Dev Guide V2 - Sei DApps V2 Integration

Welcome to Fin Extension Wallet Developer Guide. This documentation contains guides for developers to get started developing on Fin Extension Wallet.‌

Connect

The easiest way to connect to Fin Wallet

Check if the provider is window.fin.provider, if not, please replace it with the exclusive Fin Wallet provider window.fin.provider.

For example, see below:

function getProvider() {
  const provider = window.fin.provider;
  if (!provider) {
    return window.open('https://chromewebstore.google.com/detail/fin-wallet-for-sei/dbgnhckhnppddckangcjbkjnlddbjkna');
  }
  return provider;
}

To detect Fin Wallet Extension

if(window.fin.provider ){
    console.log('Fin Extension is installed!');
}

To connect Fin Extension Wallet

To connect Fin Extension means to access the user's [blockchain - like Ethereum] account(s).

---

Access a user's accounts

We recommend providing a button to allow users to connect Fin Wallet to your dapp. Selecting this button should call eth_requestAccounts to access the user's accounts.

//Alias for connection
window.fin.provider.request({method: 'eth_requestAccounts'});​

Handle accounts​

Use the eth_accounts RPC method to handle user accounts. Listen to the accountsChanged provider event to be notified when the user changes accounts.

// Connect & get accounts
window.fin.provider.request({method: 'eth_accounts'});

To check if Dapp connected

window.fin.provider.isConnected();

To disconnect Fin Extension Wallet

To disconnect Fin Extension, please use:

window.fin.provider.disconnect()

To experience functions

Once your account is connected, let's start experiencing more functions.‌

Account

How to get Current Account

return Promise<Array[String]>

• If wallet can not be found, return [] instead of throw Error

window.fin.provider.request({ method: 'eth_accounts' }).then(accounts => {
  if (accounts[0]) {
    // Do something with accounts
  } else {
    // Wallet not found
  }
})

Sign Transaction

Important

eth_signTypedData_v1, and eth_signTypedData_v3 are deprecated. We highly recommend user to use eth_signTypedData_v4 or personal_sign.

Personal_sign

personal_sign provides a simple means to request signatures that are human-readable and don't require efficient processing on-chain. It's commonly used for signature challenges authenticated on a web server.

Fin Wallet implements both personal_sign and eth_sign. You might need to check what method your supported signers use for a given implementation.

method: 'personal_sign',
params: [msg, from],

eth_signTypedData_v4

eth_signTypedData_v4 offers highly legible signatures that can be processed efficiently on-chain. Adheres to the EIP-712 standard, enabling users to sign sign typed structured data that can be confirmed on-chain.

  const msgParams = JSON.stringify({
    domain: {
      chainId: 0x58,
      name: 'Ether Mail',
      verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC',
      version: '1',
    },

    message: {
      contents: 'Hello, Bob!',
      attachedMoneyInEth: 4.2,
      from: {
        name: 'Cow',
        wallets: [
          '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826',
          '0xDeaDbeefdEAdbeefdEadbEEFdeadbeEFdEaDbeeF',
        ],
      },
      to: [
        {
          name: 'Bob',
          wallets: [
            '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB',
            '0xB0BdaBea57B0BDABeA57b0bdABEA57b0BDabEa57',
            '0xB0B0b0b0b0b0B000000000000000000000000000',
          ],
        },
      ],
    },
    
    primaryType: 'Mail',
    types: {
      EIP712Domain: [
        { name: 'name', type: 'string' },
        { name: 'version', type: 'string' },
        { name: 'chainId', type: 'uint256' },
        { name: 'verifyingContract', type: 'address' },
      ],
      Group: [
        { name: 'name', type: 'string' },
        { name: 'members', type: 'Person[]' },
      ],
      Mail: [
        { name: 'from', type: 'Person' },
        { name: 'to', type: 'Person[]' },
        { name: 'contents', type: 'string' },
      ],
      Person: [
        { name: 'name', type: 'string' },
        { name: 'wallets', type: 'address[]' },
      ],
    },
  ;

Note:

Gas limit​ : is an optional parameter, since Fin Wallet automatically calculates a reasonable gas price.

chainid: The chain ID is derived from the user's current selected network at window.fin.provider.net_version.

personal_ecRecover

personal_ecRecover returns the address associated with the private key that was used to calculate a signature.

method: 'personal_ecRecover',
params: [message, signature],

Transfer

This method requires that the user has granted permission to interact with their account first, so please make sure to call eth_requestAccounts or wallet_requestPermissions first.

eth_sendTransaction

return Promise<hash>

window.fin.provider.request({
  method: 'eth_sendTransaction',
  params: [
    {
      from: 'string',
      to: 'string',
      gas: 'string',
      gasPrice: 'string',
      value: 'string',
      data: 'string',
      nonce: 'string'
    }
  ]
})

Decrypt & Encrypt

eth_decrypt

Requests that Fin Wallet decrypt the specified encrypted message.

• The message must have been encrypted using the public encryption key of the specified Ethereum address.

return Promise<string>

window.fin.provider.request({
  method: 'eth_decrypt',
  params: [encryptedMessage, accounts[0]],
  })
   .then((decryptedMessage) =>
    console.log('The decrypted message is:', decryptedMessage)
  )
  .catch((error) => console.log(error.message));
})

eth_getEncryptionPublicKey

Requests that the user share their public encryption key. Returns a public encryption key, or rejects if the user denies the request.

return Promise<string>- The public encryption key of the Ethereum account whose encryption key should be retrived

let encryptionPublicKey
window.fin.provider.request({
  method: 'eth_getEncryptionPublicKey',
  params: [accounts[0]], // you must have access to the specified account
  })
  .then((result) => {
    encryptionPublicKey = result;
  })
  .catch((error) => {
    if (error.code === 4001) {
     
      // EIP-1193 userRejectedRequest error
      console.log("We can't encrypt anything without the key.");
    } else {
      console.error(error);
    }
  });

Encrypt

const ethUtil = require('ethereumjs-util');
const encryptedMessage = ethUtil.bufferToHex(

  Buffer.from(
    JSON.stringify(
      sigUtil.encrypt(
        {
          publicKey: encryptionPublicKey,
          data: 'hello world!,
          version: 'x25519-xsalsa20-poly1305',
        }
      )
    ),
    'utf8'
  )
);

List of events

Currently we only support some action event from wallet extension

window.ethereum.on('event_name', callback);

​//Example

window.fin.provider.on('disconnect', () => window.location.reload());

window.fin.provider.on('accountsChanged', () => window.location.reload());

Events	Trigger
accountsChanged	Receive when active account changed in Extension
disconnect	When active account remove connection with Dapp
chainChanged	Receive when active network changed in Extension

Method	Description
on(event, callback)	Add event listener
off(event, callback)	Remove event listener