createConfig

Creates new Config object.

Import

import { createConfig } from '@wagmi/core'

Usage

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

Integrating a Viem Client

Instead of using transports, it's possible to provide a function that returns a Viem Client via the client property for more fine-grained control over Wagmi's internal Client creation.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'
import { createClient } from 'viem'

const config = createConfig({
  chains: [mainnet, sepolia],
  client({ chain }) {
    return createClient({ chain, transport: http() })
  },
})

Parameters

import { type CreateConfigParameters } from '@wagmi/core'

chains

readonly [Chain, ...Chain[]]

• Chains used by the Config.
• See Chains for more details about built-in chains and the Chain type.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia], 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

connectors

CreateConnectorFn[] | undefined

Connectors used by the Config.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'
import { injected } from '@wagmi/connectors'

const config = createConfig({
  chains: [mainnet, sepolia],
  connectors: [injected()], 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

multiInjectedProviderDiscovery

boolean | undefined

• Enables discovery of injected providers via EIP-6963 using the mipd library and converting to injected connectors.
• Defaults to true.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  multiInjectedProviderDiscovery: false, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

ssr

boolean | undefined

Flag to indicate if the config is being used in a server-side rendering environment. Defaults to false.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  ssr: true, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

storage

Storage | null | undefined

• Storage used by the config. Persists Config's State between sessions.
• Defaults to createStorage({ storage: typeof window !== 'undefined' && window.localStorage ? window.localStorage : noopStorage }).

import { createConfig, createStorage, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  storage: createStorage({ storage: window.localStorage }), 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

syncConnectedChain

boolean | undefined

• Keep the State['chainId'] in sync with the current connection.
• Defaults to true.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  syncConnectedChain: false, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

---

batch

{ multicall?: boolean | { batchSize?: number | undefined; wait?: number | undefined } | undefined } | { [_ in chains[number]["id"]]?: { multicall?: boolean | { batchSize?: number | undefined; wait?: number | undefined } | undefined } | undefined } | undefined

• Batch settings. See Viem docs for more info.
• Defaults to { multicall: true }.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  batch: { multicall: true }, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

cacheTime

number | { [_ in chains[number]['id']]?: number | undefined } | undefined

• Frequency in milliseconds for polling enabled features. See Viem docs for more info.
• Defaults to pollingInterval or 4_000.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  cacheTime: 4_000, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

pollingInterval

number | { [_ in chains[number]['id']]?: number | undefined } | undefined

• Frequency in milliseconds for polling enabled features. See Viem docs for more info.
• Defaults to 4_000.

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  pollingInterval: 4_000, 
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

transports

Record<chains[number]['id'], Transport>

Mapping of chain IDs to Transports. This mapping is used internally when creating chain-aware Viem Client objects. See the Transport docs for more info.

import { createConfig, fallback, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  transports: { 
    [mainnet.id]: fallback([ 
      http('https://...'), 
      http('https://...'), 
    ]), 
    [sepolia.id]: http('https://...'), 
  }, 
})

---

client

(parameters: { chain: chains[number] }) => Client<Transport, chains[number]>

Function for creating new Viem Client to be used internally. Exposes more control over the internal Client creation logic versus using the transports property.

import { createClient, http } from 'viem'
import { createConfig } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

const config = createConfig({
  chains: [mainnet, sepolia],
  client({ chain }) { 
    return createClient({ chain, transport: http('https://...') }) 
  }, 
})

WARNING

When using this option, you likely want to pass parameters.chain straight through to createClient to ensure the Viem Client is in sync with any active connections.

Return Type

import { type Config } from '@wagmi/core'

Config

Object responsible for managing Wagmi state and internals.

import { type Config } from '@wagmi/core'

chains

readonly [Chain, ...Chain[]]

chains passed to createConfig.

connectors

readonly Connector[]

Connectors set up from passing connectors and multiInjectedProviderDiscovery to createConfig.

state

State<chains>

The Config object's internal state. See State for more info.

storage

Storage | null

storage passed to createConfig.

getClient

(parameters?: { chainId?: chainId | chains[number]['id'] | undefined }): Client<transports[chainId], Extract<chains[number], { id: chainId }>>

Creates new Viem Client object.

index.ts

import { config } from './config'

const client = config.getClient({ chainId: 1 })

config.ts

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

setState

(value: State<chains> | ((state: State<chains>) => State<chains>)) => void

Updates the Config object's internal state. See State for more info.

index.ts

import { mainnet } from '@wagmi/core/chains'
import { config } from './config'

config.setState((x) => ({
  ...x,
  chainId: x.current ? x.chainId : mainnet.id,
}))

config.ts

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

WARNING

Exercise caution when using this method. It is intended for internal and advanced use-cases only. Manually setting state can cause unexpected behavior.

subscribe

(selector: (state: State<chains>) => state, listener: (selectedState: state, previousSelectedState: state) => void, options?: { emitImmediately?: boolean | undefined; equalityFn?: ((a: state, b: state) => boolean) | undefined } | undefined) => (() => void)

Listens for state changes matching the selector function. Returns a function that can be called to unsubscribe the listener.

index.ts

import { config } from './config'

const unsubscribe = config.subscribe(
  (state) => state.chainId,
  (chainId) => console.log(`Chain ID changed to ${chainId}`),
)
unsubscribe()

config.ts

import { createConfig, http } from '@wagmi/core'
import { mainnet, sepolia } from '@wagmi/core/chains'

export const config = createConfig({
  chains: [mainnet, sepolia],
  transports: {
    [mainnet.id]: http('https://mainnet.example.com'),
    [sepolia.id]: http('https://sepolia.example.com'),
  },
})

State

import { type State } from '@wagmi/core'

chainId

chains[number]['id']

Current chain ID. When syncConnectedChain is true, chainId is kept in sync with the current connection. Defaults to first chain in chains.

connections

Map<string, Connection>

Mapping of unique connector identifier to Connection object.

current

string | undefined

Unique identifier of the current connection.

status

'connected' | 'connecting' | 'disconnected' | 'reconnecting'

Current connection status.

• 'connecting' attempting to establish connection.
• 'reconnecting' attempting to re-establish connection to one or more connectors.
• 'connected' at least one connector is connected.
• 'disconnected' no connection to any connector.

Connection

import { type Connection } from '@wagmi/core'

accounts

readonly [Address, ...Address[]]

Array of addresses associated with the connection.

chainId

number

Chain ID associated with the connection.

connector

Connector

Connector associated with the connection.