ClientProxyFactory

Kind: Class

Source: packages/microservices/client/client-proxy-factory.ts

Part of: Microservices

ClientProxyFactory creates microservice client proxies based on the configured transport strategy, such as TCP, Redis, NATS, gRPC, or Kafka. It centralizes transport-specific client selection so application code can interact with a common ClientProxy interface for sending messages and emitting events.

Methods

Diagram

mermaid
graph LR
  A[Client Options] --> B[ClientProxyFactory.create]
  B --> C{Transport Type}
  C -->|TCP / Redis / NATS / RMQ / MQTT| D[ClientProxy]
  C -->|gRPC| E[ClientGrpcProxy]
  C -->|Kafka| F[ClientKafkaProxy]
  D --> G[Microservice Broker or Server]
  E --> G
  F --> G

Usage

ts
import { ClientProxyFactory, Transport } from '@nestjs/microservices';

const client = ClientProxyFactory.create({
  transport: Transport.TCP,
  options: {
    host: 'localhost',
    port: 3001,
  },
});

// Request-response communication
const result = await client.send('users.findOne', { id: '123' }).toPromise();

// Event-based communication
client.emit('users.created', {
  id: '123',
  email: 'user@example.com',
});

AI Coding Instructions

• Use ClientProxyFactory.create() when creating clients dynamically outside of Nest dependency injection.
• Match the client transport and connection options with the corresponding microservice server configuration.
• Use send() for request-response patterns and emit() for fire-and-forget event patterns.
• Call connect() explicitly when eager connection validation is required; otherwise, clients connect lazily on first use.
• Prefer injected clients registered through ClientsModule for application services, reserving this factory for runtime or infrastructure-level client creation.

Used by

7 references from 7 files. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

Imported by (7)

• DisconnectedClientController — integration/microservices/src/disconnected.controller.ts:12
• NatsController — integration/microservices/src/nats/nats.controller.ts:19
• RMQFanoutExchangeProducerController — integration/microservices/src/rmq/fanout-exchange-producer-rmq.controller.ts:9
• RMQBroadcastController — integration/microservices/src/rmq/rmq-broadcast.controller.ts:11
• RMQController — integration/microservices/src/rmq/rmq.controller.ts:16
• RMQTopicExchangeController — integration/microservices/src/rmq/topic-exchange-rmq.controller.ts:12
• HttpController — integration/scopes/src/msvc/http.controller.ts:4