MCP Cloudflare CrunchTools

A secure MCP (Model Context Protocol) server for Cloudflare DNS, Transform Rules, Page Rules, and cache management.

Overview

This MCP server is designed to be:

• Secure by default - Threat modeling, input validation, and token protection
• No third-party services - Runs locally via stdio, your API token never leaves your machine
• Cross-platform - Works on Linux, macOS, and Windows
• Automatically updated - GitHub Actions monitor for CVEs and update dependencies
• Containerized - Available at quay.io/crunchtools/mcp-cloudflare built on Hummingbird Python base image

Naming Convention

Why Hummingbird?

The container image is built on the Hummingbird Python base image from Project Hummingbird, which provides:

• Minimal CVE exposure - Hummingbird images are built with a minimal package set, dramatically reducing the attack surface compared to general-purpose images
• Regular updates - Security patches are applied promptly, keeping CVE counts low
• Optimized for Python - Pre-configured Python environment with uv package manager for fast, reproducible builds
• Production-ready - Designed for production workloads with proper signal handling and non-root user defaults

This means your MCP server runs in a hardened environment with fewer vulnerabilities than typical Python container images

Features

Zone Management (2 tools)

• list_zones - List all zones accessible by your API token
• get_zone - Get zone details by ID or domain name

DNS Records (5 tools)

• list_dns_records - List DNS records with filtering
• get_dns_record - Get a single DNS record
• create_dns_record - Create A, AAAA, CNAME, MX, TXT, NS, SRV, CAA records
• update_dns_record - Update existing records
• delete_dns_record - Delete records

Transform Rules (6 tools)

• list_request_header_rules / set_request_header_rules - Modify request headers
• list_response_header_rules / set_response_header_rules - Modify response headers
• list_url_rewrite_rules / set_url_rewrite_rules - URL path/query rewrites

Page Rules (4 tools)

• list_page_rules - List all page rules
• create_page_rule - Create redirects, cache settings, SSL modes
• update_page_rule - Modify existing rules
• delete_page_rule - Remove rules

Access (8 tools)

• get_access_organization - The Zero Trust organization and its team login domain
• list_access_apps / get_access_app - Applications on a zone, with their audience tags
• create_access_app / delete_access_app - Put a hostname behind an Access login, or take it out
• list_access_policies - Who an application admits
• create_access_policy / delete_access_policy - Allow, deny or bypass by email, email domain, IP or everyone

Cache Management (1 tool)

• purge_cache - Purge by URL, tag, host, prefix, or everything

Installation

With uvx (Recommended)

uvx mcp-cloudflare-crunchtools

With pip

pip install mcp-cloudflare-crunchtools

With Container

podman run -e CLOUDFLARE_API_TOKEN=your_token \
    quay.io/crunchtools/mcp-cloudflare

Configuration

Creating a Cloudflare API Token

1. Navigate to API Tokens

   • Go to https://dash.cloudflare.com/profile/api-tokens
   • Click "Create Token"
   • Click "Get started" next to "Create Custom Token"

2. Configure Token Name

   • Enter: mcp-cloudflare-crunchtools

3. Configure Permissions

   The Permissions section has three dropdowns per row:

   • First dropdown: Resource type (Account or Zone)
   • Second dropdown: Specific permission category
   • Third dropdown: Access level (Read or Edit)

   Click "+ Add more" to add each permission row. For full management, add:

   Resource	Permission	Access
   Zone	Zone	Read
   Zone	DNS	Edit
   Zone	Page Rules	Edit
   Zone	Transform Rules	Edit
   Zone	Cache Purge	Purge
   Account	Access: Apps and Policies	Edit
   Account	Access: Organizations, Identity Providers, and Groups	Read

4. Configure Zone Resources

   • First dropdown: Select "Include"
   • Second dropdown: Select "All zones" or "Specific zone"

5. Configure Client IP Address Filtering (Optional)

   • Click "Use my IP" button to restrict token to your current IP

6. Create and Copy Token

   • Click "Continue to summary" → "Create Token"
   • IMPORTANT: Copy the token immediately - it's only shown once!

Add to Claude Code

claude mcp add mcp-cloudflare-crunchtools \
    --env CLOUDFLARE_API_TOKEN=your_token_here \
    -- uvx mcp-cloudflare-crunchtools

Or for the container version:

claude mcp add mcp-cloudflare-crunchtools \
    --env CLOUDFLARE_API_TOKEN=your_token_here \
    -- podman run -i --rm -e CLOUDFLARE_API_TOKEN quay.io/crunchtools/mcp-cloudflare

Permission Sets by Use Case

Read-Only (viewing only)

DNS Management Only

Full Management (all features)

Usage Examples

List Your Zones

User: List my Cloudflare zones
Assistant: [calls list_zones]

Create a DNS Record

User: Create an A record for www.example.com pointing to 192.168.1.1
Assistant: [calls create_dns_record with type=A, name=www, content=192.168.1.1]

Add Security Headers

User: Add X-Content-Type-Options: nosniff to all responses for zone abc123...
Assistant: [calls set_response_header_rules with appropriate rule]

Purge Cache

User: Purge the cache for https://example.com/styles.css
Assistant: [calls purge_cache with files=["https://example.com/styles.css"]]

Security

This server was designed with security as a primary concern. See SECURITY.md for:

• Threat model and attack vectors
• Defense in depth architecture
• Token handling best practices
• Input validation rules
• Audit logging

Key Security Features

1. Token Protection

   • Stored as SecretStr (never accidentally logged)
   • Environment variable only (never in files or args)
   • Sanitized from all error messages

2. Input Validation

   • Pydantic models for all inputs
   • Allowlist for record types, actions
   • Strict format validation for IDs

3. API Hardening

   • Hardcoded API base URL (prevents SSRF)
   • TLS certificate validation
   • Request timeouts
   • Response size limits

4. Automated CVE Scanning

   • GitHub Actions scan dependencies weekly
   • Automatic PRs for security updates
   • Dependabot alerts enabled

Development

Setup

git clone https://github.com/crunchtools/mcp-cloudflare.git
cd mcp-cloudflare
uv sync

Run Tests

uv run pytest

Lint and Type Check

uv run ruff check src tests
uv run mypy src

Build Container

podman build -t mcp-cloudflare .

License

AGPL-3.0-or-later

Contributing

Contributions welcome! Please read SECURITY.md before submitting security-related changes.

Links

• Cloudflare API Documentation
• FastMCP Documentation
• MCP Specification
• crunchtools.com