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Getting Started

This guide will help you get started with Crashless in minutes.

Installation​

npm install crashless

Basic Setup​

The simplest way to use Crashless is with default settings:

import express from 'express';
import crashless from 'crashless';

const app = express();

// One line setup
app.use(crashless());

// Your routes - errors automatically caught
app.get('/users/:id', async (req, res) => {
  const user = await db.getUser(req.params.id);
  res.json(user);
});

app.listen(3000);

That's it! Your server is now protected from crashes.

Access Dashboard: http://localhost:3000/_crashless

What Happens Now?​

Automatic Error Handling​

All errors are caught automatically:

// Async errors - automatically caught
app.get('/data', async (req, res) => {
  const data = await fetchData(); // If this throws, Crashless catches it
  res.json(data);
});

// Sync errors - also caught
app.get('/test', (req, res) => {
  throw new Error('Test error'); // Automatically handled
});

Standardized Error Responses​

Errors are returned in a consistent format:

{
  "success": false,
  "message": "Error message",
  "code": "ERR_500"
}

Built-in Dashboard​

Visit http://localhost:3000/_crashless to see:

  • Real-time request metrics
  • Error analytics
  • Performance insights
  • Distributed traces

Common Configurations​

Minimal (Error Handling Only)​

For high-traffic applications needing only error handling:

app.use(crashless({
  telemetry: { engine: 'none' }
}));

Overhead: ~3% vs plain Express

Standard Production​

For most production applications:

app.use(crashless({
  telemetry: { engine: 'builtin' }
}));

Overhead: ~20% vs plain Express

Full Observability​

For debugging and development:

app.use(crashless({
  telemetry: {
    engine: 'builtin',
    traces: {
      enabled: true,
      samplingRate: 0.2 // Sample 20% of requests
    }
  }
}));

Overhead: ~27% vs plain Express

Next Steps​