Move MCP slash command to new system (#3678)

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Abhi <[email protected]>

1 files changed, 236 insertions, 0 deletions

diff --git a/packages/cli/src/ui/commands/mcpCommand.ts b/packages/cli/src/ui/commands/mcpCommand.ts
new file mode 100644
index 00000000..fc266362
--- /dev/null
+++ b/packages/cli/src/ui/commands/mcpCommand.ts
@@ -0,0 +1,236 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  SlashCommand,
+  SlashCommandActionReturn,
+  CommandContext,
+} from './types.js';
+import {
+  DiscoveredMCPTool,
+  getMCPDiscoveryState,
+  getMCPServerStatus,
+  MCPDiscoveryState,
+  MCPServerStatus,
+} from '@google/gemini-cli-core';
+import open from 'open';
+
+const COLOR_GREEN = '\u001b[32m';
+const COLOR_YELLOW = '\u001b[33m';
+const COLOR_CYAN = '\u001b[36m';
+const RESET_COLOR = '\u001b[0m';
+
+const getMcpStatus = async (
+  context: CommandContext,
+  showDescriptions: boolean,
+  showSchema: boolean,
+  showTips: boolean = false,
+): Promise<SlashCommandActionReturn> => {
+  const { config } = context.services;
+  if (!config) {
+    return {
+      type: 'message',
+      messageType: 'error',
+      content: 'Config not loaded.',
+    };
+  }
+
+  const toolRegistry = await config.getToolRegistry();
+  if (!toolRegistry) {
+    return {
+      type: 'message',
+      messageType: 'error',
+      content: 'Could not retrieve tool registry.',
+    };
+  }
+
+  const mcpServers = config.getMcpServers() || {};
+  const serverNames = Object.keys(mcpServers);
+
+  if (serverNames.length === 0) {
+    const docsUrl = 'https://goo.gle/gemini-cli-docs-mcp';
+    if (process.env.SANDBOX && process.env.SANDBOX !== 'sandbox-exec') {
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: `No MCP servers configured. Please open the following URL in your browser to view documentation:\n${docsUrl}`,
+      };
+    } else {
+      // Open the URL in the browser
+      await open(docsUrl);
+      return {
+        type: 'message',
+        messageType: 'info',
+        content: `No MCP servers configured. Opening documentation in your browser: ${docsUrl}`,
+      };
+    }
+  }
+
+  // Check if any servers are still connecting
+  const connectingServers = serverNames.filter(
+    (name) => getMCPServerStatus(name) === MCPServerStatus.CONNECTING,
+  );
+  const discoveryState = getMCPDiscoveryState();
+
+  let message = '';
+
+  // Add overall discovery status message if needed
+  if (
+    discoveryState === MCPDiscoveryState.IN_PROGRESS ||
+    connectingServers.length > 0
+  ) {
+    message += `${COLOR_YELLOW}⏳ MCP servers are starting up (${connectingServers.length} initializing)...${RESET_COLOR}\n`;
+    message += `${COLOR_CYAN}Note: First startup may take longer. Tool availability will update automatically.${RESET_COLOR}\n\n`;
+  }
+
+  message += 'Configured MCP servers:\n\n';
+
+  const allTools = toolRegistry.getAllTools();
+  for (const serverName of serverNames) {
+    const serverTools = allTools.filter(
+      (tool) =>
+        tool instanceof DiscoveredMCPTool && tool.serverName === serverName,
+    ) as DiscoveredMCPTool[];
+
+    const status = getMCPServerStatus(serverName);
+
+    // Add status indicator with descriptive text
+    let statusIndicator = '';
+    let statusText = '';
+    switch (status) {
+      case MCPServerStatus.CONNECTED:
+        statusIndicator = '🟢';
+        statusText = 'Ready';
+        break;
+      case MCPServerStatus.CONNECTING:
+        statusIndicator = '🔄';
+        statusText = 'Starting... (first startup may take longer)';
+        break;
+      case MCPServerStatus.DISCONNECTED:
+      default:
+        statusIndicator = '🔴';
+        statusText = 'Disconnected';
+        break;
+    }
+
+    // Get server description if available
+    const server = mcpServers[serverName];
+
+    // Format server header with bold formatting and status
+    message += `${statusIndicator} \u001b[1m${serverName}\u001b[0m - ${statusText}`;
+
+    // Add tool count with conditional messaging
+    if (status === MCPServerStatus.CONNECTED) {
+      message += ` (${serverTools.length} tools)`;
+    } else if (status === MCPServerStatus.CONNECTING) {
+      message += ` (tools will appear when ready)`;
+    } else {
+      message += ` (${serverTools.length} tools cached)`;
+    }
+
+    // Add server description with proper handling of multi-line descriptions
+    if (showDescriptions && server?.description) {
+      const descLines = server.description.trim().split('\n');
+      if (descLines) {
+        message += ':\n';
+        for (const descLine of descLines) {
+          message += `    ${COLOR_GREEN}${descLine}${RESET_COLOR}\n`;
+        }
+      } else {
+        message += '\n';
+      }
+    } else {
+      message += '\n';
+    }
+
+    // Reset formatting after server entry
+    message += RESET_COLOR;
+
+    if (serverTools.length > 0) {
+      serverTools.forEach((tool) => {
+        if (showDescriptions && tool.description) {
+          // Format tool name in cyan using simple ANSI cyan color
+          message += `  - ${COLOR_CYAN}${tool.name}${RESET_COLOR}`;
+
+          // Handle multi-line descriptions by properly indenting and preserving formatting
+          const descLines = tool.description.trim().split('\n');
+          if (descLines) {
+            message += ':\n';
+            for (const descLine of descLines) {
+              message += `      ${COLOR_GREEN}${descLine}${RESET_COLOR}\n`;
+            }
+          } else {
+            message += '\n';
+          }
+          // Reset is handled inline with each line now
+        } else {
+          // Use cyan color for the tool name even when not showing descriptions
+          message += `  - ${COLOR_CYAN}${tool.name}${RESET_COLOR}\n`;
+        }
+        if (showSchema && tool.parameterSchema) {
+          // Prefix the parameters in cyan
+          message += `    ${COLOR_CYAN}Parameters:${RESET_COLOR}\n`;
+
+          const paramsLines = JSON.stringify(tool.parameterSchema, null, 2)
+            .trim()
+            .split('\n');
+          if (paramsLines) {
+            for (const paramsLine of paramsLines) {
+              message += `      ${COLOR_GREEN}${paramsLine}${RESET_COLOR}\n`;
+            }
+          }
+        }
+      });
+    } else {
+      message += '  No tools available\n';
+    }
+    message += '\n';
+  }
+
+  // Add helpful tips when no arguments are provided
+  if (showTips) {
+    message += '\n';
+    message += `${COLOR_CYAN}💡 Tips:${RESET_COLOR}\n`;
+    message += `  • Use ${COLOR_CYAN}/mcp desc${RESET_COLOR} to show server and tool descriptions\n`;
+    message += `  • Use ${COLOR_CYAN}/mcp schema${RESET_COLOR} to show tool parameter schemas\n`;
+    message += `  • Use ${COLOR_CYAN}/mcp nodesc${RESET_COLOR} to hide descriptions\n`;
+    message += `  • Press ${COLOR_CYAN}Ctrl+T${RESET_COLOR} to toggle tool descriptions on/off\n`;
+    message += '\n';
+  }
+
+  // Make sure to reset any ANSI formatting at the end to prevent it from affecting the terminal
+  message += RESET_COLOR;
+
+  return {
+    type: 'message',
+    messageType: 'info',
+    content: message,
+  };
+};
+
+export const mcpCommand: SlashCommand = {
+  name: 'mcp',
+  description: 'list configured MCP servers and tools',
+  action: async (context: CommandContext, args: string) => {
+    const lowerCaseArgs = args.toLowerCase().split(/\s+/).filter(Boolean);
+
+    const hasDesc =
+      lowerCaseArgs.includes('desc') || lowerCaseArgs.includes('descriptions');
+    const hasNodesc =
+      lowerCaseArgs.includes('nodesc') ||
+      lowerCaseArgs.includes('nodescriptions');
+    const showSchema = lowerCaseArgs.includes('schema');
+
+    // Show descriptions if `desc` or `schema` is present,
+    // but `nodesc` takes precedence and disables them.
+    const showDescriptions = !hasNodesc && (hasDesc || showSchema);
+
+    // Show tips only when no arguments are provided
+    const showTips = lowerCaseArgs.length === 0;
+
+    return getMcpStatus(context, showDescriptions, showSchema, showTips);
+  },
+};