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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

  1. New model

    GPT-6.1 Terra in Work and Codex

    GPT-6.1 Terra is now available in ChatGPT Work and Codex on Plus, Pro, Business, Enterprise, and Edu plans. It's a fast, efficient model for professional work that combines strong image understanding with precise computer use. Reason about images and screens, then act on what you find across your browser, desktop, and apps. Terra also provides clear, direct writing that puts results first and explains supporting details in plain language. Choose GPT-6.1 Terra from the model list in Advanced in the ChatGPT desktop app or ChatGPT Work on the web. Work also supports Terra on mobile. The model isn't available in Chat and does not support UAE inference residency. Enterprise access depends on workspace availability and administrator controls.

  2. New model

    GPT-6.1 Sol Ultrafast in Codex and ChatGPT Work

    Ultrafast mode speeds up token generation with GPT-6.1 Sol in Codex and ChatGPT Work. Ultrafast is available on Pro $500 and eligible Enterprise and Edu plans. Enterprise access is off by default; workspace owners must enable it. GPT-6.1 Sol Ultrafast supports inference residency in the United States and Europe (EEA + Switzerland).

  3. New model

    GPT-6.1 Sol in Codex and ChatGPT Work

    GPT-6.1 Sol offers near-Astra performance for complex work at a lower cost than Astra. Consider it for repeated, long-running work across code, apps, and documents. Availability depends on your plan, client, and workspace settings. Use gpt-6.1-sol.

  4. New model

    GPT-6 Sol and Luna in Codex and ChatGPT Work

    GPT-6 Sol and GPT-6 Luna are rolling out to Codex and ChatGPT Work at lower token prices than their GPT-5.6 predecessors. Use Sol for complex coding and agentic workflows, and Luna for focused, high-volume tasks. Both models are rolling out to Plus, Pro, Business, Enterprise, and Edu users. Free and Go users can access Luna in the desktop app. Availability depends on rollout and workspace settings; Enterprise administrators must enable the new models. In ChatGPT, the models are available in Work and Codex, but not Chat. Choose a model in the picker when available. In the CLI, use /model or start a task with codex --model gpt-6-sol or codex --model gpt-6-luna.

  5. New modelAnnouncement

    GPT-5.5 and Codex app updates

    GPT-5.5 is now available in Codex as OpenAI's newest frontier model for complex coding, computer use, knowledge work, and research workflows. GPT-5.5 in Codex. GPT-5.5 is the recommended choice for most Codex tasks when it appears in your model picker. It's especially useful for implementation, refactors, debugging, testing, validation, and knowledge-work artifacts. To switch to GPT-5.5: In the CLI, start a new thread with: bash codex --model gpt-5.5 Or use /model during a session. In the IDE extension, choose GPT-5.5 from the model selector in the composer. In the Codex app, choose GPT-5.5 from the model selector in the composer. If you don't see GPT-5.5 yet, update the CLI, IDE extension, or Codex app to the latest version. During the rollout, continue using GPT-5.4 if GPT-5.5 is not yet available. The Codex app can now let Codex operate the in-app browser for local development servers and file-backed pages. Ask Codex to use the browser when it needs to click through a rendered UI, reproduce a visual bug, or verify a local fix inside the app. Browser use runs through the bundled Browser plugin. In settings, you can manage the plugin and review allowed or blocked websites. Codex can route eligible approval prompts through an automatic reviewer agent before the request runs. When configured, the Codex app shows an automatic review item with the review status and risk level, so you can see whether the reviewer approved, denied, stopped, or timed out before deciding. Performance improvements and bug fixes. Fixed duplicate queued follow-up messages across app windows. Fixed new chats reverting to outdated model and thinking settings. Kept edits to the same file grouped together after reopening a chat.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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”.

  13. New modelAnnouncement

    Introducing GPT-5.1-Codex-Max

    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: bash 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: toml model = "gpt-5.1-codex-max”.

  14. New modelAnnouncement

    Introducing GPT-5.1-Codex and GPT-5.1-Codex-Mini

    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: bash 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: toml model = "gpt-5.1-codex”.

  15. New model

    Introducing GPT-5-Codex-Mini

    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: bash 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: toml model = "gpt-5-codex-mini”.

  16. New model

    GPT-5-Codex model update

    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.

  17. New model

    GPT-5-Codex in the API

    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.

  18. New modelAnnouncement

    Introducing GPT-5-Codex

    New model: GPT-5-Codex. !codex-switch-model. 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. !codex-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. 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.