Syscoin + ZMQ + Node.js = Realtime Blockchain Updates!
Realtime Updates from the Syscoin Blockchain
You can use the ZMQ topic message queues in Syscoin to receive realtime updates for your application. Using in conjunction with syscoin-core to blockchain-enable your applications in no time.
Syscoin Configuration
Make sure to enable the ZMQ listeners in your syscoin.conf file and restart syscoind or Syscoin Core Qt.
# server server=1 daemon=1 # indexes addressindex=1 txindex=1 litemode=0 # rpc rpcuser=u rpcpassword=p rpcport=8370 rpcallowip=127.0.0.1 # zmq listener config zmqpubaliasrecord=tcp://127.0.0.1:3030 zmqpubaliashistory=tcp://127.0.0.1:3030 zmqpubaliastxhistory=tcp://127.0.0.1:3030 zmqpubassetrecord=tcp://127.0.0.1:3030 zmqpubassetallocation=tcp://127.0.0.1:3030 zmqpubassethistory=tcp://127.0.0.1:3030 zmqpubcertrecord=tcp://127.0.0.1:3030 zmqpubcerthistory=tcp://127.0.0.1:3030 zmqpubescrowrecord=tcp://127.0.0.1:3030 zmqpubescrowbid=tcp://127.0.0.1:3030 zmqpubescrowfeedback=tcp://127.0.0.1:3030 zmqpubofferrecord=tcp://127.0.0.1:3030 zmqpubofferhistory=tcp://127.0.0.1:3030 zmqpubhashblock=tcp://127.0.0.1:3030 zmqpubhashtx=tcp://127.0.0.1:3030 zmqpubhashtxlock=tcp://127.0.0.1:3030 zmqpubrawblock=tcp://127.0.0.1:3030 zmqpubrawtx=tcp://127.0.0.1:3030 zmqpubrawtxlock=tcp://127.0.0.1:3030
Create ZMQ Client
You will need to npm install the module zeromq.
const zeromq = require('zeromq');
const subscriber = zeromq.socket('sub');
subscriber.on('message', async (topic, message) => {
topic = topic.toString('utf8');
message = message.toString('utf8')
const alias = JSON.parse(message);
console.log(JSON.stringify(alias, null, 2));
});
// connect to message producer
subscriber.connect('tcp://127.0.0.1:3030');
subscriber.subscribe('aliasrecord');
console.log('subscribed to syscoin topic aliasrecord');
Run your script with the following:
> node zmq-client.js
subscribed to syscoin topic aliasrecord
{
"_id": "gldm1",
"address": "SRxK2GjfzTrm8z5PgCtLKzheN5ebd5kN8f",
"expires_on": 1590601936,
"encryption_privatekey": "",
"encryption_publickey": ""
}
{
"_id": "elatte",
"address": "Sd8JMHxtuFVSVJN2V51M27S6MkBBMjgjHY",
"expires_on": 1559077278,
"encryption_privatekey": "",
"encryption_publickey": ""
}
{
"_id": "primitive7",
"address": "Sk7q3kZcttBNVkUwpMXU59yQf9Pco4sAAJ",
"expires_on": 1558656041,
"encryption_privatekey": "",
"encryption_publickey": ""
}
{
"_id": "primitive9",
"address": "SYKff6VzkrzmSn9tL3zZE7FmV2dGFSKfxs",
"expires_on": 1558656041,
"encryption_privatekey": "",
"encryption_publickey": ""
}
// ....
