Sample MCP Server with SSE (Golang)

A Model Context Protocol (MCP) server implementation in Go using the official MCP Go SDK with Server-Sent Events (SSE) transport.

Features

This MCP server provides 3 tools:

1. calculate - Performs basic arithmetic operations (add, subtract, multiply, divide)
2. generate_uuid - Generates a random UUID (v4)
3. reverse_string - Reverses a given string

Requirements

• Go 1.23 or later
• Docker (for containerization)
• Kubernetes cluster (for deployment)

Architecture

Built with the official MCP Go SDK (github.com/modelcontextprotocol/go-sdk), this server:

• Uses the SDK's built-in SSE transport implementation
• Automatically handles JSON-RPC 2.0 protocol
• Provides comprehensive logging for debugging
• Includes CORS support for browser-based clients

Endpoints

• /sse - SSE endpoint for establishing the event stream (handled by SDK)
• /health - Health check endpoint

Installation

cd sample-mcp-server-sse
go mod download
go build -o mcp-server

Running the Server

./mcp-server

The server will start on http://localhost:8080

Kubernetes Deployment

Build and Push Docker Image

cd sample-mcp-server-sse

# Build for linux/amd64 architecture
docker build -t aliok/mcp-server-sse:latest .

# Push to Docker Hub (or your registry)
docker push aliok/mcp-server-sse:latest

Note: Replace aliok with your Docker Hub username or registry path. The Dockerfile is configured to build for linux/amd64 architecture.

Deploy to Kubernetes

Deploy using kubectl:

# Apply manifests
kubectl apply -f k8s/

Note: The deployment uses aliok/mcp-server-sse:latest. Update k8s/deployment.yaml if using a different registry.

Verify Deployment

# Check deployment status
kubectl get deployments mcp-server-sse

# Check pods
kubectl get pods -l app=mcp-server-sse

# Check service
kubectl get svc mcp-server-sse

Access the Service

Using kubectl proxy (for remote clusters)

For remote Kubernetes clusters, use kubectl proxy to access the service:

# Start kubectl proxy (this will run in the foreground)
kubectl proxy --port=8001

The service will be available at:

http://localhost:8001/api/v1/namespaces/default/services/mcp-server-sse:http/proxy/

For the SSE endpoint specifically:

http://localhost:8001/api/v1/namespaces/default/services/mcp-server-sse:http/proxy/sse

For the health endpoint:

http://localhost:8001/api/v1/namespaces/default/services/mcp-server-sse:http/proxy/health

Port Forward (for testing)

kubectl port-forward svc/mcp-server-sse 8080:80

Then access at http://localhost:8080

Ingress (for production)

Create an Ingress resource to expose the service:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: mcp-server-sse
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: mcp-server.example.com
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: mcp-server-sse
            port:
              number: 80

Kubernetes Configuration

The deployment includes:

• Replicas: 2 pods for high availability
• Health Checks: Liveness and readiness probes on /health
• Resources: CPU and memory limits configured
• Service: ClusterIP service on port 80

To scale the deployment:

kubectl scale deployment mcp-server-sse --replicas=3

Clean Up

kubectl delete -k k8s/

Testing with MCP Inspector

The MCP Inspector is a visual interface for testing and debugging MCP servers. It provides an interactive way to explore your server's tools and test them without writing code.

Prerequisites

Install the MCP Inspector:

npx @modelcontextprotocol/inspe

... [View full README on GitHub](https://github.com/mcp-kube/sample-mcp-server-sse#readme)