I need to connect to Ropsten network from my Node.js backend . I need to read logs and extract data from them and listen to changes in the network for my contract. The problem is that i don't know how to input credentials of the account that's going to read it (address and private key )

 if (typeof web3 !== 'undefined') {
    web3 = new Web3(web3.currentProvider);
} else {
    web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

This is my code from frontend . I'm using metamask and it's getting me the current provider perfectly. But when changing to Node.js , there's no provider of course (Metamask in my case ) .

So the question is : How to input Ropsten network instead of "http://localhost:8545" which refers to a private network and how can i input the account's address and secret key ? Thanks .

1 Answer 1


You need to set up a ropsten node, either in remote or in local, as you would do for a real Ethereum node.

Simplest answer I can give you for testing is to use the infura.io node. Subscribe to the service and they will send you by mail an url of the form https://ropsten.infura.io/API_KEY. Just input the url in your code like this:

web3 = new Web3(new Web3.providers.HttpProvider("https://ropsten.infura.io/API_KEY"))

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.