Chronicle runs in the background and uses an AI agent to generate summaries from screen recordings. These summaries are stored locally as Markdown files. The recordings themselves are kept only temporarily and, according to OpenAI, are deleted after six hours.

The feature is initially available as an opt-in preview for ChatGPT Pro subscribers on macOS, but not in the EU, the UK, or Switzerland. Users can enable Chronicle in the Codex settings under Personalization, where Memories must be turned on first, followed by Chronicle. After that, macOS permissions for screen recording and accessibility are required.

OpenAI notes that Chronicle can consume available rate limits quickly, increases the risk of prompt injection attacks — meaning malicious instructions embedded in displayed web content — and stores the generated memories unencrypted on the device.

From a product perspective, Chronicle is meant to make Codex more context-aware and persistent across sessions. At the same time, the feature raises clear security and privacy concerns, especially because it relies on background screen capture and local storage of unencrypted memory files.