ServerGrpc

Kind: Class

Source: packages/microservices/server/server-grpc.ts

Part of: Microservices

ServerGrpc is the NestJS microservices transport server responsible for exposing message handlers as gRPC service methods. It initializes the gRPC server, binds configured services and RPC handlers, applies keepalive options, and translates incoming gRPC requests into Nest message handler calls.

Extends: Server

Methods

Properties

Where it refuses work

• ServerGrpc stops the work with an early return when hasDrained, in 2 places.
• ServerGrpc stops the work with an early return when !isObject(this.options.keepalive).
• ServerGrpc stops the work with an early return when streamType === GrpcMethodStreamingType.PT_STREAMING.
• ServerGrpc stops the work with an early return when !writing.
• ServerGrpc stops the work with an early return when !isObject(grpcDefinition).
• ServerGrpc stops the work with an early return when name.length === 0.

When something fails

• ServerGrpc handles failure in 3 places: it logs it and continues in 1, turns it into a return value in 1, and lets it reach the caller in 1.

Diagram

mermaid
graph LR
  Client[gRPC Client] -->|RPC request| GrpcServer[ServerGrpc]
  GrpcServer -->|bindEvents| Services[gRPC Service Definitions]
  Services -->|createServiceMethod| Handlers[Nest Message Handlers]
  Handlers -->|getMessageHandler| Controllers[Controller Methods]
  Controllers -->|response / stream| Client

Usage

ts
import { NestFactory } from '@nestjs/core';
import { MicroserviceOptions, Transport } from '@nestjs/microservices';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.createMicroservice<MicroserviceOptions>(
    AppModule,
    {
      transport: Transport.GRPC,
      options: {
        package: 'users',
        protoPath: 'proto/users.proto',
        url: '0.0.0.0:50051',
      },
    },
  );

  // Internally creates and starts a ServerGrpc instance.
  await app.listen();
}

bootstrap();

AI Coding Instructions

• Configure ServerGrpc through Nest's Transport.GRPC microservice options rather than manually instantiating it in application code.
• Ensure package, protoPath, and service names match the .proto definition exactly; mismatches prevent handlers from being bound.
• Use controller methods decorated with @GrpcMethod() or @GrpcStreamMethod() so bindEvents() can map RPC methods to Nest message handlers.
• Keep unary and streaming RPC implementations distinct; createUnaryServiceMethod() handles request/response calls, while streaming methods require stream-aware handlers.
• When changing connection behavior, preserve the expected gRPC keepalive option format used by getKeepaliveOptions().

How it works

ServerGrpc

ServerGrpc is the gRPC transport implementation of the abstract Server base class. It identifies itself as Transport.GRPC and stores the bound gRPC server instance in grpcClient. packages/microservices/server/server-grpc.ts:59-63

Relationships

• IMPORTS → isObject
• IMPORTS → isString
• IMPORTS → isUndefined