Set up the profiler

Install @eleven-labs/nest-profiler and inspect HTTP requests in the profiler UI.

This tutorial shows how to add @eleven-labs/nest-profiler to a NestJS application and inspect collected request data in the built-in profiler UI.

Step 1 — Install the package

pnpm add @eleven-labs/nest-profiler nestjs-cls

nestjs-cls is required for per-request context propagation.

Step 2 — Register the module

Import ProfilerModule in your root module:

app.module.ts

import { Module } from '@nestjs/common';
import { ProfilerModule } from '@eleven-labs/nest-profiler';

@Module({
  imports: [
    ProfilerModule.forRoot({
      isGlobal: true,
      enabled: process.env.NODE_ENV !== 'production',
    }),
  ],
})
export class AppModule {}

Step 3 — Enable log capture

Wrap your existing logger in main.ts so log entries appear in the profiler's Logs tab:

main.ts

import { ConsoleLogger } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { ProfilerService } from '@eleven-labs/nest-profiler';
import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule, { bufferLogs: true });

  const profilerService = app.get(ProfilerService);

  app.useLogger(profilerService.createLogger(new ConsoleLogger('MyApplication')));

  await app.listen(3000);
}

void bootstrap();

The capture is logger-agnostic and keeps structured context — message, context name and payload all land in the Logs tab whichever logger the app uses. The Log capture with context tutorial and the Log capture page cover the supported conventions in detail.

Step 4 — Make a request and inspect the profile

Start the application, then make any HTTP request:

curl -i http://localhost:3000/health

The response includes two headers:

X-Debug-Token: 550e8400-e29b-...
X-Debug-Token-Link: /_profiler/550e8400-e29b-...

Open http://localhost:3000/_profiler in your browser to see the list of recent profiles. Click a token to open the detail view with tabs:

Request — method, URL, headers, query params
Response — status code, headers
Performance — duration, memory delta
Logs — log entries captured during the request
Exceptions — errors thrown during the request

Step 5 — Secure the profiler (optional)

Set PROFILER_TOKEN in your environment to restrict access to /_profiler/*:

PROFILER_TOKEN=my-dev-secret pnpm start:dev

Then access the profiler with:

curl -H "Authorization: Bearer my-dev-secret" http://localhost:3000/_profiler

Production warning

Never enable the profiler in production. It exposes internal request data including headers, query parameters, and logs. Use enabled: false or an environment-based condition (e.g. process.env.NODE_ENV !== 'production') to disable it in non-development environments.

When disabled, the core registers only an inert layer: ProfilerService stays injectable — so app.useLogger(...) and any service that injects it keep working — but all its methods are no-ops, and no controller, interceptor, middleware, storage or collector is registered. Collector modules register nothing at all.