Codex Meter is a free Chrome extension designed to enhance the ChatGPT Codex analytics page by providing local quota and token analytics. This tool adds a Meter button next to the usage details, allowing users to view their current Credits, Tokens, cache hit rate, estimated weekly limits, and daily breakdowns. It serves as a valuable resource for tracking usage and understanding costs associated with the Codex features.

The extension offers several key functionalities, including the ability to switch between official source charts and Codex Meter metrics. Users can analyze their data through various charts based on Credits, total Tokens, and other metrics. Additionally, it allows for the export of data in CSV or JSON formats while securely storing snapshots locally in Chrome. Importantly, Codex Meter prioritizes user privacy by not saving any ChatGPT Web bearer tokens.