DCP-AI ↔ W3C DID/VC Bridge

Converts between DCP artifacts and W3C Decentralized Identifiers (DIDs) and Verifiable Credentials (VCs).

Supported DCP Specifications

DCP-01 through DCP-09.

Overview

This bridge enables interoperability between the DCP-AI identity layer and the W3C decentralized identity ecosystem. It supports bidirectional conversion of:

• Responsible Principal Records ↔ DID Documents — map DCP human identities to did:dcp: method DIDs with verification methods derived from RPR keys.
• Agent Passports ↔ Verifiable Credentials — represent DCP agent certifications as W3C VCs, including capabilities, liability mode, and jurisdiction.
• Signed Bundles → Verifiable Presentations — wrap full DCP Citizenship Bundles as W3C VPs for presentation to external verifiers.

Functions

| Function | Direction | Description | |---|---|---| | rprToDIDDocument(rpr) | DCP → W3C | Convert a Responsible Principal Record to a DID Document | | didDocumentToRPR(didDoc) | W3C → DCP | Convert a DID Document back to an RPR skeleton | | passportToVC(passport, issuerDid) | DCP → W3C | Convert an Agent Passport to a Verifiable Credential | | vcToPassport(vc) | W3C → DCP | Convert a Verifiable Credential back to a Passport skeleton | | bundleToVP(signedBundle, holderDid) | DCP → W3C | Wrap a signed bundle as a Verifiable Presentation | | rightsToServiceEndpoints(rightsDeclaration) | DCP → W3C | Convert rights declaration to DID service endpoints (DCP-08) |

DID Method

This bridge uses the did:dcp: method namespace. DID identifiers are derived directly from RPR human IDs:

did:dcp:<human-id-uuid>

Verification methods support both Ed25519 (classical) and post-quantum key types.

Usage

import { rprToDIDDocument, passportToVC, bundleToVP } from './index.js';

// Convert an RPR to a DID Document
const didDoc = rprToDIDDocument(myRpr);

// Issue a Verifiable Credential for an agent
const vc = passportToVC(myPassport, 'did:dcp:issuer-id');

// Wrap a full bundle as a Verifiable Presentation
const vp = bundleToVP(signedBundle, 'did:dcp:holder-id');

Notes

• Skeleton conversions (W3C → DCP) produce partial records that require additional processing (key ID recomputation, signing, etc.) before they are valid DCP artifacts.
• The publicKeyMultibase encoding uses the z prefix (base64url) as specified in the DID Core specification.