MCP Tools — ManyAI Desktop

Overview

ManyAI Desktop implements an MCP (Model Context Protocol) client. It connects to external MCP servers — stdio child processes or HTTP endpoints — and exposes their tools dynamically to the agent loop. MCP tools are namespaced and merged with the 9 native agent tools at the start of every agent run.

McpClientManager (`src/main/mcp.ts`)

Singleton in the main process. Manages connection lifecycle for all configured MCP servers. Server configurations are persisted to userData/mcp-servers.json and all saved servers are reconnected on app start.

Method	Description
`connect(config)`	Spawns or connects to a server, lists its tools, stores the client
`disconnect(name)`	Closes the transport and removes the client from memory
`addServer(config)`	Upserts config to disk, disconnects any existing connection, reconnects
`removeServer(name)`	Disconnects and removes config from disk
`connectAll()`	Called at app start — reconnects all saved configs silently
`listAllTools()`	Returns flat list of all tools from all connected servers
`callTool(serverName, toolName, args)`	Forwards a tool call to the named server; returns result string

SDK & Transports

Uses @modelcontextprotocol/sdk@1.29.0 — Anthropic's official MCP client SDK.

stdio: StdioClientTransport — spawns a child process, communicates over stdin/stdout. Suitable for local MCP servers (e.g. npx @modelcontextprotocol/server-filesystem).
HTTP: StreamableHTTPClientTransport — connects to a remote HTTP endpoint. Suitable for cloud-hosted MCP servers.

Server Config Schema

interface McpServerConfig {
  name: string           // unique identifier — used as the namespace prefix
  transport: 'stdio' | 'http'
  // stdio fields:
  command?: string       // e.g. "npx"
  args?: string[]        // e.g. ["-y", "@modelcontextprotocol/server-filesystem", "/path"]
  env?: Record<string, string>  // extra environment variables for the child process
  // http fields:
  url?: string           // e.g. "http://localhost:3000"
}

IPC Channels (`src/main/ipc/mcpIpc.ts`)

Channel	Description
`mcp-list-servers`	Returns all configs + live status (connected/error) and tool count per server
`mcp-add-server`	Upserts a server config and connects; returns `{ ok, error? }`
`mcp-remove-server`	Disconnects and removes config from disk
`mcp-reconnect`	Disconnects and reconnects a named server; returns `{ ok, error? }`
`mcp-list-tools`	Returns all tools from all connected servers: fullName, description, inputSchema, serverName
`mcp-call-tool`	Calls a tool on a named server with args; returns `{ result }` or `{ error }`

Tool Naming Convention

All MCP tools are prefixed to prevent collisions with native agent tools:

mcp__<serverName>__<toolName>

Examples: mcp__filesystem__read_file, mcp__my-db__query_table. Native tools never begin with mcp__, so dispatch routing is unambiguous.

Agent Loop Integration

At the start of every runAgentLoop() call (src/renderer/src/lib/agentLoop.ts):

Calls window.api.listTools() to discover all currently-connected MCP tools
Builds a mcpToolIndex: Map<string, { serverName, toolName }>
Converts each MCP tool to OpenAI function format via buildMcpToolDef()
Merges MCP defs with the 9 native tools into allTools
Sends the merged list to the model in every API call within the run

When the model calls an MCP tool, executeTool() detects the mcp__ prefix, looks up the entry in mcpToolIndex, and forwards to window.api.callTool(serverName, toolName, args). The result is a plain string tool result returned to the model. MCP tools display the 🔌 emoji in the agent event log.

McpTool Interface (`src/preload/types/mcp.ts`)

interface McpTool {
  name: string           // raw tool name as reported by the server
  fullName: string       // namespaced: mcp__serverName__name
  description?: string
  inputSchema: Record<string, unknown>  // JSON Schema for parameters
  serverName: string     // which server this tool came from
}

Settings UI (`src/renderer/src/features/settings/McpScreen.tsx`)

Accessible via Settings → MCP tab. Features:

Server list: name, status dot (colored by connected/error), tool count, command+args or URL
Add Server form: name, transport selector, command/args/env fields (stdio) or URL field (HTTP)
Edit button: pre-fills the form with the existing config; name field is locked (readOnly) during edit; save button label changes to "Save & Reconnect"
Reconnect button: triggers a disconnect + reconnect cycle in place
Remove button: disconnects and deletes the config permanently
Tool viewer (ToolList): shown at the bottom when at least one server has connected tools — lists each tool's fullName and description

Overview

McpClientManager (src/main/mcp.ts)