Ethereum Provider API

Brave injects a windows.ethereum provider object on all pages.
This object is defined by EIP-1193.

This object gives websites the ability to:

• Make requests to an Ethereum node (or a compatible network) to read data from the blockchain
• Request permission to 1 or more Ethereum accounts
• Ask the user (if given permission previously) to sign / submit a transaction
• Ask the user (if given permission previously) to sign a message

Provider methods

window.ethereum.request

interface RequestArguments {
  readonly method: string;
  readonly params?: readonly unknown[] | object;
}

Provider.request(args: RequestArguments): Promise<unknown>;

window.ethereum.isConnected

Provider.isConnected(): boolean;

Provider events

connect

The Provider emits connect when it:

• first connects to a chain after being initialized.
• first connects to a chain, after the disconnect event was emitted.

interface ProviderConnectInfo {
  readonly chainId: string;
}

Provider.on('connect', listener: (connectInfo: ProviderConnectInfo) => void): Provider;

disconnect

The Provider emits disconnect when it becomes disconnected from all chains.

Provider.on('disconnect', listener: (error: ProviderRpcError) => void): Provider;

chainChanged

The Provider emits chainChanged when connecting to a new chain.

Provider.on('chainChanged', listener: (chainId: string) => void): Provider;

accountsChanged

The Provider emits accountsChanged if the accounts returned from the Provider (eth_accounts) change.

Provider.on('accountsChanged', listener: (accounts: string[]) => void): Provider;

Permissions

Websites can call:

window.ethereum.request({ method: 'eth_requestAccounts' })

To make a request for permissions to an account. If granted, the website will be able to see the allowed account address. The website will also be able to ask the user to approve (sing / send) transactions and to sign data. Signing transactions and messages require separate approval after the initial account approval.

Adding other chains

Websites can request that alternate chains be added by using:

window.ethereum.request({ method: 'wallet_addEthereumChain' }, params)

wallet_addEthereumChain accepts a single object parameter, specified by the following TypeScript interface:

interface AddEthereumChainParameter {
  chainId: string;
  blockExplorerUrls?: string[];
  chainName?: string;
  iconUrls?: string[];
  nativeCurrency?: {
    name: string;
    symbol: string;
    decimals: number;
  };
  rpcUrls?: string[];
}

Sending transactions

Sites can request that a transaction be signed / sent by using the eth_sendTransaction method.

For more information, see: https://eth.wiki/json-rpc/API#eth_sendtransaction

Signing data

Signing data can be done with:

• eth_sign
• personal_sign
• signTypedData
• signTypedData_v1 (same as signTypedData)
• signTypedData_v3
• signTypedData_v4

These are not implemented yet in Brave and they are being tracked here: https://github.com/brave/brave-browser/issues/17986

Legacy Provider methods

A number of legacy provider methods are provided for backwards compatibility:

enable (deprecated)

Allows a website to request permissions.

This method is superseded by a request with eth_requestAccounts.

Provider.request({ method: 'eth_requestAccounts' })

sendAsync (deprecated)

Provider.sendAsync(request: Object, callback: Function): void;

This method is superseded by request.

send (deprecated)

Provider.send(...args: unknown[]): unknown;

This method is superseded by request.

Legacy Provider events

close (deprecated)

Not yet implemented, but Brave may implement it. This event close is superseded by disconnect.

networkChanged (deprecated)

Not yet implemented, but Brave may implement it.

The event networkChanged is superseded by chainChanged.

notification (deprecated)

This event is superseded by message.

message (deprecated)

Brave has not implemented this event yet.

The message event is intended for arbitrary notifications not covered by other events.

The event will be emitted with an object argument of the following form:

interface ProviderMessage {
  readonly type: string;
  readonly data: unknown;
}

Built-in networks

Chain ID	Network name
0x1	Ethereum mainnet
0x3	Ropsten Testnet
0x3	Ropsten Testnet
0x5	Rinkeby Testnet
0x2a	Kovan Testnet

Disabling the Ethereum provider object insertion

The Ethereum provider object can be disabled from brave://settings/wallet by changing the Default cryptocurrency wallet to None.