Setup Credo Agent

Pre-requisites

• Node.js - v16 or v18

• yarn or npm

• Node.js or React Native project.

For more details, check Credo Getting Started guide.

Installing Cheqd

When using cheqd method with Credo, there are a few extra dependencies that need to be installed. We need to install the @credo-ts/cheqd package, which implements the needed interfaces for the agent.

React Native​

To enable react-native support we need to follow the steps below:

In the package.json file add the below code snippet, which replaces the cosmjs dependencies with the cosmjs-rn packages.

Using NPM overrides or Yarn resolutions we can point the cosmjs packages to cosmjs-rn.

NPM

{
  "overrides": {
    "@cosmjs/amino": "npm:@cosmjs-rn/amino@^0.27.1",
    "@cosmjs/encoding": "npm:@cosmjs-rn/encoding@^0.27.1",
    "@cosmjs/math": "npm:@cosmjs-rn/math@^0.27.1",
    "@cosmjs/stargate": "npm:@cosmjs-rn/stargate@^0.27.1",
    "@cosmjs/tendermint-rpc": "npm:@cosmjs-rn/tendermint-rpc@^0.27.1",
    "@cosmjs/utils": "npm:@cosmjs-rn/utils@^0.27.1",
    "@cosmjs/proto-signing": "npm:@cosmjs-rn/proto-signing@^0.27.1",
    "@cosmjs/crypto": "npm:@cosmjs-rn/crypto@^0.27.1"
  }
}

Yarn

{
  "resolutions": {
    "@cosmjs/amino": "npm:@cosmjs-rn/amino@^0.27.1",
    "@cosmjs/encoding": "npm:@cosmjs-rn/encoding@^0.27.1",
    "@cosmjs/math": "npm:@cosmjs-rn/math@^0.27.1",
    "@cosmjs/stargate": "npm:@cosmjs-rn/stargate@^0.27.1",
    "@cosmjs/tendermint-rpc": "npm:@cosmjs-rn/tendermint-rpc@^0.27.1",
    "@cosmjs/utils": "npm:@cosmjs-rn/utils@^0.27.1",
    "@cosmjs/proto-signing": "npm:@cosmjs-rn/proto-signing@^0.27.1",
    "@cosmjs/crypto": "npm:@cosmjs-rn/crypto@^0.27.1"
  }
}

After that, we need to add a buffer polyfill

yarn add buffer

Then, create a shim.js file with the below code snippet

import { Buffer } from 'buffer'
global.Buffer = Buffer

import shim.js file into your file where the App is imported.

Adding cheqd to the Agent​

After installing the dependencies, we can register the cheqd module on the agent by adding the below code snippet to the agent constructor.

import { Agent, DidsModule, KeyType, DidDocument } from '@credo-ts/core'
import { agentDependencies } from '@credo-ts/node'
import { AskarModule } from '@credo-ts/askar'
import { askar } from '@openwallet-foundation/askar-nodejs'
import {
  ConnectionsModule,
  V2ProofProtocol,
  V2CredentialProtocol,
  ProofsModule,
  AutoAcceptProof,
  AutoAcceptCredential,
  CredentialsModule,
  HttpOutboundTransport,
  getDefaultDidcommModules,
} from '@credo-ts/didcomm'
import {
  CheqdAnonCredsRegistry,
  CheqdDidRegistrar,
  CheqdDidResolver,
  CheqdModule,
  CheqdModuleConfig,
} from '@credo-ts/cheqd'
import { AnonCredsModule } from '@credo-ts/anoncreds'
import { anoncreds } from '@hyperledger/anoncreds-nodejs'

const agent = new Agent({
  config,
  dependencies: agentDependencies,
  modules: {
    dids: new DidsModule({
      registrars: [new CheqdDidRegistrar()],
      resolvers: [new CheqdDidResolver()],
    }),

    // AnonCreds
    anoncreds: new AnonCredsModule({
      registries: [new CheqdAnonCredsRegistry()],
      anoncreds,
    }),

    // Add cheqd module
    cheqd: new CheqdModule(
      new CheqdModuleConfig({
        networks: [
          {
            network: '<mainnet or testnet>',
            cosmosPayerSeed: '<cosmos payer seed or mnemonic>',
          },
        ],
      })
    ),
    // Indy VDR can optionally be used with Askar as wallet and storage implementation
    askar: new AskarModule({
      askar,
    }),
    connections: new ConnectionsModule({
      autoAcceptConnections: true,
    }),
    credentials: new CredentialsModule({
      autoAcceptCredentials: AutoAcceptCredential.ContentApproved,
      credentialProtocols: [
        new V2CredentialProtocol({
          credentialFormats: [new LegacyIndyCredentialFormatService(), new AnonCredsCredentialFormatService()],
        }),
      ],
    }),
  },
})

The cosmosPayerSeed can be a 32-bit seed value or mnemonic. It can be managed using the Keplr wallet, which is available as a mobile app or browser extension for Chrome and Safari. Keplr enables users to create accounts, exchange tokens, etc. To setup Keplr wallet for cheqd follow this tutorial.

Next steps

Now that your Credo agent is successfully set up to work with cheqd, try following our tutorials for creating a new DID or issuing Verifiable Credentials.

Create a DID

Create an Issuer DID using the did:cheqd DID method.

Issue a Verifiable Credential

Issue a Verifiable Credential using Credo signed by a cheqd DID.