Initial import

src/server/index.ts

@@ -0,0 +1,83 @@
+import { Protocol } from "../shared/protocol.js";
+import {
+  ClientCapabilities,
+  ClientNotification,
+  ClientRequest,
+  ClientResult,
+  Implementation,
+  InitializeRequest,
+  InitializeResult,
+  PROTOCOL_VERSION,
+  ServerNotification,
+  ServerRequest,
+  ServerResult,
+} from "../types/index.js";
+
+/**
+ * An MCP server on top of a pluggable transport.
+ *
+ * This server will automatically respond to the initialization flow as initiated from the client.
+ */
+export class Server extends Protocol<
+  ClientRequest,
+  ClientNotification,
+  ClientResult,
+  ServerRequest,
+  ServerNotification,
+  ServerResult
+> {
+  private _clientCapabilities?: ClientCapabilities;
+  private _clientVersion?: Implementation;
+
+  /**
+   * Callback for when initialization has fully completed (i.e., the client has sent an `initialized` notification).
+   */
+  oninitialized?: () => void;
+
+  /**
+   * Initializes this server with the given name and version information.
+   */
+  constructor(private _serverInfo: Implementation) {
+    super();
+
+    this.setRequestHandler("initialize", (request) =>
+      this._oninitialize(request as InitializeRequest),
+    );
+    this.setNotificationHandler("notification/initialized", () =>
+      this.oninitialized?.(),
+    );
+  }
+
+  private async _oninitialize(
+    request: InitializeRequest,
+  ): Promise<InitializeResult> {
+    if (request.params.protocolVersion !== PROTOCOL_VERSION) {
+      throw new Error(
+        `Client's protocol version is not supported: ${request.params.protocolVersion}`,
+      );
+    }
+
+    this._clientCapabilities = request.params.capabilities;
+    this._clientVersion = request.params.clientInfo;
+
+    return {
+      protocolVersion: PROTOCOL_VERSION,
+      capabilities: {},
+      serverInfo: this._serverInfo,
+    };
+  }
+
+  /**
+   * After initialization has completed, this will be populated with the client's reported capabilities.
+   */
+  getClientCapabilities(): ClientCapabilities | undefined {
+    return this._clientCapabilities;
+  }
+
+  /**
+   * After initialization has completed, this will be populated with information about the client's name and version.
+   */
+  getClientVersion(): Implementation | undefined {
+    return this._clientVersion;
+  }
+}