.

Starting today, the CLI and IDE Extension will default to gpt-5.1-codex-max for users that are signed in with ChatGPT. API access for the model will come soon.

For non-latency-sensitive tasks, we’ve also added a new Extra High (xhigh) reasoning effort, which lets the model think for an even longer period of time for a better answer. We still recommend medium as your daily driver for most tasks.

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

codex --model gpt-5.1-codex-max

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-max by updating your config.toml configuration file:

model = "gpt-5.1-codex-max”

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”

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”

We've shipped a minor update to GPT-5-Codex:

• More reliable file edits with apply_patch.
• Fewer destructive actions such as git reset.
• More collaborative behavior when encountering user edits in files.
• 3% more efficient in time and usage.

Codex users on ChatGPT Plus and Pro can now use on-demand credits for more Codex usage beyond what's included in your plan. Learn more.

You can now tag @codex on a teammate's pull request to ask clarifying questions, request a follow-up, or ask Codex to make changes. GitHub Issues now also support @codex mentions, so you can kick off tasks from any issue, without leaving your workflow.

Codex is now generally available with 3 new features — @Codex in Slack, Codex SDK, and new admin tools.

@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.

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.

GPT-5-Codex is now available in the Responses API, and you can also use it with your API Key in the Codex CLI. We plan on regularly updating this model snapshot. It is available at the same price as GPT-5. You can learn more about pricing and rate limits for this model on our model page.

New model: GPT-5-Codex

GPT-5-Codex is a version of GPT-5 further optimized for agentic coding in Codex. It's available in the IDE extension and CLI when you sign in with your ChatGPT account. It also powers the cloud agent and Code Review in GitHub.

To learn more about GPT-5-Codex and how it performs compared to GPT-5 on software engineering tasks, see our announcement blog post.

Image outputs

When working in the cloud on front-end engineering tasks, GPT-5-Codex can now display screenshots of the UI in Codex web for you to review. With image output, you can iterate on the design without needing to check out the branch locally.

New in Codex CLI

• You can now resume sessions where you left off with codex resume.
• Context compaction automatically summarizes the session as it approaches the context window limit.

Learn more in the latest release notes

IDE extension (Compatible with VS Code, Cursor, Windsurf)

Codex now runs in your IDE with an interactive UI for fast local iteration. Easily switch between modes and reasoning efforts.

Sign in with ChatGPT (IDE & CLI)

One-click authentication that removes API keys and uses ChatGPT Enterprise credits.

Move work between local ↔ cloud

Hand off tasks to Codex web from the IDE with the ability to apply changes locally so you can delegate jobs without leaving your editor.

Code Reviews

Codex goes beyond static analysis. It checks a PR against its intent, reasons across the codebase and dependencies, and can run code to validate the behavior of changes.

Image inputs

You can now attach images to your prompts in Codex web. This is great for asking Codex to implement frontend changes or follow up on whiteboarding sessions.

Container caching

Codex now caches containers to start new tasks and followups 90% faster, dropping the median start time from 48 seconds to 5 seconds. You can optionally configure a maintenance script to update the environment from its cached state to prepare for new tasks. See the docs for more.

Automatic environment setup

Now, environments without manual setup scripts automatically run the standard installation commands for common package managers like yarn, pnpm, npm, go mod, gradle, pip, poetry, uv, and cargo. This reduces test failures for new environments by 40%.

Codex can now generate multiple responses simultaneously for a single task, helping you quickly explore possible solutions to pick the best approach.

Fixes & improvements

• Added some keyboard shortcuts and a page to explore them. Open it by pressing ⌘-/ on macOS and Ctrl+/ on other platforms.
• Added a “branch” query parameter in addition to the existing “environment”, “prompt” and “tab=archived” parameters.
• Added a loading indicator when downloading a repo during container setup.
• Added support for cancelling tasks.
• Fixed issues causing tasks to fail during setup.
• Fixed issues running followups in environments where the setup script changes files that are gitignored.
• Improved how the agent understands and reacts to network access restrictions.
• Increased the update rate of text describing what Codex is doing.
• Increased the limit for setup script duration to 20 minutes for Pro and Business users.
• Polished code diffs: You can now option-click a code diff header to expand/collapse all of them.

Agent internet access

Now you can give Codex access to the internet during task execution to install dependencies, upgrade packages, run tests that need external resources, and more.

Internet access is off by default. Plus, Pro, and Business users can enable it for specific environments, with granular control of which domains and HTTP methods Codex can access. Internet access for Enterprise users is coming soon.

Learn more about usage and risks in the docs.

Update existing PRs

Now you can update existing pull requests when following up on a task.

Voice dictation

Now you can dictate tasks to Codex.

Fixes & improvements

• Added a link to this changelog from the profile menu.
• Added support for binary files: When applying patches, all file operations are supported. When using PRs, only deleting or renaming binary files is supported for now.
• Fixed an issue on iOS where follow up tasks where shown duplicated in the task list.
• Fixed an issue on iOS where pull request statuses were out of date.
• Fixed an issue with follow ups where the environments were incorrectly started with the state from the first turn, rather than the most recent state.
• Fixed internationalization of task events and logs.
• Improved error messages for setup scripts.
• Increased the limit on task diffs from 1 MB to 5 MB.
• Increased the limit for setup script duration from 5 to 10 minutes.
• Polished GitHub connection flow.
• Re-enabled Live Activities on iOS after resolving an issue with missed notifications.
• Removed the mandatory two-factor authentication requirement for users using SSO or social logins.

It's now easier and faster to set up code execution.

Fixes & improvements

• Added a button to retry failed tasks
• Added indicators to show that the agent runs without network access after setup
• Added options to copy git patches after pushing a PR
• Added support for unicode branch names
• Fixed a bug where secrets were not piped to the setup script
• Fixed creating branches when there’s a branch name conflict.
• Fixed rendering diffs with multi-character emojis.
• Improved error messages when starting tasks, running setup scripts, pushing PRs, or disconnected from GitHub to be more specific and indicate how to resolve the error.
• Improved onboarding for teams.
• Polished how new tasks look while loading.
• Polished the followup composer.
• Reduced GitHub disconnects by 90%.
• Reduced PR creation latency by 35%.
• Reduced tool call latency by 50%.
• Reduced task completion latency by 20%.
• Started setting page titles to task names so Codex tabs are easier to tell apart.
• Tweaked the system prompt so that agent knows it’s working without network, and can suggest that the user set up dependencies.
• Updated the docs.

Start tasks, view diffs, and push PRs—while you're away from your desk.