MCP Weather Server

# 🎯 MCP Weather Server Requirements Specification ## Overview This document outlines the critical and non-critical requirements for the MCP Weather Server, written in Gherkin format as an outcome of example mapping sessions. Each requirement is categorized by criticality and mapped to acceptance tests. --- ## 🔴 CRITICAL REQUIREMENTS (Pipeline-Blocking) ### CR-01: MCP Protocol Compliance **Epic**: As an AI assistant, I need the server to follow MCP protocol exactly so I can integrate successfully #### Scenario: Tool Discovery Must Follow MCP Schema ```gherkin Given an MCP client connects to the weather server When the client requests tool discovery Then the server must return a valid MCP tools list And each tool must have name, description, and inputSchema And the schema must follow JSON Schema specification And the response must be valid JSON-RPC 2.0 format ``` #### Scenario: Tool Execution Must Return Valid MCP Response ```gherkin Given an MCP client has discovered available tools When the client calls the "getWeather" tool with valid parameters Then the server must return an MCP-compliant response And the response must have "content" array with "type" and "text" fields And the response must not contain any protocol violations ``` #### Scenario: Error Responses Must Follow MCP Format ```gherkin Given an MCP client calls a tool with invalid parameters When the server encounters an error Then the server must return a properly formatted MCP error response And the error must include a clear, user-friendly message And the error must not expose internal system details ``` ### CR-02: Core Weather Functionality **Epic**: As a user, I need reliable weather data for any valid city #### Scenario: Valid City Weather Retrieval ```gherkin Given the weather service is available When I request weather for a valid city like "London" Then I should receive current weather data And the data should include temperature, apparent temperature, and conditions And the data should include location coordinates And the response should be returned within 15 seconds ``` #### Scenario: Invalid City Handling ```gherkin Given the weather service is available When I request weather for an invalid city like "NonExistentCity123" Then I should receive a clear error message And the message should indicate the city was not found And the message should suggest checking spelling And the message should not expose any user input for security ``` #### Scenario: Empty Input Validation ```gherkin Given the weather service is available When I request weather with an empty city name Then I should receive a validation error And the error should indicate that city name is required And the server should not attempt external API calls ``` ### CR-03: Security and Input Sanitization **Epic**: As a system administrator, I need the server to be secure against attacks #### Scenario: SQL Injection Prevention ```gherkin Given a malicious user provides SQL injection input When they call getWeather with city: "'; DROP TABLE cities; --" Then the server must sanitize the input And the server must not execute any SQL commands And the error message must not reveal the attempted injection And the response should be a safe "city not found" message ``` #### Scenario: XSS Prevention in Responses ```gherkin Given a user provides XSS input When they call getWeather with city: "<script>alert('xss')</script>" Then the server must sanitize the input And the response must not contain executable script tags And the error message must be safe for display in web interfaces ``` #### Scenario: Error Message Security ```gherkin Given the server encounters any error condition When returning error messages to the client Then the error message must not expose file paths And the error message must not expose API keys or credentials And the error message must not expose internal service details And the error message must be safe for display to end users ``` ### CR-04: Performance and Availability **Epic**: As an AI assistant, I need fast, reliable responses for real-time user interactions #### Scenario: Response Time SLA Compliance ```gherkin Given the weather server is running normally When a client requests weather for any valid city Then the response must be returned within 15 seconds And 95% of requests must complete within 8 seconds And tool discovery must complete within 1 second ``` #### Scenario: Concurrent Request Handling ```gherkin Given multiple AI assistants are using the server When 5 concurrent weather requests are made Then all requests must be processed successfully And no request should timeout due to concurrency And memory usage should remain stable during concurrent load ``` #### Scenario: External API Failure Resilience ```gherkin Given the external weather API is unavailable When a client requests weather data Then the server must return a graceful error message And the server must not crash or become unresponsive And subsequent requests after API recovery must work normally ``` --- ## 🟡 NON-CRITICAL REQUIREMENTS (Quality Improvements) ### NCR-01: Enhanced User Experience **Epic**: As a user, I want helpful and informative responses #### Scenario: Rich Weather Data Display ```gherkin Given I request weather for a valid city When the server returns weather data Then the response should include hourly forecasts And the response should include timezone information And the data should be formatted for easy reading ``` #### Scenario: City Name Flexibility ```gherkin Given I want weather for a city with special characters When I request weather for "São Paulo" or "Zürich" Then the server should handle international characters correctly And the response should include proper location data ``` #### Scenario: Helpful Error Suggestions ```gherkin Given I make a typo in a city name When I request weather for "Londn" (missing 'o') Then the error message should be helpful And ideally suggest similar city names if possible ``` ### NCR-02: Performance Optimization **Epic**: As a system administrator, I want optimal resource usage #### Scenario: Memory Usage Stability ```gherkin Given the server runs continuously for 24 hours When processing normal weather request load Then memory usage should remain stable And there should be no significant memory leaks And CPU usage should return to baseline between requests ``` #### Scenario: Caching for Performance ```gherkin Given the same city is requested multiple times When the requests happen within a reasonable timeframe Then the server may cache responses to improve performance And cached responses should still be accurate And cache invalidation should prevent stale data ``` ### NCR-03: Monitoring and Observability **Epic**: As a developer, I need visibility into server health and performance #### Scenario: Health Check Endpoint (Future) ```gherkin Given monitoring tools need to check server health When a health check is requested Then the server should respond with health status And include basic performance metrics And indicate external API connectivity status ``` #### Scenario: Structured Logging (Future) ```gherkin Given the server is processing requests When any significant event occurs Then appropriate log messages should be generated And logs should be structured for easy parsing And logs should not contain sensitive information ``` --- ## 📊 Requirement Coverage Matrix | Requirement ID | Scenario | Test File | Test Status | |---------------|----------|-----------|-------------| | CR-01.1 | Tool Discovery Schema | `tests/integration/mcp-compliance.test.ts` | ✅ COVERED | | CR-01.2 | Tool Execution Response | `tests/integration/mcp-server.test.ts` | ✅ COVERED | | CR-01.3 | Error Response Format | `tests/integration/mcp-compliance.test.ts` | ✅ COVERED | | CR-02.1 | Valid City Weather | `tests/acceptance/user-scenarios.test.ts` | ✅ COVERED | | CR-02.2 | Invalid City Handling | `tests/acceptance/user-scenarios.test.ts` | ✅ COVERED | | CR-02.3 | Empty Input Validation | `tests/services/weather.test.ts` | ✅ COVERED | | CR-03.1 | SQL Injection Prevention | `tests/security/security-validation.test.ts` | ✅ COVERED | | CR-03.2 | XSS Prevention | `tests/security/security-validation.test.ts` | ✅ COVERED | | CR-03.3 | Error Message Security | `tests/security/security-validation.test.ts` | ✅ COVERED | | CR-04.1 | Response Time SLA | `tests/performance/load-testing.test.ts` | ✅ COVERED | | CR-04.2 | Concurrent Requests | `tests/performance/load-testing.test.ts` | ✅ COVERED | | CR-04.3 | API Failure Resilience | `tests/resilience/system-resilience.test.ts` | ✅ COVERED | | NCR-01.1 | Rich Weather Data | `tests/acceptance/user-scenarios.test.ts` | ✅ COVERED | | NCR-01.2 | International Characters | `tests/acceptance/user-scenarios.test.ts` | ✅ COVERED | | NCR-01.3 | Helpful Error Messages | `tests/acceptance/user-scenarios.test.ts` | ✅ COVERED | | NCR-02.1 | Memory Stability | `tests/performance/load-testing.test.ts` | ✅ COVERED | | NCR-02.2 | Caching Performance | `tests/performance/load-testing.test.ts` | 🟡 PARTIAL | | NCR-03.1 | Health Check | Not Implemented | ❌ MISSING | | NCR-03.2 | Structured Logging | Not Implemented | ❌ MISSING | --- ## 🎯 Acceptance Criteria Summary ### Critical Success Criteria (Must Pass for Release) 1. **100% of CR scenarios must be covered by automated tests** 2. **All critical tests must pass in CI pipeline** 3. **No security vulnerabilities in critical flows** 4. **Performance SLA must be met under normal load** 5. **MCP protocol compliance must be perfect** ### Quality Gates - **Test Coverage**: >90% for critical requirements - **Performance**: P95 < 8s, P99 < 15s response times - **Security**: Zero critical vulnerabilities - **Reliability**: 99.9% uptime under normal load - **Compatibility**: Works with all major MCP clients ### Definition of Done - [ ] All critical scenarios have corresponding automated tests - [ ] All tests pass consistently in CI environment - [ ] Performance benchmarks meet SLA requirements - [ ] Security scanning shows no critical issues - [ ] Manual testing with real MCP clients succeeds - [ ] Documentation reflects actual behavior --- ## 🔄 Requirement Evolution ### Version 1.0 (Current) - Focus on core weather functionality - MCP protocol compliance - Basic security and performance ### Future Versions - Additional data services (news, finance, sports) - Advanced caching and performance optimization - Comprehensive monitoring and observability - Multi-language support and internationalization ### Change Management - New requirements must be added to this document - Each requirement must have corresponding acceptance tests - Breaking changes require careful migration planning - Backward compatibility must be maintained when possible --- *This document serves as the single source of truth for MCP Weather Server requirements. All development and testing should align with these specifications.*