Wallet-Connect-SDK Core functionality

Usage no npm install needed!

<script type="module">
  import cityofzionWalletConnectSdkCore from 'https://cdn.skypack.dev/@cityofzion/wallet-connect-sdk-core';


WalletConnect 2.0 Core SDK for Neo
Made by COZ.IO


For more documentation check out our docs.

For React, try out the React SDK.


Install the dependency on your client-side application:

npm i @cityofzion/wallet-connect-sdk-core


Initialize the client:

import {WcSdk} from "@cityofzion/wallet-connect-sdk-core";

const wcInstance = new WcSdk()

await wcInstance.initClient(
  "debug", // logger: use 'debug' to show all log information on browser console, use 'error' to show only errors
  "wss://relay.walletconnect.org" // we are using walletconnect's official relay server

Subscribe to Wallet Connect events

    onProposal: (uri: string) => {
        // show the QRCode, you can use @walletconnect/qrcode-modal to do so, but any QRCode presentation is fine
        QRCodeModal.open(uri, () => {})
        // alternatively you can show Neon Wallet Connect's website, which is more welcoming
        window.open(`https://neon.coz.io/connect?uri=${uri}`, '_blank').focus();
    onDeleted: () => {
        // here is where you describe a logout callback

Load any existing connection, it should be called after the initialization, to reestablish connections made previously

await wcInstance.loadSession()


Check if the user has a Session and get its Accounts

if (wcInstance.session) {
  console.log(wcInstance.accountAddress) // print the first connected account address
  console.log(wcInstance.chainId) // print the first connected account chain info
  console.log(wcInstance.session.state.accounts); // print all the connected accounts (with the chain info)
  console.log(wcInstance.session.peer.metadata); // print the wallet metadata

Connect to the Wallet

Start the process of establishing a new connection, to be used when there is no wcInstance.session

if (!wcInstance.session) {
  await wcInstance.connect({
    chains: ["neo3:testnet", "neo3:mainnet"], // the blockchains your dapp accepts to connect
    methods: [ // which RPC methods do you plan to call
    appMetadata: {
      name: "MyApplicationName", // your application name to be displayed on the wallet
      description: "My Application description", // description to be shown on the wallet
      url: "https://myapplicationdescription.app/", // url to be linked on the wallet
      icons: ["https://myapplicationdescription.app/myappicon.png"], // icon to be shown on the wallet
  // the promise will be resolved after the connection is accepted or refused, you can close the QRCode modal here
  // and check if there is a connection
  console.log(wcInstance.session ? 'Connected successfully' : 'Connection refused')


It's interesting to have a button to allow the user to disconnect it's wallet, call disconnect when this happen:

await wcInstance.disconnect();

Make a JSON-RPC call

Every request is made via JSON-RPC. You need to provide a method name that is expected by the wallet and listed on the methods property of the options object as well as some additional parameters.

The JSON-RPC format accepts parameters in many formats. The rules on how to construct this request will depend entirely on the blockchain you are using. The code below is an example of a request constructed for the Neo Blockchain:

const result = await wcInstance.sendRequest({
  method: 'getapplicationlog',
  params: ['0x7da6ae7ff9d0b7af3d32f3a2feb2aa96c2a27ef8b651f9a132cfaad6ef20724c']

// the response format depends interely on the blockchain response format
if (resp.result.error && resp.result.error.message) {

Invoking a SmartContract method on Neo Blockchain

To invoke a SmartContract method you can use WcSdk.sendRequest with invokeFunction as method, but WcSdk has a shortcut: WcSdk.invokeFunction.

On the example below we are invoking the transfer method of the GAS token. Neo blockchain expect params with { type, value } format, and on type you should provide one of the types mentioned here. WcSdk has some special types to facilitate: Address and ScriptHash.

For reference, developers should reference the contract manifest on the contracts details pages on dora to understand the methods and argument types needed. For this example: GAS

Check it out:

const invocation: ContractInvocation = {
  scriptHash: '0xd2a4cff31913016155e38e474a2c06d08be276cf', // GAS token
  operation: 'transfer',
  args: [
    { type: 'Address', value: wcInstance.accountAddress },
    { type: 'Address', value: 'NbnjKGMBJzJ6j5PHeYhjJDaQ5Vy5UYu4Fv' },
    { type: 'Integer', value: 100000000 },
    { type: 'Array', value: [] }

const signer: Signer = {
  scope: WitnessScope.Global

const resp = await wcInstance.invokeFunction(invocation, signer)

Calling TestInvoke will not require user acceptance

To retrieve information from a SmartContract without persisting any information on the blockchain you can use WcSdk.sendRequest with testInvoke as method, but WcSdk has a shortcut: walletConnectCtx.testInvoke.

On the example below we are invoking the balanceOf method of the GAS token.

Is expected for the Wallets to not ask the user for authorization on testInvoke.

Check it out:

const invocation: ContractInvocation = {
  scriptHash: '0xd2a4cff31913016155e38e474a2c06d08be276cf', // GAS token
    operation: 'balanceOf',
    args: [
       {type: 'Address', value: wcInstance.accountAddress}

const signer: Signer = {
  scopes: WitnessScope.Global

const resp = await wcInstance.testInvoke(invocation, signer)

Read the Docs

There is more information on the documentation website