State module

One of the core modules we have so far. We get runtime metadata using it, and fetching storage items for all of other modules.

public protocol StateModule: AnyObject {
    func runtimeMetadata() async throws -> RuntimeMetadata?
    
    func fetchStorageItem<T: Decodable>(
        item: RuntimeModuleStorageItem,
        storage: RuntimeModuleStorage
    ) async throws -> T?
    
    func fetchStorageItem<T: Decodable>(
        item: RuntimeModuleStorageItem,
        key: Data,
        storage: RuntimeModuleStorage
    ) async throws -> T?
    
    func fetchStorageItem<T: Decodable>(
        item: RuntimeModuleStorageItem,
        keys: [Data],
        storage: RuntimeModuleStorage
    ) async throws -> T?
}

To simply get metadata of runtime use this:

let client: SubstrateClient
let metadata = try await client.modules.state.runtimeMetadata()

For fetching storage items, we strongly encourage not to use them as we have a powerful storage service.