Inbound

Overview

@kubiks/otel-inbound provides comprehensive OpenTelemetry instrumentation for inbound HTTP requests. Automatically trace all incoming requests to your application with detailed metadata about request/response cycles, headers, status codes, and performance metrics.

Visualize every inbound HTTP request with detailed span information including URL, method, headers, response status, and timing.

Installation

npm install @kubiks/otel-inbound

Peer Dependencies: @opentelemetry/api >= 1.9.0

Supported Frameworks

Works with any TypeScript framework and Node.js runtime:

Next.js

App Router & Pages Router

Fastify

High-performance server

NestJS

Enterprise framework

Express

Classic Node.js server

Remix

Full-stack framework

SvelteKit

Modern web framework

Supported Platforms

Works with any observability platform that supports OpenTelemetry:

Kubiks
Sentry
Axiom
Datadog
New Relic
SigNoz
And many more…

Quick Start

Use InboundInstrumentation to automatically trace all incoming HTTP requests:

import { InboundInstrumentation } from '@kubiks/otel-inbound';
import { registerOTel } from '@vercel/otel';

// Register OpenTelemetry with Inbound instrumentation
export function register() {
  registerOTel({
    serviceName: 'your-app',
    instrumentations: [
      new InboundInstrumentation(),
    ],
  });
}

// That's it! All inbound HTTP requests are now automatically traced

This is zero-config—just add the instrumentation and all inbound requests are automatically traced with no code changes required!

Configuration Options

new InboundInstrumentation({
  captureHeaders: true,           // Capture request/response headers (default: true)
  captureBody: false,            // Capture request/response body (default: false)
  maxBodyLength: 1000,           // Max body length to capture (default: 1000)
  ignorePaths: ['/health'],      // Paths to ignore (default: [])
  ignoreUserAgents: [],          // User agents to ignore (default: [])
  captureQueryString: true,      // Include query strings (default: true)
})

By default, headers and query strings are captured but not request/response bodies. Enable captureBody carefully as it can expose sensitive data.

What You Get

Each inbound HTTP request automatically creates a span with rich telemetry data:

Span Information

Span name: HTTP method + route (e.g., GET /api/users)
HTTP method: GET, POST, PUT, DELETE, etc.
URL: Full request URL including query parameters
Route: Matched route pattern
Status code: Response status code (200, 404, 500, etc.)
Duration: Total request/response time

Request Details

Request headers (configurable)
Query parameters
Request body (optional)
User agent
Client IP address
Content type and length

Response Details

Response status code
Response headers (configurable)
Response body (optional)
Content type and length

Performance Metrics

Total request duration
Time to first byte
Response size

Error Tracking

Exceptions are recorded with stack traces
Proper span status (OK, ERROR)
Error messages and HTTP status codes
Failed request details

Span Attributes

The instrumentation adds the following attributes to each span following OpenTelemetry semantic conventions:

Attribute	Description	Example
`http.method`	HTTP method	`GET`
`http.url`	Full URL	`https://api.example.com/users?page=1`
`http.route`	Route pattern	`/api/users`
`http.status_code`	Response status	`200`
`http.user_agent`	Client user agent	`Mozilla/5.0...`
`http.client_ip`	Client IP	`192.168.1.1`
`http.request_content_length`	Request size (bytes)	`1024`
`http.response_content_length`	Response size (bytes)	`2048`

Usage Examples

Basic HTTP Tracing

Next.js App Router

// app/api/users/route.ts
import { NextRequest, NextResponse } from 'next/server';

// All requests are automatically traced
export async function GET(request: NextRequest) {
  const users = await fetchUsers();
  return NextResponse.json(users);
}

export async function POST(request: NextRequest) {
  const body = await request.json();
  const user = await createUser(body);
  return NextResponse.json(user, { status: 201 });
}

Next.js Pages Router

// pages/api/users.ts
import type { NextApiRequest, NextApiResponse } from 'next';

// All requests are automatically traced
export default async function handler(
  req: NextApiRequest,
  res: NextApiResponse
) {
  if (req.method === 'GET') {
    const users = await fetchUsers();
    return res.status(200).json(users);
  }
  
  if (req.method === 'POST') {
    const user = await createUser(req.body);
    return res.status(201).json(user);
  }
  
  return res.status(405).json({ error: 'Method not allowed' });
}

Custom Configuration

import { InboundInstrumentation } from '@kubiks/otel-inbound';
import { registerOTel } from '@vercel/otel';

export function register() {
  registerOTel({
    serviceName: 'your-app',
    instrumentations: [
      new InboundInstrumentation({
        // Capture headers except sensitive ones
        captureHeaders: true,
        
        // Don't trace health checks
        ignorePaths: ['/health', '/ping', '/metrics'],
        
        // Don't trace monitoring bots
        ignoreUserAgents: ['UptimeRobot', 'Pingdom'],
        
        // Capture query strings for analytics
        captureQueryString: true,
        
        // Don't capture request bodies (may contain sensitive data)
        captureBody: false,
      }),
    ],
  });
}

Error Handling

// app/api/error-test/route.ts
import { NextRequest, NextResponse } from 'next/server';

export async function GET(request: NextRequest) {
  try {
    // This error will be captured in the trace
    throw new Error('Something went wrong');
  } catch (error) {
    // Error details are automatically added to the span
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 }
    );
  }
}

Complete Integration Example

Here’s a complete example with Inbound instrumentation in a Next.js application:

instrumentation.ts

import { registerOTel } from '@vercel/otel';
import { InboundInstrumentation } from '@kubiks/otel-inbound';

export function register() {
  registerOTel({
    serviceName: 'my-next-app',
    instrumentations: [
      new InboundInstrumentation({
        captureHeaders: true,
        ignorePaths: ['/health', '/_next'],
        captureQueryString: true,
      }),
    ],
  });
}

app/api/users/[id]/route.ts

import { NextRequest, NextResponse } from 'next/server';

// GET /api/users/123 - automatically traced
export async function GET(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  const user = await fetchUser(params.id);
  
  if (!user) {
    return NextResponse.json(
      { error: 'User not found' },
      { status: 404 }
    );
  }
  
  return NextResponse.json(user);
}

// PUT /api/users/123 - automatically traced
export async function PUT(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  const body = await request.json();
  const user = await updateUser(params.id, body);
  
  return NextResponse.json(user);
}

// DELETE /api/users/123 - automatically traced
export async function DELETE(
  request: NextRequest,
  { params }: { params: { id: string } }
) {
  await deleteUser(params.id);
  
  return NextResponse.json({ success: true });
}

Best Practices

Filter Sensitive Data

Be careful with capturing headers and bodies:

new InboundInstrumentation({
  captureHeaders: true,
  captureBody: false, // Bodies may contain sensitive data
  // Filter sensitive headers in your collector/exporter
})

Ignore Health Checks

Exclude monitoring endpoints to reduce noise:

new InboundInstrumentation({
  ignorePaths: [
    '/health',
    '/ping',
    '/metrics',
    '/_next/static',
  ],
})

Monitor Performance

Use traces to identify slow endpoints and optimize them:

Look for high-duration spans
Identify N+1 query problems
Optimize database queries
Add caching where appropriate

Set Up Alerts

Configure alerts for high error rates or slow responses based on span data.

Performance Considerations

Minimal Overhead

The instrumentation adds minimal overhead (~1ms per request) for tracing operations.

Sampling

Use sampling for high-traffic applications:

import { TraceIdRatioBasedSampler } from '@opentelemetry/sdk-trace-base';

registerOTel({
  serviceName: 'your-app',
  sampler: new TraceIdRatioBasedSampler(0.1), // Sample 10% of traces
});

Ignore Static Assets

Don’t trace static assets to reduce volume:

new InboundInstrumentation({
  ignorePaths: [
    '/_next/static',
    '/static',
    '/favicon.ico',
    '/*.png',
  ],
})

Troubleshooting

Spans Not Appearing

Ensure OpenTelemetry is initialized before the server starts:

// In instrumentation.ts or instrumentation.node.ts
export function register() {
  registerOTel({
    serviceName: 'your-app',
    instrumentations: [new InboundInstrumentation()],
  });
}

Headers Not Captured

Check that captureHeaders is enabled:

new InboundInstrumentation({
  captureHeaders: true,
})

Some Paths Not Traced

Check if they’re in the ignore list:

new InboundInstrumentation({
  ignorePaths: ['/health'], // These paths won't be traced
})

Too Many Spans

Consider sampling or ignoring more paths:

new InboundInstrumentation({
  ignorePaths: [
    '/health',
    '/_next',
    '/static',
  ],
})

Resources

OpenTelemetry HTTP Conventions

Learn about HTTP semantic conventions

GitHub Repository

View source code and examples

npm Package

View package on npm

Report Issues

Found a bug? Let us know!

License

MIT

Frameworks

Vercel

OpenTelemetry Integrations

Overview

Installation

Supported Frameworks

Next.js

Fastify

NestJS

Express

Remix

SvelteKit

Supported Platforms

Quick Start

Configuration Options

What You Get

Span Attributes

Usage Examples

Basic HTTP Tracing

Custom Configuration

Error Handling

Complete Integration Example

Best Practices

Performance Considerations

Troubleshooting

Resources

OpenTelemetry HTTP Conventions

GitHub Repository

npm Package

Report Issues

License

Frameworks

Vercel

OpenTelemetry Integrations

​Overview

​Installation

​Supported Frameworks

Next.js

Fastify

NestJS

Express

Remix

SvelteKit

​Supported Platforms

​Quick Start

​Configuration Options

​What You Get

​Span Attributes

​Usage Examples

​Basic HTTP Tracing

​Custom Configuration

​Error Handling

​Complete Integration Example

​Best Practices

​Performance Considerations

​Troubleshooting

​Resources

OpenTelemetry HTTP Conventions

GitHub Repository

npm Package

Report Issues

​License

Overview

Installation

Supported Frameworks

Supported Platforms

Quick Start

Configuration Options

What You Get

Span Attributes

Usage Examples

Basic HTTP Tracing

Custom Configuration

Error Handling

Complete Integration Example

Best Practices

Performance Considerations

Troubleshooting

Resources

License