LogSentinel NestJS SDK

Logging middleware for NestJS applications. Captures HTTP requests and responses, batches them asynchronously, and sends to a remote monitoring for analysis.

Features

• Zero Impact: Never crashes or blocks your application
• Async Batching: High-performance batch processing (default: 5 logs per batch)
• Graceful Shutdown: Flushes all pending logs before exit
• Debug Mode: Beautiful colorized console output for development
• Type-Safe: Full TypeScript support with strict typing
• Production Ready: Fail-safe error handling and retry logic

Installation

npm install logsentinel-nestjs

Quick Start

1. Set Environment Variables

Create a .env file in your project root:

LOGSENTINEL_API_KEY=your_api_key_here
LOGSENTINEL_BASE_URL=https://your-monitoring-server.com
LOGSENTINEL_DEBUG=true

2. Initialize SDK in main.ts

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { LogSentinelSDK } from 'logsentinel-nestjs';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  
  // Initialize LogSentinel SDK (one line!)
  const logSentinel = new LogSentinelSDK();
  logSentinel.install(app);
  
  await app.listen(3000);
}
bootstrap();

That's it! Your application is now logging all requests and responses.

Configuration

Environment Variables

| Variable | Required | Default | Description | |----------|----------|---------|-------------| | LOGSENTINEL_API_KEY | Yes | - | API key for authentication | | LOGSENTINEL_BASE_URL | Yes | - | Base URL of your monitoring server | | LOGSENTINEL_DEBUG | No | false | Enable debug mode with colorized logs | | LOGSENTINEL_BATCH_SIZE | No | 5 | Number of logs per batch |

Programmatic Configuration

const logSentinel = new LogSentinelSDK({
  debug: true,
  batchSize: 10,
});
logSentinel.install(app);

How It Works

1. Middleware captures incoming requests (method, URL, headers, body)
2. Interceptor captures outgoing responses (status, body, execution time)
3. Batch Queue holds logs in memory until batch size is reached
4. Flusher sends logs asynchronously to your monitoring server
5. Graceful Shutdown flushes remaining logs on process exit

API Endpoint

The SDK sends POST requests to:

POST {baseUrl}/api/sdk/logs
Authorization: Bearer {apiKey}
Content-Type: application/json

Request Body:

{
  "timestamp": "2024-01-15T10:30:00.000Z",
  "method": "POST",
  "url": "/api/users",
  "query": {},
  "requestHeaders": { "content-type": "application/json" },
  "requestBody": { "name": "John" },
  "statusCode": 201,
  "responseBody": { "id": "123", "name": "John" },
  "executionTimeMs": 45.67
}

Debug Mode

Enable debug mode to see console output:

LOGSENTINEL_DEBUG=true

Output example:

[LogSentinel] ✓ SDK initialized successfully
[LogSentinel] Captured POST /api/users - 201 (45.67ms)
[LogSentinel] Flushing 5 log entries
[LogSentinel] ✓ Successfully sent 5 logs

Production Mode

In production, set LOGSENTINEL_DEBUG=false or omit it entirely.

Requirements

• Node.js 16+
• NestJS 10+

License

MIT

Support

Open an issue on GitHub.