import { SchemaLoader, SingleFileOptions, Source } from '@graphql-toolkit/common';
import { ClientConfig } from 'apollo-language-server';
export declare class ApolloEngineLoader implements SchemaLoader {
    loaderId(): string;
    canLoad(ptr: string): Promise<boolean>;
    canLoadSync(): boolean;
    load(_: 'apollo-engine', options: ClientConfig & SingleFileOptions): Promise<Source>;
    loadSync(): never;
}