@pathos-labs/dacs-verifier

The pathos-dacs-ref attestation-bundle verifier as a package: a stable programmatic API, a command line, a small HTTP service, and an MCP verify_bundle tool. Every surface calls the same verifyDocument() from the repository's src/lib/verify-document.ts; the package is a compile of the repository's verifier, not a second implementation (see provenance.json).

Verdicts are pass, fail or indeterminate and are never coerced: an unanchored bundle is indeterminate unless the caller opted into offline (receipt-archive audit); a document that cannot be classified or loaded is indeterminate; a chain failure during verification is indeterminate. Exit codes: 0 pass, 1 fail, 2 indeterminate, 3 usage error.

API

import { verifyDocument, loadBundleSource } from '@pathos-labs/dacs-verifier';
const result = await verifyDocument(bundle, { offline: true });
// { apiVersion: 'pathos-dacs-verifier:1', bundleKind: 'v1' | 'legacy' | 'unrecognised', verdict, exitCode }

schemas/verify-verdict.schema.json describes the result; schemas/verify-request.schema.json describes the HTTP body and the MCP tool arguments. bundleKind is v1 for bundleVersion:"1" bundles and legacy for v:"dacs-5-bundle:0.1".

Command line

dacs-verifier --bundle-file bundle.json --offline --json
dacs-verifier --stdin --offline --json < bundle.json
dacs-verifier --bundle-anchor stor-... --rpc https://demosnode.discus.sh/
dacs-verifier --jobId <uuid>

HTTP service

dacs-verifier-http --host 127.0.0.1 --port 8787 --rpc https://demosnode.discus.sh/
POST /verify            {"bundle": {...}, "offline": true}      -> 200 with the result
GET  /healthz           -> {ok, name, version, apiVersion}
GET  /schemas/verify-request.json, /schemas/verify-verdict.json

A well-formed request always answers 200 with a verdict. Caller-side problems answer 4xx; bodies over 1 MiB answer 413. The Demos RPC is server configuration (--rpc or DACS_VERIFIER_RPC), never a request field. The service has no authentication and binds 127.0.0.1 by default; put it behind something that authenticates before exposing it.

MCP server

dacs-verifier-mcp speaks JSON-RPC over stdio (protocol 2024-11-05) with tools verify_bundle (bundle, offline?, requireSignatures?) and verifier_info. Verification policy is server-owned and defaults to live-enforcing. Set DACS_VERIFIER_MCP_POLICY=offline-enforcing for a signed receipt-archive harness that does not claim live two-sided anchoring, or offline-fixture only for illustrative fixtures whose placeholder identities cannot be cryptographically verified. Caller flags may echo the effective policy for compatibility but cannot weaken it. verifier_info reports the effective policy without changing the pathos-dacs-verifier:1 verdict schema. Its live policy says the two-sided lookup is required for a pass; it is configuration disclosure, not proof that any particular bundle was anchored. The verdict's two-sided-anchoring step carries that evidence.

Container

docker build -t dacs-verifier packages/verifier
docker run --rm -p 8787:8787 dacs-verifier
docker run --rm -i dacs-verifier dist/packages/verifier/src/mcp.js
docker run --rm -i dacs-verifier dist/packages/verifier/src/cli.js --stdin --offline --json < bundle.json

The image's entrypoint is node; the default command is the HTTP service. Dependencies are installed with npm ci from the committed package-lock.json, so two builds run the same dependency versions. The repository's patches/ are not applied inside the image, so anchored text that depends on the demosdk UTF-8 patch is verified by the in-tree CLI, not by the container, until that patch is upstream.

Provenance and reproducibility

provenance.json lists every compiled source with its SHA-256 and every emitted file with its SHA-256; no git revision or timestamp is embedded. In the repository, node --import tsx scripts/build-verifier-package.mts --check fails on any byte difference between the committed dist and a fresh build, and CI runs that check.

This package is a reference implementation and not a DACS-Standard publication. It is published on npm as @pathos-labs/dacs-verifier; the exact published versions are recorded in packages/registry-versions.json. Version 0.2.0 includes the server-owned MCP policy described above. See CHANGELOG.md for the caller-visible behavior change.

Install:

npm install @pathos-labs/[email protected]