Chronicle – Codex

Chronicle is an opt-in research preview that extends Codex memory with screen context. It is currently available only to ChatGPT Pro subscribers on macOS, and is not yet available in EU, UK, Switzerland.

When turned on, Codex understands the user's current work context based on what they are looking at on screen, requiring less explanation. Because it builds memory using recent screen information, users don't need to re-explain what they were doing, and Codex can better pick up related sources, tools, and workflows.

The main behaviors are as follows.

• Understands the current situation based on what's visible on screen.
• Automatically fills in missing context, reducing the need to explain from scratch.
• Remembers frequently used tools and workflows to reduce repeated explanations over the long term.
• When a more appropriate source exists—such as a file, Slack thread, Google Doc, dashboard, or pull request—Chronicle helps find and use that source directly.

To activate it, turn on Memories under Settings > Personalization > Memories in the Codex app, then enable Chronicle below it and click Continue in the consent dialog. After that, users must grant Screen Recording and Accessibility permissions, and once setup is complete, they can select Try it out or start a new thread.

While running, users can pause or resume at any time using Pause Chronicle and Resume Chronicle. Pausing is recommended before meetings or when viewing sensitive content, and to turn it off completely, go back to Settings > Personalization > Memories and disable Chronicle.

There are clear points of caution. Chronicle runs sand-boxed agents in the background to generate memories, so it can consume rate limits quickly, and because it relies on screen captures, the risk of prompt injection increases. Screen captures may also contain sensitive information, and Chronicle does not access the microphone or system audio.

Data is stored as follows.

• Screen captures are stored only as temporary files, visible briefly only while running.
• Temporary capture files are typically created under $TMPDIR/chronicle/screen_recording/.
• Captures older than 6 hours are automatically deleted during runtime.
• Generated memories are stored locally as unencrypted Markdown files.
• The storage location is $CODEX_HOME/memories_extensions/chronicle/, typically ~/.codex/memories_extensions/chronicle.

When Chronicle creates memories, a separate ephemeral Codex session is opened based on local screen context, and that session processes selected screenshot frames, OCR text, timing information, and local file paths from the relevant time. Generated screenshots are not permanently stored on servers, and except where legally required, they are not retained or used for training.

Memory files can be read and edited by the user, and if needed, files can be deleted or edited to make Chronicle forget specific content. However, manually adding new information is not recommended, and related memories may be included again as context in future sessions.