A one-page markdown summary of a repository: size, shape, languages, dependencies, history, and what is missing.
\nFor the thirty seconds before you open an unfamiliar codebase, and for giving an agent enough context to start without reading every file.
\nRead-only. No dependencies. Node 18 or newer.
\nnode scripts/digest.mjs # this repo, to stdout\nnode scripts/digest.mjs ../other-repo # somewhere else\nnode scripts/digest.mjs . --out DIGEST.md\nnode scripts/digest.mjs . --json # the same facts, machine-readable\n# my-service\n\n**412** tracked files · **38,204** lines · **1.9 MB** · mostly **TypeScript**.\n\n**History.** 1,284 commits by 9 authors on `main`, 2023-04-02 → 2026-08-14. 31 tags,\nlatest `v4.2.0`.\n\n## Languages\n\n| Language | Files | Lines | Share |\n|---|---:|---:|---:|\n| TypeScript | 231 | 24,918 | 65.2% |\n| Markdown | 44 | 6,110 | 16.0% |\n| CSS | 18 | 3,401 | 8.9% |\n\n## Layout\n\n- `src/` — 231 files\n- `tests/` — 88 files\n- `docs/` — 41 files\n- `package.json`\n\n## Dependencies\n\n**npm** (`package.json`) — 14 runtime, 22 dev.\n\n`fastify`, `pino`, `zod`, `postgres`, …\n\n## Signals\n\nPresent: **Readme**, **Licence**, **Tests**, **CI**, **Lockfile**.\nAbsent: Contributing guide, Changelog, Dockerfile, Types.\n| Section | Source |
|---|---|
| Files | git ls-files in a checkout, so .gitignore is honoured and node_modules is never walked. A plain directory walk otherwise, skipping the usual build and vendor directories. |
| Languages | Extension, plus the handful of files named rather than suffixed (Dockerfile, Makefile, Gemfile). Lines are counted, not estimated — but only for text files under 2 MB, so a checked-in bundle cannot dominate the table. |
| Primary language | The most lines among things that are actually code. Markdown, JSON, YAML and TOML are counted but never named the primary language. |
| Layout | Top-level entries with a file count under each, biggest first. |
| Dependencies | The manifest, not the lockfile: package.json, pyproject.toml or requirements.txt, go.mod, Cargo.toml, Gemfile. Declared intent, not the resolved tree. |
| Signals | Presence of a readme, a licence, a contributing guide, a changelog, tests, CI, a Dockerfile, type declarations, a lockfile — and, deliberately, the list of which of those are absent. |
| History | git rev-list, git shortlog, git tag: commit count, author count, first and last commit dates, tag count and the latest tag. Omitted for a non-git directory. |
No score. There is no health grade, no percentile, no letter. Every field is a count of something you could verify by hand. A number that has been through a weighting function looks like a fact and is not one; deciding what "412 files" means about a repo is a human judgement, and the digest declines to make it for you.
\nAbsences are reported. "No tests, no CI, no licence" is the most useful sentence the tool can produce, and it only exists if you print what is missing rather than only what is there.
\nLines are counted, not sampled. Reading every text file under 2 MB costs milliseconds on any repo a person would open, and an estimate would be wrong in exactly the cases that matter.
\nUntracked files are invisible. In a git checkout, if it is not tracked, it is not in the digest. That is what makes two runs on two clones comparable.
\nskills/repo-digest.md turns the output into a procedure: read the sections in a specific order, then open the four files the numbers point at — the README, the entry point, the largest file in the primary language, and one test. It also carries the rules for writing an onboarding brief from the digest: quote the numbers rather than characterising them, list absences as facts rather than criticism, and say what you did not check.
Drop it into wherever your agent reads skills from.
\n.h file is called C whether or not it is C++, and a .m is called Objective-C whether or not it is MATLAB.pyproject.toml reads only PEP 621 [project] dependencies, so a Poetry-only project shows zero.git ls-files but not on disk; those entries are skipped rather than crashing the run.MIT. See LICENSE.