@nest-mcp/client

NestJS module for connecting to and consuming Model Context Protocol (MCP) servers with typed injection, notifications, health checks, and reconnection support.

Installation

npm install @nest-mcp/client @modelcontextprotocol/sdk zod@^4
npm install @nestjs/common @nestjs/core reflect-metadata rxjs

Quick start

// app.module.ts
import { Module } from '@nestjs/common';
import { McpClientModule } from '@nest-mcp/client';
import { McpTransportType } from '@nest-mcp/client';

@Module({
  imports: [
    McpClientModule.forRoot({
      connections: [
        {
          name: 'my-server',
          transport: {
            type: McpTransportType.STREAMABLE_HTTP,
            url: 'http://localhost:3000/mcp',
          },
        },
      ],
    }),
  ],
})
export class AppModule {}

// my.service.ts
import { Injectable } from '@nestjs/common';
import { InjectMcpClient, McpClient } from '@nest-mcp/client';

@Injectable()
export class MyService {
  constructor(@InjectMcpClient('my-server') private client: McpClient) {}

  async greet(name: string) {
    return this.client.callTool({ name: 'greet', arguments: { name } });
  }
}

Features

• @InjectMcpClient(name) — inject a named client into any service
• McpClientsService — programmatic access to all clients by name
• @OnMcpNotification(method) — subscribe to server-sent notifications
• McpClientHealthIndicator — health check integration (NestJS Terminus)
• Automatic reconnection with configurable backoff
• OAuth support for authenticated servers

Transports

• Streamable HTTP (McpTransportType.STREAMABLE_HTTP)
• SSE (McpTransportType.SSE)
• STDIO (McpTransportType.STDIO)

Documentation

Full documentation: github.com/btwld/nest-mcp/docs/client

License

BSD-3-Clause