@vercel/mcp-adapter
A Vercel adapter for the Model Context Protocol (MCP), enabling real-time communication between your applications and AI models. Currently supports Next.js with more framework adapters coming soon.
[!WARNING] This package is pinned to
@modelcontextprotocol/sdk@1.12.0to ensure compatibility and stability. Using a different version may cause unexpected behavior.
Installation
npm install @vercel/mcp-adapter @modelcontextprotocol/sdk
# or
yarn add @vercel/mcp-adapter @modelcontextprotocol/sdk
# or
pnpm add @vercel/mcp-adapter @modelcontextprotocol/sdk
# or
bun add @vercel/mcp-adapter @modelcontextprotocol/sdk
Next.js Usage
// app/api/[transport]/route.ts
import { createMcpHandler } from '@vercel/mcp-adapter';
const handler = createMcpHandler(
server => {
server.tool(
'roll_dice',
'Rolls an N-sided die',
{
sides: z.number().int().min(2)
},
async ({ sides }) => {
const value = 1 + Math.floor(Math.random() * sides);
return {
content: [{ type: 'text', text: `🎲 You rolled a ${value}!` }],
};
}
);
},
{
// Optional server options
},
{
// Optional redis config
redisUrl: process.env.REDIS_URL,
// You need these endpoints
basePath: '/api', // this needs to match where the [transport] is located.
// @deprecated use 'basePath' instead
streamableHttpEndpoint?: string; // Endpoint for streamable HTTP transport
// @deprecated use 'basePath' instead
sseEndpoint?: string; // Endpoint for SSE transport
// @deprecated use 'basePath' instead
sseMessageEndpoint?: string; // Endpoint for SSE message transport
maxDuration: 60,
verboseLogs: true,
}
);
export { handler as GET, handler as POST };
Integrating into your client
When you want to use it in your MCP client of choice:
Claude Desktop
In order to add an MCP server to Claude Desktop you need to edit the configuration file located at:
"remote-example": {
"command": "npx",
"args": [
"mcp-remote",
"http://localhost:3000/api/mcp" // this is your app/api/[transport]/route.ts
]
}
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json If it does not exist yet, you may need to enable it under Settings > Developer.
Restart Claude Desktop to pick up the changes in the configuration file. Upon restarting, you should see a hammer icon in the bottom right corner of the input box.
Cursor
The configuration file is located at ~/.cursor/mcp.json.
As of version 0.48.0, Cursor supports unauthed SSE servers directly. If your MCP server is using the official MCP OAuth authorization protocol, you still need to add a "command" server and call mcp-remote.
Windsurf
The configuration file is located at ~/.codeium/windsurf/mcp_config.json.
Usage in your app
- Use the MCP client in your application:
// app/components/YourComponent.tsx
import { McpClient } from "@modelcontextprotocol/sdk/client";
const client = new McpClient({
// When using basePath, the SSE endpoint will be automatically derived
transport: new SSEClientTransport("/api/mcp/mcp"),
});
// Use the client to make requests
const result = await client.request("yourMethod", { param: "value" });
Configuration Options
The initializeMcpApiHandler function accepts the following configuration options:
interface Config {
redisUrl?: string; // Redis connection URL for pub/sub
basePath?: string; // string; // Base path for MCP endpoints
maxDuration?: number; // Maximum duration for SSE connections in seconds
verboseLogs?: boolean; // Log debugging information
}
Features
- Framework Support: Currently supports Next.js with more framework adapters coming soon
- Multiple Transport Options: Supports both Streamable HTTP and Server-Sent Events (SSE) transports
- Redis Integration: For SSE transport resumability
- TypeScript Support: Full TypeScript support with type definitions
Requirements
- Next.js 13 or later (for Next.js adapter)
- Node.js 18 or later
- Redis (optional, for SSE transport)
License
Apache-2.0