Official Node.js library for the JSON-RPC API of MultiChain, the enterprise blockchain platform. This library uses a "catch-all" approach rather than a fixed list of API commands and parameters, so it will continue to work as new commands and parameters appear in new versions of MultiChain.

• MultiChain Community, Enterprise Demo or Enterprise
• Node.js 6.4+

1. Ensure the multichain.js file is accessible from within your Node.js project.

2. Add the following to the top of any Node.js file which accesses the API, replacing /path/to as appropriate:

   const MultiChainClient = require('/path/to/multichain.js');

3. Within your code, initialize the connection to MultiChain as follows, replacing variable values as appropriate:

var rpchost='127.0.0.1'; // change if multichaind is not running locally
var rpcport=1234; // usually default-rpc-port in blockchain parameters
var rpcuser='multichainrpc'; // see multichain.conf in blockchain directory
var rpcpassword='CowAa1xM47GVrasYq71UU2KfhNV9fCuba28WkoiZmCa3'; // see multichain.conf in blockchain directory

const mc=new MultiChainClient(rpchost, rpcport, rpcuser, rpcpassword);

4. Access any of MultiChain's API commands in the intuitive way. The last parameter is a callback function that is called with two arguments. The first argument is a status object containing three properties – success, errorcode and errormessage. The second contains the result of the API call. Example of usage:

mc.publish('stream1', 'key1', {'json' : {'name' : 'John', 'age' : 30}}, (status, txid) => {
	if (status.success) {
		// operation was successful, do something with txid

	} else { // operation failed
		console.log('Error code: '+status.errorcode);
		console.log('Error message: '+status.errormessage);
	}
});

5. If you're not sure what to expect in an API response, console.log() and the JSON.stringify() function can help.

6. See the examples.js file for an extensive list of examples.

If multichaind is running on a different server to your application, you may wish to set up an SSL proxy for accessing the MultiChain API. This proxy should run on the same server as multichaind, accept incoming SSL connections on your port of choice, and forward them to the rpcport being used by MultiChain. A huge number of free and open source SSL proxies are available, so we won't recommend anything specific.

After setting up the API proxy, use this library to connect to it as follows:

var rpchost='127.0.0.1'; // change if multichaind is not running locally
var rpcport=1234; // usually default-rpc-port in blockchain parameters
var rpcuser='multichainrpc'; // see multichain.conf in blockchain directory
var rpcpassword='CowAa1xM47GVrasYq71UU2KfhNV9fCuba28WkoiZmCa3'; // see multichain.conf in blockchain directory
var usessl=true;

const mc=new MultiChainClient(rpchost, rpcport, rpcuser, rpcpassword, usessl);

If you wish to turn off SSL certification verification (less secure), set the NODE_TLS_REJECT_UNAUTHORIZED environment variable to 0 when running your Node.js project.

All options should be set after creating the mc object and before sending API commands.

• To verify the blockchain name, set the option below. If the chain name does not match, all API commands will return an error.

mc.setoption('chainname', 'chain1');