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Use MetaMask SDK with JavaScript

Import MetaMask SDK into your JavaScript dapp to enable your users to easily connect to the MetaMask browser extension and MetaMask Mobile. The following instructions work for web dapps based on standard JavaScript. You can also see instructions for the following JavaScript-based platforms:

Prerequisites

Steps

1. Install the SDK

In your project directory, install the SDK using Yarn or npm:

yarn add @metamask/sdk

or

npm i @metamask/sdk

2. Import the SDK

In your project script, add the following to import the SDK:

import { MetaMaskSDK } from "@metamask/sdk";

3. Instantiate the SDK

Instantiate the SDK using any options:

const MMSDK = new MetaMaskSDK({
dappMetadata: {
name: "JavaScript example dapp",
url: window.location.href,
},
// Other options
});

// You can also access via window.ethereum
const ethereum = MMSDK.getProvider();
Important SDK options

4. Use the SDK

Use the SDK by calling any provider API methods. Always call eth_requestAccounts using ethereum.request() first, since it prompts the installation or connection popup to appear.

ethereum.request({ method: "eth_requestAccounts", params: [] });

Example

You can copy the full JavaScript example to get started:

index.js
import { MetaMaskSDK } from "@metamask/sdk";

const MMSDK = new MetaMaskSDK({
dappMetadata: {
name: "Example JavaScript Dapp",
url: window.location.href,
},
// Other options
});

// You can also access via window.ethereum
const ethereum = MMSDK.getProvider();

ethereum.request({ method: 'eth_requestAccounts', params: [] });

See the example JavaScript dapps in the JavaScript SDK GitHub repository for more information.