开始

This guide will explain how to install the js-mcs-sdk and its basic usage

Prerequisites

• Node.js - This SDK was built using version v16.13.0 (npm v8.1.0)

• Polygon Mumbai Testnet Wallet - Metamask Tutorial

• Polygon Mumbai Testnet Alchemy RPC - Alchemy Tutorial

Mumbai Testnet USDC and MATIC funds are also necessary - Swan Faucet Tutorial

Installation

Install the package using npm. It is recommended to create a new directory for a new project. Run the init command to setup a package.json file

npm init -y
npm install js-mcs-sdk

Environment Variables

Once you have your Mumbai wallet and RPC URL, create a file named .env in your project directory and store your wallet's private key and the RPC URL.

PRIVATE_KEY=<PRIVATE_KEY>
RPC_URL=https://polygon-mumbai.g.alchemy.com/v2/<API_KEY>

Be careful not to expose this information! Revealing your private key to others will give them access to your wallet.

Writing SDK Scripts

To begin writing a script utilizing the SDK, create a new .js file. Let's create a file named demo.js

At the top of this file, require the necessary packages for the script.

// demo.js
require('dotenv').config()
const { mcsSDK } = require('js-mcs-sdk')

• require('donenv').config() will add the variables in your .env file to process.env

• const { mcsSDK } = require('js-mcs-sdk') will require the SDK

Next, after requiring the SDK, we still need to initialize it

require('dotenv').config()
const { mcsSDK } = require('js-mcs-sdk')

// set up js-mcs-sdk
const mcs = new mcsSDK({
  privateKey: process.env.PRIVATE_KEY,
  rpcUrl: process.env.RPC_URL,
})

Now we can begin using the SDK methods. Since these functions are asynchronous, we will need to create an async function to run the SDK methods.

require('dotenv').config()
const { mcsSDK } = require('js-mcs-sdk')

// set up js-mcs-sdk
const mcs = new mcsSDK({
  privateKey: process.env.PRIVATE_KEY,
  rpcUrl: process.env.RPC_URL,
})

async function main() {
  // code snippets found in the documentation go here
}

main()

This is the boilerplate code for all snippets found in the SDK documentation

Upload File Example

Here is a simple example to upload a single file to MCS. Made a new file named upload.js

require('dotenv').config()
const { mcsSDK } = require('js-mcs-sdk')

// set up js-mcs-sdk
const mcs = new mcsSDK({
  privateKey: process.env.PRIVATE_KEY,
  rpcUrl: process.env.RPC_URL,
})

async function main() {
  const testFile = JSON.stringify({ address: mcs.publicKey })
  const fileArray = [{ fileName: `${mcs.publicKey}.txt`, file: testFile }]

  const uploadResponse = await mcs.upload(fileArray)
  console.log(uploadResponse)
}

main()

Use the command node upload.js to run the code. This snippet creates the MCS SDK instance, creates a JSON file with your wallet address, and uploads the file to MCS.