# MCP Server Implementation Plan
This document outlines the implementation plan for the MeteoSwiss MCP server.
## Phase 1: Setup and Infrastructure
**Duration: 1-2 weeks**
1. Set up development environment
- Initialize Node.js v18+ project with TypeScript
- Install MCP TypeScript SDK (`@modelcontextprotocol/sdk`)
- Install Zod for schema validation (`zod`)
- Configure TypeScript with strict settings (based on Total TypeScript recommendations)
- Configure ESLint and Prettier
- Set up Jest for testing
2. Create basic server structure
- Implement MCP server core using the McpServer class from SDK
- Set up project structure for components (using ES modules)
- Implement basic logging and error handling
- Configure HTTP server with Server-Sent Events (SSE) transport
3. Create Docker setup for development and deployment
- Dockerfile using Node.js v24 Alpine image
- Dockerfile for production with multi-stage build
- Docker Compose for local development
## Phase 2: Data Pipeline Implementation
**Duration: 2-3 weeks**
1. Implement Data Fetcher
- Create HTTP client using Node.js native fetch API
- Implement fetching for each data source
- Implement error handling with proper typing and retry logic
- Set up data freshness monitoring
2. Implement Data Transformer
- Define Zod schemas for all data types
- Create TypeScript types from Zod schemas
- Implement transformers with schema validation
- Create unit tests for transformers
3. Implement Data Cache
- Set up in-memory cache with proper TypeScript interfaces
- Implement cache invalidation strategies
- Optimize cache performance
- Add metrics for cache effectiveness
## Phase 3: Resource and Tool Implementation
**Duration: 2-3 weeks**
1. Implement Resource Providers
- Create base provider class with TypeScript generics
- Define resource schemas using Zod
- Implement provider for each resource type
- Register resources with the MCP server
2. Implement Tool Providers
- Define tool schemas using Zod for parameters and return types
- Implement each tool using the SDK's tool interface
- Add tools to MCP server
- Create comprehensive type safety across the tool chain
3. Implement helper functions
- Location lookup and validation with TypeScript interfaces
- Weather condition mapping with proper type safety
- Date and time utilities with TypeScript support
## Phase 4: Testing and Optimization
**Duration: 1-2 weeks**
1. Create comprehensive test suite
- Unit tests for each component using Jest
- Integration tests for the server
- End-to-end tests with LLM clients
- Type testing using TypeScript's testing utilities
2. Optimize performance
- Identify and fix bottlenecks
- Improve caching strategies
- Reduce response times
- Leverage Node.js performance features
3. Implement monitoring and observability
- Add metrics collection
- Set up structured logging
- Create dashboards
- Implement proper error boundaries and typing
## Phase 5: Documentation and Deployment
**Duration: 1-2 weeks**
1. Complete documentation
- API documentation with TypeScript interfaces
- Developer guide with setup instructions
- Deployment guide
2. Set up CI/CD pipeline
- Automated testing with type checking
- Automated deployment
- Version management
- Docker image building and publishing
3. Deploy server
- Setup production environment with Node.js v18+
- Configure monitoring
- Establish update process
## Code Structure
```
src/
├── index.ts # Main HTTP server entry point
├── server.ts # MCP server implementation
├── transports/ # Transport implementations
│ └── streamable-http.ts # HTTP/SSE transport
├── tools/ # MCP tool implementations
│ └── get-weather-report.ts # Weather report tool
├── data/ # Data fetching logic
│ └── weather-report-data.ts # MeteoSwiss data fetcher
├── schemas/ # Zod schemas
│ └── weather-report.ts # Weather data schemas
├── support/ # Supporting infrastructure (non-domain-specific)
│ ├── environment-validation.ts # Environment variable validation
│ ├── session-management.ts # SSE session management
│ ├── http-communication.ts # HTTP client for external APIs
│ └── logging.ts # Debug and file logging
└── test/ # Tests
├── integration/ # Integration tests
└── __fixtures__/ # Test data
```
## TypeScript Configuration
```json
{
"compilerOptions": {
"target": "ES2022",
"module": "NodeNext",
"moduleResolution": "NodeNext",
"esModuleInterop": true,
"strict": true,
"skipLibCheck": true,
"forceConsistentCasingInFileNames": true,
"outDir": "dist",
"declaration": true,
"sourceMap": true,
"noUncheckedIndexedAccess": true,
"exactOptionalPropertyTypes": true
},
"include": ["src/**/*"],
"exclude": ["node_modules", "dist"]
}
```
## Additional Considerations
### Dependencies
- **Core Dependencies**:
- `@modelcontextprotocol/sdk`: MCP TypeScript SDK
- `zod`: Runtime type validation and schema definition
- `node-fetch` (if needed for polyfills in older Node versions)
- **Development Dependencies**:
- `typescript`: TypeScript compiler
- `ts-node`: TypeScript execution
- `jest`: Testing framework
- `ts-jest`: TypeScript support for Jest
- `@types/node`: Node.js type definitions
- `eslint`: Linting
- `prettier`: Code formatting
### Risks and Mitigation
1. **Risk**: MeteoSwiss API changes
- **Mitigation**: Design adapters that isolate API-specific code, monitor for changes
2. **Risk**: High request volume
- **Mitigation**: Implement robust caching, rate limiting, and scaling
- Leverage Node.js performance characteristics
3. **Risk**: Data quality issues
- **Mitigation**: Add Zod validation, fallbacks, and alerts for data quality problems
4. **Risk**: MCP SDK limitations
- **Mitigation**: Engage with MCP community, contribute improvements as needed
## Timeline and Milestones
1. **Milestone 1**: Basic server setup with MCP SDK integration (Week 2)
2. **Milestone 2**: Data fetching and transformation pipeline with Zod validation (Week 5)
3. **Milestone 3**: First resource and tool implementation (Week 7)
4. **Milestone 4**: Complete resource and tool set (Week 9)
5. **Milestone 5**: Production-ready server (Week 11)
## Next Steps
1. Finalize the architecture and design documents
2. Set up development environment with Node.js v18+ and TypeScript
3. Begin implementation of Phase 1
