import * as protobuf from 'protobufjs';
import * as grpc from '@grpc/grpc-js';
/**
 * gRPC client.
 *
 * @public
 */
export interface GrpcClient extends grpc.Client {
    [methodName: string]: Function;
}
/**
 * gRPC client creator for a service.
 *
 * @public
 */
export interface GrpcClientCreator {
    /**
     * Create a new client for service.
     *
     * @param address - the address for the service, or undefined if client is for another component in this Kalix Service
     * @param credentials - the credentials for the connection
     * @returns a new gRPC client for the service
     */
    createClient(address?: string, credentials?: grpc.ChannelCredentials): GrpcClient;
}
/**
 * gRPC client lookup, using fully qualified name for service.
 *
 * @public
 */
export interface GrpcClientLookup {
    [index: string]: GrpcClientLookup | GrpcClientCreator;
}
/** @public */
export declare class GrpcUtil {
    /**
     * Iterate through a (resolved) protobufjs reflection object to find services.
     */
    static getServiceNames(obj: protobuf.ReflectionObject, parentName?: string): Array<string>;
    /**
     * Add default headers/metadata to all request methods
     */
    static addHeadersToAllRequests(client: any, metadataWithHeaders: grpc.Metadata): void;
    /**
     * add async versions of unary request methods, suffixed with the given suffix
     */
    static promisifyClient(client: any, suffix?: string): any;
}