✨ feat: add Model Context Protocol (MCP) support (#2809)

* ✨ feat: add Model Context Protocol (MCP) server configuration (main)

- Added `@modelcontextprotocol/sdk` dependency for MCP integration.
- Introduced MCP server configuration UI in settings with add, edit, delete, and activation functionalities.
- Created `useMCPServers` hook to manage MCP server state and actions.
- Added i18n support for MCP settings with translation keys.
- Integrated MCP settings into the application's settings navigation and routing.
- Implemented Redux state management for MCP servers.
- Updated `yarn.lock` with new dependencies and their resolutions.

* 🌟 feat: implement mcp service and integrate with ipc handlers

- Added `MCPService` class to manage Model Context Protocol servers.
- Implemented various handlers in `ipc.ts` for managing MCP servers including listing, adding, updating, deleting, and activating/deactivating servers.
- Integrated MCP related types into existing type declarations for consistency across the application.
- Updated `preload` to expose new MCP related APIs to the renderer process.
- Enhanced `MCPSettings` component to interact directly with the new MCP service for adding, updating, deleting servers and setting their active states.
- Introduced selectors in the MCP Redux slice for fetching active and all servers from the store.
- Moved MCP types to a centralized location in `@renderer/types` for reuse across different parts of the application.

* feat: enhance MCPService initialization to prevent recursive calls and improve error handling

* feat: enhance MCP integration by adding MCPTool type and updating related methods

* feat: implement streaming support for tool calls in OpenAIProvider and enhance message processing

src/preload/index.d.ts

@@ -1,9 +1,7 @@
 import { ElectronAPI } from '@electron-toolkit/preload'
 import type { FileMetadataResponse, ListFilesResponse, UploadFileResponse } from '@google/generative-ai/server'
 import { ExtractChunkData } from '@llm-tools/embedjs-interfaces'
-import { FileType } from '@renderer/types'
-import { WebDavConfig } from '@renderer/types'
-import { AppInfo, KnowledgeBaseParams, KnowledgeItem, LanguageVarious } from '@renderer/types'
+import { AppInfo, FileType, KnowledgeBaseParams, KnowledgeItem, LanguageVarious, WebDavConfig } from '@renderer/types'
 import type { LoaderReturn } from '@shared/config/types'
 import type { OpenDialogOptions } from 'electron'
 import type { UpdateInfo } from 'electron-updater'
@@ -123,6 +121,19 @@ declare global {
       shell: {
         openExternal: (url: string, options?: OpenExternalOptions) => Promise<void>
       }
+      mcp: {
+        // servers
+        listServers: () => Promise<MCPServer[]>
+        addServer: (server: MCPServer) => Promise<void>
+        updateServer: (server: MCPServer) => Promise<void>
+        deleteServer: (serverName: string) => Promise<void>
+        setServerActive: (name: string, isActive: boolean) => Promise<void>
+        // tools
+        listTools: () => Promise<MCPTool>
+        callTool: ({ client, name, args }: { client: string; name: string; args: any }) => Promise<any>
+        // status
+        cleanup: () => Promise<void>
+      }
     }
   }
 }

src/preload/index.ts

@@ -1,5 +1,5 @@
 import { electronAPI } from '@electron-toolkit/preload'
-import { FileType, KnowledgeBaseParams, KnowledgeItem, Shortcut, WebDavConfig } from '@types'
+import { FileType, KnowledgeBaseParams, KnowledgeItem, MCPServer, Shortcut, WebDavConfig } from '@types'
 import { contextBridge, ipcRenderer, OpenDialogOptions, shell } from 'electron'
 
 // Custom APIs for renderer
@@ -106,6 +106,17 @@ const api = {
     decrypt: (encryptedData: string, iv: string, secretKey: string) =>
       ipcRenderer.invoke('aes:decrypt', encryptedData, iv, secretKey)
   },
+  mcp: {
+    listServers: () => ipcRenderer.invoke('mcp:list-servers'),
+    addServer: (server: MCPServer) => ipcRenderer.invoke('mcp:add-server', server),
+    updateServer: (server: MCPServer) => ipcRenderer.invoke('mcp:update-server', server),
+    deleteServer: (serverName: string) => ipcRenderer.invoke('mcp:delete-server', serverName),
+    setServerActive: (name: string, isActive: boolean) =>
+      ipcRenderer.invoke('mcp:set-server-active', { name, isActive }),
+    listTools: (serverName?: string) => ipcRenderer.invoke('mcp:list-tools', serverName),
+    callTool: (params: { client: string; name: string; args: any }) => ipcRenderer.invoke('mcp:call-tool', params),
+    cleanup: () => ipcRenderer.invoke('mcp:cleanup')
+  },
   shell: {
     openExternal: shell.openExternal
   }