Configuring EVM networks

Read below to learn how to configure supported EVM networks for the Expo SDK and how to switch the embedded wallet’s current network.

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Configuring networks

Privy embedded wallets can support any EVM-compatible chain. You can configure EVM networks for Privy via the supportedChains property of the PrivyProvider component, per the instructions below.

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Configuring viem-supported networks

To configure viem-supported networks for Privy, first, install the viem package. This package contains JSON representations of several EVM networks, which will be used to initialize the Privy SDK.

npm i viem

Next, import your required chains from the viem/chains package:

// Replace this with any of the networks listed at https://viem.sh/docs/chains/introduction#chains
import {base, baseGoerli, mainnet, goerli, polygon, polygonMumbai} from 'viem/chains';

Lastly, configure the supportedChains prop of your PrivyProvider with an array including your required networks.:

<PrivyProvider
  appId="your-privy-app-id"
  supportedChains={[base, baseGoerli, mainnet, goerli, polygon, polygonMumbai]}
>
  {/* your app's content */}
</PrivyProvider>

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Other Networks

First, import viem and use the package’s defineChain method to build a JSON representation of your desired network.

import {defineChain} from 'viem';

export const myCustomChain = defineChain({
  id: 123456789, // Replace this with your chain's ID
  name: 'My Custom Chain',
  network: 'my-custom-chain',
  nativeCurrency: {
    decimals: 18, // Replace this with the number of decimals for your chain's native token
    name: 'My Native Currency Name',
    symbol: 'My Native Currency Symbol'
  },
  rpcUrls: {
    default: {
      http: ['https://my-custom-chain-https-rpc'],
      webSocket: ['wss://my-custom-chain-websocket-rpc']
    }
  },
  blockExplorers: {
    default: {name: 'Explorer', url: 'my-custom-chain-block-explorer'}
  }
});

At minimum, you must provide the network’s name and chain ID, native currency, RPC URLs, and a blockexplorer URL.

Then, pass the returned object (myCustomChain in the example above) to the supportedChains array of the PrivyProvider, like above.

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Overriding a chain’s RPC provider

By default, transactions from the embedded wallet will be sent using Privy’s default RPC providers. Please note that Privy’s default providers are subject to rate limits; these limits are sufficiently generous for developing your integration and moderate amounts of app usage.

As your app’s usage scales, we recommend that you setup your own RPC providers (with Alchemy, QuickNode, Blast, etc.) and configure Privy to use these providers per the instructions below. Setting up your own providers gives you maximum control over RPC throughput and rate limits, and offers you much more visibility into RPC analytics and common errors.

To configure Privy to use a custom RPC provider, first, import the chain you want to override, and import the helper function addRpcUrlOverrideToChain from @privy-io/chains to override the RPC provider

import {mainnet} from 'viem/chains';

import {addRpcUrlOverrideToChain} from '@privy-io/chains';

const mainnetOverride = addRpcUrlOverrideToChain(mainnet, INSERT_CUSTOM_RPC_URL);

Now, you can add the chain returned by addRpcUrlOverrideToChain (e.g. mainnetOverride) to the supportedChains config option like before.

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Default Configuration

If neither defaultChain nor supportedChains is explicitly set for your app, Privy will automatically default to the following list of EVM-compatible networks: