App Tracker for Web & Node.js

App Tracker is a TypeScript/JavaScript library for logging and tracking events in web and Node.js applications. It supports batching, flexible configuration, and sending logs to a central endpoint.

Runtime support: Node.js 16 or newer and modern browsers with fetch/XHR, Promise, and WeakSet. Missing browser storage or sendBeacon support is handled with fallbacks.

Installation

npm i app-tracker

Registration & API Key

• Register at App Tracker and create an application to get your API key.

Quick Start

import { AppTracker, AppTrackerService } from "app-tracker";

const config = {
	userAgentOrOs: typeof window !== 'undefined' ? navigator.userAgent : require('os'),
	logInConsole: true,
	sendLogsInDevelopment: true,
	// more options below
};
const tracker: AppTrackerService = AppTracker.init("API_KEY", config);

tracker.debug("Debug message", { foo: "bar" });
tracker.error("An error occurred", errorObj);

Configuration

| Property | Type | Default | Description | |-----------------------------|--------------|--------------------------------|-------------| | sendLogsInDevelopment | boolean | false | Send logs during development | | logInConsole | boolean | false | Also log to the console | | endpointUrl | string | https://app-tracker-api.azurewebsites.net/ | Target endpoint for logs | | maxSendTries | number | 5 | Max. send attempts on error | | retryDelayMs | number | 10000 | Delay between send attempts in milliseconds | | requestTimeoutMs | number | 10000 | Timeout for each HTTP attempt in milliseconds | | maxLogsCount | number | 10 | Batch size for sending logs | | logLevel | LogType[] | [LogType.error] | Which log types are sent | | sendLogsByTypesImmediately | LogType[] | [LogType.error, LogType.critical] | Types sent immediately | | userAgentOrOs | any | | Browser: navigator.userAgent, Node: require('os') |

LogType: debug, info, log, warn, error, critical

Architecture & Features

• Singleton Service: Always access via AppTracker.init() or AppTracker.getService()
• Batching: Logs are collected and sent after maxLogsCount or immediately for critical errors
• Explicit flush: Call and await tracker.flush() before a controlled Node.js shutdown
• Environment Awareness: Automatically adapts for browser/Node.js
• Browser correlation: Generates one in-memory correlation ID per page lifetime and includes it in every browser log batch. Node.js payloads do not include it. Use tracker.getCorrelationId() to display the current ID when needed.
• Secure Sending: API key required, retry mechanism on errors
• External Dependency: Uses cross-fetch for HTTP requests

Build & Development

• Build: npm run build (TypeScript compile & copy to lib/)
• Minify: npm run terser (Terser minification of JS files)
• Lint: npm run lint (TSLint)
• Format: npm run format (Prettier)

FAQ

Where do I get my API key?

Register at https://www.app-tracker.cloud/ and create an application.

How can I suppress logs in development?

Set sendLogsInDevelopment: false in the configuration.

How do I send custom log types?

Use the debug, info, warn, error, critical methods of the service object.

Further Information

• See src/app-tracker.service.ts for service logic
• See src/log.ts for configuration and log types
• See .github/copilot-instructions.md for developer guidelines