What is the connection URL for subscribing to events using websockets and Infura?

Questions
1
NETWORK DESCRIPTION URL
Mainnet JSON-RPC over websockets wss://mainnet.infura.io/ws/v3/YOUR-PROJECT-ID
Ropsten JSON-RPC over websockets wss://ropsten.infura.io/ws/v3/YOUR-PROJECT-ID
Kovan JSON-RPC over websockets wss://kovan.infura.io/ws/v3/YOUR-PROJECT-ID
Rinkeby JSON-RPC over websockets wss://rinkeby.infura.io/ws/v3/YOUR-PROJECT-ID

NOTE: Be sure to replace YOUR-PROJECT-ID with a Project ID from your Infura Dashboard.

2

Hi, I’m trying to figure out how the websockets are working.
First, there is some confusion on the correct URL. According to OP its wss://<network>.infura.io/ws/v3/<your-project-id>.
According to https://infura.io/docs/ethereum/wss/faq, it’s wss://<network>.infura.io/ws
What is correct?
Second, I’m trying this snippet:

Web3 = require('web3');

const web3 = new Web3(new Web3.providers.WebsocketProvider('wss://mainnet.infura.io/ws'));
const subscription = web3.eth.subscribe('newBlockHeaders', (error, blockHeader) => {

    if (error) {
        console.log(error);
        return console.error(error);
    }

    console.log('Successfully subscribed!', blockHeader);

}).on('data', (blockHeader) => {
    console.log('new block', blockHeader);
});

If run, this snippet does not work, but doesn’t raise any error message as well.

Christoph

3

Hello Christoph,

I don’t have much JS experience, so I’m not sure why your code is not working, but I tried using the sample code from web3.js website and it’s working fine for me.
https://web3js.readthedocs.io/en/1.0/web3-eth-subscribe.html

I tried ‘newBlockHeaders’ and also ‘pendingTransactions’ just incase and both are working great against wss://mainnet.infura.io/ws/v3/<your+project+id>

Note that you only get blockHeader when a there’s a new block so the subscription function will not necessary immediately return a new block.

as a sanity check, I use wscat to create a ‘newHeads’ subscription. Anytime you get a new block from the newHeads subscription, you should get a console output for new block header.
Here’s how to create newheads subscription using wscat, just incase:

we recommend using your v3 project id

I hope this helps,
Jee

4

Hi, the wss urls listed above are no longer correct, right?
They should not have /v3

5

The websocket endpoints listed above are correct and working. We recommend using your project ID that can be found on your infura dashboard

simple example

xxxxx- Jee$ wscat -c wss://mainnet.infura.io/ws/v3/my_v3_key
connected (press CTRL+C to quit)
>

Are they not working for you?

6