Oss Hygiene

oss-hygiene

Brings a public GitHub repo up to the GitHub Community Standards baseline and the OpenSSF Scorecard supply-chain baseline, and stages it for the OpenSSF Best Practices Badge.

This sits next to /gh-bootstrap and answers a different question: gh-bootstrap locks the merge surface; oss-hygiene fills the contributor-facing and supply-chain surface.

Where this skill fits

Run /gh-bootstrap first (so main is locked), then /oss-hygiene (so contributors can find their way in and supply-chain checks gate PRs).

What gets configured

The skill operates on three orthogonal surfaces. It diffs every file against assets/ templates and asks before overwriting anything that already exists.

Surface 1 — GitHub Community Standards

The "Community Standards" tab under repo Insights surfaces these files. Missing files fail the checklist.

For LICENSE: if missing, do not silently scaffold. License choice is a decision (MIT, Apache-2.0, AGPL-3.0, etc.) — surface the gap and link the user to https://choosealicense.com/.

For README: surface a missing-or-thin warning but do not auto-generate. README content is the project's voice.

Surface 2 — Supply chain (Scorecard checks)

OpenSSF Scorecard runs ~18 automated checks. The skill wires the ones that are scaffold-shaped:

Plus the GitHub-native Code Security features that don't go in repo files:

Surface 3 — OpenSSF Best Practices Badge

The badge is self-attested at https://www.bestpractices.dev. The skill doesn't fill it out — the project owner has to. What the skill does:

1. Checks whether the repo already has a badge (looks for the badge URL in README).
2. Prints the registration link with the repo URL pre-filled.
3. Suggests adding the badge markdown to README (assets/README-badge-snippet.md).

The badge is a Scorecard CII-Best-Practices check enabler — registering even at the in-progress level is the lowest-effort way to bump that score.

Protocol

1. Confirm scope and inspect current state

gh auth status
gh repo view --json nameWithOwner,visibility,isPrivate,licenseInfo,description
gh api "repos/$REPO/community/profile" --jq '{
  health_percentage,
  files: (.files | to_entries | map(select(.value != null)) | from_entries | keys)
}'
gh api "repos/$REPO/vulnerability-alerts" 2>/dev/null && echo "dependabot alerts: ON" || echo "dependabot alerts: OFF"
gh api "repos/$REPO" --jq '{
  secret_scanning: .security_and_analysis.secret_scanning.status,
  push_protection: .security_and_analysis.secret_scanning_push_protection.status
}'

Ask the user — once, as a single consolidated question with all decisions inline. Do not prompt sequentially; the user should be able to reply "go with defaults" and have the skill proceed. Cap the list at the items below (≤5):

• Visibility — this skill is sized for public repos. Private repos can use a subset (community files yes, secret scanning needs Advanced Security, scorecard publishing needs public visibility for the badge).
• License — if licenseInfo is null, surface and stop until the user picks one.
• CodeQL applicability — does the repo contain code in a CodeQL-supported language (actions, c-cpp, csharp, go, java-kotlin, javascript-typescript, python, ruby, swift)? If not, skip the CodeQL workflow. Surface a recommendation, don't force a question when the only matches are CI-helper scripts (e.g. .github/scripts/*.py) — those are not project code, and the default should be skip with the user opting in.
• FUNDING.yml — does the user accept sponsorship? If yes, ask for platform + handle (GitHub Sponsors, Buy Me a Coffee, Ko-fi, OpenCollective, etc.).
• CODEOWNERS — only suggest when the repo has multiple maintainers. For solo, skip.

2. Scaffold the community files

For each file under assets/, in order:

CODE_OF_CONDUCT.md
CONTRIBUTING.md
SECURITY.md
.github/ISSUE_TEMPLATE/bug_report.yml
.github/ISSUE_TEMPLATE/feature_request.yml
.github/ISSUE_TEMPLATE/config.yml
.github/PULL_REQUEST_TEMPLATE.md

Diff against the existing file (if present). If different, ask before overwriting. Substitute {{REPO}}, {{OWNER}}, {{CONTACT_EMAIL}} placeholders.

CONTRIBUTING.md includes a generic skeleton — encourage the user to project-specific-ize it after merge.

3. Scaffold the supply-chain workflows

dependabot.yml is configured with the language packages detected in the repo (look for package.json, Cargo.toml, pyproject.toml, go.mod, Gemfile, composer.json, pom.xml, etc.) plus a github-actions ecosystem entry to keep workflow action versions current.

Manifest detection scope. Only count manifests in project source roots — not under .github/scripts/, .devcontainer/, tools/ci/, or other CI-helper paths. A pyproject.toml under a project root is real; a hard-coded pip install foo==1.2.3 line in a workflow is not, and Dependabot can't track it without a real top-level manifest. When the only language presence is CI-helper code, skip that ecosystem and add a one-line comment in the generated dependabot.yml explaining why (e.g. "no top-level Python manifest; the only Python is in .github/scripts/"). This mirrors the same heuristic used for CodeQL applicability in step 1.

4. Toggle the GitHub-native security features

Use gh api to enable or verify (idempotent — re-applying is a no-op):

# Automated security fixes / Dependabot security updates
gh api -X PUT "repos/$REPO/automated-security-fixes"

# Vulnerability alerts (Dependabot alerts)
gh api -X PUT "repos/$REPO/vulnerability-alerts"

# Secret scanning alerts for users + push protection
gh api -X PATCH "repos/$REPO" \
  -F security_and_analysis[secret_scanning][status]=enabled \
  -F security_and_analysis[secret_scanning_push_protection][status]=enabled

For private repos these may 403 unless GitHub Code Security is paid for — surface and skip rather than fail.

5. Audit existing workflows for Token-Permissions and Dangerous-Workflow

This is detection, not modification. The skill reads each .github/workflows/*.yml:

• Token-Permissions: flag any workflow without a top-level permissions: block (or with permissions: write-all). Suggest the safe default permissions: { contents: read } and bump only what each job needs.
• Dangerous-Workflow: flag the unsafe pattern of pull_request_target + actions/checkout of the head SHA, and any ${{ ... }} interpolation of github.event.* inputs into shell scripts.

Print findings; don't auto-edit. These are subtle changes the user should review.

6. Surface the OpenSSF Best Practices Badge step

Print, don't apply. Substitute <owner>, <repo>, and the project ID once registered. Read assets/README-badge-snippet.md and strip the block between <!-- BEGIN-CODEQL --> and <!-- END-CODEQL --> markers when CodeQL was skipped in step 3 — the markers exist precisely so the snippet is conditionally trimmable without ambiguity.

Register at: https://www.bestpractices.dev/en/projects/new
Repo URL:    https://github.com/<owner>/<repo>
Once you have a project ID, paste this into README.md:

[![OpenSSF Scorecard](https://api.scorecard.dev/projects/github.com/<owner>/<repo>/badge)](https://scorecard.dev/viewer/?uri=github.com/<owner>/<repo>)
[![OpenSSF Best Practices](https://www.bestpractices.dev/projects/<id>/badge)](https://www.bestpractices.dev/projects/<id>)

The skill does not register the project for the user — registration is a credential and judgment step (the user attests answers).

7. Verify and report

Re-read the community profile and the workflow files. Print a small summary:

gh api "repos/$REPO/community/profile" --jq '{health_percentage, missing: ([.files | to_entries[] | select(.value == null) | .key])}'
ls .github/workflows/ | sort

The summary should call out:

• What was scaffolded (and the diff vs existing if any)
• What was already correct (no-op)
• What was skipped and why (no LICENSE, private repo, no CodeQL languages, etc.)
• The OSSF badge registration link

Idempotency

• Files: diff before overwriting; ask if the content differs.
• API toggles: PUT/PATCH are idempotent.
• Workflow audit: read-only — re-running just re-prints the same findings.
• Never delete: if a previous run left an artifact (an old workflow with a different name), surface it and let the user decide.

What this skill is NOT for

• License selection — it surfaces the gap, doesn't pick one
• README authoring — content is the project's voice
• Org-wide community files — use /safe-settings for that
• Branch protection / merge queue — use /gh-bootstrap
• Sigstore release signing — language- and pipeline-specific, out of scope
• Filling out the OSSF Best Practices Badge questionnaire — that's the maintainer's attestation
• Pinning dependencies — per-ecosystem, often contentious
• Setting up fuzzing — language-specific

Gotchas

• Default community health files: if the user/org has a .github repo with these files, they apply to every repo without its own copy. Scaffolding into a repo overrides the org default; only do it when per-repo overrides are intended.
• Dependency Review Action: works on public repos for free, and on private repos only with GitHub Advanced Security. The workflow will hard-fail on private/free.
• Scorecard workflow: needs id-token: write for OIDC publishing to scorecard.dev; the asset has the right permissions. If the workflow fails on first run with a 403, the user has org-level OIDC restrictions.
• CodeQL setup-mode: default setup is configured in the GitHub UI (Settings → Code security → CodeQL → Set up). The asset uses advanced setup (workflow file). The two are mutually exclusive — if the user enabled default first, the workflow file will conflict.
• Token-Permissions audit: actions like softprops/action-gh-release and many publish actions need contents: write. Don't tell users to set every workflow to read-only — flag and explain.
• pull_request_target is dangerous by default: don't use it just to access secrets in fork PRs. The skill flags it; the user should refactor to a separate workflow_run or labeled-PR pattern.
• OSSF badge is self-attested: a passing badge means the maintainer answered the questions, not that an audit happened. It's a signal, not a guarantee.
• Scorecard score on tiny / new repos: the Maintained check needs 90 days of activity; new repos will score low until they age in. This is a feature, not a bug.
• Scaffolded workflows trip Pinned-Dependencies against themselves: dependency-review.yml, scorecard.yml, and codeql.yml use floating tags (@v4, @v2, @v3) to match the OSSF reference templates and stay readable. Scorecard's Pinned-Dependencies check will flag this on the first run. The intentional trade-off: Dependabot (also scaffolded by this skill) keeps the tags green automatically, whereas SHA pins decay silently. If you want a clean Pinned-Dependencies score, convert the three new workflow files to commit-SHA pins after the first Dependabot PR lands — Dependabot will then maintain them in pinned form.

References

• references/scorecard-checks.md — full table of all 18 Scorecard checks, what they measure, and remediation pointers.
• references/badge-criteria.md — OpenSSF Best Practices Badge Passing criteria mapped to repo artifacts.
• references/community-standards.md — GitHub's own checklist and how each file is detected.
• references/dependabot.md — dependabot.yml schema reference and per-ecosystem examples.
• references/workflow-hardening.md — Token-Permissions and Dangerous-Workflow rules with concrete examples.