rp-sdk-js — @openvtc/rp-sdk

Repo: github.com/OpenVTC/rp-sdk-js

A server-side, framework-agnostic TypeScript SDK for relying parties (websites) that accept logins from the VTA Wallet browser plugin (window.vtaWallet.login). It exists because the plugin’s demo relying party originally accepted whatever id_token the wallet POSTed — and production sites copy-pasting the demo inherited the gap. The May 2026 cross-system auth security review (recorded in the VTI’s auth-architecture design note) flagged this as finding H2; @openvtc/rp-sdk is the fix, and the RP-side counterpart of that consolidation. Runtime dependencies are only @noble/curves, @noble/hashes, @scure/base.

What It Verifies

verifyIdToken({ idToken, audience, nonce, resolver }) pins alg to EdDSA, enforces the SIOPv2 rule iss === sub, requires an exact aud (the RP’s DID), does a constant-time nonce match, checks iat/exp within a skew window, resolves the issuer DID and verifies the JWS against its Ed25519 authentication key — with a typed IdTokenVerificationError.reason. A bundled KeyResolver handles did:key in-process; a DidResolver interface covers did:peer:2 / did:webvh / did:web (e.g. by wrapping the TDK’s resolver cache SDK). establishSession returns an HttpOnly / Secure / SameSite=Strict cookie descriptor.

Since #4 (2026-07-06, unreleased): the RP side of the confirm/{request,response}/0.1 Trust-Task consent protocol — build/sign a confirm request, verify the holder’s response (eddsa-jcs-2022 Data Integrity proof, subject === issuer === signer, challenge echo) — plus jcsCanonicalize (RFC 8785) with a cross-implementation fixture signed by pnm-core.

Where It Fits

Both wallet login shapes produce the same SIOPv2 id_token and verify identically: the self-issued path (holder did:key) and the VTA-proxied path (vault/proxy-login, a VTA-held key — typically a did:webvh, so a custom resolver is needed). did-hosting-service’s own M2B.4 login demo does this verification in Rust inside its control plane; rp-sdk is for third-party RPs outside the VTI stack.

Recent Development

• 0.1.0 (2026-05-24), 0.1.1 (05-28, metadata), 0.2.0 (06-07) — dependency advisories, noble v2, removed a phantom ./express export. #4 (07-06) added the confirm protocol (unreleased). Quiet since July.
• Roadmap: requireStepUp() (acr = aal2), refreshProxy(), Express / Fastify / Hono adapters, DIDComm packing helpers.

See also: vta-browser-plugin, vti-didcomm-js, verifiable-trust-agent