latch-sdk-nodejs

Prerequisites

• NodeJS.

• Read API documentation https://latch.telefonica.com/www/developers/doc_api

• To get the "Application ID" and "Secret", (fundamental values for integrating Latch in any application), it’s necessary to register a developer account in Latch's website: https://latch.telefonica.com. On the upper right side, click on "Developer area".

USING THE SDK IN NODEJS

• You need to include the npm package 'latch-sdk' in your package.json file and then require the "latch-sdk" in your NodeJS file.

    var latch = require('latch-sdk');

• Initialize latch with your AppId and SecretKey. Hostname and port are optional.

    latch.init({ appId: 'MY_APP_ID', secretKey: 'MY_SECRET_KEY', hostname: 'HOSTNAME:PORT' });

• Call to Latch Server. Pairing will return an account id that you should store for future api calls

    let PAIRING_CODE = "<PAIRING_CODE>"
    
    let response = latch.pair(PAIRING_CODE, function (err, result) {
        if (err) {
            console.log(util.inspect(err, {showHidden: true, depth: null, colors: true}));
        } else {
            console.log(util.inspect(result, {showHidden: true, depth: null, colors: true}));
        }
    });

USING THE SDK IN NODEJS FOR WEB3 SERVICES

For using the NodeJS SDK within an Web3 service, you must complain with the following:

• It is necessary to have a developer subscription that allows you to create web3 apps.
• You need metamask extension for Google Chrome Download metamask
• You need a wallet to operate on Polygon. You can easily create one through Metamask.

Creation of a WEB3 Latch app

Creation of a WEB3 Latch app

Once you have your developer Latch account created, you must logging in the website, and you see your application list (you could have it empty):

The two additional parameters are:

• WEB3WALLET: The Ethereum-based address wallet for the user that wants to pair the service.
• WEB3SIGNATURE: A proof-of-ownership signature of a constant, in order to verify that the user owns the private key of the wallet. You can use https://etherscan.io/verifiedSignatures# to sign the following message:
• MESSAGE TO SIGN : "Latch-Web3"

• Call to Latch Server for pairing as usual, but with the newly methods:

    let MY_APPID = "<MY_APPID>"
    let MY_SECRETKEY = "<MY_SECRETKEY>"
    
    let WEB3WALLET = "<WEB3WALLET>"
    let WEB3SIGNATURE = "<WEB3SIGNATURE>"
    let PAIRING_CODE = "<PAIRING_CODE>"
    
    latch.init({ appId: MY_APPID, secretKey: MY_SECRETKEY });
    
    let response = latch.pair(PAIRING_CODE, function (err, result) {
        if (err) {
            console.log(util.inspect(err, {showHidden: true, depth: null, colors: true}));
        } else {
            console.log(util.inspect(result, {showHidden: true, depth: null, colors: true}));
        }
    }, WEB3WALLET, WEB3SIGNATURE);

You have an example of use in the file example