API Reference

Please find the SDK here.


You can start with importing the @ont-dev/ont-tag package by running npm command below.

You can now use the following import statement to bring in all the modules from the @ont-dev/ont-tag package.

import VC from "@ont-dev/ont-tag";

The following require statement can also be used to load the modules.

var VC = require("@ont-dev/ont-tag");

To use the methods in a browser, you must use the compiled version of the library. The browser.js file is located in the lib directory. You can include it in your project using a script tag as follows.

<script src="./lib/browser.js"></script>

Everything will now be available under the VC variable. For instance, to fetch the list of available regions, you can invoke:

var areaList = VC.utils.areaList;


Method list

Method name


Sends authentication request to the trust anchor service with user's KYC details

Fetch URL to initiate social media platform authentication

Fetches any issued credentials for previously sent authentication requests

Returns a list of countries and regions with their respective aliases

Returns a list of valid authentication types

Returns the list of supported chains

Generates a valid ONT ID using a wallet addresses

Serializes the passed object data to generate a base64 string

Generates a presentation for the passed credential data payload

Deserializes the passed base64 string to an object

Sending an Authentication Request

This method is used to send authentication requests for a user's KYC data. It takes two parameters. The first one is an object literal with the KYC info. as defined below, and the second one is your API key.

params // parameters to be passed
  appId: string,    // Application ID, assigned by Ontology
  region: string,  // Nationality (area alias)
  docId: string,    // Document ID no.
  authType: string,  // Document or authentication type
  frontDoc: string, // Front page image of the selected document (encoded)
  backDoc: string,  // Last page image of the selected document (encoded)
  name: string,     // Legal name as in document
  ownerDid: string  // DID of the user, generated using the generateId utility method

Note: Both the frontDoc and backDoc images need to be passed as base64 encoded strings.

The region field takes the respective alias for each region. Use the areaList utility method to obtain the list of countries and their aliases.

The ownerDid field takes an ONT ID. You can generate one using the generateId utility method.

The authType field specifies the type of document sent for authentication. Use the authType utility method to fetch the list of valid documents.

Call the method with the user info and your API key to send an authentication request.

await VC.sendUserInfo({ ...params }, apiKey);

It returns true for a successful request and an error message if an exception occurs.

Error Message



Authentication successful


Passed appId not found


Request limit for a user exceeded


Invalid API signature


Internal error occurred

Note: Each application (identified with the combination of their appid and API key) is limited to sending 10 requests for a user's particular document/authentication method (identified with a user's DID context). Also, in case of an internal error, please get in touch with the Ontology team.

Invoking this method returns a URL that can be used to prompt user authentication for a social media platform.

getSocialAuthLink(ownerDid, authType, apiKey, appId);

It takes four parameters.

  • ownerDid: User's DID

  • authType: The authentication method (social media platform). See here

  • apiKey: Your API key

  • appId: Your app ID

The method returns a URL that triggers OAuth authentication for a particular platform.

Once successfully authorized, a credential will be issued that can be used to prove the relationship between a social media account and a DID.

Fetching Credentials

You can use this method to fetch the issued credentials for a user after having sent a data authentication request.

This method takes two parameters, the DID of the user (or owner in the context of a credential), and the ID document type.

const result = await VC.getVcList(ownerDid, authType);

If the authentication was successful, the encryptOriginData field will contain serialized credential data.

  authId: '0348xxxx-xxxx-4317-xxxx-8d6f6166a65b',
  appId: 'tesxxxx01',
  credentialContext: 'credential:sfp_passport_authentication',
  description: 'My Shuftipro Passport Authentication',
  txHash: '9494568336a4c2xxxxxxxxxxxxxxxxbaa066e1585fe47',
  status: 1,
  encryptOriginData: 'xxxxxxx', // credential information
  requestTime: 1622156645 // unix timestamp (in seconds)




Authentication successful


Authentication failed


Verification in progress

Note: The user needs to sign this data to authorize access and prove their relationship with the credential data. After fetching the credential data, you can proceed with generating a presentation with the signed credential data as its payload. The resultant token can then be used for signature verification and access control.

Utility Methods

utils class contains multiple methods that can be used to perform specific tasks. Each method is described below.


Invoking this method returns an array of all the supported countries and regions with their respective aliases.

The response is structured as follows.

  { name: 'Afghanistan', alias: 'AF' },
  { name: 'Aland Islands', alias: 'AX' },


This method returns the list of supported documents and authentication types as an object.

The response is of the following form.

  Passport: 'passport',
  IdCard: 'id_card',
  DrivingLicense: 'driving_license',
  Twitter: 'twitter',
  Github: 'github',
  Linkedin: 'linkedin',
  Line: 'line',
  Amazon: 'amazon',
  Kakao: 'kakao'


This method returns an object containing valid chain type names.

The response is as follows.

  ETH: 'etho',
  BSC: 'bnb'


Invoking this method with a wallet address prefixes it with the appropriate DID method based on the passed chainType and returns a valid ONT ID as a string. For e.g., did:etho:0xdc6...974a9.

const ownerDid = VC.utils.generateId("0xdc6...974a9", chainType);


This method returns a serialized base64 JWT string. It takes the following parameters:

  1. jwtStr - The credential JWT string

  2. audienceId - DID of the credential consumer

  3. ownerDid - DID of the Credential owner

  4. effectiveTime - Validity period of the presentation (in seconds). For e.g., 1 day = 86400

The parameters are of the following form.

  jwtStr: string,
  audienceId: string,
  ownerDid: string,
  effectiveTime: number   // Presentation Effective time, eg 1 day = 86400
const JWT = VC.utils.serializeSignMessage(params);


Invoke this method to generate a presentation with credential data signed by the user. It returns the presentation as a JWT string.

It takes an object parameter containing:

  1. signMessage - Serialized JWT string (using serializeSignMessage)

  2. signature - Serialized JWT string that has been signed by the user

The parameter object is of the following form.

  signMessage: string,
  signature: string
const JWT = VC.utils.createPresentation(params);

Presentation data can be obtained by deserializing this token. You can perform signature verification and message decryption using the Java SDK. Follow this link for reference.


You can obtain the user's verified KYC data by deserializing the encryptOriginData string in the credential object received here.

This method takes the serialized JWT string as parameter and returns an object containing credential data.

const result = VC.utils.deserialize(string);

The response object is of the following form.

  '@context': [
  id: 'urn:uuid:861cbae4-xxxx-4844-xxxx-8c8xxxx7052',
  type: [ 'VerifiableCredential' ],
  issuer: 'did:ont:APc8FBxxxxxxxxxxxxxxSUFX2HAnBuBna',
  issuanceDate: '2021-05-28T07:04:23.000Z',
  expirationDate: '2022-05-28T07:04:23.000Z',
  credentialStatus: {
    id: '4f7f159ac4xxxxxxxxxxx5f61b7d0cc6',
    type: 'AttestContract'
  credentialSubject: {
    Name: 'xxxxxxxx',
    BirthDay: 'xxxx-03-09',
    ExpirationDate: 'xxxx-03-12',
    IDDocNumber: 'xx26xxxx86',
    IssuerName: 'Shxxxxro',
    user_did: 'did:ont:5cxxxxxxxx701CbBExxxxx29b'
  proof: {
    type: 'JWT',
    verificationMethod: 'did:ont:APcxxxxxxxxq2BSUFX2xxxxxna#keys-1',
    created: '2021-05-28T07:04:23Z',
    proofPurpose: 'assertionMethod',
    jws: 'ARyjxxxxxxxxxxxxxxxxxxGDisGMJdFE/4erXIazh3n8ipPotTFA+Z4hS09GlhVaio=\\'

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