HTTP Transport
The http Transport connects to a JSON-RPC API via HTTP.
Import
ts
import { http } from 'viem'
Usage
ts
import { createPublicClient, http } from 'viem'
import { mainnet } from 'viem/chains'
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...')
const client = createPublicClient({
chain: mainnet,
transport,
})
WARNING
If no url is provided, then the transport will fall back to a public RPC URL on the chain. It is highly recommended to provide an authenticated RPC URL to prevent rate-limiting.
Parameters
url (optional)
- Type:
string - Default:
chain.rpcUrls.default.http[0]
URL of the JSON-RPC API.
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...')
fetchOptions (optional)
- Type:
RequestInit
Fetch options to pass to the internal fetch function. Useful for passing auth headers or cache options.
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...', {
fetchOptions: {
headers: {
'Authorization': 'Bearer ...'
}
}
})
key (optional)
- Type:
string - Default:
"http"
A key for the Transport.
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...', {
key: 'alchemy',
})
name (optional)
- Type:
string - Default:
"HTTP JSON-RPC"
A name for the Transport
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...', {
name: 'Alchemy HTTP Provider',
})
retryCount (optional)
- Type:
number - Default:
3
The max number of times to retry when a request fails.
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...', {
retryCount: 5,
})
retryDelay (optional)
- 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 = http('https://eth-mainnet.g.alchemy.com/v2/...', {
retryDelay: 100,
})
timeout (optional)
- Type:
number - Default:
10_000
The timeout for requests.
ts
const transport = http('https://eth-mainnet.g.alchemy.com/v2/...', {
timeout: 60_000,
})