Enable/disable MCP servers

src/core/prompts/system.ts

@@ -717,6 +717,8 @@ npm run build
 
 5. Install the MCP Server by adding the MCP server configuration to the settings file located at '${await mcpHub.getMcpSettingsFilePath()}'. The settings file may have other MCP servers already configured, so you would read it first and then add your new server to the existing \`mcpServers\` object.
 
+IMPORTANT: Regardless of what else you see in the MCP settings file, you must default any new MCP servers you create to disabled=false and alwaysAllow=[].
+
 \`\`\`json
 {
   "mcpServers": {

src/core/webview/ClineProvider.ts

@@ -608,6 +608,14 @@ export class ClineProvider implements vscode.WebviewViewProvider {
 						}
 						break
 					}
+					case "toggleMcpServer": {
+						try {
+							await this.mcpHub?.toggleServerDisabled(message.serverName!, message.disabled!)
+						} catch (error) {
+							console.error(`Failed to toggle MCP server ${message.serverName}:`, error)
+						}
+						break
+					}
 					case "toggleToolAlwaysAllow": {
 						try {
 							await this.mcpHub?.toggleToolAlwaysAllow(message.serverName!, message.toolName!, message.alwaysAllow!)

src/services/mcp/McpHub.ts

@@ -33,6 +33,7 @@ const StdioConfigSchema = z.object({
 	args: z.array(z.string()).optional(),
 	env: z.record(z.string()).optional(),
 	alwaysAllow: AlwaysAllowSchema.optional(),
+	disabled: z.boolean().optional(),
 })
 
 const McpSettingsSchema = z.object({
@@ -54,7 +55,8 @@ export class McpHub {
 	}
 
 	getServers(): McpServer[] {
-		return this.connections.map((conn) => conn.server)
+		// Only return enabled servers
+		return this.connections.filter((conn) => !conn.server.disabled).map((conn) => conn.server)
 	}
 
 	async getMcpServersPath(): Promise<string> {
@@ -192,11 +194,13 @@ export class McpHub {
 			}
 
 			// valid schema
+			const parsedConfig = StdioConfigSchema.parse(config)
 			const connection: McpConnection = {
 				server: {
 					name,
 					config: JSON.stringify(config),
 					status: "connecting",
+					disabled: parsedConfig.disabled,
 				},
 				client,
 				transport,
@@ -458,11 +462,91 @@ export class McpHub {
 
 	// Using server
 
+	// Public methods for server management
+
+	public async toggleServerDisabled(serverName: string, disabled: boolean): Promise<void> {
+		let settingsPath: string
+		try {
+			settingsPath = await this.getMcpSettingsFilePath()
+
+			// Ensure the settings file exists and is accessible
+			try {
+				await fs.access(settingsPath)
+			} catch (error) {
+				console.error("Settings file not accessible:", error)
+				throw new Error("Settings file not accessible")
+			}
+			const content = await fs.readFile(settingsPath, "utf-8")
+			const config = JSON.parse(content)
+
+			// Validate the config structure
+			if (!config || typeof config !== "object") {
+				throw new Error("Invalid config structure")
+			}
+
+			if (!config.mcpServers || typeof config.mcpServers !== "object") {
+				config.mcpServers = {}
+			}
+
+			if (config.mcpServers[serverName]) {
+				// Create a new server config object to ensure clean structure
+				const serverConfig = {
+					...config.mcpServers[serverName],
+					disabled,
+				}
+
+				// Ensure required fields exist
+				if (!serverConfig.alwaysAllow) {
+					serverConfig.alwaysAllow = []
+				}
+
+				config.mcpServers[serverName] = serverConfig
+
+				// Write the entire config back
+				const updatedConfig = {
+					mcpServers: config.mcpServers,
+				}
+
+				await fs.writeFile(settingsPath, JSON.stringify(updatedConfig, null, 2))
+
+				const connection = this.connections.find((conn) => conn.server.name === serverName)
+				if (connection) {
+					try {
+						connection.server.disabled = disabled
+
+						// Only refresh capabilities if connected
+						if (connection.server.status === "connected") {
+							connection.server.tools = await this.fetchToolsList(serverName)
+							connection.server.resources = await this.fetchResourcesList(serverName)
+							connection.server.resourceTemplates = await this.fetchResourceTemplatesList(serverName)
+						}
+					} catch (error) {
+						console.error(`Failed to refresh capabilities for ${serverName}:`, error)
+					}
+				}
+
+				await this.notifyWebviewOfServerChanges()
+			}
+		} catch (error) {
+			console.error("Failed to update server disabled state:", error)
+			if (error instanceof Error) {
+				console.error("Error details:", error.message, error.stack)
+			}
+			vscode.window.showErrorMessage(
+				`Failed to update server state: ${error instanceof Error ? error.message : String(error)}`,
+			)
+			throw error
+		}
+	}
+
 	async readResource(serverName: string, uri: string): Promise<McpResourceResponse> {
 		const connection = this.connections.find((conn) => conn.server.name === serverName)
 		if (!connection) {
 			throw new Error(`No connection found for server: ${serverName}`)
 		}
+		if (connection.server.disabled) {
+			throw new Error(`Server "${serverName}" is disabled`)
+		}
 		return await connection.client.request(
 			{
 				method: "resources/read",
@@ -481,6 +565,11 @@ export class McpHub {
 				`No connection found for server: ${serverName}. Please make sure to use MCP servers available under 'Connected MCP Servers'.`,
 			)
 		}
+
+		if (connection.server.disabled) {
+			throw new Error(`Server "${serverName}" is disabled and cannot be used`)
+		}
+
 		return await connection.client.request(
 			{
 				method: "tools/call",

src/shared/WebviewMessage.ts

@@ -36,8 +36,10 @@ export interface WebviewMessage {
 		| "openAdvisorModelSettings"
 		| "requestVsCodeLmModels"
 		| "toggleToolAlwaysAllow"
+		| "toggleMcpServer"
 	// | "relaunchChromeDebugMode"
 	text?: string
+	disabled?: boolean
 	askResponse?: ClineAskResponse
 	apiConfiguration?: ApiConfiguration
 	images?: string[]

src/shared/mcp.ts

@@ -6,6 +6,7 @@ export type McpServer = {
 	tools?: McpTool[]
 	resources?: McpResource[]
 	resourceTemplates?: McpResourceTemplate[]
+	disabled?: boolean
 }
 
 export type McpTool = {

webview-ui/src/components/mcp/McpView.tsx

@@ -190,12 +190,62 @@ const ServerRow = ({ server }: { server: McpServer }) => {
 					background: "var(--vscode-textCodeBlock-background)",
 					cursor: server.error ? "default" : "pointer",
 					borderRadius: isExpanded || server.error ? "4px 4px 0 0" : "4px",
+					opacity: server.disabled ? 0.6 : 1,
 				}}
 				onClick={handleRowClick}>
 				{!server.error && (
 					<span className={`codicon codicon-chevron-${isExpanded ? "down" : "right"}`} style={{ marginRight: "8px" }} />
 				)}
 				<span style={{ flex: 1 }}>{server.name}</span>
+				<div style={{ display: "flex", alignItems: "center", marginRight: "8px" }} onClick={(e) => e.stopPropagation()}>
+					<div
+						role="switch"
+						aria-checked={!server.disabled}
+						tabIndex={0}
+						style={{
+							width: "20px",
+							height: "10px",
+							backgroundColor: server.disabled
+								? "var(--vscode-titleBar-inactiveForeground)"
+								: "var(--vscode-testing-iconPassed)",
+							borderRadius: "5px",
+							position: "relative",
+							cursor: "pointer",
+							transition: "background-color 0.2s",
+							opacity: server.disabled ? 0.5 : 0.9,
+						}}
+						onClick={() => {
+							vscode.postMessage({
+								type: "toggleMcpServer",
+								serverName: server.name,
+								disabled: !server.disabled,
+							})
+						}}
+						onKeyDown={(e) => {
+							if (e.key === "Enter" || e.key === " ") {
+								e.preventDefault()
+								vscode.postMessage({
+									type: "toggleMcpServer",
+									serverName: server.name,
+									disabled: !server.disabled,
+								})
+							}
+						}}>
+						<div
+							style={{
+								width: "6px",
+								height: "6px",
+								backgroundColor: "white",
+								border: "1px solid #666666",
+								borderRadius: "50%",
+								position: "absolute",
+								top: "1px",
+								left: server.disabled ? "2px" : "12px",
+								transition: "left 0.2s",
+							}}
+						/>
+					</div>
+				</div>
 				<div
 					style={{
 						width: "8px",