README.md

Wallet Connect for Stacks

The goal of this tutorial is to show the minimal approach to connect Wallet Connect (and Stacks) with your app.

We'll take you through the following steps:

1. Create React app
2. Create the Wallet Connect client
3. Establish a Wallet Connect Session
4. Make wallet requests via Wallet Connect

Create React app

1. Create a React project

   npx create-react-app webapp
   cd webapp
   yarn start

2. Clear the contents of src/App.css - remove everything, leave empty file.

3. Remove everything "unnecessary" from src/App.js, the end result should look like this:

   import './App.css';
   
   function App() {
       return (
               <div>foo</div>
           );
       }
   
   export default App;

Create the Wallet Connect client

1. Install WalletConnect dependencies

   yarn add @walletconnect/utils
   yarn add @walletconnect/types
   yarn add @walletconnect/sign-client
   yarn add @walletconnect/encoding
   yarn add @walletconnect/qrcode-modal

2. Setup Wallet Connect client

   We want to store the Client "globally" and set it up as soon as possible, so:

   Open src/App.js and import dependencies:

   import { useState, useEffect } from 'react';
   import Client from "@walletconnect/sign-client";

   Add local state variable to App component like this:

   ...
   function App() {
     const [ client, setClient ] = useState(undefined);
   ...

   Now use effect hook to initialize the Client:

   useEffect(() => {
       const f = async () => {
           const c = await Client.init({
               logger: 'debug',
               relayUrl: 'wss://relay.walletconnect.com',
               projectId: 'yourProjectID', // register at WalletConnect and create one for yourself - https://cloud.walletconnect.com/
               // you need to have a valid ID or the app will not start
               metadata: {
                   name: "My Stacks WalletConnect App",
                   description: "Awesome application",
                   url: "https://your_app_url.com/",
                   icons: ["https://avatars.githubusercontent.com/u/37784886"],
               },
           });
   
           setClient(c);
       }
   
       if (client === undefined) {
           f();
       }
   }, [client]);

Establish a Wallet Connect Session

We have the Client ready, now we need to connect our app to our wallet - establish a Session.

We do that by providing selected Network's chainID to Wallet Connect client.

1. ChainID is in a form of a string containing network name and a number, ex. foo:123. The Stacks chain ID is defined on ChainAgnostic.

   In case of Stacks, the chain IDs you're interested in are:

   # Mainnet
   "stacks:1"
   
   # Testnet
   "stacks:2147483648"
   

   Add it to src/App.js after the imports:

   const chains = [
       'stacks:1',
       'stacks:2147483648',
   ];

2. Create local state that will hold our selected Chain and our Session:

   const [ chain, setChain ] = useState(undefined);
   const [ session, setSession ] = useState(undefined);

3. Add empty connection handler:

   const handleConnect = async (chain) => {};

4. Handle our Networks (chainIDs) in UI:

   Replace the return of our App component like this:

   return (
       <div className="main">
           <h1>Wallet Connect with Stacks</h1>
   
           {
               !session && (
               <div className="box">
                   <h3>Select chain:</h3>
                   {chains.map((c, idx) => {
                       return (<div key={`chain-${idx}`}>{c} <button disabled={!client} onClick={async () => await handleConnect(c)}>connect</button></div>);
                   })}
               </div>
               )
           }
       </div>
   );

5. Make it questionably prettier, replace src/App.css with:

   .main {
       margin: auto;
       width: 75%;
   }
   
   .box {
       background: #5f92ff;
       padding: 0.5rem 1rem;
       margin: 0 0 1rem 0;
   }
   
   .box.code {
       background: lightslategray;
       overflow: scroll;
   }
   
   .box h3 {
       margin: 0.3rem 0;
   }
   
   button {
       margin: 0.3rem;
   }

6. Handle connection, edit the handleConnect function:

   Reset any previously set chains with:

   setChain(undefined);

   Prior to connecting our app with the wallet, we need to know a couple of things:

   • what are the supported methods?
   • what are the supported events?
   • what are the supported chains?

   Chains are simple - it's Stacks, so we simply pass the selected chain (full chainID). Events and methods are wallet dependent.

   Our dummy wallet doesn't support events and supports only 4 example methods:

   • stacks_signMessage - for signing a message with wallet users private key
   • stacks_stxTransfer - simple STX transfer
   • stacks_contractCall - contract call (with post conditions)
   • stacks_contractDeploy - contract deploy

   See API reference for complete list.

   We pass these method names as array and keep events empty - They must match what the wallet supports.

   In our case it looks like this:

   const { uri, approval } = await client.connect({
     pairingTopic: undefined,
     requiredNamespaces: {
       "stacks":{
         "methods":[
           'stacks_signMessage',
           'stacks_stxTransfer',
           'stacks_contractCall',
           'stacks_contractDeploy',
         ],
         "chains":[
           chain
         ],
         "events":[]
       }
     },
   });

   We can use the returned uri directly, but it's easier (preferred) to use Wallet Connect QR Code modal to establish connection:

   Import the QRCodeModal:

   import QRCodeModal from "@walletconnect/qrcode-modal";

   And handle it in handleConnect:

   if (uri) {
     QRCodeModal.open(uri, () => {
       console.log("QR Code Modal closed");
     });
   }

   Wait for the wallet to approve your app, save the session, chain, close the modal:

   const session = await approval();
   setSession(session);
   setChain(chain);
   
   QRCodeModal.close();

   The full handleConnect should look like this:

   const handleConnect = async (chain) => {
       setChain(undefined);
   
       const { uri, approval } = await client.connect({
           pairingTopic: undefined,
           requiredNamespaces: {
               "stacks":{
               "methods":[
                   'stacks_signMessage',
                   'stacks_stxTransfer',
                   'stacks_contractCall',
                   'stacks_contractDeploy',
               ],
               "chains":[
                   chain
               ],
               "events":[]
               }
           },
       });
   
       if (uri) {
       QRCodeModal.open(uri, () => {
           console.log("QR Code Modal closed");
       });
       }
   
       const session = await approval();
       setSession(session);
       setChain(chain);
   
       QRCodeModal.close();
   };

Make some wallet calls via Wallet Connect

At this point, when you click connect - you should be presented with Wallet Connect QR Code modal.

If you scan the QR code with Xverse wallet, you will see a prompt to approve the connection request.

If you scan the QR code with the example wallet, it'll show the list of methods we've passed. Approve it and you'll see the connect buttons go away - indicating there's nothing to connect to anymore.

1. Show available methods, add this to src/App.js render method:

   {
       session && (
           <div className="box">
               <h3>Wallet connected!</h3>
               <div><button onClick={async () => await handleSignMessage()}>Sign Message</button></div>
               <div><button onClick={async () => await handleTransferSTX()}>Transfer STX</button></div>
               <div><button onClick={async () => await handleContractCall()}>Call Contract</button></div>
               <div><button onClick={async () => await handleContractDeploy()}>Deploy Contract</button></div>
           </div>
       )
   }

2. Add the missing handlers:

   const handleSignMessage = async () => {};
   const handleContractDeploy = async () => {};
   const handleTransferSTX = async () => {};
   const handleContractCall = async () => {};

   We'll cover each handler individually building up complexity.

   You can read more about available Stacks transactions here.

3. A little theory:

   Wallet Connect acts as RPC layer between our App and the Wallet.

   The Wallet defines RPC protocol (methods, events, etc.) and performs all of the operations.

   The App is just a client and simply sends some requests.

   So - everything we do is RPC-like request that goes through "RPC client" like this:

   const request = {
       method: 'stacks_signMessage', //here you provide the method you want to use
       params: { //and here you pass the arguments
           pubkey: address, 
           message, //this is our custom payload
       },
   };
   await client.request({
       chainId: chain, //ex. stacks:1
       topic: session.topic, //taken from session object
       request,
   });

   The request itself is heavily dependent on what Wallet requires from us!

   We'll also need an address and we can get it from the session like this:

   const address = session.namespaces.stacks.accounts[0].split(':')[2];

   Another thing is Walelt Connect as a communication layer has some limitations we have to deal with - it uses JSON serialization internally. Because of this, ClarityValues that utilize bigint will not work out of the box.

   For that reason we need a hack to allow bigint to be serialized as JSON. Add this to your src/App.js (after imports):

   /* global BigInt */
   
   BigInt.prototype.toJSON = function() { return this.toString() }

   If you use TypeScript, you can do it like this:

   (BigInt.prototype as any).toJSON = function () {
       return this.toString();
   };

4. Add some prerequisites:

   Import Stacks dependencies:

   import {
       PostConditionMode,
       FungibleConditionCode,
       uintCV,
       noneCV,
       standardPrincipalCV,
       createAssetInfo,
       makeStandardFungiblePostCondition,
       verifyMessageSignatureRsv,
   } from '@stacks/transactions';

   Set up results box, add this to our src/App.js:

   Result state in the beginning:

   const [ result, setResult ] = useState(undefined);

   And render part:

   {
       result && (
         <div className="box code">
           <pre>{JSON.stringify(result, '  ', '  ')}</pre>
         </div>
       )
   }

5. Sign Message:

   The idea is that we send a message to the wallet and it sends back a cryptographic signature (signs our message with a private key).

   Our dummy wallet implements it in a super basic form - it simply adds +SIGNED to the message.

   Edit handleSignMessage function and set it's contents to:

   const handleSignMessage = async () => {
       const address = session.namespaces.stacks.accounts[0].split(':')[2];
   
       try {
           const message = 'loremipsum';
   
           const result = await client.request({
               chainId: chain,
               topic: session.topic,
               request: {
                   method: 'stacks_signMessage',
                   params: {
                       pubkey: address, 
                       message,
                   },
               },
           });
   
           //verify the signature
           const valid = verifyMessageSignatureRsv({
               message,
               publicKey,
               signature,
           });
   
           setResult({
               method: 'stacks_signMessage',
               address,
               valid,
               result: result.signature,
           });
       } catch (error) {
           throw new Error(error);
       }
   };

   Connect your wallet and test it.

   The API strives to be as similar to the native Stacks API as possible. So looking into Stacks Connect should give you a good idea on how to create any other calls yourself.

6. Contract Deploy:

   Take Contract Deploy for example - there's not much difference! You just specify "RPC method" to call and pass some parameters et voilà!

   const handleContractDeploy = async () => {
       const address = session.namespaces.stacks.accounts[0].split(':')[2];
   
       try {
           const result = await client.request({
               chainId: chain,
               topic: session.topic,
               request: {
                   method: 'stacks_contractDeploy',
                   params: {
                       pubkey: address, 
                       contractName: 'my_contract_name_3', //XXX: Change the contract name!
                       codeBody: `
   ;; hello-world
   ;; <add a description here>
   ;; constants
   ;;
   ;; data maps and vars
   ;;
   ;; private functions
   ;;
   (define-read-only (echo-number (val int)) (ok val))
   ;; public functions
   ;;
   (define-public (say-hi) (ok "hello world"))
                       `,
                       postConditionMode: PostConditionMode.Allow,
                   },
               },
           });
   
           setResult({
               method: 'stacks_contractDeploy',
               address,
               valid: true,
               result: result.txId,
           });
       } catch (error) {
           throw new Error(error);
       }
   };

7. Transfer STX:

   Can you can see the pattern?

   const handleTransferSTX = async () => {
       const address = session.namespaces.stacks.accounts[0].split(':')[2];
   
       try {
           const result = await client.request({
               chainId: chain,
               topic: session.topic,
               request: {
                   method: 'stacks_stxTransfer',
                   params: {
                       pubkey: address, 
                       recipient: 'ST3Q85SVTW7J3XQ38V7V88653YN90728NMM46J2ZE',
                       amount: BigInt(1000),
                   },
               },
           });
   
           setResult({
               method: 'stacks_stxTransfer',
               address,
               valid: true,
               result: result.txId,
           });
       } catch (error) {
           throw new Error(error);
       }
   };

8. Contract Call:

   Calling a contract method is slightly more elaborate, but it's only due to the fact we want to provide Stacks PostConditions.

   Luckily, thanks to the BigInt defined hacks above - we can use Stacks libraries to build the transaction as we normally would.

   In our case we want to transfer some dummy ExampleCoin tokens.

   First we figure out contract related details, like the contract's name and account address. We also need the token's name - it's hidden in the contract's code (you can see it through explorer).

   Then we build the PostConditions array - we want it to transfer exactly 1000 tokens (our "order amount").

   The last thing is to simply combine it all and pass as request.

   const handleContractCall = async () => {
       const address = session.namespaces.stacks.accounts[0].split(':')[2];
   
       const contract = 'ST24YYAWQ4DK4RKCKK1RP4PX0X5SCSXTWQXFGVCVY.example-token';
       const [ contractAddress, contractName ] = contract.split('.');
       const tokenName = 'examplecoin'; 
   
       const orderAmount = 1000; 
       const addressTo = 'ST3Q85SVTW7J3XQ38V7V88653YN90728NMM46J2ZE';
   
       // Define post conditions
       const postConditions = [];
       postConditions.push(
           makeStandardFungiblePostCondition(
               address,
               FungibleConditionCode.Equal,
               orderAmount.toString(),
               createAssetInfo(
                   contractAddress,
                   contractName,
                   tokenName
               )
           )
       );
   
       try {
           const result = await client.request({
               chainId: chain,
               topic: session.topic,
               request: {
                   method: 'stacks_contractCall',
                   params: {
                       pubkey: address, 
                       postConditions,
                       contractAddress: contractAddress,
                       contractName: contractName,
                       functionName: 'transfer',
                       functionArgs: [
                           uintCV(orderAmount.toString()),
                           standardPrincipalCV(address),
                           standardPrincipalCV(addressTo),
                           noneCV(),
                       ],
                       postConditionMode: PostConditionMode.Deny,
                       version: '1'
                   },
               },
           });
   
           setResult({
               method: 'stacks_contractCall',
               address,
               valid: true,
               result: result.txId,
           });
       } catch (error) {
           throw new Error(error);
       }
   };

That's it - you can now:

• connect to your Stacks wallet through Wallet Connect
• sign a message
• transfer STX
• deploy a contract
• call a contract