webhook-mcp-server 2.1.0

MCP Server for webhook.site API integration with layered architecture

Webhook.site MCP Server

A Model Context Protocol (MCP) server for webhook.site - instantly capture HTTP requests, emails, and DNS lookups. Perfect for testing webhooks, debugging API callbacks, security testing, and bug bounty hunting.

Quick Start

Installation

# Using uvx (recommended - no install needed)
uvx webhook-mcp-server

# Or install via pip
pip install webhook-mcp-server

VS Code / GitHub Copilot

Add to .vscode/mcp.json:

{
  "servers": {
    "webhook-mcp-server": {
      "type": "stdio",
      "command": "uvx",
      "args": ["webhook-mcp-server"]
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "webhook-mcp-server": {
      "command": "uvx",
      "args": ["webhook-mcp-server"]
    }
  }
}

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What Can You Do?

Capture Webhooks

"Create a webhook and show me the URL"
"What requests have been sent to my webhook?"
"Wait for a request to come in"

Receive Emails

"Give me a temporary email address"
"Wait for a password reset email and extract the link"
"Check if any emails arrived"

Bug Bounty Testing

"Generate SSRF payloads for testing"
"Create an XSS callback to detect blind XSS"
"Check if any out-of-band callbacks came in"

Canary Tokens

"Create a canary URL to track document access"
"Generate a DNS canary for the config file"
"Set up an email tracker pixel"

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Tools Reference

Webhook Management

Tool	Description
create_webhook	Create a new webhook endpoint
create_webhook_with_config	Create with custom response, status, CORS, timeout
get_webhook_url	Get the full URL for a webhook token
get_webhook_email	Get the email address for a webhook
get_webhook_dns	Get the DNS subdomain for a webhook
get_webhook_info	Get webhook settings and statistics
update_webhook	Modify webhook configuration
delete_webhook	Delete a webhook endpoint

Request Handling

Tool	Description
send_to_webhook	Send JSON data to a webhook
get_webhook_requests	List all captured requests
search_requests	Search with filters (method, content, date)
delete_request	Delete a specific request
delete_all_requests	Bulk delete with filters

Real-Time Waiting

Tool	Description
wait_for_request	Wait for an HTTP request (polling)
wait_for_email	Wait for email with automatic link extraction

Bug Bounty / Security

Tool	Description
generate_ssrf_payload	Create SSRF test payloads (HTTP, DNS, IP-based)
generate_xss_callback	Create XSS callback payloads with cookie/DOM capture
generate_canary_token	Create trackable URLs, DNS, or email canaries
check_for_callbacks	Quick check for OOB callbacks
extract_links_from_request	Extract URLs from captured requests

Batch & Utility

Tool	Description
send_multiple_requests	Send batch of requests for load testing
clone_webhook	Copy webhook with all settings
export_webhook_data	Export all requests to JSON

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Examples

Create a Webhook

// Response from create_webhook
{
  "token": "abc123-def456-...",
  "url": "https://webhook.site/abc123-def456-...",
  "email": "[e-mail]",
  "dns": "abc123-def456-....dnshook.site"
}

Wait for Password Reset Email

// Response from wait_for_email
{
  "email_received": true,
  "subject": "Password Reset Request",
  "from": "[e-mail]",
  "links_found": ["https://example.com/reset?token=xyz789"]
}

SSRF Testing Payload

// Response from generate_ssrf_payload
{
  "payloads": {
    "http": "https://webhook.site/token?id=ssrf-test",
    "dns": "ssrf-test.token.dnshook.site",
    "ip_decimal": "http://2130706433/token",
    "ip_hex": "http://0x7f000001/token"
  }
}

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Each Webhook Token Provides

Endpoint	Format	Use Case
HTTP URL	https://webhook.site/{token}	Capture HTTP/HTTPS requests
Subdomain	https://{token}.webhook.site	Alternative URL format
Email	{token}@email.webhook.site	Capture incoming emails
DNS	{token}.dnshook.site	Capture DNS lookups

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Architecture

webhook-mcp-server/
├── server.py              # MCP entry point
├── handlers/              # Tool routing layer
├── services/              # Business logic
│   ├── webhook_service.py # Webhook CRUD
│   ├── request_service.py # Request management
│   └── bugbounty_service.py # Security payloads
├── models/                # Tool definitions & schemas
└── utils/                 # HTTP client, logging, validation

Key Features

• Async Architecture - Non-blocking I/O for optimal performance
• Retry Logic - Exponential backoff for transient failures
• Input Validation - UUID validation, parameter sanitization
• Structured Logging - JSON logs for debugging and monitoring
• Type Safety - Full type hints throughout

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Development

Setup

git clone https://github.com/zebbern/webhook-mcp-server.git
cd webhook-mcp-server
pip install -e ".[dev]"

Run Tests

pytest tests/ -v

Run Locally

python server.py

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Requirements

• Python 3.10+
• mcp >= 1.0.0
• httpx >= 0.25.0

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Changelog

See CHANGELOG.md for version history.

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Links

• 📦 PyPI Package
• 🐙 GitHub Repository
• 🌐 webhook.site - The service this MCP wraps
• 📖 Model Context Protocol - MCP specification

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