Real World Example

Delivery apps like Swiggy, Zepto and Blinkit expose an order tracking endpoint that the app polls every few seconds. A NestJS version with a fixed route before the dynamic one, a query flag and caching headers:

src/orders/orders.controller.ts

import { Controller, Get, Header, Param, ParseBoolPipe, DefaultValuePipe, Query } from '@nestjs/common';
import { OrdersService } from './orders.service';

@Controller('orders')
export class OrdersController {
  constructor(private readonly ordersService: OrdersService) {}

  @Get('active')                                   // fixed route first
  active() {
    return this.ordersService.findActiveForCurrentUser();
  }

  @Get(':orderId/track')
  @Header('Cache-Control', 'no-store')             // always fresh
  track(
    @Param('orderId') orderId: string,
    @Query('withRider', new DefaultValuePipe(false), ParseBoolPipe) withRider: boolean,
  ) {
    return this.ordersService.track(orderId, withRider);
  }
}

Example

curl "http://localhost:3000/orders/ORD-7781/track?withRider=true"

Example output

HTTP/1.1 200 OK
Cache-Control: no-store
Content-Type: application/json; charset=utf-8

{"orderId":"ORD-7781","status":"OUT_FOR_DELIVERY","etaMinutes":12,"rider":{"name":"Ravi","phone":"+91-98XXXXXX21","lat":12.9716,"lng":77.5946}}

Order Tracking Endpoint

Example