Metamask <> Polkadot snap adapter

Metamask <> Polkadot snap adapter is used to inject polkadot snap as web3 provider. It lists snap inside window.injectedWeb3[injectedSnapId](*) so it can be enabled using @polkadot/extension-dapp package.

*injectedSnapId default is "metamask-polkadot-snap"

For more details on polkadot snap itself see snap repo or read full polkadot snap documentation.

Usage

function enablePolkadotSnap(
  config?: SnapConfig,
  snapOrigin?: string,
  snapInstallationParams?: Record<SnapInstallationParamNames, unknown> = {}
): Promise<MetamaskPolkadotSnap>

Usage to inject snap in injectedWeb3 object

function initPolkadotSnap(
  {
    config?: SnapConfig,
    snapOrigin?: string,
    snapInstallationParams?: Record<SnapInstallationParamNames, unknown> = {}
  },
  injectedSnapId?: string
): Promise<MetamaskPolkadotSnap>

By providing config as argument it is possible to override default configurations.

Default config:

{
  networkName: 'westend'
}

Configuration structure is shown below.

SnapConfig {
  networkName: SnapNetworks;
  wsRpcUrl?: string;
  addressPrefix?: number;
  unit?: UnitConfiguration;
}

SnapNetworks = "polkadot" | "kusama" | "westend";

UnitConfiguration {
  symbol: string;
  decimals: number;
  image?: string;
  customViewUrl?: string;
}