3

I'm trying to listen to all emitted events from a contract with Ethers.js and Websockets.

Any idea why this is not working?

var wsProvider = new ethers.providers.WebSocketProvider("wss://rinkeby.infura.io/ws/v3/idhere");

let contract = new ethers.Contract(contractAddress, CONTRACT_ABI, wsProvider);

contract.on("*", (from, to, value, event) => {
  console.log("event: ", event);
});

The websockets connection seems to work because this returns all new blocks:

wsProvider.on('block', (blockNumber) => {
  console.log('New Block: ' + blockNumber);
});

2 Answers 2

2

Its because you have to specify the network type, otherwise it will take mainnet as default if not provided

also make sure your infura provider websocket is for rinkeby/supports rinkeby

var wsProvider = new ethers.providers.WebSocketProvider("wss://rinkeby.infura.io/ws/v3/idhere", "rinkeby");
0

The following code works though:

contract.on("*", (event) => {
  console.log("event: ", event);
});

Apparently, etherJS's event listener only returns one response, it is a JSON object.

Modified answer

This works too:

contract.on("Transfer", (from, to, value, event) => {
    console.log("event: ", event);
});

But it only works for transfer events, for other events the event object is undefined. I guess the return object has to match the event's arguements.

source code:

const { ethers } = require("ethers");
const wsurl = "your ws URL"

var wsProvider = new ethers.providers.WebSocketProvider(wsurl);
var contractAddress = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
var CONTRACT_ABI = '[{"constant":false,"inputs":[{"name":"newImplementation","type":"address"}],"name":"upgradeTo","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"newImplementation","type":"address"},{"name":"data","type":"bytes"}],"name":"upgradeToAndCall","outputs":[],"payable":true,"stateMutability":"payable","type":"function"},{"constant":true,"inputs":[],"name":"implementation","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"newAdmin","type":"address"}],"name":"changeAdmin","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"admin","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"inputs":[{"name":"_implementation","type":"address"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"payable":true,"stateMutability":"payable","type":"fallback"},{"anonymous":false,"inputs":[{"indexed":false,"name":"previousAdmin","type":"address"},{"indexed":false,"name":"newAdmin","type":"address"}],"name":"AdminChanged","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"implementation","type":"address"}],"name":"Upgraded","type":"event"}]'

let contract = new ethers.Contract(contractAddress, CONTRACT_ABI, wsProvider);

contract.on("*", (resp) => {
    console.log("response: ", resp);
});
1
  • BTW I am a Chainstack developer advocate, I tested the script using a Chainstack endpoint. If Infura doesn't work, then you can probably try our service. The developer plan is free and it comes with 3M free requests per month. Mar 9 at 9:13

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