Subscribe to an Event using Default Provider

[pascal-mueller]

Hello,

Edit: Original post below. So after some time I noticed that DefaultProvider() assumes I work in the ETH chain but I actually want to work on BSC. So I got myself a API key from bascscan.com and now trying to use it.

const ethers = require('ethers');
const { BscscanProvider } = require("@ethers-ancillary/bsc");
const addresses = {
    WBNB: "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c",
    factory: "0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73",
}

const mnemonic = "my phrase"

api_token = ".."
const provider = new BscscanProvider(null, api_token)
const wallet = ethers.Wallet.fromMnemonic(mnemonic);
const account = wallet.connect(provider)

const factory = new ethers.Contract(
    addresses.factory,
    ['event PairCreated(address indexed token0, address indexed token1, address pair, uint)'],
    account
);
console.log("Started.")

factory.on("PairCreated", async (token0, token1, addressPair, length) => {
  console.log("found new token")
})

Original post:

I hope I can ask this here. I'm currently playing around with ethers and want to check for newly created tokens on PancakeSwap. Now I don't own a subscription to one of those web3 socket services, so I just use the default provider. I found https://github.com/ethers-io/ancillary-bsc but I still must do something wrong.

Here's what I do:

const ethers = require('ethers');

const addresses = {
    WBNB: "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c",
    router: "0x10ED43C718714eb63d5aA57B78B54704E256024E",
    factory: "0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73",
    me: "my wallet address"
}

const mnemonic = "my seed phrase"

//const provider = new ethers.providers.WebSocketProvider("url to provider")
const provider = new ethers.getDefaultProvider()
const wallet = ethers.Wallet.fromMnemonic(mnemonic);
const account = wallet.connect(provider)

const factory = new ethers.Contract(
    addresses.factory,
    ['event PairCreated(address indexed token0, address indexed token1, address pair, uint)'],
    account
);
const router = new ethers.Contract(
    addresses.router,
    [
        'function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts)',
        'function swapExactTokensForTokens( uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)',
    ],
    account
);

factory.on("PairCreated", async (token0, token1, addressPair, pairLengths) => {
    console.log(`
    ~~~~~~~~~~~~~~~~~~
    New pair detected
    ~~~~~~~~~~~~~~~~~~
    token0: ${token0}
    token1: ${token1}
    addressPair: ${addressPair}
    `);
})

Now if I run that with nodejs, the event is never being triggered and I fail to see why.