Create comprehensive Component Model examples and reference implementations

[avrabe]

Summary

Develop a comprehensive set of examples and reference implementations showcasing WebAssembly Component Model usage with MCP, demonstrating various patterns, compositions, and deployment scenarios.

Background

As we implement WASI-MCP (#30), Bazel integration (#27), and WASM development tooling (#36), developers need concrete examples to understand:

• How to build MCP servers as WebAssembly components
• Component composition patterns for complex applications
• Best practices for component interfaces and resource management
• Integration with various host environments (WRT, Wasmtime, etc.)
• Real-world deployment scenarios

Implementation Tasks

Basic Component Examples

Minimal MCP Server Component

• Simple echo/ping server demonstrating basic MCP protocol
• WIT interface definitions for core MCP operations
• Host integration showing component instantiation
• Documentation explaining component structure

Resource Provider Component

• File system resource provider with WASI filesystem integration
• Demonstrates resource listing, reading, and metadata operations
• Shows proper error handling and capability management
• Example of read-only vs read-write resource access

Tool Execution Component

• Calculator/math operations tool demonstrating tool execution
• Input validation and structured output
• Error handling and timeout management
• Performance metrics collection

Intermediate Component Examples

Multi-Component Application

• Data Service Component - Provides data storage and retrieval
• Processing Component - Consumes data and performs computations
• API Gateway Component - Handles external requests and routing
• Component composition showing inter-component communication

Persistent Storage Component

• Integration with persistence patterns from loriot-websocket-mcp (Integrate loriot-websocket-mcp data persistence patterns #33)
• JSON Lines storage with two-tier memory management
• Demonstrates WASI storage interfaces
• Backup and recovery operations

Caching Service Component

• Standalone caching component using generalized framework (Extract and generalize caching framework from studio-mcp #28)
• Configurable cache policies and invalidation
• Inter-component cache sharing
• Performance monitoring and metrics

Advanced Component Examples

Plugin Architecture System

┌─────────────────┐    ┌─────────────────┐
│   Host System   │    │   Plugin Host   │
│                 │    │   Component     │
├─────────────────┤    ├─────────────────┤
│ Plugin Loader   │◄──►│ Plugin Registry │
│ Security Policy │    │ Lifecycle Mgmt  │
│ Resource Mgmt   │    │ IPC Coordinator │
└─────────────────┘    └─────────────────┘
         ▲                       ▲
         │                       │
         ▼                       ▼
┌─────────────────┐    ┌─────────────────┐
│   Plugin A      │    │   Plugin B      │
│   Component     │    │   Component     │
└─────────────────┘    └─────────────────┘

Microservices Composition

• Service discovery and registration
• Load balancing between component instances
• Circuit breaker and retry patterns
• Distributed tracing across components

Streaming Data Pipeline

• Data Source Component - Generates or ingests streaming data
• Transform Component - Processes data in real-time
• Sink Component - Outputs processed data
• Backpressure handling and flow control

Host Integration Examples

Wasmtime Host Integration

• Native application hosting WASM MCP components
• Resource provisioning and capability management
• Performance optimization techniques
• Security policy enforcement

WRT Integration Examples

• Embedded system deployment using WRT runtime (Integrate WRT WebAssembly interpreter as MCP component host #32)
• Resource-constrained environment optimizations
• Safety-critical deployment patterns
• Real-time performance characteristics

Browser Integration

• Web application hosting MCP components
• IndexedDB storage backend integration
• Web Workers for component isolation
• Service Worker for offline capability

Real-World Use Case Examples

Smart Home Automation

// Smart home MCP component interfaces
interface home-automation {
    record device {
        id: string,
        name: string,
        device-type: device-type,
        status: device-status,
    }
    
    enum device-type {
        light,
        sensor,
        thermostat,
        security-camera,
    }
    
    get-devices: func() -> list<device>
    control-device: func(id: string, command: string) -> result<string, string>
    get-sensor-data: func(sensor-id: string, duration: u64) -> result<list<sensor-reading>, string>
}

Data Analytics Pipeline

• Data ingestion component with multiple source connectors
• ETL processing component with configurable transformations
• Analytics engine component with query capabilities
• Visualization component for dashboard generation

Content Management System

• Document storage and retrieval component
• Search indexing and query component
• User authentication and authorization component
• API gateway with rate limiting and caching

Testing and Validation Examples

Component Test Suites

• Unit testing framework for components
• Integration testing across component boundaries
• Performance testing and benchmarking
• Security testing and vulnerability scanning

Deployment Scenarios

• Local Development - Single-host development setup
• Container Deployment - Docker/Kubernetes deployment
• Edge Computing - Resource-constrained edge devices
• Serverless - Function-as-a-Service deployment

Documentation and Tutorials

Getting Started Guides

• "Your First MCP Component" tutorial
• Component composition walkthrough
• Host integration guide
• Deployment and operations guide

Best Practices Documentation

• Component design patterns
• Performance optimization techniques
• Security considerations
• Error handling and resilience

API Reference

• Complete WIT interface documentation
• Host function reference
• Configuration options
• Troubleshooting guide

Example Repository Structure

examples/
├── basic/
│   ├── echo-server/
│   ├── file-resources/
│   └── simple-tools/
├── intermediate/
│   ├── multi-component-app/
│   ├── persistent-storage/
│   └── caching-service/
├── advanced/
│   ├── plugin-architecture/
│   ├── microservices/
│   └── streaming-pipeline/
├── hosts/
│   ├── wasmtime-host/
│   ├── wrt-host/
│   └── browser-host/
├── use-cases/
│   ├── smart-home/
│   ├── data-analytics/
│   └── content-management/
└── tutorials/
    ├── getting-started/
    ├── composition-guide/
    └── deployment-guide/

Integration with Development Workflow

• All examples work with mcp-wasm CLI tooling (Create comprehensive WASM development workflow and tooling #36)
• Bazel build files for each example (Integrate Bazel build system with rules_wasm_component #27)
• CI/CD validation for all examples
• Performance benchmarking for example applications

Acceptance Criteria

• Complete set of examples from basic to advanced
• All examples compile and run successfully
• Comprehensive documentation for each example
• Integration with development tooling
• Real-world use case demonstrations
• Performance benchmarks and optimizations

Related Issues

• WASI-MCP Component Interfaces (Implement WASI-MCP component model interfaces and reference implementation #30)
• Bazel Build System Integration (Integrate Bazel build system with rules_wasm_component #27)
• WASM Development Workflow (Create comprehensive WASM development workflow and tooling #36)
• WRT Integration Layer (Integrate WRT WebAssembly interpreter as MCP component host #32)

References

• Component Model Examples
• Wasmtime Component Examples
• WASI Examples Repository