Kafka Schema Registry MCP Server

A comprehensive Model Context Protocol (MCP) server that provides Claude Desktop and other MCP clients with tools for Kafka Schema Registry operations. Features advanced schema context support, multi-registry management, and comprehensive schema export capabilities.

🎯 True MCP Implementation: Uses modern FastMCP 2.8.0+ framework with full MCP 2025-06-18 specification compliance. Fully compatible with Claude Desktop and other MCP clients using JSON-RPC over stdio.

Latest Version: v2.1.3 | Docker: aywengo/kafka-schema-reg-mcp:stable

📋 Table of Contents

• 🚀 Quick Start
• ✨ Key Features
• 📦 Installation
• ⚙️ Configuration
• 💬 Usage Examples
• 🔒 Authentication & Security
• 📚 Documentation
• 🧪 Testing
• 🚀 Deployment
• 🤝 Contributing
• 🆕 What's New

🚀 Quick Start

1. Run with Docker (Recommended)

# Latest stable release
docker pull aywengo/kafka-schema-reg-mcp:stable

# Recommended: Run with SLIM_MODE for optimal performance (reduced essential tool set)
docker run -e SCHEMA_REGISTRY_URL=http://localhost:8081 -e SLIM_MODE=true aywengo/kafka-schema-reg-mcp:stable

# OR run with full feature set for administrators/SRE
docker run -e SCHEMA_REGISTRY_URL=http://localhost:8081 aywengo/kafka-schema-reg-mcp:stable

2. Configure Claude Desktop

Copy a ready-to-use configuration from config-examples/:

# macOS
cp config-examples/claude_desktop_stable_config.json ~/Library/Application\ Support/Claude/claude_desktop_config.json

# Linux  
cp config-examples/claude_desktop_stable_config.json ~/.config/claude-desktop/config.json

3. Start Using with Claude

Restart Claude Desktop and try these prompts:

• "List all schema contexts"
• "Show me the subjects in the production context"
• "Register a new user schema with fields for id, name, and email"

✨ Key Features

• 🤖 Claude Desktop Integration - Direct MCP integration with natural language interface
• 🏢 Multi-Registry Support - Manage up to 8 Schema Registry instances simultaneously
• 📋 Schema Contexts - Logical grouping for production/staging environment isolation
• 🔄 Schema Migration - Cross-registry migration with backup and verification
• 📊 Comprehensive Export - JSON, Avro IDL formats for backup and documentation
• 🔒 Production Safety - VIEWONLY mode and per-registry access control
• 🔐 OAuth 2.1 Authentication - Enterprise-grade security with scope-based permissions
• 📈 Real-time Progress - Async operations with progress tracking and cancellation
• 🔗 Resource Linking - HATEOAS navigation with enhanced tool responses
• 🧪 Full MCP Compliance - 57+ tools following MCP 2025-06-18 specification
• 🚀 SLIM_MODE - Reduce tool overhead from 57+ to ~9 essential tools for better LLM performance

📖 See detailed feature descriptions: docs/api-reference.md

📦 Installation

Option A: Docker (Recommended)

# Production stable
docker pull aywengo/kafka-schema-reg-mcp:stable

# Latest development  
docker pull aywengo/kafka-schema-reg-mcp:latest

# Specific version
docker pull aywengo/kafka-schema-reg-mcp:2.1.3

Running with SLIM_MODE

To reduce LLM overhead, run with SLIM_MODE enabled:

# Run with a reduced essential tool set
docker run -e SCHEMA_REGISTRY_URL=http://localhost:8081 -e SLIM_MODE=true aywengo/kafka-schema-reg-mcp:stable

💡 SLIM_MODE Benefits:

• Reduces tool count to an essential subset
• Significantly faster LLM response times
• Lower token usage and reduced costs
• Ideal for production read-only operations
• Maintains full remote deployment support

Option B: Local Python

git clone https://github.com/aywengo/kafka-schema-reg-mcp
cd kafka-schema-reg-mcp
pip install -r requirements.txt
python kafka_schema_registry_unified_mcp.py

Option C: Docker Compose

docker-compose up -d  # Includes Schema Registry for testing

📖 Detailed installation guide: docs/deployment.md

⚙️ Configuration

Single Registry Mode

export SCHEMA_REGISTRY_URL="http://localhost:8081"
export SCHEMA_REGISTRY_USER=""           # Optional
export SCHEMA_REGISTRY_PASSWORD=""       # Optional
export VIEWONLY="false"                  # Production safety
export SLIM_MODE="false"                 # Optional: Enable to reduce tool overhead (default: false)

Multi-Registry Mode (Up to 8 Registries)

# Development Registry
export SCHEMA_REGISTRY_NAME_1="development"
export SCHEMA_REGISTRY_URL_1="http://dev-registry:8081"
export VIEWONLY_1="false"

# Production Registry (with safety)
export SCHEMA_REGISTRY_NAME_2="production"  
export SCHEMA_REGISTRY_URL_2="http://prod-registry:8081"
export VIEWONLY_2="true"                     # Read-only protection

Claude Desktop Configuration

Pre-configured examples available in config-examples/:

📖 Complete configuration guide: config-examples/README.md

SLIM_MODE Configuration (Performance Optimization)

SLIM_MODE reduces the number of exposed MCP tools to an essential subset, significantly reducing LLM overhead and improving response times.

💡 Recommendation: SLIM_MODE is recommended for most use cases as it provides all essential schema management capabilities with optimal performance.

When to Use SLIM_MODE (Recommended)

• Default choice for most users and day-to-day operations
• When experiencing slow LLM responses due to too many tools
• For production environments focused on read-only operations
• When you only need basic schema management capabilities
• To reduce token usage and improve performance

When to Use Non-SLIM Mode

• For administrators or SRE teams performing long-running operations
• When you need advanced operations like:
  • Schema migrations across registries
  • Bulk schema removals and cleanup operations
  • Complex batch operations and workflows
  • Interactive guided wizards for complex tasks
  • Comprehensive export/import operations

Enable SLIM_MODE

export SLIM_MODE="true"  # Reduces tools from 57+ to ~9
# Enables reduced essential tool set

Tools Available in SLIM_MODE

Essential Read-Only Tools:

• ping - Server health check
• set_default_registry, get_default_registry - Registry management
• count_contexts, count_schemas, count_schema_versions - Statistics

Basic Write Operations:

• register_schema - Register new schemas
• check_compatibility - Schema compatibility checking
• create_context - Create new contexts

Essential Export Operations:

• export_schema - Export single schema
• export_subject - Export all subject versions

Resources Available (All Modes):

• All 19 resources remain available in SLIM_MODE
• registry://, schema://, subject:// resource URIs
• Full read access through resource-first approach

Tools Hidden in SLIM_MODE:

• All migration tools (migrate_schema, migrate_context)
• All batch operations (clear_context_batch)
• Advanced export/import tools (export_context, export_global)
• All interactive/elicitation tools (*_interactive variants)
• Heavy statistics tools with async operations
• Task management and workflow tools
• Configuration update tools
• Delete operations

Note: You can switch between modes by restarting with SLIM_MODE=false to access the full tool set.

📊 MCP Tools and Resources

This section provides a comprehensive analysis of all MCP tools and resources exposed by the Kafka Schema Registry MCP Server.

Backward Compatibility Wrapper Tools

These tools are maintained for backward compatibility with existing clients. They internally use efficient implementations but are exposed as tools to prevent "Tool not listed" errors. Consider migrating to the corresponding resources for better performance.

Core MCP Tools

💬 Usage Examples

Schema Management

# In Claude Desktop, use natural language:
"Register a user schema with id, name, email fields"
"Check if my updated schema is compatible"
"Export all schemas from staging context"
"List subjects in production context"

Multi-Registry Operations

"Compare development and production registries"
"Migrate user-events schema from staging to production"
"Test connections to all registries"
"Show me registry statistics"

Batch Operations

"Clear all schemas from test context"
"Export global schemas for backup"
"Count schemas across all contexts"

📖 More examples: examples/ | 📖 Use cases: docs/use-cases.md

🔒 Authentication & Security

OAuth 2.1 Support (Optional)

# Enable authentication
export ENABLE_AUTH=true
export AUTH_ISSUER_URL="https://your-oauth-provider.com"
export AUTH_AUDIENCE="your-client-id"

Supported Providers: Azure AD, Google OAuth, Keycloak, Okta, GitHub

Permission Scopes:

• read - View schemas, configurations
• write - Register schemas, update configs (includes read)
• admin - Delete subjects, full control (includes write + read)

Production Safety Features

• VIEWONLY Mode - Prevent accidental changes in production
• URL Validation - SSRF protection with configurable localhost access
• Scope-based Authorization - Fine-grained tool-level permissions
• Per-Registry Controls - Independent safety settings

📖 Security guide: docs/deployment.md#security

📚 Documentation

Additional Resources

• Examples - Usage examples and code samples
• Scripts - Utility scripts and automation
• Helm Charts - Kubernetes deployment
• Tests - Test suites and validation

🧪 Testing

Quick Test

cd tests/
./run_all_tests.sh --quick    # Essential tests
./run_all_tests.sh           # Complete test suite

Docker Testing

python tests/test_docker_mcp.py

MCP Inspector Tests (UI-driven)

# From repository root
cd inspector-tests

# Single registry (DEV)
./run-inspector-tests.sh stable

# Multi-registry (DEV + PROD)
./run-inspector-tests.sh multi

# Test a specific Docker tag
DOCKER_VERSION=latest ./run-inspector-tests.sh stable

📖 Testing guide: TESTING_SETUP_GUIDE.md

🚀 Deployment

Production Docker

# With docker-compose
docker-compose up -d

# Direct Docker  
docker run -d -p 38000:8000 \
  -e SCHEMA_REGISTRY_URL=http://registry:8081 \
  aywengo/kafka-schema-reg-mcp:stable

Kubernetes

# Using Helm charts
helm install kafka-schema-mcp ./helm/kafka-schema-reg-mcp

📖 Deployment guide: docs/deployment.md

🤝 Contributing

We welcome contributions! Please see:

• Contributing Guidelines
• Code of Conduct
• Development Setup

Quick Development Setup

git clone https://github.com/aywengo/kafka-schema-reg-mcp
cd kafka-schema-reg-mcp
python -m venv .venv && source .venv/bin/activate
pip install -r requirements.txt
python kafka_schema_registry_unified_mcp.py

🆕 What's New

v2.1.x (Latest)

• 🧭 Subject Aliasing - New tools add_subject_alias and delete_subject_alias
• 🛠️ Fixes - Evolution assistant and import interactive fixes
• 📦 Enhancements - Continued MCP tool refinements and testing improvements

v2.0.x

• 🔒 Security Fixes - Resolved credential exposure in logging
• 🤖 Interactive Schema Migration - Smart migration with user preference elicitation
• 💾 Automatic Backups - Pre-migration backup creation
• ✅ Post-Migration Verification - Comprehensive schema validation
• 🚀 FastMCP 2.8.0+ Framework - Complete architecture upgrade
• 📊 MCP 2025-06-18 Compliance - Latest protocol specification
• 🔐 OAuth 2.1 Generic Discovery - Universal provider compatibility
• 🔗 Resource Linking - HATEOAS navigation in tool responses

📖 Full changelog: CHANGELOG.md | 📖 v2.0.0 features: README-v2.0.0-HIGHLIGHTS.md

🐳 Glama.ai:

🐳 Docker Hub: aywengo/kafka-schema-reg-mcp | 📊 Stats: 70+ MCP Tools (12 backward compatibility), 19 Resources, 8 Registries, OAuth 2.1, Multi-platform

License: MIT | Maintainer: @aywengo | Issues: GitHub Issues