Features

• Multiple Credential Formats: Support for Linked Data Proof (LDP) verifiable credentials with extensible architecture for additional formats
• Policy-Based Validation: Configurable business rules and validation policies to ensure credential integrity
• Cryptographic Flexibility: Integration with various cryptographic suites including Ed25519 signatures
• Schema Management: Flexible schema loading and validation for credential structures
• Decorator Pattern: Extensible decoration system for adding metadata and custom properties to credentials
• TypeScript Support: Full TypeScript definitions for enhanced developer experience and type safety

Installation

npm install @the-hashgraph-group-ag/issuer

Quick Start

Basic Usage

import {
  createCredentialIssuer,
  LdpHandler,
  RequiredClaimsPolicy,
} from '@the-hashgraph-group-ag/issuer';
import { InternalEd25519Signer } from '@the-hashgraph-group-ag/signer-internal-ed25519';
import { randomBytes } from 'crypto';

// Create a signer
const privateKey = randomBytes(64);
const signer = new InternalEd25519Signer(privateKey);

// Create a schema loader
const schemaLoader = {
  load: async (schemaId: string) => ({
    context: ['https://www.w3.org/2018/credentials/v1'],
    type: ['VerifiableCredential', 'UniversityDegreeCredential'],
    id: schemaId,
  }),
};

// Create an LDP handler
const ldpHandler = new LdpHandler({
  signer,
  schemaLoader,
});

// Create validation policies
const namePolicy = new RequiredClaimsPolicy(['name', 'degree']);

// Create the credential issuer
const issuer = createCredentialIssuer({
  handlers: [ldpHandler],
  policies: [namePolicy],
});

// Issue a credential
const result = await issuer.issue({
  claims: {
    name: 'John Doe',
    degree: 'Bachelor of Science in Computer Science',
  },
  format: 'ldp_vc',
  options: {
    schema: 'https://example.com/schemas/degree',
    issuer: 'did:key:z6MkqYqJQdiwZXUmvLHn79eJ4iv2w7CqCpyQ8CvGtPuLZr1e',
    subjectId: 'did:key:z6MkqYqJQdiwZXUmvLHn79eJ4iv2w7CqCpyQ8CvGtPuLZr1e',
    proofPurpose: 'assertionMethod',
    verificationMethod:
      'did:key:z6MkqYqJQdiwZXUmvLHn79eJ4iv2w7CqCpyQ8CvGtPuLZr1e',
  },
});

if (result.success) {
  console.log('Credential issued successfully:', result.credential);
} else {
  console.error('Issuance failed:', result.error);
}

Contributing

Contributions are welcome! Please see the main project repository for contribution guidelines.

License

This SDK is licensed under the Apache License 2.0.

Support

For support and questions:

• Check the documentation
• Open an issue on GitHub
• Contact the development team