How to connect to RSK node over websockets?

Question

I'm trying to connect to my RSK node via a websocket:

wscat -c ws://localhost:4445/websocket

However, I get this result: Error: connect ECONNREFUSED 127.0.0.1:4445.

The docs say that websocket listens to port 4445 by default.

How do I connect correctly?

score 7 · Accepted Answer · edited Feb 16 '21 at 02:00

Websockets are disabled by default. See RSKj configuration reference

To enable websockets on RSKj: (1) Add -Drpc.providers.web.ws.enabled=true to your java command when starting RSKj. (2) Update the configuration file. The file is named mainnet.conf for RSK Mainnet.

See RSKj node configuration for how to locate and edit the config file.
See RPC protocol configuration reference for a detailed explanation about the various RPC configurations available, including the ones related to websockets.

Your config file should look like this:

rpc {
providers : {
    web: {
        cors: "*",
        http: {
            enabled: true,
            bind_address = "0.0.0.0",
            hosts = ["localhost", "127.0.0.1"],
            port: 4444,
            }
        ws: {
            enabled: true,
            bind_address: "127.0.0.1",
            hosts = ["localhost", "127.0.0.1"],
            port: 4445,
            }
        }
    }
    ...
}

After this, restart your RSKj for the config to take effect. Now if you repeat the same command from your question:

wscat -c ws://localhost:4445/websocket

You should be able to establish a connection.

score 3 · Answer 2 · answered Feb 16 '21 at 07:54

You're trying to connect in a correct way.

However, make sure that you have a right to connect to this port,

For example,

rpc.providers.web.ws.bind_address=127.0.0.1

or

rpc.providers.web.ws.bind_address=0.0.0.0

You have to specify that Websockets are on rpc.providers.web.ws.enabled=true

How to connect to RSK node over websockets?

2 Answers2