Swift MCP Server Generator

Swift MCP Server Generator

Generate a complete, production-ready MCP server in Swift using the official Swift SDK package.

Project Generation

When asked to create a Swift MCP server, generate a complete project with this structure:

my-mcp-server/
├── Package.swift
├── Sources/
│   └── MyMCPServer/
│       ├── main.swift
│       ├── Server.swift
│       ├── Tools/
│       │   ├── ToolDefinitions.swift
│       │   └── ToolHandlers.swift
│       ├── Resources/
│       │   ├── ResourceDefinitions.swift
│       │   └── ResourceHandlers.swift
│       └── Prompts/
│           ├── PromptDefinitions.swift
│           └── PromptHandlers.swift
├── Tests/
│   └── MyMCPServerTests/
│       └── ServerTests.swift
└── README.md

Package.swift Template

// swift-tools-version: 6.0
import PackageDescription

let package = Package(
    name: "MyMCPServer",
    platforms: [
        .macOS(.v13),
        .iOS(.v16),
        .watchOS(.v9),
        .tvOS(.v16),
        .visionOS(.v1)
    ],
    dependencies: [
        .package(
            url: "https://github.com/modelcontextprotocol/swift-sdk.git",
            from: "0.10.0"
        ),
        .package(
            url: "https://github.com/apple/swift-log.git",
            from: "1.5.0"
        ),
        .package(
            url: "https://github.com/swift-server/swift-service-lifecycle.git",
            from: "2.0.0"
        )
    ],
    targets: [
        .executableTarget(
            name: "MyMCPServer",
            dependencies: [
                .product(name: "MCP", package: "swift-sdk"),
                .product(name: "Logging", package: "swift-log"),
                .product(name: "ServiceLifecycle", package: "swift-service-lifecycle")
            ]
        ),
        .testTarget(
            name: "MyMCPServerTests",
            dependencies: ["MyMCPServer"]
        )
    ]
)

main.swift Template

import MCP
import Logging
import ServiceLifecycle

struct MCPService: Service {
    let server: Server
    let transport: Transport
    
    func run() async throws {
        try await server.start(transport: transport) { clientInfo, capabilities in
            logger.info("Client connected", metadata: [
                "name": .string(clientInfo.name),
                "version": .string(clientInfo.version)
            ])
        }
        
        // Keep service running
        try await Task.sleep(for: .days(365 * 100))
    }
    
    func shutdown() async throws {
        logger.info("Shutting down MCP server")
        await server.stop()
    }
}

var logger = Logger(label: "com.example.mcp-server")
logger.logLevel = .info

do {
    let server = await createServer()
    let transport = StdioTransport(logger: logger)
    let service = MCPService(server: server, transport: transport)
    
    let serviceGroup = ServiceGroup(
        services: [service],
        configuration: .init(
            gracefulShutdownSignals: [.sigterm, .sigint]
        ),
        logger: logger
    )
    
    try await serviceGroup.run()
} catch {
    logger.error("Fatal error", metadata: ["error": .string("\(error)")])
    throw error
}

Server.swift Template

import MCP
import Logging

func createServer() async -> Server {
    let server = Server(
        name: "MyMCPServer",
        version: "1.0.0",
        capabilities: .init(
            prompts: .init(listChanged: true),
            resources: .init(subscribe: true, listChanged: true),
            tools: .init(listChanged: true)
        )
    )
    
    // Register tool handlers
    await registerToolHandlers(server: server)
    
    // Register resource handlers
    await registerResourceHandlers(server: server)
    
    // Register prompt handlers
    await registerPromptHandlers(server: server)
    
    return server
}

ToolDefinitions.swift Template

import MCP

func getToolDefinitions() -> [Tool] {
    [
        Tool(
            name: "greet",
            description: "Generate a greeting message",
            inputSchema: .object([
                "type": .string("object"),
                "properties": .object([
                    "name": .object([
                        "type": .string("string"),
                        "description": .string("Name to greet")
                    ])
                ]),
                "required": .array([.string("name")])
            ])
        ),
        Tool(
            name: "calculate",
            description: "Perform mathematical calculations",
            inputSchema: .object([
                "type": .string("object"),
                "properties": .object([
                    "operation": .object([
                        "type": .string("string"),
                        "enum": .array([
                            .string("add"),
                            .string("subtract"),
                            .string("multiply"),
                            .string("divide")
                        ]),
                        "description": .string("Operation to perform")
                    ]),
                    "a": .object([
                        "type": .string("number"),
                        "description": .string("First operand")
                    ]),
                    "b": .object([
                        "type": .string("number"),
                        "description": .string("Second operand")
                    ])
                ]),
                "required": .array([
                    .string("operation"),
                    .string("a"),
                    .string("b")
                ])
            ])
        )
    ]
}

ToolHandlers.swift Template

import MCP
import Logging

private let logger = Logger(label: "com.example.mcp-server.tools")

func registerToolHandlers(server: Server) async {
    await server.withMethodHandler(ListTools.self) { _ in
        logger.debug("Listing available tools")
        return .init(tools: getToolDefinitions())
    }
    
    await server.withMethodHandler(CallTool.self) { params in
        logger.info("Tool called", metadata: ["name": .string(params.name)])
        
        switch params.name {
        case "greet":
            return handleGreet(params: params)
            
        case "calculate":
            return handleCalculate(params: params)
            
        default:
            logger.warning("Unknown tool requested", metadata: ["name": .string(params.name)])
            return .init(
                content: [.text("Unknown tool: \(params.name)")],
                isError: true
            )
        }
    }
}

private func handleGreet(params: CallTool.Params) -> CallTool.Result {
    guard let name = params.arguments?["name"]?.stringValue else {
        return .init(
            content: [.text("Missing 'name' parameter")],
            isError: true
        )
    }
    
    let greeting = "Hello, \(name)! Welcome to MCP."
    logger.debug("Generated greeting", metadata: ["name": .string(name)])
    
    return .init(
        content: [.text(greeting)],
        isError: false
    )
}

private func handleCalculate(params: CallTool.Params) -> CallTool.Result {
    guard let operation = params.arguments?["operation"]?.stringValue,
          let a = params.arguments?["a"]?.doubleValue,
          let b = params.arguments?["b"]?.doubleValue else {
        return .init(
            content: [.text("Missing or invalid parameters")],
            isError: true
        )
    }
    
    let result: Double
    switch operation {
    case "add":
        result = a + b
    case "subtract":
        result = a - b
    case "multiply":
        result = a * b
    case "divide":
        guard b != 0 else {
            return .init(
                content: [.text("Division by zero")],
                isError: true
            )
        }
        result = a / b
    default:
        return .init(
            content: [.text("Unknown operation: \(operation)")],