About Rulefiles

Rulefiles follows two things for people who work with AI coding tools. One is the weekly list of changes in Cursor, Claude Code, Codex and GitHub Copilot. The other is a matrix of which instruction file each tool reads, such as AGENTS.md, CLAUDE.md or .github/copilot-instructions.md.

How the data is made

Every digest item and every matrix cell has a date and a link to an official page. Digest items quote the wording of the source. They do not restate a release note in new words, so a line cannot say more than the source does.

A watch script reads the official changelogs and release feeds and writes a draft with each entry's title, date and link. A person or a bot reviews the draft before anything moves into a digest. The script respects robots.txt, identifies itself in its User-Agent header, and waits between requests.

Matrix cells that we could not confirm on an official page are marked "unverified", with the date of the check. A cell is marked "migration only" when the page mentions the file only as input to a migration command such as /init. In the current data, last reviewed on 2026-10-16, 15 of 36 cells are unverified and 4 are migration only.

What this site is not

It is an independent project. It is not affiliated with Cursor, Anthropic, OpenAI, GitHub or Google, and the product names belong to their owners. It does not rank tools, and it does not summarize release notes with a model.

Data files

The matrix and the digests are available as JSON files: matrix.json and digests.json. The llms.txt file lists the pages for chatbots and crawlers.

License

The code is under the MIT license. The data (the matrix and the digests, in the JSON files above) and the text of this site are under CC BY 4.0. You can copy, share and adapt them, including for commercial use or with AI tools, if you credit the project, link the license and say what you changed.

Suggested credit: "Rulefiles data by Rulefiles contributors, https://rulefiles.dev/, licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)."

The license covers what this project adds: the selection, the dates, the statuses, the notes and the structure. The excerpts quoted from official pages belong to their authors, and the product names belong to their owners. Neither is licensed here.

Corrections

To report a mistake, or to ask for an excerpt to be removed, write to contact@rulefiles.dev. Say which page, which line and which official page shows the difference.