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Ethers.js Adapters ​

It is recommended for projects to migrate to Viem when using wagmi, but there are some cases where you might still need to use Ethers.js in your project:

  • You may want to incrementally migrate Ethers.js usage to Viem
  • Some third-party libraries & SDKs may only support Ethers.js
  • Personal preference

We have provided reference implementations for Viem → Ethers.js adapters that you can copy + paste in your project.

Client → Provider ​

Reference Implementation ​

Copy the following reference implementation into a file of your choice:

ts
import { providers } from 'ethers'
import { useMemo } from 'react'
import type { Chain, Client, Transport } from 'viem'
import { Config, useClient } from 'wagmi'

export function clientToProvider(client: Client<Transport, Chain>) {
  const { chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  if (transport.type === 'fallback')
    return new providers.FallbackProvider(
      (transport.transports as ReturnType<Transport>[]).map(
        ({ value }) => new providers.JsonRpcProvider(value?.url, network),
      ),
    )
  return new providers.JsonRpcProvider(transport.url, network)
}

/** Hook to convert a viem Client to an ethers.js Provider. */
export function useEthersProvider({
  chainId,
}: { chainId?: number | undefined } = {}) {
  const client = useClient<Config>({ chainId })
  return useMemo(() => clientToProvider(client), [client])
}
ts
import { FallbackProvider, JsonRpcProvider } from 'ethers'
import { useMemo } from 'react'
import type { Chain, Client, Transport } from 'viem'
import { type Config, useClient } from 'wagmi'

export function clientToProvider(client: Client<Transport, Chain>) {
  const { chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  if (transport.type === 'fallback') {
    const providers = (transport.transports as ReturnType<Transport>[]).map(
      ({ value }) => new JsonRpcProvider(value?.url, network),
    )
    if (providers.length === 1) return providers[0]
    return new FallbackProvider(providers)
  }
  return new JsonRpcProvider(transport.url, network)
}

/** Action to convert a viem Client to an ethers.js Provider. */
export function useEthersProvider({ chainId }: { chainId?: number } = {}) {
  const client = useClient<Config>({ chainId })
  return useMemo(() => clientToProvider(client), [client])
}

Usage ​

Now you can use the useEthersProvider function in your components:

ts
import { useEthersProvider } from './ethers'

function Example() {
  const provider = useEthersProvider()
  ...
}
ts
import { providers } from 'ethers'
import { useMemo } from 'react'
import type { Chain, Client, Transport } from 'viem'
import { Config, useClient } from 'wagmi'

export function clientToProvider(client: Client<Transport, Chain>) {
  const { chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  if (transport.type === 'fallback')
    return new providers.FallbackProvider(
      (transport.transports as ReturnType<Transport>[]).map(
        ({ value }) => new providers.JsonRpcProvider(value?.url, network),
      ),
    )
  return new providers.JsonRpcProvider(transport.url, network)
}

/** Hook to convert a viem Client to an ethers.js Provider. */
export function useEthersProvider({
  chainId,
}: { chainId?: number | undefined } = {}) {
  const client = useClient<Config>({ chainId })
  return useMemo(() => clientToProvider(client), [client])
}
ts
import { FallbackProvider, JsonRpcProvider } from 'ethers'
import { useMemo } from 'react'
import type { Chain, Client, Transport } from 'viem'
import { type Config, useClient } from 'wagmi'

export function clientToProvider(client: Client<Transport, Chain>) {
  const { chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  if (transport.type === 'fallback') {
    const providers = (transport.transports as ReturnType<Transport>[]).map(
      ({ value }) => new JsonRpcProvider(value?.url, network),
    )
    if (providers.length === 1) return providers[0]
    return new FallbackProvider(providers)
  }
  return new JsonRpcProvider(transport.url, network)
}

/** Action to convert a viem Client to an ethers.js Provider. */
export function useEthersProvider({ chainId }: { chainId?: number } = {}) {
  const client = useClient<Config>({ chainId })
  return useMemo(() => clientToProvider(client), [client])
}

Connector Client → Signer ​

Reference Implementation ​

Copy the following reference implementation into a file of your choice:

ts
import { providers } from 'ethers'
import { useMemo } from 'react'
import type { Account, Chain, Client, Transport } from 'viem'
import { Config, useConnectorClient } from 'wagmi'

export function clientToSigner(client: Client<Transport, Chain, Account>) {
  const { account, chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  const provider = new providers.Web3Provider(transport, network)
  const signer = provider.getSigner(account.address)
  return signer
}

/** Hook to convert a Viem Client to an ethers.js Signer. */
export function useEthersSigner({ chainId }: { chainId?: number } = {}) {
  const { data: client } = useConnectorClient<Config>({ chainId })
  return useMemo(() => (client ? clientToSigner(client) : undefined), [client])
}
ts
import { BrowserProvider, JsonRpcSigner } from 'ethers'
import { useMemo } from 'react'
import type { Account, Chain, Client, Transport } from 'viem'
import { type Config, useConnectorClient } from 'wagmi'

export function clientToSigner(client: Client<Transport, Chain, Account>) {
  const { account, chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  const provider = new BrowserProvider(transport, network)
  const signer = new JsonRpcSigner(provider, account.address)
  return signer
}

/** Hook to convert a viem Wallet Client to an ethers.js Signer. */
export function useEthersSigner({ chainId }: { chainId?: number } = {}) {
  const { data: client } = useConnectorClient<Config>({ chainId })
  return useMemo(() => (client ? clientToSigner(client) : undefined), [client])
}

Usage ​

Now you can use the useEthersSigner function in your components:

ts
import { useEthersSigner } from './ethers'

function example() {
  const signer = useEthersSigner()
  ...
}
ts
import { providers } from 'ethers'
import { useMemo } from 'react'
import type { Account, Chain, Client, Transport } from 'viem'
import { Config, useConnectorClient } from 'wagmi'

export function clientToSigner(client: Client<Transport, Chain, Account>) {
  const { account, chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  const provider = new providers.Web3Provider(transport, network)
  const signer = provider.getSigner(account.address)
  return signer
}

/** Action to convert a Viem Client to an ethers.js Signer. */
export function useEthersSigner({ chainId }: { chainId?: number } = {}) {
  const { data: client } = useConnectorClient<Config>({ chainId })
  return useMemo(() => (client ? clientToSigner(client) : undefined), [client])
}
ts
import { BrowserProvider, JsonRpcSigner } from 'ethers'
import { useMemo } from 'react'
import type { Account, Chain, Client, Transport } from 'viem'
import { type Config, useConnectorClient } from 'wagmi'

export function clientToSigner(client: Client<Transport, Chain, Account>) {
  const { account, chain, transport } = client
  const network = {
    chainId: chain.id,
    name: chain.name,
    ensAddress: chain.contracts?.ensRegistry?.address,
  }
  const provider = new BrowserProvider(transport, network)
  const signer = new JsonRpcSigner(provider, account.address)
  return signer
}

/** Hook to convert a viem Wallet Client to an ethers.js Signer. */
export function useEthersSigner({ chainId }: { chainId?: number } = {}) {
  const { data: client } = useConnectorClient<Config>({ chainId })
  return useMemo(() => (client ? clientToSigner(client) : undefined), [client])
}

Released under the MIT License.

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