vp-toolkit-models

A TypeScript/JavaScript library containing models for w3c verifiable credentials:

• Verifiable Credential
• Verifiable Presentation
• Challenge Request (not part of the official specification)
• Proof (will be part of the objects above)

Installation

In an existing project (with package.json), install vp-toolkit-models

npm install vp-toolkit-models --save

Usage

We strongly advise the vp-toolkit library to generate and verify these models more easily. You can create the models by passing the required values through the constructor.

Example (VerifiableCredential)

The example below creates an unsigned VerifiableCredential object. To create a signed object, please use vp-toolkit.

import { VerifiableCredential, IVerifiableCredentialParams } from 'vp-toolkit-models'
 
const verifiableCredential = new VerifiableCredential({
  '@context': ['https://www.w3.org/2018/credentials/v1'], // Optional
  type: ['VerifiableCredential'],
  issuer: 'did:eth:0x6E29B1AE22195f9d59C1a468E292b78A8E6e15D1', // Issuer DID
  issuanceDate: new Date(),
  credentialSubject: {
    // The id is the DID as received from the holder / end-user, mandatory field
    id: 'did:eth:0x37F0d79f04b9C15dE4b31Bb70e828243644F5f49',
    givenName: 'John'
    // We advise to attest one property per credential to reduce correlation
  },
  credentialStatus: { // Optional
    // The ID/url/contract address of the credential (revoke) registry
    id: '0x6AbAAFB672f60C16C604A29426aDA1Af9d96d440',
    type: 'vcStatusRegistry2019' // The registry type
  },
  someOtherRandomField: 'anyValue', // Dynamic fields are accepted
  issuerName: 'YourOrganisation', // Optional
  issuerIcon: 'https://example.com/logo.png', // Optional
  proof: { // Required when sending to the counterparty
    type: 'SignatureAlgorithmName',
    created: new Date(), // UTC time will be used from this value
    verificationMethod: 'publicKey',
    nonce: '547d06de-7f1b-4040-8ad0-cbee414a4a7f',
    signatureValue: 'generated signature value'
  }
} as IVerifiableCredentialParams)
 
// Dynamic fields can be found in the additionalFields property
const someOtherRandomField = verifiableCredential.additionalFields['someOtherRandomField']
 
// Models can be stringified and parsed - the order of fields will not change.
const string = JSON.stringify(verifiableCredential)

The same approach works for a VerifiablePresentation and ChallengeRequest - but with different fields, obviously. The ChallengeRequest object supports Zero Knowledge Range Proof by offering the lowerBound and upperBound fields.

Extending models

If you don't prefer to use the dynamic fields, you can also extend the models in your own codebase. But when using the vp-toolkit, you might need to write or override a signer and generator in order to include your custom fields into the signature.

Running tests

Besides unit testing with Mocha, the effectivity of all tests are also measured with the Stryker mutation testing framework.

npm run test
npm run stryker

We aim to achieve a coverage of 100%. Stryker and/or mocha test scores below 80% will fail the build.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

Please make sure to update tests as appropriate.

License and disclaimer

apache-2.0 with a notice.

We discourage the use of this work in production environments as it is in active development and not mature enough.