@sygnl/health-check

Production-ready health check framework with status aggregation and dependency tracking.

Install

npm install @sygnl/health-check

Quick Start

import { HealthChecker } from '@sygnl/health-check';

const health = new HealthChecker();

// Register checks
health.register('database', async () => {
  const connected = await db.ping();
  return { healthy: connected };
});

health.register('redis', async () => {
  const ok = await redis.ping();
  return { healthy: ok };
});

// Run all checks
const result = await health.check();
console.log(result.status); // 'healthy' | 'degraded' | 'unhealthy'

Features

• Parallel check execution
• Status aggregation (healthy, degraded, unhealthy)
• Critical vs non-critical checks
• Built-in common checks (HTTP, exists, condition)
• Response time tracking
• Type-safe with TypeScript

API

HealthChecker

const health = new HealthChecker({
  timeout: 5000,        // Default timeout per check (ms)
  parallel: true        // Run checks in parallel
});

// Register a check
health.register('api', async () => ({
  healthy: true,
  message: 'API is responsive'
}));

// Run all checks
const result = await health.check();

// Run specific checks
const result = await health.check(['database', 'redis']);

Common Checks

import { checkHttp, checkExists, checkCondition } from '@sygnl/health-check';

// HTTP endpoint check
health.register('api', checkHttp('https://api.example.com/health'));

// Check value exists
health.register('config', checkExists(process.env.API_KEY, 'API key missing'));

// Custom condition
health.register('memory', checkCondition(
  () => process.memoryUsage().heapUsed < 500_000_000,
  'Memory usage too high'
));

Result Format

{
  status: 'healthy',           // Overall status
  timestamp: 1234567890,       // Unix timestamp
  checks: {
    database: {
      status: 'healthy',
      responseTime: 45,        // ms
      message: 'Connected'
    },
    redis: {
      status: 'healthy',
      responseTime: 12
    }
  }
}

License

Apache-2.0

Copyright 2026 Edge Foundry, Inc.