import { Client } from "@modelcontextprotocol/sdk/client/index.js"
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js"
export interface MCPConnection {
client: Client
transport: StdioClientTransport
}
/**
* Connect to an external MCP server via stdio
*/
export async function connectToMCPServer(
command: string,
args: string[] = [],
options?: {
cwd?: string
env?: Record<string, string>
}
): Promise<MCPConnection> {
// Create the client
const client = new Client(
{
name: "next-devtools-mcp-client",
version: "0.1.0",
},
{
capabilities: {},
}
)
// Create stdio transport with server parameters
const transport = new StdioClientTransport({
command,
args,
cwd: options?.cwd,
env: options?.env,
stderr: "pipe", // Pipe stderr so we can listen to it
})
// Listen to stderr for debugging
const stderrStream = transport.stderr
if (stderrStream) {
stderrStream.on("data", (data) => {
console.error(`[MCP Server stderr]: ${data}`)
})
}
// Connect client to transport (this also starts the server process)
await client.connect(transport)
return {
client,
transport,
}
}
/**
* Check if a tool is available on the connected MCP server
*/
export async function listServerTools(connection: MCPConnection): Promise<string[]> {
try {
const result = await connection.client.listTools()
return result.tools.map((tool) => tool.name)
} catch (error) {
console.error("Failed to list tools:", error)
return []
}
}
/**
* Call a tool on the connected MCP server
*/
export async function callServerTool(
connection: MCPConnection,
toolName: string,
args: Record<string, unknown>
): Promise<unknown> {
try {
const result = await connection.client.callTool({
name: toolName,
arguments: args,
})
return result
} catch (error) {
console.error(`Failed to call tool ${toolName}:`, error)
throw error
}
}
/**
* Disconnect from MCP server and cleanup
*/
export async function disconnectFromMCPServer(connection: MCPConnection): Promise<void> {
try {
await connection.transport.close()
await connection.client.close()
} catch (error) {
console.error("Error disconnecting from MCP server:", error)
throw error
}
}
