Debug logs faster.
Without leaving your machine.

npm install lognest-node

const LogNest = require('lognest-node')

const log = new LogNest({ service: 'api-gateway' })

// Use it anywhere
log.info('Server started', { port: 3000 })
log.warn('High memory', { usedMb: 512 })
log.error('Request failed', { userId, endpoint })

const LogNest = require('lognest-node')

// Add this one line at app startup
new LogNest({ service: 'my-app', patchConsole: true })

// All existing console calls now go to LogNest:
console.log('User logged in')   // → INFO
console.warn('Slow query')      // → WARN
console.error('DB timeout')     // → ERROR

// Attach metadata to every log in a request
app.use((req, res, next) => {
  req.log = log.child({
    requestId: req.id,
    userId:    req.user?.id,
  })
  next()
})

// Later in route handlers:
req.log.info('Checkout started')
// → metadata: {requestId, userId} auto-included

new LogNest({
  service:      'my-service',
  url:          'http://localhost:9000/logs', // default
  level:        'DEBUG',   // min level to send
  enabled:      true,
  patchConsole: false,
})

pip install lognest

import lognest
lognest.setup(service='ml-pipeline')

# All existing logging calls now go to LogNest:
import logging
logging.error('Model training failed')
logging.warning('Low disk space')
logging.info('Batch job completed')

LOGGING = {
    'version': 1,
    'handlers': {
        'lognest': {
            'class':   'lognest.LogNestHandler',
            'service': 'django-app',
        },
    },
    'root': {
        'handlers': ['lognest'],
        'level':    'DEBUG',
    },
}

from fastapi import FastAPI
import lognest, logging

# Add at top of main.py — done
lognest.setup(service='fastapi-app')
logger = logging.getLogger(__name__)

app = FastAPI()

@app.get('/checkout')
async def checkout(order_id: str):
    logger.info(f'Processing order {order_id}')
    # ... your existing code unchanged
    logger.error('Payment gateway timeout')

from lognest import LogNestHandler
import logging

handler = LogNestHandler(
    service='my-service',
    url='http://localhost:9000/logs',
)
handler.setLevel(logging.WARNING)  # only WARN+
logging.getLogger().addHandler(handler)

curl -X POST http://localhost:9000/logs \
  -H "Content-Type: application/json" \
  -d '{
    "level":    "ERROR",
    "service":  "payment-service",
    "message":  "Null pointer at PaymentController:42",
    "trace_id": "abc-123",
    "timestamp": 1710000000000,
    "metadata": {
      "userId":  "u1",
      "orderId": "o99"
    }
  }'

payload := map[string]interface{}{
    "level":   "ERROR",
    "service": "go-service",
    "message": err.Error(),
}
data, _ := json.Marshal(payload)
http.Post(
    "http://localhost:9000/logs",
    "application/json",
    bytes.NewBuffer(data),
)

require 'net/http'
require 'json'

uri = URI('http://localhost:9000/logs')
Net::HTTP.post(
  uri,
  { level: 'ERROR', service: 'rails-app',
    message: e.message }.to_json,
  'Content-Type' => 'application/json'
)

$ch = curl_init('http://localhost:9000/logs');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
    'level'   => 'ERROR',
    'service' => 'php-app',
    'message' => $e->getMessage(),
]));
curl_setopt($ch, CURLOPT_HTTPHEADER,
    ['Content-Type: application/json']);
curl_exec($ch);

# Legacy app — forward stderr + stdout
./my-legacy-app 2>&1 | python lognest-agent.py pipe \
  --service legacy-app

# Docker container (live)
docker logs -f my-container | python lognest-agent.py pipe \
  --service my-container

# systemd journal
journalctl -f -u my-service | python lognest-agent.py pipe \
  --service my-service

# nginx access log via tail
tail -f /var/log/nginx/access.log | python lognest-agent.py pipe \
  --service nginx-access