DRAFT: Server Sent Events Example

SSEExample/.gitignore

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+.DS_Store
+/.build
+/Packages
+xcuserdata/
+DerivedData/
+.swiftpm/configuration/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc

SSEExample/Package.swift

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+// swift-tools-version: 6.1
+
+import PackageDescription
+
+let package = Package(
+    name: "SSEExample",
+    platforms: [
+         .macOS(.v15)
+    ],
+    products: [
+        .library(
+            name: "Client",
+            targets: ["Client"]
+        )
+    ],
+    dependencies: [
+        .package(url: "https://github.com/Cocoanetics/SwiftMCP.git", branch: "swift6"),
+        .package(url: "https://github.com/apple/swift-argument-parser", from: "1.2.0"),
+
+        // Client
+        .package(url: "https://github.com/apple/swift-openapi-generator", from: "1.6.0"),
+        .package(url: "https://github.com/apple/swift-openapi-runtime", from: "1.7.0"),
+        .package(url: "https://github.com/apple/swift-openapi-urlsession", from: "1.0.0"),
+    ],
+    targets: [
+        .target(
+            name: "Client",
+            dependencies: [
+                .product(name: "OpenAPIRuntime", package: "swift-openapi-runtime"),
+                .product(name: "OpenAPIURLSession", package: "swift-openapi-urlsession"),
+            ],
+            plugins: [.plugin(name: "OpenAPIGenerator", package: "swift-openapi-generator")]
+        ),
+        .target(
+            name: "LibServer",
+            dependencies: [
+                .product(name: "SwiftMCP", package: "SwiftMCP"),
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+            ]
+        ),
+        .executableTarget(
+            name: "Server",
+            dependencies: [
+                .byName(name: "LibServer"),
+                .product(name: "ArgumentParser", package: "swift-argument-parser"),
+            ]
+        ),
+        .executableTarget(
+            name: "ClientApp",
+            dependencies: [
+                .target(name: "Client")
+            ]
+        ),
+    ]
+)

SSEExample/Sources/Client/App.swift

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+//
+//  File.swift
+//  SSEExample
+//
+//  Created by Steven Prichard on 2025-03-20.
+//
+
+import Foundation

SSEExample/Sources/Client/openapi-generator-config.yaml

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+generate:
+  - types
+  - client
+accessModifier: public
+namingStrategy: idiomatic

SSEExample/Sources/Client/openapi.json

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+{
+  "info" : {
+    "description" : "API for SSEServer providing various tools.",
+    "title" : "SSEServer",
+    "version" : "0.0.1"
+  },
+  "openapi" : "3.1.0",
+  "paths" : {
+    "\/sseserver\/ping" : {
+      "post" : {
+        "description" : "A tool to test if this is working",
+        "operationId" : "ping",
+        "requestBody" : {
+          "content" : {
+            "application\/json" : {
+              "schema" : {
+                "description" : "A tool to test if this is working",
+                "properties" : {
+
+                },
+                "type" : "object"
+              }
+            }
+          },
+          "required" : true
+        },
+        "responses" : {
+          "200" : {
+            "content" : {
+              "application\/json" : {
+                "schema" : {
+                  "type" : "string"
+                }
+              }
+            },
+            "description" : "The returned value of the tool"
+          }
+        },
+        "summary" : "ping"
+      }
+    }
+  },
+  "servers" : [
+    {
+      "description" : "Production Server",
+      "url" : "http:\/\/127.0.0.1"
+    }
+  ]
+}

SSEExample/Sources/ClientApp/ClientApp.swift

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+//
+//  ClientApp.swift
+//  SSEExample
+//
+//  Created by Steven Prichard on 2025-03-20.
+//
+
+import Client
+import Foundation
+import OpenAPIRuntime
+import OpenAPIURLSession
+
+@main
+struct ClientApp {
+    static func main() async throws {
+        let client = Client(
+            serverURL: URL(string: "http://localhost:8080")!,
+            transport: URLSessionTransport()
+        )
+
+        let response = try await client.ping(.init(body: .json(.init())))
+        print("ℹ️ Response: \(response)")
+    }
+}

SSEExample/Sources/LibServer/SSEServer.swift

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+//
+//  SSEServer.swift
+//  SSEExample
+//
+//  Created by Steven Prichard on 2025-03-20.
+//
+
+import ArgumentParser
+@preconcurrency import SwiftMCP
+
+@MCPServer(name: "SSEServer", version: "0.0.1")
+actor SSEServer {
+    init() {}
+
+    @MCPTool(description: "A tool to test if this is working")
+    func ping() -> String {
+        return "pong"
+    }
+
+
+}
+
+public struct SSEServerCommand: AsyncParsableCommand {
+    public init() {}
+
+    @Option(name: .long, help: "The hostname to listen on")
+    var hostname: String = "127.0.0.1"
+
+    @Option(name: .long, help: "The port to listen on")
+    var port: Int = 8080
+
+    @Option(name: .long, help: "Bearer token for authorization")
+    var token: String?
+
+    public func run() async throws {
+        let server = SSEServer()
+
+        let transport = HTTPSSETransport(
+            server: server,
+            host: hostname,
+            port: port
+        )
+        transport.serveOpenAPI = true // TODO: Accept this as a flag
+
+        try await transport.run()
+    }
+}

SSEExample/Sources/Server/Server.swift

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+import LibServer
+import ArgumentParser
+
+@main
+struct ServerCommand: AsyncParsableCommand {    
+    static let configuration: CommandConfiguration = .init(
+        commandName: "server",
+        abstract: "Start an HTTP server with Server-Sent Events (SSE) support",
+        subcommands: [
+            SSEServerCommand.self
+        ],
+        defaultSubcommand: SSEServerCommand.self
+    )
+}