Invoke all method instance of geth using json rpc call

Posted By : Md Imroz Alam | 10-Apr-2017

nodejs

We can invoke all method instance of geth using json-rpc call.

we are just going to invoke this eth.coinbase method using normal api call by nodejs.

Following are the request body of an api

var sendData = {
    "jsonrpc": "2.0",
    "method": "eth_coinbase",
    "params": [],
    "id": new Date().getTime()
};
var bodyJson = JSON.stringify(sendData);
var options = {
    url: "http://localhost:8454", // local geth instance 
    method: "POST",
    headers: {
        'Content-type': 'application/json',
    },
    body: bodyJson
};
var request = require('request');
request(options, function(error, response, body) {
    if (error) {
        console.log("Error : ", error);
    } else {
        var body = JSON.parse(body);
        if (body.error) {
            console.log("error: ", body.error);
        } else {
            console.log("result: ", body.result); // body.result will return geth coinbase account address  
        }
    }
})

There is a refrence link about json-rpc of geth instance method https://github.com/ethereum/wiki/wiki/JSON-RPC

We can also request by terminal ( following line of code).

// Request
curl -X POST --data '{"jsonrpc":"2.0","method":"eth_coinbase","params":[],"id":1}'

// Result
{
  "id":1,
  "jsonrpc": "2.0",
  "result": "0x306e52t7a49eeb85d32cf465507dd71d507100c1"
}