Use MetaMask SDK with React Native
You can import MetaMask SDK into your React Native dapp to enable your users to easily connect to the MetaMask browser extension and MetaMask Mobile.
Prerequisites
- A React Native project set up with React Native version 0.71 or above
- MetaMask Mobile version 5.8.1 or above
- Yarn or npm
Install the SDK
A metamask-react-native-sdk
package that simplifies the installation of the SDK for React Native
dapps is coming soon.
Use rn-nodeify
to install the SDK.
In your project directory, install rn-nodeify
:
yarn add --dev rn-nodeify
or
npm i --dev rn-nodeify
Install the rn-nodeify
libraries:
yarn add react-native-crypto
yarn add react-native-randombytes
yarn add crypto
yarn add process
yarn add stream
yarn add events
In your project's package.json
file, insert the rn-nodeify
command into the postinstall script:
"scripts": {
...,
"postinstall": "rn-nodeify --install 'crypto,process,stream,events' --hack"
}
rn-nodeify
creates a shim.js
file in your project root directory.
Import it in the root file of your application:
import './shim'
Install react-native-background-timer
:
yarn add react-native-background-timer
cd ios && pod install && cd ..
Install MetaMask SDK:
yarn add @metamask/sdk
Run the postinstall script after everything is installed:
yarn postinstall
Finally, install the necessary pods that come with the libraries:
cd ios && pod install && cd ..
Use the SDK
Import, instantiate, and use the SDK by adding something similar to the following to your project script:
import MetaMaskSDK from '@metamask/sdk';
import { Linking } from 'react-native';
import BackgroundTimer from 'react-native-background-timer';
const MMSDK = new MetaMaskSDK({
openDeeplink: (link) => {
Linking.openURL(link); // Use React Native Linking method or another way of opening deeplinks.
},
timer: BackgroundTimer, // To keep the dapp alive once it goes to background.
dappMetadata: {
name: 'My dapp', // The name of your dapp.
url: 'https://mydapp.com', // The URL of your website.
},
});
const ethereum = MMSDK.getProvider();
const accounts = await ethereum.request({ method: 'eth_requestAccounts' });
You can configure the SDK using any options and call any
provider API methods.
Always call eth_requestAccounts
using
ethereum.request(args)
first,
since it prompts the installation or connection popup to appear.
You can use EthersJS with your React Native app:
const provider = new ethers.providers.Web3Provider(ethereum);
// Get the balance of an account (by address or ENS name, if supported by network).
const balance = await provider.getBalance(ethereum.selectedAddress);
// Often you need to format the output to something more user-friendly,
// such as in ether (instead of wei).
const balanceInETH = ethers.utils.formatEther(balance);
// '0.182826475815887608'