NatsRequestJSONDeserializer

Kind: Class

Source: packages/microservices/deserializers/nats-request-json.deserializer.ts

Part of: Microservices

NatsRequestJSONDeserializer converts raw NATS request messages into Nest microservice IncomingRequest or IncomingEvent objects. It parses the JSON payload, reads the correlation ID from NATS headers, and attaches a response function backed by the original NATS message.

Extends: IncomingRequestDeserializer

Methods

Diagram

mermaid
graph LR
  A[NATS message] --> B[NatsRequestJSONDeserializer.deserialize]
  B --> C[Parse JSON payload]
  B --> D[Read correlation ID header]
  B --> E[Bind message.respond]
  C --> F[IncomingRequest or IncomingEvent]
  D --> F
  E --> F

Usage

ts
import { NatsRequestJSONDeserializer } from '@nestjs/microservices';

const deserializer = new NatsRequestJSONDeserializer();

const natsMessage = {
  data: Buffer.from(
    JSON.stringify({
      pattern: 'users.findOne',
      data: { id: '42' },
    }),
  ),
  headers: {
    get: (key: string) =>
      key === 'Nats-Correlation-Id' ? 'request-123' : undefined,
  },
  respond: (payload: Uint8Array) => {
    // Send a response through NATS
  },
};

const request = deserializer.deserialize(natsMessage);

console.log(request.pattern); // "users.findOne"
console.log(request.data); // { id: "42" }
console.log(request.id); // "request-123"

AI Coding Instructions

• Preserve the expected NATS message shape: payload data, optional headers, and a respond function.
• Keep payloads JSON-serializable because deserialize() parses the message body as JSON.
• Do not remove the bound response function; request-response handlers depend on it to publish replies.
• Ensure clients include the NATS correlation ID header when request identity or response matching is required.
• Treat the deserialized result as either an IncomingRequest or IncomingEvent, depending on the payload shape and transport flow.

Relationships

• IMPORTS → loadPackage