Custom Transport โ
The custom Transport accepts an EIP-1193 request function as a parameter. This transport is useful for integrating with injected wallets, wallets that provide an EIP-1193 provider (eg. WalletConnect or Coinbase SDK), or even providing your own custom request function.
Import โ
ts
import { custom } from 'viem'
Usage โ
You can use any EIP-1193 compatible Ethereum Provider with the custom Transport:
ts
import { createWalletClient, custom } from 'viem'
import { mainnet } from 'viem/chains'
const client = createWalletClient({
  chain: mainnet,
  transport: custom(window.ethereum)
})
Or you can define your own:
ts
import { createWalletClient, custom } from 'viem'
import { mainnet } from 'viem/chains'
import { customRpc } from './rpc'
const client = createWalletClient({ 
  chain: mainnet,
  transport: custom({
    async request({ method, params }) {
      const response = await customRpc.request(method, params)
      return response
    }
  })
})
Parameters โ
provider โ
- Type: 
custom 
An EIP-1193 request function function.
ts
import { customRpc } from './rpc'
const transport = custom({
  async request({ method, params }) { 
    const response = await customRpc.request(method, params)
    return response
  }
})
key (optional) โ
- Type: 
string - Default: 
"custom" 
A key for the Transport.
ts
const transport = custom(
  window.ethereum,
  { 
    key: 'windowProvider', 
  }
)
name (optional) โ
- Type: 
string - Default: 
"Ethereum Provider" 
A name for the Transport
ts
const transport = custom(
  window.ethereum,
  { 
    name: 'Window Ethereum Provider', 
  }
)
retryCount (optional) โ
- Type: 
number - Default: 
3 
The max number of times to retry when a request fails.
ts
const transport = custom(window.ethereum, {
  retryCount: 5, 
})
retryDelay (optional) โ
- Type: 
number - Default: 
150 
The base delay (in ms) between retries. By default, the Transport will use exponential backoff (~~(1 << count) * retryDelay), which means the time between retries is not constant.
ts
const transport = custom(window.ethereum, {
  retryDelay: 100, 
})
Gotchas โ
- If you are pairing the 
customTransport with a Public Client, ensure that your provider supports Public Actions.