@marketnow/trust-gateway

MCP middleware for enforcing trust decisions on agent tool calls.

@marketnow/trust-gateway sits between an agent runtime and its tool servers: every tools/call passes through a configurable trust gate that verifies the caller's credential (Agent Trust Card / EAT), scores trust with a 12-stage verification pipeline, and emits signed audit receipts for every decision.

agent ──tools/call──▶ [ TrustGateway.check() ] ──▶ tool server
                          │  credential verify (Ed25519 + JCS)
                          │  policy (min score, stage gates)
                          ▼
                    ReceiptStore (signed, hash-chained)

Install

npm install @marketnow/trust-gateway

Zero runtime dependencies. Node ≥ 16 (uses node:crypto Ed25519 only).

Quick start

const { TrustGateway, withTrustGateway } = require('@marketnow/trust-gateway');

const gateway = new TrustGateway({
  min_trust_score: 5,
  require_pinned_ca: true,   // card must chain to a pinned CA
});

// Decision object: { allowed: boolean, reason, trust_score }
const decision = await gateway.check(agentCredential, 'search_web', { q: 'weather' });
if (!decision.allowed) console.error('DENY:', decision.reason);

// Or wrap a handler — denials throw TRUST_GATEWAY_DENY:<reason>
const secured = withTrustGateway(myToolHandler, gateway);

Signed receipts

Every allow/deny is recorded by ReceiptGenerator / ReceiptStore: hash-chained, Ed25519-signed audit receipts you can replay later to prove what was allowed and why.

const { ReceiptStore } = require('@marketnow/trust-gateway');
const store = new ReceiptStore('/var/log/uta/receipts.jsonl');

What's inside

| Export | Purpose | |---|---| | TrustGateway | Policy gate for tools/call (allow/deny + reason) | | withTrustGateway(handler, gw) | One-liner middleware wrapper | | DEFAULT_CONFIG | Reference policy (min score 5, pinned CA, stage gates) | | ReceiptGenerator / ReceiptStore | Signed, hash-chained audit trail | | verifyCredential | Standalone 12-stage credential verification |

Verification pipeline

The gate delegates to a 12-stage pipeline (signature → canonical form (RFC 8785 JCS) → PoP → validity window → CA pinning → ... → trust score). Fail-closed: any stage error denies the call with the stage name in reason.

Project

Part of the Universal Trust Adapter stack — live public infrastructure at marketnow.site:

• MCP endpoint with trust tools: https://www.marketnow.site/api/mcp
• OCSP-style revocation: https://www.marketnow.site/api/ocsp
• Signed CRL: https://www.marketnow.site/api/crl

Sister packages: @marketnow/trust-core, @marketnow/trust-adapters, @marketnow/cline-trust-plugin (interceptor with revocation gate).

1.0.2 — what changed

• Fix: published 1.0.1 tarball was missing the core/ runtime files (dist/index.js required ../core/* → require() threw on a clean install). The needed core modules are now vendored under core/ — the package is fully self-contained.
• README, LICENSE (AL-1.0) and NOTICE now ship in the tarball (npm page was blank).
• Dependencies removed — zero-dep install.

License

AL-1.0 (AliceLabs Source-Available). See LICENSE-AL-1.0. Commercial licensing: [email protected]