2.0.63 • Public • Published


    This CLI has been deprecated in favor of open-attestation CLI. Please read OpenCerts documentation to find out more.

    Open Certificate

    This library supplies the schemas used for OpenCerts standards, in the form of json schemas


    Using npm:

    npm install @govtechsg/open-certificate


    If you are writing a certificate issuer: you probably want to issue a certificate or issue multiple certificates

    If you are writing a certificate verifier or viewer: you probably want to

    1. validate that a certificate is well-formed
    2. verify that a certificate has not been tampered with
    3. retrieve certificate contents
    4. obfuscate fields

    Using OpenCerts

    const openCert = require("@govtechsg/open-certificate")
    const exampleCert = require("exampleCert.json") // reading an example certificate file

    Validate Schema

    This library comes with the schemas in the ./schema folder, all of them are loaded as valid schemas upon initialization.


    Verifying Certificate Signature

    Certificates are considered untampered-with if they have a valid signature field. Refer to the Open Attestation library for more details on this.


    Issue a Certificate

    A single Certificate can be issued using the .issueCertificate(certificate) method. Issuing a certificate in this manner will append a signature field to the certificate.

    The return value of the method will be the signed certificate.

    const issuedCert = openCert.issueCertificate(exampleCert)

    Issue Multiple Certificates

    Multiple Certificates can be issued at once with the .issueCertificates(certificate[]) method.

    The return value of the method will be an array of signed certificates.

    const exampleCerts = [cert1, cert2, cert3, ...]
    const issuedCerts = openCert.issueCertificates(exampleCerts)

    Retrieving Certificate contents

    The raw certificate has salt in the fields to prevent enumeration, we provide a convenience method to retrieve the unsalted contents of the certificate using the method .certificateData(certificate)

    const data = openCert.certificateData(exampleCert)

    Obfuscating Fields in a Certificate

    To obfuscate fields in a cert, the method .obfuscateFields(certificate, paths[]) is provided. The paths[] parameter is simply the JSON path for the fields to be obfuscated.

    The method returns the obfuscated certificate.

    const obfuscatedCert = openCert.obfuscateFields(exampleCert, [


    The code is written to ES6 specs with stage-3 presets and is compiled by Babel.


    npm run test


    npm run build

    Related Projects

    Open Attestation Certificate Contract OpenCert Web UI




    npm i @govtechsg/open-certificate

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