Initial implementation

Sources/MCP/Base/Lifecycle.swift

@@ -0,0 +1,56 @@
+/// The initialization phase MUST be the first interaction between client and server.
+/// During this phase, the client and server:
+/// - Establish protocol version compatibility
+/// - Exchange and negotiate capabilities
+/// - Share implementation details
+///
+/// - SeeAlso: https://spec.modelcontextprotocol.io/specification/2024-11-05/basic/lifecycle/#initialization
+public enum Initialize: Method {
+    public static let name: String = "initialize"
+
+    public struct Parameters: Hashable, Codable, Sendable {
+        public let protocolVersion: String
+        public let capabilities: Client.Capabilities
+        public let clientInfo: Client.Info
+
+        public init(
+            protocolVersion: String = Version.latest,
+            capabilities: Client.Capabilities,
+            clientInfo: Client.Info
+        ) {
+            self.protocolVersion = protocolVersion
+            self.capabilities = capabilities
+            self.clientInfo = clientInfo
+        }
+
+        private enum CodingKeys: String, CodingKey {
+            case protocolVersion, capabilities, clientInfo
+        }
+
+        public init(from decoder: Decoder) throws {
+            let container = try decoder.container(keyedBy: CodingKeys.self)
+            protocolVersion =
+                try container.decodeIfPresent(String.self, forKey: .protocolVersion)
+                ?? Version.latest
+            capabilities =
+                try container.decodeIfPresent(Client.Capabilities.self, forKey: .capabilities)
+                ?? .init()
+            clientInfo =
+                try container.decodeIfPresent(Client.Info.self, forKey: .clientInfo)
+                ?? .init(name: "unknown", version: "0.0.0")
+        }
+    }
+
+    public struct Result: Hashable, Codable, Sendable {
+        public let protocolVersion: String
+        public let capabilities: Server.Capabilities
+        public let serverInfo: Server.Info
+        public let instructions: String?
+    }
+}
+
+/// After successful initialization, the client MUST send an initialized notification to indicate it is ready to begin normal operations.
+/// - SeeAlso: https://spec.modelcontextprotocol.io/specification/2024-11-05/basic/lifecycle/#initialization
+public struct InitializedNotification: Notification {
+    public static let name: String = "notifications/initialized"
+}