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Introduction to SDK Ecosystem Providers

The LI.FI SDK supports different blockchain ecosystems, allowing you to integrate with EVM and Solana networks, with more ecosystems on the way. Internally, providers act as abstractions for each ecosystem, handling crucial tasks such as address resolution, balance checking, and transaction handling during route/quote execution. These ecosystem providers are designed with modularity in mind and are fully tree-shakable, ensuring that they do not add unnecessary weight to your bundle if not used. The SDK offers two providers, EVM and Solana, both with similar configuration options respective to their ecosystems. 
import { EVM, Solana } from '@lifi/sdk'
The setup for both providers focuses on utilizing a wallet client, wallet adapter, or a similar wallet interface concept depending on the ecosystem-specific libraries and standards. This unified approach simplifies managing wallets and transactions across EVM-compatible and Solana chains.

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Different types of wallets/accounts

To execute quotes/routes via a specific provider, that provider must be capable of signing transactions. SDK providers support signing transactions over the following types of wallets/accounts:
  • Local Accounts (e.g. private key/mnemonic wallets).
Local accounts are wallets managed using private keys or mnemonic phrases. This setup is often used in backend services or scenarios where automated signing and transaction management are required.
  • JSON-RPC Accounts (e.g. Browser Extension Wallets, WalletConnect, etc.).
Using JSON-RPC accounts involves connecting through a Web3 provider, e.g. window.ethereum, and managing the user’s account within the browser or mobile context. This setup is popular among dApps UIs and is often used together with libraries like Wagmi or @solana/web3.js. These account types and interaction methods allow developers to choose the most suitable approach for integrating the SDK with their applications.

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Setup EVM Provider

The EVM provider execution logic is built based on the Viem library, using some of its types and terminology. Options available for configuring the EVM provider:
  • getWalletClient: A function that returns a WalletClient instance.
  • switchChain: A hook for switching between different networks.

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Local Accounts

When using local accounts, developers need a predefined list of chains they plan to interact with in order to switch chains during transaction execution. These chains can be either from the viem/chains package or fetched from LI.FI API and adopted to viem’s Chain type. Here’s a basic example using chains from viem/chains: 
import { createConfig, EVM } from '@lifi/sdk'
import type { Chain } from 'viem'
import { createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { arbitrum, mainnet, optimism, polygon, scroll } from 'viem/chains'

const account = privateKeyToAccount('PRIVATE_KEY')

const chains = [arbitrum, mainnet, optimism, polygon, scroll]

const client = createWalletClient({
  account,
  chain: mainnet,
  transport: http(),
})

createConfig({
  integrator: 'Your dApp/company name',
  providers: [
    EVM({
      getWalletClient: async () => client,
      switchChain: async (chainId) =>
        // Switch chain by creating a new wallet client
        createWalletClient({
          account,
          chain: chains.find((chain) => chain.id == chainId) as Chain,
          transport: http(),
        }),
    }),
  ],
})

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JSON-RPC Accounts

The best way to interact with JSON-RPC accounts and pass WalletClient to the EVM provider is to use the Wagmi library. Developers can configure Wagmi chains either by using chains from the viem/chains package or fetching chains from LI.FI API and adapting them to Viem’s Chain type. Below is a simplified example of how to set up the EVM provider using chains from the LI.FI API in conjunction with Wagmi and React. We provide a useSyncWagmiConfig hook that synchronizes fetched chains with the Wagmi configuration and updates connectors. Please note that we do not initialize the Wagmi configuration with connectors. Additionally, we set reconnectOnMount to false since the reconnect action will be called within useSyncWagmiConfig hook after the chains are synchronized with the configuration and connectors. 
import { ChainType, EVM, config, createConfig, getChains } from '@lifi/sdk';
import { useSyncWagmiConfig } from '@lifi/wallet-management';
import { useQuery } from '@tanstack/react-query';
import { getWalletClient, switchChain } from '@wagmi/core';
import { type FC, type PropsWithChildren } from 'react';
import { createClient, http } from 'viem';
import { mainnet } from 'viem/chains';
import type { Config, CreateConnectorFn } from 'wagmi';
import { WagmiProvider, createConfig as createWagmiConfig } from 'wagmi';
import { injected } from 'wagmi/connectors';

// List of Wagmi connectors
const connectors: CreateConnectorFn[] = [injected()];

// Create Wagmi config with default chain and without connectors
const wagmiConfig: Config = createWagmiConfig({
  chains: [mainnet],
  client({ chain }) {
    return createClient({ chain, transport: http() });
  },
});

// Create SDK config using Wagmi actions and configuration
createConfig({
  integrator: 'Your dApp/company name',
  providers: [
    EVM({
      getWalletClient: () => getWalletClient(wagmiConfig),
      switchChain: async (chainId) => {
        const chain = await switchChain(wagmiConfig, { chainId });
        return getWalletClient(wagmiConfig, { chainId: chain.id });
      },
    }),
  ],
  // We disable chain preloading and will update chain configuration in runtime
  preloadChains: false,
});

export const CustomWagmiProvider: FC<PropsWithChildren> = ({ children }) => {
  // Load EVM chains from LI.FI API using getChains action from LI.FI SDK
  const { data: chains } = useQuery({
    queryKey: ['chains'] as const,
    queryFn: async () => {
      const chains = await getChains({
        chainTypes: [ChainType.EVM],
      });
      // Update chain configuration for LI.FI SDK
      config.setChains(chains);
      return chains;
    },
  });

  // Synchronize fetched chains with Wagmi config and update connectors
  useSyncWagmiConfig(wagmiConfig, connectors, chains);

  return (
    <WagmiProvider config={wagmiConfig} reconnectOnMount={false}>
      {children}
    </WagmiProvider>
  );
};

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Update provider configuration

Additionally, providers allow for dynamic updates to its initial configuration via the setOptions function. Here’s an example of how to modify the initial configuration for EVM provider: 
import { createConfig, EVM } from '@lifi/sdk'
import { createWalletClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { arbitrum, mainnet } from 'viem/chains'

const account = privateKeyToAccount('PRIVATE_KEY')

const mainnetClient = createWalletClient({
  account,
  chain: mainnet,
  transport: http(),
})

const evmProvider = EVM({
  getWalletClient: async () => mainnetClient,
})

createConfig({
  integrator: 'Your dApp/company name',
  providers: [evmProvider],
})

const optimismClient = createWalletClient({
  account,
  chain: arbitrum,
  transport: http(),
})

evmProvider.setOptions({
  getWalletClient: async () => optimismClient,
})

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Support for Ethers.js and other alternatives

Developers can still use Ethers.js or any other alternative Web3 library in their project and convert Signer/Provider objects to Viem’s WalletClient before passing it to the EVM provider configuration.

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Setup Solana Provider

The Solana provider execution logic is built based on the @solana/web3.js and @solana/wallet-adapter-base libraries, using some of its types and terminology. Options available for configuring the EVM provider:
  • getWalletAdapter: A function that returns a WalletAdapter instance.

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Local Wallet Adapter

Standard Solana libraries do not offer a built-in method for creating a wallet adapter directly from a private key. To address this limitation, we provide the KeypairWalletAdapter. This custom adapter enables users to create a wallet adapter from a private key. It is worth noting that the KeypairWalletAdapter is designed specifically for backend or testing purposes and should not be used in user-facing code to prevent the risk of exposing your private key. 
import { createConfig, KeypairWalletAdapter, Solana } from '@lifi/sdk'

const walletAdapter = new KeypairWalletAdapter('PRIVATE_KEY')

createConfig({
  integrator: 'Your dApp/company name',
  providers: [
    Solana({
      getWalletAdapter: async () => walletAdapter,
    }),
  ],
})

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JSON-RPC Wallet Adapter

To interact with JSON-RPC accounts and pass WalletAdapter to the Solana provider, we recommend using the @solana/wallet-adapter-base and @solana/wallet-adapter-react libraries. Unlike Wagmi, Solana configuration for React does not have global configurations. Therefore, we need to use React hooks to update the SDK configuration at runtime. Below is a simplified example of how to set up the Solana provider. 
import { Solana, config, createConfig } from '@lifi/sdk';
import type { SignerWalletAdapter } from '@solana/wallet-adapter-base';
import { useWallet } from '@solana/wallet-adapter-react';
import { useEffect } from 'react';

createConfig({
  integrator: 'Your dApp/company name',
});

export const SDKProviders = () => {
  const { wallet } = useWallet();

  useEffect(() => {
    // Configure SDK Providers
    config.setProviders([
      Solana({
        async getWalletAdapter() {
          return wallet?.adapter as SignerWalletAdapter;
        },
      }),
    ]);
  }, [wallet?.adapter]);

  return null;
};