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HTTP Ledger

HTTP Ledger is a comprehensive Express.js middleware for detailed API request and response logging. It provides beautiful console output, advanced security features, performance metrics, and highly customizable logging options.

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Overview

HTTP Ledger captures complete information about every HTTP request and response in your Express application, making it easy to monitor, debug, and analyze your API traffic. The middleware is designed to be production-ready with minimal overhead and extensive configuration options.

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Key Features

Comprehensive Logging

Captures method, URL, status code, timing, request/response sizes, headers, query parameters, and bodies

Advanced Security

Field masking for sensitive data like passwords, tokens, and API keys with support for nested fields

Custom Logging

Custom formatters, log levels, and selective logging to match your application’s needs

Performance Optimized

Log sampling, conditional logging, and async operations for minimal performance impact

Request Tracking

Auto-generated request IDs for distributed tracing and request correlation

Error Handling

Robust error handling with graceful fallbacks and comprehensive error capture

IP Information

Optional IP geolocation support for geographic analysis of API traffic

TypeScript Support

Full TypeScript support with comprehensive type definitions included

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What Gets Logged?

HTTP Ledger captures detailed information about each request:
  • Request Details: HTTP method, URL, headers, query parameters, body
  • Response Details: Status code, headers, body, content type
  • Performance Metrics: Time taken, request size, response size
  • Client Information: User agent, referer, IP address, geolocation
  • Request Tracking: Request IDs, timestamps, HTTP version
  • Error Information: Error messages, stack traces, error codes

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Use Cases

  • Development: Debug API issues with detailed request/response logs
  • Production Monitoring: Track API performance and identify bottlenecks
  • Security Auditing: Monitor API access patterns and detect anomalies
  • Analytics: Send log data to external services for analysis
  • Compliance: Maintain audit trails of API access
  • Performance Optimization: Identify slow endpoints and optimize them

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Example Output

Here’s an example of the JSON output produced by HTTP Ledger: 
{
  "method": "POST",
  "url": "/api/users?page=1&limit=10",
  "statusCode": 201,
  "timeTaken": 45.23,
  "requestSize": 256,
  "responseSize": 1024,
  "timestamp": {
    "request": "2024-01-01T12:00:00.000Z",
    "response": "2024-01-01T12:00:00.045Z"
  },
  "headers": {
    "user-agent": "Mozilla/5.0...",
    "content-type": "application/json"
  },
  "queryParams": {
    "page": "1",
    "limit": "10"
  },
  "body": {
    "name": "John Doe",
    "email": "[email protected]",
    "password": "***"
  },
  "responseBody": {
    "id": 123,
    "name": "John Doe",
    "email": "[email protected]"
  },
  "requestId": "req-abc123def456",
  "logLevel": "info"
}

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Performance Considerations

HTTP Ledger is optimized for production use:
  • Minimal Overhead: Efficient implementation with minimal performance impact
  • Async Operations: IP lookups and callbacks run asynchronously without blocking
  • Memory Efficient: Streams large responses without buffering
  • Configurable: Disable expensive operations when not needed
  • Log Sampling: Reduce logging overhead in high-traffic environments
  • Selective Logging: Skip logging for health checks and static assets
HTTP Ledger requires Node.js 18.0.0 or higher and Express 4.x or higher.

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Next Steps

Installation

Install HTTP Ledger in your project

Quick Start

Get started with a working example

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