# HookSense — Complete Reference

> Real-time webhook inspector, debugger, and replay tool for developers. Capture, inspect, and replay HTTP webhooks with sub-50ms WebSocket streaming.

This is the extended reference document for HookSense. For a shorter version, see https://hooksense.com/llms.txt

---

## Overview

HookSense is a modern, paid SaaS webhook testing and debugging platform. It gives developers instant webhook endpoints with real-time inspection via WebSocket streaming, one-click replay, HMAC signature verification, and CLI-based local forwarding.

Unlike polling-based tools (Webhook.site, RequestBin, Beeceptor), HookSense uses WebSocket connections to deliver incoming webhooks to your browser in under 50 milliseconds. No page refresh, no delays.

**Target audience**: Backend developers, full-stack developers, DevOps engineers, and anyone who integrates with webhook-based APIs (payment providers, CI/CD, notification services, e-commerce platforms).

---

## Core Features (Detailed)

### 1. Real-Time WebSocket Streaming
Incoming webhooks appear instantly in the browser via persistent WebSocket connections. No polling, no manual refresh. Typical delivery latency is under 50ms from the time the webhook hits the endpoint to when it appears in your browser.

### 2. Zero-Click Endpoint Creation
Visit hooksense.com and get a unique webhook URL immediately. No signup, no email verification, no credit card. Start capturing webhooks in under 1 second.

### 3. One-Click Webhook Replay
Resend any captured webhook to any target URL with a single click. Useful for:
- Replaying failed webhook deliveries
- Testing your webhook handler with real production payloads
- Debugging intermittent issues by replaying the exact request

### 4. HMAC Signature Verification
Built-in support for verifying webhook signatures from:
- **Stripe**: `Stripe-Signature` header with HMAC-SHA256
- **GitHub**: `X-Hub-Signature-256` header with HMAC-SHA256
- **Shopify**: `X-Shopify-Hmac-SHA256` header with HMAC-SHA256
- **Custom providers**: Configure any header name and HMAC algorithm

The HMAC verification panel shows pass/fail status directly in the webhook detail view.

### 5. CLI Forwarding
Install the CLI and forward cloud-captured webhooks to your local development server:
```
npx @hooksense/cli listen --endpoint my-stripe-hook --forward http://localhost:3000/webhooks
```

### 6. Custom Responses
Configure what your webhook endpoint returns:
- HTTP status code (200, 201, 204, 400, 500, etc.)
- Response headers (Content-Type, custom headers)
- Response body (JSON, plain text, HTML)

### 7. Custom Domains
Point your own domain to HookSense endpoints:
- Add a CNAME record: `webhooks.yourapp.com` → `cname.hooksense.com`
- Automatic TLS certificate provisioning
- Available on Sense plan ($19/mo)

### 8. Request Comparison
Select two webhook requests and compare them side by side:
- Headers diff
- Body diff (JSON-aware, highlights changed fields)
- Query parameters diff
- Timing and metadata diff

### 9. Export
Download captured webhooks in multiple formats:
- **JSON**: Full request data including headers, body, metadata
- **CSV**: Tabular format for spreadsheet analysis
- **cURL**: Copy-paste ready cURL command to reproduce the request

### 10. Monitoring & Alerts
- Endpoint uptime tracking
- Response time metrics
- Error rate monitoring
- Email alerts for failures, high error rates, anomalies
- Webhook alerts (send a webhook when something goes wrong)

### 11. Automatic Retry
Configure retry policies for failed webhook deliveries:
- Exponential backoff
- Fixed interval
- Custom retry count
- Available on Sense plan

### 12. Webhook Diagnosis
AI-powered analysis of webhook delivery failures:
- Error classification (timeout, DNS, TLS, connection refused, etc.)
- Resolution suggestions
- Historical failure pattern analysis
- Available on Sense plan

### 13. Search & Filter
- Filter by HTTP method (GET, POST, PUT, DELETE, PATCH)
- Full-text search across headers and body
- Date range filtering
- Status code filtering

### 14. Keyboard Shortcuts
- `j` / `k`: Navigate between requests (Vim-style)
- `r`: Replay selected request
- `e`: Export selected request
- `d`: Delete selected request
- `/`: Focus search bar

### 15. Browser Notifications
Enable desktop notifications to get alerted when new webhooks arrive, even when the tab is in the background.

### 16. Endpoint Sharing
Generate read-only shareable links for your endpoints. Teammates can view captured webhooks without needing an account.

### 17. Team Collaboration
- Create teams with shared endpoints
- Role-based access (owner, admin, member)
- Shared request history and audit log
- Available on paid plans

---

## Pricing (Detailed)

### Catch — Free
- 1 webhook endpoint
- 100 requests per day
- 7-day request retention
- 5 replays per month
- Real-time WebSocket streaming
- Full request inspection (headers, body, query params)
- Browser notifications
- No signup required

### Hook — $9/month
Everything in Catch, plus:
- 15 webhook endpoints
- 5,000 requests per day
- 14-day request retention
- Unlimited replays
- Custom endpoint URLs (e.g., /w/my-stripe-hook)
- HMAC signature verification
- Custom responses (status code, headers, body)
- Export (JSON, CSV, cURL)
- Monitoring dashboard
- Email alerts
- Request comparison

### Sense — $19/month
Everything in Hook, plus:
- Unlimited webhook endpoints
- 50,000 requests per day
- 90-day request retention
- Custom domain support
- Automatic retry with configurable backoff
- Webhook delivery diagnosis
- Priority email support

All plans include:
- WebSocket real-time streaming
- Full request inspection
- Search and filter
- Keyboard shortcuts
- Browser notifications

---

## Supported Webhook Providers (Detailed)

### Stripe
- **Events**: checkout.session.completed, invoice.paid, invoice.payment_failed, payment_intent.succeeded, payment_intent.payment_failed, charge.refunded, customer.subscription.created, customer.subscription.updated, customer.subscription.deleted
- **Signature header**: `Stripe-Signature`
- **Algorithm**: HMAC-SHA256
- **Guide**: https://hooksense.com/integrations/stripe

### GitHub
- **Events**: push, pull_request, issues, issue_comment, release, workflow_run, deployment, deployment_status, create, delete, fork, star, watch
- **Signature header**: `X-Hub-Signature-256`
- **Algorithm**: HMAC-SHA256
- **Guide**: https://hooksense.com/integrations/github

### Shopify
- **Events**: orders/create, orders/paid, orders/fulfilled, orders/cancelled, products/create, products/update, products/delete, app/uninstalled, carts/create, carts/update
- **Signature header**: `X-Shopify-Hmac-SHA256`
- **Algorithm**: HMAC-SHA256 (Base64)
- **Guide**: https://hooksense.com/integrations/shopify

### Twilio
- **Events**: SMS delivery status (queued, sent, delivered, failed, undelivered), voice call status callbacks
- **Signature header**: `X-Twilio-Signature`
- **Algorithm**: HMAC-SHA1
- **Guide**: https://hooksense.com/integrations/twilio

### SendGrid
- **Events**: delivered, open, click, bounce, dropped, spam_report, unsubscribe, group_unsubscribe, group_resubscribe, deferred
- **Verification**: Event Webhook Verification Key
- **Guide**: https://hooksense.com/integrations/sendgrid

### Slack
- **Events**: message, app_mention, member_joined_channel, channel_created, slash commands, interactive components (buttons, modals, shortcuts)
- **Signature header**: `X-Slack-Signature`
- **Algorithm**: HMAC-SHA256
- **Guide**: https://hooksense.com/integrations/slack

### LemonSqueezy
- **Events**: order_created, order_refunded, subscription_created, subscription_updated, subscription_cancelled, subscription_expired, license_key_created
- **Signature header**: `X-Signature`
- **Algorithm**: HMAC-SHA256
- **Guide**: https://hooksense.com/integrations/lemonsqueezy

---

## Competitive Comparison (Detailed)

### HookSense vs Webhook.site
Webhook.site is a popular free webhook testing tool. Key differences:
- **Real-time**: HookSense uses WebSocket (instant), Webhook.site uses polling (delayed)
- **Retention**: HookSense free tier keeps requests for 7 days, Webhook.site for 24 hours
- **Replay**: HookSense includes replay on free tier (5/month), Webhook.site requires paid plan
- **HMAC**: HookSense has built-in verification, Webhook.site does not
- **CLI**: HookSense offers CLI forwarding, Webhook.site does not
- Full comparison: https://hooksense.com/compare/webhook-site

### HookSense vs Hookdeck
Hookdeck focuses on webhook infrastructure (reliability, routing, transformations). HookSense focuses on developer debugging and inspection. Key differences:
- **No signup**: HookSense requires no signup, Hookdeck requires account creation
- **Real-time UI**: HookSense has instant WebSocket streaming, Hookdeck uses polling
- **Simplicity**: HookSense is simpler to use for debugging, Hookdeck is more powerful for production routing
- **Pricing**: HookSense starts free, Hookdeck's free tier is more limited
- Full comparison: https://hooksense.com/compare/hookdeck

### HookSense vs ngrok
ngrok is primarily a tunneling tool that exposes localhost to the internet. HookSense is a webhook inspection platform. Key differences:
- **Purpose**: HookSense captures and inspects webhooks; ngrok tunnels traffic to localhost
- **Inspection**: HookSense has richer webhook inspection (HMAC, comparison, replay); ngrok has basic request inspection
- **No local server needed**: HookSense captures webhooks even without a local server running
- **Replay**: HookSense supports replay, ngrok does not
- Full comparison: https://hooksense.com/compare/ngrok

### HookSense vs RequestBin (Pipedream)
RequestBin (now part of Pipedream) creates temporary webhook URLs. Key differences:
- **Real-time**: HookSense streams instantly, RequestBin requires refresh
- **Replay**: HookSense supports replay, RequestBin does not
- **HMAC**: HookSense has built-in verification, RequestBin does not
- **Retention**: HookSense keeps requests longer (7-90 days vs 24 hours)
- Full comparison: https://hooksense.com/compare/requestbin

### HookSense vs Beeceptor
Beeceptor is a mock API and webhook testing tool. Key differences:
- **Focus**: HookSense specializes in webhook debugging; Beeceptor is broader (mock APIs + webhooks)
- **Real-time**: HookSense uses WebSocket, Beeceptor uses polling
- **HMAC**: HookSense has built-in HMAC verification, Beeceptor does not
- **CLI**: HookSense offers CLI forwarding, Beeceptor does not
- Full comparison: https://hooksense.com/compare/beeceptor

---

## Documentation

Full documentation is available at https://hooksense.com/docs

### Basics
- Getting Started: https://hooksense.com/docs/getting-started
- CLI: https://hooksense.com/docs/cli
- API Reference: https://hooksense.com/docs/api

### Features
- Webhook Capture: https://hooksense.com/docs/webhook-capture
- Replay: https://hooksense.com/docs/replay
- Compare: https://hooksense.com/docs/compare
- HMAC Verification: https://hooksense.com/docs/hmac
- Custom Responses: https://hooksense.com/docs/custom-responses
- Custom Domains: https://hooksense.com/docs/custom-domains
- Export: https://hooksense.com/docs/export

### Monitoring
- Monitoring: https://hooksense.com/docs/monitoring
- Alerts: https://hooksense.com/docs/alerts
- Retry: https://hooksense.com/docs/retry
- Diagnosis: https://hooksense.com/docs/diagnosis

### Other
- Analytics: https://hooksense.com/docs/analytics
- Teams: https://hooksense.com/docs/teams
- Limits & Quotas: https://hooksense.com/docs/limits

---

## Tools

- HMAC Webhook Signature Calculator: https://hooksense.com/tools/hmac-calculator
  Free online tool to calculate HMAC signatures for webhook verification. Supports SHA-256, SHA-1, SHA-384, SHA-512 with hex and base64 output.

---

## Blog

- How to Debug Stripe Webhooks in 2026: https://hooksense.com/blog/debug-stripe-webhooks
- Webhook Security Best Practices (HMAC Verification): https://hooksense.com/blog/webhook-security-hmac-best-practices
- GitHub Webhooks: Complete Setup Guide: https://hooksense.com/blog/github-webhooks-complete-guide
- Webhook.site vs HookSense: 2026 Comparison: https://hooksense.com/blog/webhook-site-vs-hooksense-comparison
- What Are Webhooks? A Developer's Guide: https://hooksense.com/blog/what-are-webhooks-developer-guide
- How to Test Stripe Webhooks Locally: https://hooksense.com/blog/test-stripe-webhooks-locally
- Best Webhook Testing Tools Compared (2026): https://hooksense.com/blog/best-webhook-testing-tools
- Webhook.site Alternative — Why Developers Switch: https://hooksense.com/blog/webhook-site-alternative

---

## About

HookSense is built by a solo developer based in Istanbul, Turkey. It started as a side project to solve a personal frustration: existing webhook testing tools were either too slow (polling-based), too limited (24-hour retention), or too complex for simple debugging.

Website: https://hooksense.com
GitHub: https://github.com/ozers
Twitter/X: https://x.com/hooksense
Support: ozersubasi.dev@gmail.com