Enhance MCPServer integration with Cursor by programmatically registering and unregistering the server. Removed outdated comments and improved logging for server registration status.

[Feature]

Signed-off-by: Markus Alexander Kuppe <[email protected]>

Author: lemmy

src/lm/MCPServer.ts

@@ -7,6 +7,26 @@ import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
 import { StreamableHTTPServerTransport } from '@modelcontextprotocol/sdk/server/streamableHttp.js';
 import * as vscode from 'vscode';
 import { exists } from '../common';
+
+// Type declarations for Cursor's MCP Extension API
+// These types are only available in Cursor, not in VSCode
+declare module 'vscode' {
+    // eslint-disable-next-line @typescript-eslint/no-namespace
+    export namespace cursor {
+        // eslint-disable-next-line @typescript-eslint/no-namespace
+        export namespace mcp {
+            export interface RemoteServerConfig {
+                name: string;
+                server: {
+                    url: string;
+                };
+            }
+
+            export function registerServer(config: RemoteServerConfig): void;
+            export function unregisterServer(serverName: string): void;
+        }
+    }
+}
 import { applyDCollection } from '../diagnostic';
 import { TLADocumentSymbolProvider } from '../symbols/tlaSymbols';
 import { parseSpec, transpilePlusCal } from '../commands/parseModule';
@@ -282,39 +302,23 @@ export class MCPServer implements vscode.Disposable {
             this.mcpServer = app.listen(port, () => {
                 // Get the actual port that was assigned (important when port is 0)
                 const actualPort = (this.mcpServer?.address() as { port: number })?.port || port;
+
                 console.log(`TLA+ MCP server listening at http://localhost:${actualPort}/mcp`);
-                // Only show the information message if running in Cursor, not VSCode.
+
+                // Programmatically register the MCP server in Cursor using the extension API
                 const isCursor = vscode.env.appName?.toLowerCase().includes('cursor');
-                if (isCursor) {
-                    // Show an information message in Cursor including a button to add the MCP server to Cursor.
-                    const addToCursor = 'Add to Cursor';
-                    vscode.window.showInformationMessage(
-                        `TLA+ MCP server listening at http://localhost:${actualPort}/mcp`,
-                        addToCursor
-                    ).then(opt => {
-                        if (opt === addToCursor) {
-                            // We will display the information message in Cursor regardless of whether the user has
-                            // already added the MCP server.
-                            // Fortunately, adding the MCP server is idempotent, so it can be safely repeated
-                            // without causing issues.
-                            vscode.workspace.getConfiguration().update(
-                                'tlaplus.mcp.port',
-                                actualPort,
-                                vscode.ConfigurationTarget.Global
-                            );
-                            // base64 encode the URL
-                            const CURSOR_CONFIG = JSON.stringify({
+                if (isCursor && (vscode as any).cursor?.mcp?.registerServer) {
+                    try {
+                        (vscode as any).cursor.mcp.registerServer({
+                            name: 'TLA+ MCP Server',
+                            server: {
                                 url: `http://localhost:${actualPort}/mcp`
-                            });
-                            // https://docs.cursor.com/deeplinks
-                            // eslint-disable-next-line max-len
-                            const CURSOR_DEEPLINK = `cursor://anysphere.cursor-deeplink/mcp/install?name=TLA+MCP+Server&config=${Buffer.from(CURSOR_CONFIG).toString('base64')}`;
-                            console.log(`Cursor deeplink: ${CURSOR_DEEPLINK}`);
-                            // Use the external URI handler to open the deeplink in Cursor because
-                            // vscode.commands.executeCommand('vscode.open', CURSOR_DEEPLINK) doesn't work.
-                            vscode.env.openExternal(vscode.Uri.parse(CURSOR_DEEPLINK));
-                        }
-                    });
+                            }
+                        });
+                        console.log(`TLA+ MCP server registered programmatically in Cursor at http://localhost:${actualPort}/mcp`);
+                    } catch (error) {
+                        console.warn('Failed to register TLA+ MCP server programmatically:', error);
+                    }
                 }
             }).on('error', (err) => {
                 vscode.window.showErrorMessage(
@@ -323,14 +327,24 @@ export class MCPServer implements vscode.Disposable {
                 );
                 console.error('Error starting TLA+ MCP server:', err);
             });
-
         } catch (err) {
             // eslint-disable-next-line max-len
             vscode.window.showErrorMessage(`Failed to start TLA+ MCP server: ${err instanceof Error ? err.message : String(err)}`);
         }
     }
 
     public dispose(): void {
+        // Unregister from Cursor
+        const isCursor = vscode.env.appName?.toLowerCase().includes('cursor');
+        if (isCursor && (vscode as any).cursor?.mcp?.unregisterServer) {
+            try {
+                (vscode as any).cursor.mcp.unregisterServer('TLA+ MCP Server');
+                console.log('TLA+ MCP server unregistered from Cursor');
+            } catch (error) {
+                console.warn('Failed to unregister TLA+ MCP server from Cursor:', error);
+            }
+        }
+
         if (this.mcpServer) {
             this.mcpServer.close();
             this.mcpServer = undefined;

src/main.ts

@@ -271,10 +271,6 @@ export async function activate(context: vscode.ExtensionContext): Promise<void>
     if (typeof mcpPort === 'number' && (mcpPort >= 1024 && mcpPort <= 65535 || mcpPort === 0)) {
         const tlaMcpServer = new MCPServer(mcpPort);
         context.subscriptions.push(tlaMcpServer);
-
-        // TODO : At this point, we would like to programmatically register the MCP server in Cursor
-        // without creating a permanent file.  A permanent file, i.e., static configuration makes sense for
-        // an external MCP server, but not for the transient MCP server that is started by the extension.
     }
     syncTlcStatisticsSetting()
         .catch((err) => console.error(err))