--- pretty_name: AGENTS.md and CLAUDE.md in popular GitHub repositories (snapshot 2026-10-16) license: other license_name: per-repository license_details: File texts keep the license of the repository they come from (column `license`). See the Licensing section. language: - en size_categories: - 10K= 2026-07-18, a push to any branch counts); - it is neither a fork nor archived. ## Files The study covers only `/AGENTS.md` and `/CLAUDE.md`, at the repository root, with exact case, on the default branch, in their current version (the commit is in `head_oid`). Other formats are out of scope, for example `.cursor/rules`, `.github/copilot-instructions.md` and nested AGENTS.md files. ## Configs All three configs join on `full_name` (`owner/repo`). ### `files` (8,394 rows): one row per file | column | meaning | |---|---| | `full_name`, `path` | repository and file (`AGENTS.md` or `CLAUDE.md`) | | `license` | the repository's license, an SPDX id from GitHub; `NOASSERTION` means GitHub couldn't identify it, null means no license file | | `head_oid`, `head_date` | the default-branch commit the file was read from, and its date | | `is_symlink`, `link_target` | whether the file is a symlink, and its target path | | `byte_size` | size in bytes as reported by GitHub | | `text_status` | `included`, `withheld_license`, `unresolved_symlink` or `binary` | | `text` | the file content (UTF-8); null unless `text_status = included` | Symlinks are resolved, so a symlink row carries the **target's** text. Of the 874 symlink rows, most are a CLAUDE.md that points to the same repository's AGENTS.md. Filter on `is_symlink` to avoid counting that content twice. Text status in this release: | text_status | count | |---|---:| | included | 8,387 | | unresolved_symlink | 6 | | binary | 1 | Included texts: 79.0 MB. ### `repos` (6,006 rows): one row per repository with at least one file Repository metadata from GitHub at enrich time: - `stars`, `forks`, `watchers`, `disk_usage_kb`, `code_bytes`; - `languages` (bytes per language), `topics`, `license`, `description`, `homepage_url`, `default_branch`, `created_at`, `pushed_at`, `is_fork`, `is_archived`, `is_template`; - `releases`, `open_issues`, `closed_issues`, `open_prs`, `merged_prs`, `commits_total`. Activity metrics: - `commits_12m`: default-branch commits in the 365 days before the snapshot; - `recent_*`: computed from the latest (up to) 100 of those commits. They are `recent_sample` (how many commits were sampled), `recent_authors`, `recent_human_authors` (bots excluded), `recent_bot_commits` and `recent_ai_commits` (commits with a co-author trailer or signature of Claude, Codex, Copilot, Cursor, Devin, Aider or Gemini). How the two files relate: - `relation`: one label per repository. The rules are applied in order and the first match wins: symlink, thin `@AGENTS.md` import (300 characters or fewer), short pointer, import plus own content, identical copies, separate files; - `relation_detail`: for example, the symlink target. | relation | count | |---|---:| | AGENTS.md only | 2,549 | | CLAUDE.md only | 1,040 | | both: CLAUDE.md is a thin @AGENTS.md import (<=300 chars) | 771 | | both: CLAUDE.md is a symlink to AGENTS.md | 629 | | both: separate files | 262 | | both: separate files, CLAUDE.md mentions AGENTS.md | 171 | | both: AGENTS.md is a symlink to CLAUDE.md | 155 | | both: CLAUDE.md is a short pointer to AGENTS.md | 140 | | both: CLAUDE.md imports @AGENTS.md and adds content | 101 | | both: separate files, AGENTS.md mentions CLAUDE.md | 64 | | both: identical copies | 40 | | both: symlinks to the same other file | 28 | | both: AGENTS.md only imports or points to CLAUDE.md | 27 | | AGENTS.md only (symlink to another file) | 17 | | CLAUDE.md only (symlink to another file) | 12 | ### `population` (22,854 rows): every repository that was checked | column | meaning | |---|---| | `full_name`, `repo_id` | repository | | `primary_language`, `stars`, `created_at`, `pushed_at` | from GitHub search at discovery time | | `found` | the repository still resolved when presence was checked | | `has_agents_md`, `has_claude_md` | whether each root file exists | | `agents_md_size`, `claude_md_size` | file size in bytes, if the file exists | Use `population` for adoption rates, for example by language or star band. Note that `population.stars` and `population.pushed_at` come from search time, while the `repos` columns come from enrich time a few hours later, so the values can differ slightly. ## Collection All data came through the GitHub GraphQL and REST APIs with one token, on 2026-10-16; no repository was cloned. The pipeline's code and its parameters are in the study repository (`metastudy/`). Known limitations: - 103 adopters have a default-branch HEAD older than the 90-day window. They passed the filter because of pushes to other branches. - Stars and `pushed_at` are a snapshot, so repositories near the 1,000-star cut-off move in and out over time. - A repository is classified only by its primary language. - 7 files have no text: 6 symlinks can't be resolved (their targets are outside the repository or not in it), and GitHub flags 1 file as binary. ## Licensing The file texts are third-party content. Each text keeps the license of the repository it comes from, given in `license`. Check that license, and attribute the repository (`full_name`, `head_oid`), before you reuse a text. This release includes every text that was collected. 1,358 included texts come from repositories with `NOASSERTION` or no license; their reuse terms are unclear. Repository licenses among adopters: | license | count | |---|---:| | MIT | 2,334 | | Apache-2.0 | 1,525 | | NOASSERTION | 816 | | GPL-3.0 | 389 | | AGPL-3.0 | 347 | | (none) | 157 | | BSD-3-Clause | 131 | | GPL-2.0 | 98 | | MPL-2.0 | 50 | | BSD-2-Clause | 38 | | LGPL-3.0 | 31 | | CC0-1.0 | 12 | | ISC | 11 | | LGPL-2.1 | 8 | | Unlicense | 8 | | CC-BY-SA-4.0 | 7 | | EPL-2.0 | 7 | | CC-BY-4.0 | 6 | | Zlib | 6 | | EUPL-1.2 | 5 | | MIT-0 | 4 | | OSL-3.0 | 3 | | 0BSD | 3 | | BSL-1.0 | 2 | | EPL-1.0 | 2 | | MS-PL | 1 | | WTFPL | 1 | | OFL-1.1 | 1 | | UPL-1.0 | 1 | | ECL-2.0 | 1 | | PostgreSQL | 1 | The metadata columns (counts, flags, labels) are facts about public repositories, compiled by the author. ## Personal information The texts are published files from public repositories. Some contain names, GitHub handles or e-mail addresses of maintainers: 302 of the included texts contain at least one e-mail address. They were not removed. Please don't use this dataset to contact or profile individuals. ## Citation If you use this dataset in your research, please cite: ```bibtex @misc{zarzycki2026codingagents, title = {What Open-Source Projects Tell Their Coding Agents: A Census of {AGENTS.md} and {CLAUDE.md}}, author = {Pawel Zarzycki}, year = {2026}, eprint = {2610.31715}, archivePrefix = {arXiv}, primaryClass = {cs.SE}, url = {https://arxiv.org/abs/2610.31715} } ```