Avail Provider

Avail Provider API

Binance Web3 Wallet's Avail API is fully compliant with the polkadot extension. Dapps can use it to integrate with Binance Web3 Wallet.

Provider Detection

We will inject the window.injectedWeb3 object into the global scope. The object contains the binancew3w object, which is the bridge object for the Avail protocol.

Code
window.injectedWeb3 = {
  'binancew3w': {
    // semver for the package
    version: '1.0.0',
    // this is called to enable the injection, and returns an injected
    // object containing the accounts, signer and provider interfaces
    // (or it will reject if not authorized)
    enable (originName: string): Promise<Injected>
  }
}

You can get the provider object by calling window.injectedWeb3['binancew3w'].enable('my dapp'). and then use the accounts and signer interfaces to interact with the injected account.

Code
const provider = await window.injectedWeb3["subwallet-js"].enable("my dapp");
const allAccounts = provider.accounts.get();
const AVAIL_GENESIS_HASH = isTest ? "0xd3d2f3a3495dc597434a99d7d449ebad6616db45e4e4f178f31cc6fa14378b70" : "0xb91746b45e0346cc2f815a520b9c6cb4d5c0902af848db0a80f85932d2e8276a";
if (allAccounts.length > 0) {
  console.log("Injected accounts:", allAccounts);
  for (let i = 0; i < allAccounts.length; i++) {
    if (allAccounts[i].genesisHash === AVAIL_GENESIS_HASH) {
      console.log("Injected avail account:", allAccounts[i]);
    }
  }
}

You can also use the @polkadot/extension-dapp package to detect the provider:

Code
const AVAIL_GENESIS_HASH = isTest ? "0xd3d2f3a3495dc597434a99d7d449ebad6616db45e4e4f178f31cc6fa14378b70" : "0xb91746b45e0346cc2f815a520b9c6cb4d5c0902af848db0a80f85932d2e8276a";
const allAccounts = await web3Accounts();
if (allAccounts.length > 0) {
  console.log("Injected accounts:", allAccounts);
  for (let i = 0; i < allAccounts.length; i++) {
    if (allAccounts[i].genesisHash === AVAIL_GENESIS_HASH) {
      console.log("Injected avail account:", allAccounts[i]);
    }
  }
}

Injection information

And here is the related interfaces:

Code
interface Injected {
  // the interface for Accounts, as detailed below
  readonly accounts: Accounts;
  // the standard Signer interface for the API, as detailed below
  readonly signer: Signer;
}

interface Account = {
  // ss-58 encoded address
  readonly address: string;
  // the genesisHash for this account (empty if applicable to all)
  readonly genesisHash?: string;
  // (optional) name for display
  readonly name?: string;
};

// exposes accounts
interface Accounts {
  // retrieves the list of accounts for right now
  get: () => Promise<Account[]>;
  // (optional) subscribe to all accounts, updating as they change
  subscribe?: (cb: (accounts: Account[]) => any) => () => void
}

// a signer that communicates with the extension via sendMessage
interface Signer {
    /**
     * @description signs an extrinsic payload from a serialized form
     */
    signPayload?: (payload: SignerPayloadJSON) => Promise<SignerResult>;
    /**
     * @description signs a raw payload, only the bytes data as supplied
     */
    signRaw?: (raw: SignerPayloadRaw) => Promise<SignerResult>;
}

Provide metadata

You may need to provide metadata for the wallet, such as the chain name, chain type, color, genesis hash, icon, and meta calls.

Code
// the address we use to use for signing, as injected
const SENDER = '5DTestUPts3kjeXSTMyerHihn1uwMfLj8vU8sqF7qYrFabHE';

// finds an injector for an address
const injector = await web3FromAddress(SENDER);
injector.metadata.provide({
    chain: 'Avail DA Mainnet',
    chainType: 'substrate',
    color: '#1B1E26',
    genesisHash: '0xb91746b45e0346cc2f815a520b9c6cb4d5c0902af848db0a80f85932d2e8276a',
    icon: 'substrate',
    metaCalls: ...
})

signAndSend

You can use the signAndSend method to sign and send a transaction.

Code
import { web3Accounts, web3Enable, web3FromAddress } from '@polkadot/extension-dapp';

// returns an array of all the injected sources
// (this needs to be called first, before other requests)
const allInjected = await web3Enable('my cool dapp');

// returns an array of { address, meta: { name, source } }
// meta.source contains the name of the extension that provides this account
const allAccounts = await web3Accounts();

// the address we use to use for signing, as injected
const SENDER = '5DTestUPts3kjeXSTMyerHihn1uwMfLj8vU8sqF7qYrFabHE';

// finds an injector for an address
const injector = await web3FromAddress(SENDER);

// sign and send our transaction - notice here that the address of the account
// (as retrieved injected) is passed through as the param to the `signAndSend`,
// the API then calls the extension to present to the user and get it signed.
// Once complete, the api sends the tx + signature via the normal process
api.tx.balances
  .transfer('5C5555yEXUcmEJ5kkcCMvdZjUo7NGJiQJMS7vZXEeoMhj3VQ', 123456)
  .signAndSend(SENDER, { signer: injector.signer }, (status) => { ... });