Business
Jobs
  • About Us
  • Solutions
    • Job Postings
      Post your job and receive qualified candidates in 48h.
    • Candidate Assessments
      500+ technical and psychological tests, plus anti-fraud.
    • Headhunting
      Tailor-made executive search from start to finish.
    • Payroll + EOR
      Payroll dispersal and EOR across 15+ LATAM countries.
  • Pricing
  • Jobs

0

234
Views
how to resolve connection not open to send() error when subscribe event from smart contract

I am going to subscribe event from polygon mainnet token contract, but connection not open to send() error comes out

const { contractAddress } = process.env;

const Web3 = require('web3');

const url = 'wss://ws-mumbai.matic.today/';
const web3 = new Web3(url);

const options = {
reconnect: {
auto: true,
delay: 1000, // ms
maxAttempts: 1,
onTimeout: false,
},
address: contractAddress,
topics: [
'0xddf252ad1be2c89b69c2b068fc378daa952ba7f163c4a11628f55a4df523b3ef',
],

function initSubscription() {
web3.eth
.subscribe('logs', options, (error, result) => {
if (!error) console.log('got result');
else console.log('error - ', error);
})
.on('data', (log) => {
console.log('got data', log);
})
.on('changed', (log) => {
console.log('changed');
});
}
};

wss url is not right? if so, what is the matter with this issue?

about 4 years ago · Juan Pablo Isaza
Answer question
Find remote jobs

Discover the new way to find a job!

Top jobs
Top job categories
Business
Post vacancy Pricing Sales
Legal
Terms and conditions Privacy policy
© 2026 PeakU Inc. All Rights Reserved.
Andres GPT
Show me some job opportunities
There's an error!