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 FastMCP 3.2.0+ (3.x, capped below 4) with MCP 2025-11-25 specification compliance. Fully compatible with Claude Desktop and other MCP clients using JSON-RPC over stdio.

Latest Version: v2.2.2 | Docker: aywengo/kafka-schema-reg-mcp:stable

🚀 Quick Start

1. Run with Docker (Recommended)

bash

# 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/:

bash

# 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 - 50+ tools following MCP 2025-11-25 specification
🚀 SLIM_MODE - Reduce tool overhead from 50+ to ~9 essential tools for better LLM performance

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

🛠️ Claude Code Skills

This project includes 5 specialized Claude Code skills – 4 for automated schema development workflows plus 1 for schema context comparison (/context-compare, documented below):

Available Skills

/schema-generate - Generate production-ready Avro schemas from natural language

Code

/schema-generate event UserRegistered "user registration with userId, email, timestamp"

/schema-evolve - Safely evolve schemas with automatic compatibility checking
Code
```
/schema-evolve user-profile "add optional phoneNumber field"
```
/migration-plan - Create detailed migration plans between environments
Code
```
/migration-plan development staging
```

/lint-and-test - Automated quality assurance workflows

Code

/lint-and-test quick        # Before commit (2-3s)
/lint-and-test fix          # Auto-fix issues (20-30s)
/lint-and-test pre-push     # Before push (10-15s)

Getting Started with Skills

Quick Start: Read .claude-code/SKILLS_GUIDE.md - 5-minute tutorial

Complete Reference: .claude-code/skills/README.md - Full documentation

Setup Summary: .claude-code/skills/README.md - Configuration details

Skills Features

✅ Natural language schema generation with templates
✅ Automatic compatibility checking (BACKWARD, FORWARD, FULL)
✅ Migration planning with rollback procedures
✅ Pre-commit and pre-push quality automation
✅ Integration with Black, Ruff, isort, Flake8
✅ Docker-based test execution
✅ Comprehensive error handling and auto-fix

Try it now: /schema-generate event TestEvent "test with id and timestamp"

📦 Installation

Option A: Docker (Recommended)

bash

# 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:

bash

# 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

bash

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

bash

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

📖 Detailed installation guide: docs/deployment.md

⚙️ Configuration

Single Registry Mode

server.ts

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)

server.ts

# 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/:

Configuration	Use Case	File
Production	Stable Docker deployment	`claude_desktop_stable_config.json`
Multi-Environment	DEV/STAGING/PROD registries	`claude_desktop_multi_registry_docker.json`
Local Development	Python local execution	`claude_desktop_config.json`
View-Only Safety	Production with safety	`claude_desktop_viewonly_config.json`

📖 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

server.ts

export SLIM_MODE="true"  # Reduces tools from 50+ 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
Workflow tools
Configuration update tools
Delete operations

Note: Task status tracking is now handled by FastMCP's built-in Docket system. Custom task management tools have been removed in favor of FastMCP's native task tracking.

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.

Tool Name	SLIM_MODE	Scope	Recommended Resource	Description
`list_registries`	✅	read	`registry://names`	List all configured registries
`get_registry_info`	✅	read	`registry://info/{name}`	Get registry information
`test_registry_connection`	✅	read	`registry://status/{name}`	Test registry connection
`test_all_registries`	✅	read	`registry://status`	Test all registry connections
`list_subjects`	✅	read	`registry://{name}/subjects`	List all subjects
`get_schema`	✅	read	`schema://{name}/{context}/{subject}`	Get schema content
`get_schema_versions`	✅	read	`schema://{name}/{context}/{subject}/versions`	Get schema versions
`get_global_config`	✅	read	`registry://{name}/config`	Get global configuration
`get_mode`	✅	read	`registry://mode`	Get registry mode
`list_contexts`	✅	read	`registry://{name}/contexts`	List all contexts
`get_subject_config`	✅	read	`subject://{name}/{context}/{subject}/config`	Get subject configuration
`get_subject_mode`	✅	read	`subject://{name}/{context}/{subject}/mode`	Get subject mode

Core MCP Tools

Category	Name	Type	SLIM_MODE	Scope	Description
Core	`ping`	Tool	✅	read	MCP ping/pong health check
Registry Management	`set_default_registry`	Tool	✅	admin	Set default registry
Registry Management	`get_default_registry`	Tool	✅	read	Get current default registry
Schema Operations	`register_schema`	Tool	✅	write	Register new schema version
Schema Operations	`check_compatibility`	Tool	✅	read	Check schema compatibility
Context Management	`create_context`	Tool	✅	write	Create new context
Context Management	`delete_context`	Tool	❌	admin	Delete context
Subject Management	`delete_subject`	Tool	❌	admin	Delete subject and versions
Configuration	`update_global_config`	Tool	❌	admin	Update global configuration
Configuration	`update_subject_config`	Tool	❌	admin	Update subject configuration
Configuration	`add_subject_alias`	Tool	❌	write	Create alias subject pointing to an existing subject
Configuration	`delete_subject_alias`	Tool	❌	write	Remove an alias subject
Mode Management	`update_mode`	Tool	❌	admin	Update registry mode
Mode Management	`update_subject_mode`	Tool	❌	admin	Update subject mode
Statistics	`count_contexts`	Tool	✅	read	Count contexts
Statistics	`count_schemas`	Tool	✅	read	Count schemas
Statistics	`count_schema_versions`	Tool	✅	read	Count schema versions
Statistics	`get_registry_statistics`	Tool	❌	read	Get comprehensive registry stats
Export	`export_schema`	Tool	✅	read	Export single schema
Export	`export_subject`	Tool	✅	read	Export all subject versions
Export	`export_context`	Tool	❌	read	Export all context subjects
Export	`export_global`	Tool	❌	read	Export all contexts/schemas
Export	`export_global_interactive`	Tool	❌	read	Interactive global export
Migration	`migrate_schema`	Tool	❌	admin	Migrate schema between registries
Migration	`migrate_context`	Tool	❌	admin	Migrate context between registries
Migration	`migrate_context_interactive`	Tool	❌	admin	Interactive context migration
Comparison	`compare_registries`	Tool	❌	read	Compare two registries
Comparison	`compare_contexts_across_registries`	Tool	❌	read	Compare contexts across registries
Comparison	`find_missing_schemas`	Tool	❌	read	Find missing schemas
Batch Operations	`clear_context_batch`	Tool	❌	admin	Clear context with batch operations
Batch Operations	`clear_multiple_contexts_batch`	Tool	❌	admin	Clear multiple contexts
Interactive	`register_schema_interactive`	Tool	❌	write	Interactive schema registration
Interactive	`check_compatibility_interactive`	Tool	❌	read	Interactive compatibility check
Interactive	`create_context_interactive`	Tool	❌	write	Interactive context creation
Resource Discovery	`list_available_resources`	Tool	✅	read	List all available resources
Resource Discovery	`suggest_resource_for_tool`	Tool	✅	read	Get resource migration suggestions
Resource Discovery	`generate_resource_templates`	Tool	✅	read	Generate resource URI templates
Elicitation	`submit_elicitation_response`	Tool	❌	write	Submit elicitation response
Elicitation	`list_elicitation_requests`	Tool	❌	read	List elicitation requests
Elicitation	`get_elicitation_request`	Tool	❌	read	Get elicitation request details
Elicitation	`cancel_elicitation_request`	Tool	❌	admin	Cancel elicitation request
Elicitation	`get_elicitation_status`	Tool	❌	read	Get elicitation system status
Workflows	`list_available_workflows`	Tool	❌	read	List available workflows
Workflows	`get_workflow_status`	Tool	❌	read	Get workflow status
Workflows	`guided_schema_migration`	Tool	❌	admin	Start schema migration wizard
Workflows	`guided_context_reorganization`	Tool	❌	admin	Start context reorganization wizard
Workflows	`guided_disaster_recovery`	Tool	❌	admin	Start disaster recovery wizard
Utility	`get_mcp_compliance_status_tool`	Tool	❌	read	Get MCP compliance status
Utility	`get_oauth_scopes_info_tool`	Tool	❌	read	Get OAuth scopes information
Utility	`test_oauth_discovery_endpoints`	Tool	❌	read	Test OAuth discovery endpoints
Utility	`get_operation_info_tool`	Tool	❌	read	Get operation metadata
Utility	`check_viewonly_mode`	Tool	❌	read	Check if registry is in viewonly mode
RESOURCES	`registry://status`	Resource	✅	read	Overall registry connection status
RESOURCES	`registry://info`	Resource	✅	read	Detailed server configuration
RESOURCES	`registry://mode`	Resource	✅	read	Registry mode detection
RESOURCES	`registry://names`	Resource	✅	read	List of configured registry names
RESOURCES	`registry://status/{name}`	Resource	✅	read	Specific registry connection status
RESOURCES	`registry://info/{name}`	Resource	✅	read	Specific registry configuration
RESOURCES	`registry://mode/{name}`	Resource	✅	read	Specific registry mode
RESOURCES	`registry://{name}/subjects`	Resource	✅	read	List subjects for registry
RESOURCES	`registry://{name}/contexts`	Resource	✅	read	List contexts for registry
RESOURCES	`registry://{name}/config`	Resource	✅	read	Global config for registry
RESOURCES	`schema://{name}/{context}/{subject}`	Resource	✅	read	Schema content with context
RESOURCES	`schema://{name}/{subject}`	Resource	✅	read	Schema content default context
RESOURCES	`schema://{name}/{context}/{subject}/versions`	Resource	✅	read	Schema versions with context
RESOURCES	`schema://{name}/{subject}/versions`	Resource	✅	read	Schema versions default context
RESOURCES	`subject://{name}/{context}/{subject}/config`	Resource	✅	read	Subject config with context
RESOURCES	`subject://{name}/{subject}/config`	Resource	✅	read	Subject config default context
RESOURCES	`subject://{name}/{context}/{subject}/mode`	Resource	✅	read	Subject mode with context
RESOURCES	`subject://{name}/{subject}/mode`	Resource	✅	read	Subject mode default context
RESOURCES	`elicitation://response/{request_id}`	Resource	❌	write	Elicitation response handling

💬 Usage Examples

Schema Management

bash

# 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

bash

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

Batch Operations

bash

"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)

server.ts

# 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

Guide	Description
API Reference	Complete tool documentation with examples
Subject Aliasing	How to add and remove subject aliases
Use Cases	Real-world scenarios and implementation patterns
Deployment Guide	Docker, Kubernetes, cloud platforms, CI/CD
IDE Integration	VS Code, Claude Code, Cursor setup
Configuration Examples	Ready-to-use Claude Desktop configs
Testing Guide	Comprehensive testing setup
Changelog	Version history and migration notes
v2.0.0 Highlights	Major version features

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

bash

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

Docker Testing

bash

python tests/test_docker_mcp.py

MCP Inspector Tests (UI-driven)

bash

# 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

bash

# 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

bash

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

📖 Deployment guide: docs/deployment.md

🤝 Contributing

We welcome contributions! Please see:

Quick Development Setup

bash

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

v2.2.x (Latest)

📋 MCP 2025-11-25 - Protocol compliance with FastMCP native background tasks
🔒 FastMCP 3.2.0+ - 3.x, capped below 4 until FastMCP 4 GA (#177)

v2.1.x

🧭 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
🗑️ Removed Deprecated Tools - Custom task management tools removed in favor of FastMCP's built-in Docket system

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: 50+ MCP Tools (12 backward compatibility), 19 Resources, 8 Registries, OAuth 2.1, Multi-platform

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