feat: simple MCP example

app/mcp/client.ts

@@ -0,0 +1,87 @@
+import { Client } from "@modelcontextprotocol/sdk/client/index.js";
+import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
+import { MCPClientLogger } from "./logger";
+import { z } from "zod";
+
+export interface ServerConfig {
+  command: string;
+  args?: string[];
+  env?: Record<string, string>;
+}
+
+const logger = new MCPClientLogger();
+
+export async function createClient(
+  serverConfig: ServerConfig,
+  name: string,
+): Promise<Client> {
+  logger.info(`Creating client for server ${name}`);
+
+  const transport = new StdioClientTransport({
+    command: serverConfig.command,
+    args: serverConfig.args,
+    env: serverConfig.env,
+  });
+  const client = new Client(
+    {
+      name: `nextchat-mcp-client-${name}`,
+      version: "1.0.0",
+    },
+    {
+      capabilities: {
+        roots: {
+          // listChanged indicates whether the client will emit notifications when the list of roots changes.
+          // listChanged 指示客户端在根列表更改时是否发出通知。
+          listChanged: true,
+        },
+      },
+    },
+  );
+  await client.connect(transport);
+  return client;
+}
+
+interface Primitive {
+  type: "resource" | "tool" | "prompt";
+  value: any;
+}
+
+/** List all resources, tools, and prompts */
+export async function listPrimitives(client: Client) {
+  const capabilities = client.getServerCapabilities();
+  const primitives: Primitive[] = [];
+  const promises = [];
+  if (capabilities?.resources) {
+    promises.push(
+      client.listResources().then(({ resources }) => {
+        resources.forEach((item) =>
+          primitives.push({ type: "resource", value: item }),
+        );
+      }),
+    );
+  }
+  if (capabilities?.tools) {
+    promises.push(
+      client.listTools().then(({ tools }) => {
+        tools.forEach((item) => primitives.push({ type: "tool", value: item }));
+      }),
+    );
+  }
+  if (capabilities?.prompts) {
+    promises.push(
+      client.listPrompts().then(({ prompts }) => {
+        prompts.forEach((item) =>
+          primitives.push({ type: "prompt", value: item }),
+        );
+      }),
+    );
+  }
+  await Promise.all(promises);
+  return primitives;
+}
+
+export async function executeRequest(client: Client, request: any) {
+  const r = client.request(request, z.any());
+  console.log(r);
+  return r;
+}