swift mcp server generator

Author's original introduction

Generate a complete Model Context Protocol server project in Swift using the official MCP Swift SDK package.

SkillPi interpretation

Tasks

swift mcp server generator

Audience

Use the scenarios stated in the author's introduction.

Inputs and outputs

See the complete author document; outputs have not been runtime verified by SkillPi.

Software, accounts and paid services

Check required software, accounts, costs and permissions in the full document; confirm and authorize actual file access and external services in your host. Domains referenced in the documents (not a runtime allowlist): github.com

Limits and differences

Functionality, version status and outcome statements in the introduction are author claims. Only pinned source and static attachment evidence were checked; runtime behavior, external services and compatibility are not guaranteed.

Testing

Not tested

Security rating and access scope

caution · Static evidence review; not a runtime safety guarantee.

Check required software, accounts, costs and permissions in the full document; confirm and authorize actual file access and external services in your host. Domains referenced in the documents (not a runtime allowlist): github.com

Before use, confirm and authorize actual file access, external services and network destinations in your host. This review grants no runtime permissions.

Original SKILL.md

---
name: swift-mcp-server-generator
description: 'Generate a complete Model Context Protocol server project in Swift using the official MCP Swift SDK package.'
---

# 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
// 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

```swift
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

```swift
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

```swift
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

```swift
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)")],
            isError: true
        )
    }
    
    logger.debug("Calculation performed", metadata: [
        "operation": .string(operation),
        "result": .string("\(result)")
    ])
    
    return .init(
        content: [.text("Result: \(result)")],
        isError: false
    )
}
```

## ResourceDefinitions.swift Template

```swift
import MCP

func getResourceDefinitions() -> [Resource] {
    [
        Resource(
            name: "Example Data",
            uri: "resource://data/example",
            description: "Example resource data",
            mimeType: "application/json"
        ),
        Resource(
            name: "Configuration",
            uri: "resource://config",
            description: "Server configuration",
            mimeType: "application/json"
        )
    ]
}
```

## ResourceHandlers.swift Template

```swift
import MCP
import Logging
import Foundation

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

actor ResourceState {
    private var subscriptions: Set<String> = []
    
    func addSubscription(_ uri: String) {
        subscriptions.insert(uri)
    }
    
    func removeSubscription(_ uri: String) {
        subscriptions.remove(uri)
    }
    
    func isSubscribed(_ uri: String) -> Bool {
        subscriptions.contains(uri)
    }
}

private let state = ResourceState()

func registerResourceHandlers(server: Server) async {
    await server.withMethodHandler(ListResources.self) { params in
        logger.debug("Listing available resources")
        return .init(resources: getResourceDefinitions(), nextCursor: nil)
    }
    
    await server.withMethodHandler(ReadResource.self) { params in
        logger.info("Reading resource", metadata: ["uri": .string(params.uri)])
        
        switch params.uri {
        case "resource://data/example":
            let jsonData = """
            {
                "message": "Example resource data",
                "timestamp": "\(Date())"
            }
            """
            return .init(contents: [
                .text(jsonData, uri: params.uri, mimeType: "application/json")
            ])
            
        case "resource://config":
            let config = """
            {
                "serverName": "MyMCPServer",
                "version": "1.0.0"
            }
            """
            return .init(contents: [
                .text(config, uri: params.uri, mimeType: "application/json")
            ])
            
        default:
            logger.warning("Unknown resource requested", metadata: ["uri": .string(params.uri)])
            throw MCPError.invalidParams("Unknown resource URI: \(params.uri)")
        }
    }
    
    await server.withMethodHandler(ResourceSubscribe.self) { params in
        logger.info("Client subscribed to resource", metadata: ["uri": .string(params.uri)])
        await state.addSubscription(params.uri)
        return .init()
    }
    
    await server.withMethodHandler(ResourceUnsubscribe.self) { params in
        logger.info("Client unsubscribed from resource", metadata: ["uri": .string(params.uri)])
        await state.removeSubscription(params.uri)
        return .init()
    }
}
```

## PromptDefinitions.swift Template

```swift
import MCP

func getPromptDefinitions() -> [Prompt] {
    [
        Prompt(
            name: "code-review",
            description: "Generate a code review prompt",
            arguments: [
                .init(name: "language", description: "Programming language", required: true),
                .init(name: "focus", description: "Review focus area", required: false)
            ]
        )
    ]
}
```

## PromptHandlers.swift Template

```swift
import MCP
import Logging

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

func registerPromptHandlers(server: Server) async {
    await server.withMethodHandler(ListPrompts.self) { params in
        logger.debug("Listing available prompts")
        return .init(prompts: getPromptDefinitions(), nextCursor: nil)
    }
    
    await server.withMethodHandler(GetPrompt.self) { params in
        logger.info("Getting prompt", metadata: ["name": .string(params.name)])
        
        switch params.name {
        case "code-review":
            return handleCodeReviewPrompt(params: params)
            
        default:
            logger.warning("Unknown prompt requested", metadata: ["name": .string(params.name)])
            throw MCPError.invalidParams("Unknown prompt: \(params.name)")
        }
    }
}

private func handleCodeReviewPrompt(params: GetPrompt.Params) -> GetPrompt.Result {
    guard let language = params.arguments?["language"]?.stringValue else {
        return .init(
            description: "Missing language parameter",
            messages: []
        )
    }
    
    let focus = params.arguments?["focus"]?.stringValue ?? "general quality"
    
    let description = "Code review for \(language) with focus on \(focus)"
    let messages: [Prompt.Message] = [
        .user("Please review this \(language) code with focus on \(focus)."),
        .assistant("I'll review the code focusing on \(focus). Please share the code."),
        .user("Here's the code to review: [paste code here]")
    ]
    
    logger.debug("Generated code review prompt", metadata: [
        "language": .string(language),
        "focus": .string(focus)
    ])
    
    return .init(description: description, messages: messages)
}
```

## ServerTests.swift Template

```swift
import XCTest
@testable import MyMCPServer

final class ServerTests: XCTestCase {
    func testGreetTool() async throws {
        let params = CallTool.Params(
            name: "greet",
            arguments: ["name": .string("Swift")]
        )
        
        let result = handleGreet(params: params)
        
        XCTAssertFalse(result.isError ?? true)
        XCTAssertEqual(result.content.count, 1)
        
        if case .text(let message) = result.content[0] {
            XCTAssertTrue(message.contains("Swift"))
        } else {
            XCTFail("Expected text content")
        }
    }
    
    func testCalculateTool() async throws {
        let params = CallTool.Params(
            name: "calculate",
            arguments: [
                "operation": .string("add"),
                "a": .number(5),
                "b": .number(3)
            ]
        )
        
        let result = handleCalculate(params: params)
        
        XCTAssertFalse(result.isError ?? true)
        XCTAssertEqual(result.content.count, 1)
        
        if case .text(let message) = result.content[0] {
            XCTAssertTrue(message.contains("8"))
        } else {
            XCTFail("Expected text content")
        }
    }
    
    func testDivideByZero() async throws {
        let params = CallTool.Params(
            name: "calculate",
            arguments: [
                "operation": .string("divide"),
                "a": .number(10),
                "b": .number(0)
            ]
        )
        
        let result = handleCalculate(params: params)
        
        XCTAssertTrue(result.isError ?? false)
    }
}
```

## README.md Template

```markdown
# MyMCPServer

A Model Context Protocol server built with Swift.

## Features

- ✅ Tools: greet, calculate
- ✅ Resources: example data, configuration
- ✅ Prompts: code-review
- ✅ Graceful shutdown with ServiceLifecycle
- ✅ Structured logging with swift-log
- ✅ Full test coverage

## Requirements

- Swift 6.0+
- macOS 13+, iOS 16+, or Linux

## Installation

```bash
swift build -c release
```

## Usage

Run the server:

```bash
swift run
```

Or with logging:

```bash
LOG_LEVEL=debug swift run
```

## Testing

```bash
swift test
```

## Development

The server uses:
- [MCP Swift SDK](https://github.com/modelcontextprotocol/swift-sdk) - MCP protocol implementation
- [swift-log](https://github.com/apple/swift-log) - Structured logging
- [swift-service-lifecycle](https://github.com/swift-server/swift-service-lifecycle) - Graceful shutdown

## Project Structure

- `Sources/MyMCPServer/main.swift` - Entry point with ServiceLifecycle
- `Sources/MyMCPServer/Server.swift` - Server configuration
- `Sources/MyMCPServer/Tools/` - Tool definitions and handlers
- `Sources/MyMCPServer/Resources/` - Resource definitions and handlers
- `Sources/MyMCPServer/Prompts/` - Prompt definitions and handlers
- `Tests/` - Unit tests

## License

MIT
```

## Generation Instructions

1. **Ask for project name and description**
2. **Generate all files** with proper naming
3. **Use actor-based state** for thread safety
4. **Include comprehensive logging** with swift-log
5. **Implement graceful shutdown** with ServiceLifecycle
6. **Add tests** for all handlers
7. **Use modern Swift concurrency** (async/await)
8. **Follow Swift naming conventions** (camelCase, PascalCase)
9. **Include error handling** with proper MCPError usage
10. **Document public APIs** with doc comments

## Build and Run

```bash
# Build
swift build

# Run
swift run

# Test
swift test

# Release build
swift build -c release

# Install
swift build -c release
cp .build/release/MyMCPServer /usr/local/bin/
```

## Integration with Claude Desktop

Add to `claude_desktop_config.json`:

```json
{
  "mcpServers": {
    "my-mcp-server": {
      "command": "/path/to/MyMCPServer"
    }
  }
}
```

Copyright and license notice

MIT License

Copyright GitHub, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.