SkillSync

Verify Agent Skills before you trust them. SkillSync checks a local Skill's provenance, compatibility, and changes without executing it.

Alpha · source candidate v0.1.7 · Node.js 20+ SkillSync performs offline checks of local Skill content. It does not execute Skill scripts, does not read credentials, and does not enable live provider, remote-worker, or runtime capabilities.

Source v0.1.7 adds an offline human acceptance report on top of bounded composite-key reconciliation. The published GitHub package is still v0.1.4 and npm is still 0.1.0; neither includes the new rule.

Install

From npm (stable 0.1.0):

npx --yes @chumanic/skillsync@0.1.0 verify --path . --target codex
# or install globally
npm install -g @chumanic/skillsync@0.1.0
skillsync verify --path . --target codex

From source (0.1.7 candidate):

git clone https://github.com/Chumaniac/skillsync.git
cd skillsync
npm ci
npm run build
node dist/cli/index.js verify --path fixtures/product/trust-loop/review --target codex

From GitHub releases (no npm account required):

Tagged builds now publish a CLI tarball, checksums, a validated CycloneDX SBOM and a source manifest on GitHub Releases. GitHub v0.1.4 is published. Release run 37897733439 passed its source/main binding, tests, actual package allowlist, locked production SBOM and required GitHub provenance. The downloaded archive, SBOM and source manifest matched their checksums and public asset digests; an isolated install reported 0.1.4 and passed the packaged synthetic delivery-coverage example with execution: not-run. Installation still uses Node.js 20+ and fetches the package's public dependencies; it needs no npm login.

release_base="https://github.com/Chumaniac/skillsync/releases/download/v0.1.4"
for asset in chumanic-skillsync-0.1.4.tgz checksums.txt sbom.cyclonedx.json release-manifest.json; do
  curl --fail --location --output "$asset" "$release_base/$asset"
done
shasum -a 256 -c checksums.txt
npm install --prefix ./skillsync-tools ./chumanic-skillsync-0.1.4.tgz
./skillsync-tools/node_modules/.bin/skillsync --version

The public npm registry remains at 0.1.0. Generated npm-based CI templates pin that existing public version; a source/GitHub installation supplies the newer artifact and target-coverage commands. Older tags and the existing npm package remain available independently of this distribution.

The command above verifies the included sample Skill. Replace the fixture path with a directory containing your own SKILL.md when you are ready.

What you get

• Source0.1.7 produces an offline acceptance report with artifacts --format html. Reviewers see file binding, failed or incomplete identity checks, affected metadata and concrete review actions in a browser. The report includes no raw record values, scripts or network requests; see the visible review guide.
• Source0.1.6 supports ordered two-to-four-column identity tuples for integer reconciliation. The multi-organization example separates repeated local IDs, without delimiter collisions or raw ID reporting.
• Source keyed_integer_sum_equals checks compare each record key's integer total across CSV files, including split deliveries. They detect balanced but wrongly allocated results that global sums cannot identify. The synthetic reconciliation example demonstrates the difference without running Skill code or revealing record IDs.
• The source artifacts command independently checks actual CSV/JSON delivery files, Receipt/file hashes and cross-file count/integer sums. See actual artifact checks; it runs no Skill code. The knowledge source inventory adds exact declared HTTPS hosts to physical CSV/JSON checks without fetching sources. Optional target coverage catches expected records with no delivery/evidence rows; see the delivery coverage example. CSV reference_exists checks also bind exact string IDs to a declared unique CSV target, with a 100,000-cell reference limit and no raw IDs in findings. The reference-integrity example demonstrates missing citations using synthetic files; it does not fetch or authenticate sources. The material intake catalog rejects unknown classification labels using bounded one_of strings; labels do not prove approval.
• verify reviews one local Skill for provenance, target compatibility, and changes without running its scripts.
• scan inventories local Skills, while compat checks their declared features against agent profiles.
• diff shows the meaningful changes between two Skill versions before you accept them.
• The trust loop is explicit: verify, review the findings, use fix --plan, confirm with fix --apply, run verify again, then use report to compare the before and after evidence.
• When report includes both --plan and --receipt, their plan digests must match. This consistency check does not authenticate externally supplied evidence or replace a fresh verification run.

pass, warn, fail, and unknown are findings to review, not an automatic approval. fix --apply records an explicit change; only a subsequent verify establishes the new state.

Reference

• Project overview
• Offline domain adaptation
• Expansion and deep optimization roadmap
• Security and privacy
• Compatibility profiles
• CI
• Runner
• Full design