Library receipt checker

What and why

check-library checks that a research ledger's opened claims have consistent local fetch receipts. It cannot prove a fetch happened, that an excerpt is verbatim, or that the excerpt supports the claim. Independent live-page review remains required.

Trigger

Run before research acceptance and again when claims or receipts change. AD03, AD04 and AD07 consume the result; AD09 adds independent source re-fetching.

Invocation chain

Run website-build-skill check-library <site-work-dir>. In a repository checkout, run node bin/website-build-skill.mjs check-library <site-work-dir>. The binary calls src/cli.mjs, which calls checkLibrary in src/library-check.mjs. The binary prints the result and sets its process exit code. Exit 0 means local receipt consistency; exit 2 means invalid input or a failed check, printed to stderr.

Dependencies

Node and the package's own modules. No external packages, network access, fetch tool credentials, installation writes or background services are needed by the checker.

Reads

Relative to the supplied site-work directory, read research/library/sources.md and research/library/receipts/<CLAIM-ID>.md for each ledger claim. Refuse symlink paths and unsafe claim IDs. Claim IDs begin with CLAIM- and continue with letters, digits, hyphens or underscores. Every table row has these columns:

| Claim ID | Domain | Statement | URL | Published | Accessed | Status | Dependents |
| --- | --- | --- | --- | --- | --- | --- | --- |

Use plain cells, escape a literal pipe as \|, and write unknown for an absent publication date. Column names ignore case, spaces, hyphens and underscores. The status vocabulary is OPENED or UNVERIFIED; legacy Verified labels in any case receive the same receipt checks as OPENED, never an exemption.

Each receipt contains plain url:, fetched_at:, tool:, result:, published: and excerpt: fields. Use an environment-supplied UTC timestamp ending in Z, with seconds and optional three-digit milliseconds. Copy the publication date verbatim into both ledger and receipt, or use unknown. The date must appear in the excerpt. Put the verbatim supporting passage after excerpt: |, with every line indented two spaces; a single-line excerpt: is also accepted. The trimmed passage must contain at least 80 characters. Preserve fetch evidence at fetch time.

Writes

None. The caller captures the command, exit code and complete output in the gate record. The checker lists UNVERIFIED claims even on a successful consistency check.

The closed loop

Nothing watches a project library automatically. Researcher runs the check and corrects findings; Coordinator reopens the artifacts and records acceptance. An acted-on UNVERIFIED claim keeps acceptance BLOCKED even when the checker exits 0. Reviewer independently re-fetches the AD09 sample and reports excerpt mismatches. Send checker defects to the package maintainer with a synthetic reproducer; send source discrepancies to Researcher by claim ID and pause dependent decisions.

Failure modes

Missing or malformed ledgers, unsafe paths, duplicate claim IDs, absent or incomplete receipts, short excerpts, URL differences, inconsistent publication dates and blanket verification over unreceipted rows produce failures. A consistent fabricated receipt can still pass: this is a local consistency check, not fetch authentication. Timestamp provenance, live support for the claim and freshness require gate review.

Run and verify by hand

From the repository root:

node bin/website-build-skill.mjs check-library test/fixtures/library-red
node bin/website-build-skill.mjs check-library test/fixtures/library-green
node --test test/library-check.test.mjs

Expect the RED fixture to exit 2 and name both unreceipted claims plus its blanket verification claim. Expect GREEN to exit 0 with counts. The fixtures are synthetic or inactive regression data, never live research evidence.

Source of truth

The implementation is src/library-check.mjs. The research policy lives in skills/website-build-skill/checklists/research.md; receipt authoring is specified in skills/website-build-skill/templates/evidence.md and skills/website-build-skill/playbooks/research-and-memory.md. Tests live in test/library-check.test.mjs. Hosted and live-client behavior remains UNVERIFIED until an actual trial is separately authorized and recorded.