Overview

import { Agentica, assertMcpController } from "@wrtnlabs/agentica";
import { StdioClientTransport } from "@modelcontextprotocol/sdk/client/stdio.js";
import { Client } from "@modelcontextprotocol/sdk/client/index.js";
 
const client = new Client({
  name: "calculator",
  version: "1.0.0",
});
 
await client.connect(new StdioClientTransport({
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-github"],
  env: {
    GITHUB_PERSONAL_ACCESS_TOKEN: process.env.GITHUB_PERSONAL_ACCESS_TOKEN,
    // Add other environment variables as needed
  }
}));
 
const agent = new Agentica({
  model: "chatgpt",
  vendor: {
    api: new OpenAI({ apiKey: "*****"})
    model: "gpt-4o-mini"
  },
  controllers: [
    await assertMcpController({
      name: "calculator",
      model: "chatgpt",
      client,
    }),
  ],
});
await agent.conversate("What can you do?");

MCP (Model Context Protocol) is a protocol for connecting LLM applications with various transports. Currently, MCP only supports tools functionality, while prompts and resources are not yet supported.

To use MCP, you need to install the MCP SDK package separately:

npm install @modelcontextprotocol/sdk

Transport Options

Stdio Transport

The example above uses StdioClientTransport which is suitable for Node.js environments.

SSE Transport

For Server-Sent Events (SSE) connections, you should use the SseClientTransport instead. This is particularly useful for web-based applications.

import { SseClientTransport } from "@modelcontextprotocol/sdk/client/sse.js";
 
await client.connect(new SseClientTransport({
  url: "your-sse-endpoint"
}));

Authentication

Transport Authentication

For Stdio transport, you can pass environment variables to the child process:

await client.connect(new StdioClientTransport({
  command: "npx",
  args: ["-y", "@modelcontextprotocol/server-github"],
  env: {
    GITHUB_PERSONAL_ACCESS_TOKEN: process.env.GITHUB_PERSONAL_ACCESS_TOKEN,
    // Add other environment variables as needed
  }
}));

Important Notes

Connection Requirements

The await client.connect() call is mandatory. If you omit this step, the application will throw an error as the client needs to establish a connection before it can be used.

Browser Compatibility

Note that StdioClientTransport uses Node.js’s child_process module internally, which means it will not work in browser environments. For browser-based applications, you should use SseClientTransport instead.

Feature Support

Currently, MCP only supports tools functionality. Prompts and resources are not yet supported in the current version.

LLM Model Compatibility

The compatibility of custom MCP servers with different LLM models may vary. This is because each LLM model supports different JSON schemas for function calling. If an MCP server provides a schema that doesn’t match the LLM’s expected format, the model may not be able to understand or properly use the provided tools. Always verify that your MCP server’s schema is compatible with your chosen LLM model.