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AI release notes
OpenAI's official Codex changelog. Codex app: Codex in ChatGPT, the desktop app and the web. Codex CLI: the version that runs in a terminal window.
Compiled by the Toolstash team · Updated
New model
Introducing GPT-5.4 mini in Codex
GPT-5.4 mini is now available in Codex as a fast, efficient model for lighter coding tasks and subagents. It improves over GPT-5 mini across coding, reasoning, image understanding, and tool use while running more than 2x faster. In Codex, GPT-5.4 mini uses 30% as much of your included limits as GPT-5.4, so comparable tasks can last about 3.3x longer before you hit those limits. GPT-5.4 mini is available in the Codex app, the CLI, the IDE extension, and Codex on the web. GPT-5.4 mini is also available in the API. Use GPT-5.4 mini for codebase exploration, large-file review, processing supporting documents, and other less reasoning-intensive subagent work. For more complex planning, coordination, and final judgment, start with GPT-5.4. To switch to GPT-5.4 mini: In the CLI, start a new thread with: bash codex --model gpt-5.4-mini Or use /model during a session. In the IDE extension, choose GPT-5.4 mini from the model selector in the composer. In the Codex app, choose GPT-5.4 mini from the model selector in the composer. If you don't see GPT-5.4 mini yet, update the CLI, IDE extension, or Codex app to the latest version.
Codex app
Codex app
Added back and forward buttons in the header so you can move between recent screens more quickly. Added an Open in Finder, Open in Explorer, or Open in File Manager action from thread menus to jump straight to a thread's project folder. Performance improvements and bug fixes. Improved resume and thread error toasts with clearer details when something goes wrong. Additional performance improvements and bug fixes.
Codex app
Codex app
Change the Codex app appearance in Settings by choosing a base theme, adjusting accent, background, and foreground colors, and changing the UI and code fonts. You can also share your custom theme with friends. !Codex app theme settings showing custom themes, color controls, and font settings. You can now choose whether automations run locally or on a worktree, define custom reasoning levels and models, and use templates to find inspiration for new automations. !Automations settings showing local and worktree options alongside scheduling controls. Performance improvements and bug fixes. Various bug fixes and performance improvements.
Codex app
Codex app
Also covers version 26.309. Codex can now read the integrated terminal for the current thread, so it can check the status of a running development server or refer back to failed build output while it works with you. Performance improvements and bug fixes. Remembered the last local, worktree, or cloud selection after restarting the app. Restored the button for adding inline comments from the diff gutter. Refreshed branch information after creating a branch. Additional performance improvements and bug fixes.
Codex app
Codex app
Performance improvements and bug fixes. Improved remote connections with clearer connection errors, better status updates, and clearer host labels in thread and settings views. Fixed copy and paste shortcuts in the integrated terminal on Windows. Fixed an issue where archived pinned threads could reappear in the sidebar. Fixed an issue where repeated codex://new links could stop prefilling a new conversation when the app was already open. Additional performance improvements and bug fixes.
New model
Introducing GPT-5.4 in Codex
GPT-5.4 is now available in Codex as OpenAI's most capable and efficient frontier model for professional work. It combines recent advances in reasoning, coding, and agentic workflows in one model, and it's the recommended choice for most Codex tasks. In Codex, GPT-5.4 is the first general-purpose model with native computer-use capabilities. GPT-5.4 in Codex includes experimental support for the 1M context window. It supports complex workflows across applications and long-horizon tasks, with stronger tool use and tool search that help agents find and use the right tools more efficiently. GPT-5.4 is available everywhere you can use Codex: the Codex app, the CLI, the IDE extension, and Codex Cloud on the web. GPT-5.4 is also available in the API. To switch to GPT-5.4: In the CLI, start a new thread with: bash codex --model gpt-5.4 Or use /model during a session. In the IDE extension, choose GPT-5.4 from the model selector in the composer. In the Codex app, choose GPT-5.4 from the model selector in the composer. If you don't see GPT-5.4 yet, update the CLI, IDE extension, or Codex app to the latest version.
Codex app
Codex app
!Codex app for Windows showing a project sidebar, active thread, and review pane. The Codex app is now available on Windows. The app gives you one interface for working across projects, running parallel agent threads, and reviewing results in one place. The Codex app runs natively on Windows using PowerShell and a native Windows sandbox for bounded permissions, so you can use Codex on Windows without moving your workflow into WSL, onto a virtual machine, or by deactivating the sandbox. The Windows app includes the same core features as the rest of the Codex app: Skills to discover and extend Codex capabilities. Automations to run work in the background. Worktrees to handle independent tasks in the same project. If you prefer to develop in WSL, you can also switch the Codex agent and the integrated terminal to run there. Download it from the Microsoft Store and sign in with your ChatGPT account or an API key. For setup and configuration details, see Setup, Use WSL with the Codex app, and Customize the app for your development setup.
Codex app
Codex app
Added a Worktrees setting to turn automatic cleanup of Codex-managed worktrees on or off. Added Handoff support for moving a thread between Local and Worktree. Added an explicit English option in the language menu. Performance improvements and bug fixes. Improved GitHub and pull request workflows. Improved approval prompts and app connection sign-in flows. Additional performance improvements and bug fixes.
Codex app
Codex app
Performance improvements and bug fixes. Fixed a regression where conversation and task views could stop updating while Codex was streaming a response. Additional performance improvements and bug fixes.
Codex app
Codex app
Added pull request status badges in task rows and PR buttons, including draft, open, merged, and closed states. Added a Worktrees setting to choose how many Codex-managed worktrees to keep before older ones are cleaned up. Performance improvements and bug fixes. Improved scrolling and navigation in long conversations and code review, including fixes for thread jumpiness, sidebar jitter, and diff scrolling. Improved app startup reliability and keyboard zoom behavior. Additional performance improvements and bug fixes.
Codex app
Codex app
Added new MCP shortcuts in the composer, including install keyword suggestions and an MCP server submenu in Add context. Added support for @mentions and skill mentions in inline review comments. Performance improvements and bug fixes. Improved rendering of MCP tool calls and Mermaid diagram error handling. Fixed an issue where stopped terminal commands could continue appearing as running. Additional performance improvements and bug fixes.
Codex app
Codex app
Added an option to run automations in a dedicated worktree or directly in a project folder. Performance improvements and bug fixes. Moved configuration warnings to settings, with links to the affected files. Improved prompt history navigation and preserved line breaks in draft messages.
Codex app
Codex app
Added drag-and-drop support to reorder queued messages. Added a warning when the selected model is downgraded. Improved file workflows with fuzzy file search and better attachment recovery after restart. Additional performance improvements and bug fixes.
Codex appAnnouncement
Codex app
Support for GPT-5.3-Codex-Spark. Added floating pop-out window to take a conversation with you. Improved performance and bug fixes. Alpha testing for the Codex app on Windows is also starting. Sign up here to be a potential alpha tester.
New modelAnnouncement
Introducing GPT-5.3-Codex-Spark
Today, we're releasing a research preview of GPT-5.3-Codex-Spark, a smaller version of GPT-5.3-Codex and our first model designed for real-time coding. Codex-Spark is optimized to feel near-instant, delivering more than 1000 tokens per second while remaining highly capable for real-world coding tasks. Codex-Spark is available in research preview for ChatGPT Pro users in the latest Codex app, CLI, and IDE extension. This release also marks the first milestone in our partnership with Cerebras. At launch, Codex-Spark is text-only with a 128k context window. During the research preview, usage has separate model-specific limits and doesn't count against standard Codex limits. During high demand, access may slow down or queue while we balance reliability across users. To switch to GPT-5.3-Codex-Spark: In the CLI, start a new thread with: bash codex --model gpt-5.3-codex-spark Or use /model during a session. In the IDE extension, choose GPT-5.3-Codex-Spark from the model selector in the composer. In the Codex app, choose GPT-5.3-Codex-Spark from the model selector in the composer. If you don't see GPT-5.3-Codex-Spark yet, update the CLI, IDE extension, or Codex app to the latest version. GPT-5.3-Codex-Spark isn't available in the API at launch. For API-key workflows, continue using gpt-5.2-codex.
Codex app
Codex app
Added branch search in the branch picker. Added clearer guidance for entering plan mode when you type plan in the composer. Added support for parallel approvals. Additional performance improvements and bug fixes.
New model
GPT-5.3-Codex in Cursor and VS Code
Starting today, GPT-5.3-Codex is available natively in Cursor and VS Code. API access is starting with a small set of customers as part of a phased release. This is the first model treated as a high security capability under the Preparedness Framework. Safety controls will continue to scale, and API access will expand over the next few weeks.
Codex app
Codex app
Added MCP and personality actions to the command palette. Updated follow-up behavior to queue by default. Additional performance improvements and bug fixes.
Codex app
Codex app
Added a file-reference action to reveal files directly in your OS file manager. Improved handling of large reviews by removing the overall diff-size cap in the review pane. Additional performance improvements and bug fixes.
Codex appAnnouncement
Codex app
Support for GPT-5.3-Codex. Added mid-turn steering. Submit a message while Codex is working to direct its behavior. Attach or drop any file type. Fix flickering of the app.
New modelAnnouncement
Introducing GPT-5.3-Codex
Today we're releasing GPT-5.3-Codex, the most capable agentic coding model to date for complex, real-world software engineering. GPT-5.3-Codex combines the frontier coding performance of GPT-5.2-Codex with stronger reasoning and professional knowledge capabilities, and runs 25% faster for Codex users. It's also better at collaboration while the agent is working—delivering more frequent progress updates and responding to steering in real time. GPT-5.3-Codex is available with paid ChatGPT plans everywhere you can use Codex: the Codex app, the CLI, the IDE extension, and Codex Cloud on the web. API access for the model will come soon. To switch to GPT-5.3-Codex: In the CLI, start a new thread with: bash codex --model gpt-5.3-codex Or use /model during a session. In the IDE extension, make sure you are signed in with ChatGPT, then choose GPT-5.3-Codex from the model selector in the composer. In the Codex app, make sure you are signed in with ChatGPT, then choose GPT-5.3-Codex from the model selector in the composer. If you don't see GPT-5.3-Codex, update the CLI, IDE extension, or Codex app to the latest version. For API-key workflows, continue using gpt-5.2-codex while API support rolls out.
Codex app
Codex app
Added Zed and Textmate as options to open files and folders. Added PDF preview in the review panel. Performance improvements.
Codex app
Codex app
Added thread renaming on double-click in the thread list. Renamed Sync to Handoff and added clearer source/destination stats in the handoff UI. Additional performance improvements and bug fixes.
Codex appAnnouncement
Introducing the Codex app
!Codex app showing a project sidebar, thread list, and review pane. The Codex app for macOS is a desktop interface for running agent threads in parallel and collaborating with agents on long-running tasks. It includes a project sidebar, thread list, and review pane for tracking work across projects. Key features: Multitask across projects. Built-in worktree support. Voice dictation. Built-in Git tooling. Skills. Automations. For a limited time, ChatGPT Free and Go include Codex, and Plus, Pro, Business, Enterprise, and Edu plans get double rate limits. Those higher limits apply in the app, the CLI, your IDE, and the cloud. Learn more in the Introducing the Codex app blog post. Check out the Codex app documentation for more.
Codex app
Web search is now enabled by default
Codex now enables web search for local tasks in the Codex CLI and IDE Extension. By default, Codex uses a web search cache, which is an OpenAI-maintained index of web results. Cached mode returns pre-indexed results instead of fetching live pages, while live mode fetches the most recent data from the web. If you are using --yolo or another full access sandbox setting, web search defaults to live results. To disable this behavior or switch modes, use the web_search configuration option: web_search = "cached" (default; serves results from the web search cache). web_search = "live" (fetches the most recent data from the web; same as --search). web_search = "disabled" to remove the tool. To learn more, check out the configuration documentation.
Codex app
Team Config for shared configuration
Team Config groups the files teams use to standardize Codex across repositories and machines. Use it to share: config.toml defaults. rules/ for command controls outside the sandbox. skills/ for reusable workflows. Codex loads these layers from.codex/ folders in the current working directory, parent folders, and the repo root, plus user (~/.codex/) and system (/etc/codex/) locations. Higher-precedence locations override lower-precedence ones. Admins can still enforce constraints with requirements.toml, which overrides defaults regardless of location. Learn more in Team Config.
Codex app
Custom prompts deprecated
Custom prompts are now deprecated. Use skills for reusable instructions and workflows instead.
New model
GPT-5.2-Codex API availability
GPT-5.2-Codex is now available in the API and for users who sign into Codex with the API. To learn more about using GPT-5.2-Codex check out our API documentation.
Codex app
Agent skills in Codex
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... 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: text 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). 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.
New modelAnnouncement
Introducing GPT-5.2-Codex
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: bash 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: toml model = "gpt-5.2-codex”.