What is gpt-timekeeper?

GPT Timekeeper is a small browser extension that adds a clear sense of time to long ChatGPT conversations. Normally ChatGPT can recall what was said earlier in a chat, but it has no reliable way of knowing exactly when each message was sent, since it only sees the words themselves. This extension fixes that by adding a plain text timestamp to the start of each message before it is sent, so the time is written directly into what the model reads. You can set it to automatically add a timestamp to every message you send, or add one manually to a single message at any time, even if the message box is empty. The extension also keeps a local record of the timestamps for messages already loaded in the page, and lets you export that record as a plain text file. You can export the entire currently loaded conversation, or just a chosen time range, and the exported file includes a summary with the conversation title, the export time, how many turns were included, and how many came from the user versus the assistant. There is an honest limitation described in the README: no browser extension can reliably rewrite ChatGPT's own hidden system context, so the only dependable method is putting the timestamp inside the visible message text itself. The small time badges shown in the interface are only for the person using the extension to read, not something the model can see. Tracking also only starts once the extension is installed and opened on a conversation, so it cannot recover exact times for messages that were already there beforehand. To install it, you load the unpacked extension folder into Chrome or Edge through the browser's developer mode, then open ChatGPT as usual. On the privacy side, everything stays in the browser's local extension storage: there is no server involved, no account tokens are read, and message text itself is not stored by default, only details like role, position, and timestamps. The project has no build step, so anyone editing the code can just reload the extension directly in the browser to test changes, and a small test file is included to check the core timestamp logic. It is released under the MIT license.