add streamable-http transport

Author: yinebebt

Dockerfile

@@ -0,0 +1,33 @@
+FROM golang:1.23-alpine AS builder
+
+RUN apk add --no-cache git ca-certificates
+
+WORKDIR /app
+
+COPY go.mod go.sum ./
+RUN go mod download
+
+COPY . .
+RUN GOOS=linux go build -o mcp-calculator-server ./server.go
+
+FROM alpine:3.21
+
+RUN apk --no-cache add ca-certificates wget
+
+RUN addgroup -g 1001 -S mcp && \
+    adduser -S -D -H -u 1001 -s /sbin/nologin -G mcp mcp
+
+WORKDIR /app
+
+COPY --from=builder /app/mcp-calculator-server .
+
+RUN chown mcp:mcp mcp-calculator-server
+
+USER mcp
+
+EXPOSE 8080
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD wget --no-verbose --tries=1 --spider http://localhost:8080/health || exit 1
+
+CMD ["./mcp-calculator-server"]

README.md

@@ -1,55 +1,87 @@
 # MCP Calculator Server
 
-A Model Context Protocol (MCP) server that provides calculator functionality for MCP clients.
+A Model Context Protocol (MCP) server that provides calculator functionality with support for mathematical expressions.
 
 ## Features
 
-- **Mathematical Operations**: Supports addition (+), subtraction (-), multiplication (*), and division (/)
-- **MCP Protocol Compliance**: Fully compatible with Claude Desktop and other MCP clients
+- **Mathematical Operations**: Addition (+), subtraction (-), multiplication (*), division (/)
+- **Expression Parsing**: Proper operator precedence and parentheses support
+- **Dual Transport Modes**:
+  - **stdio** for local development and MCP Inspector
+  - **streamable-http** for web deployments and containers
+- **Health Check Endpoint**: Health monitoring for HTTP deployments
+
+## Transport Configuration
+
+Simple environment-based configuration:
+
+```bash
+TRANSPORT=stdio        # For local development/debugging
+TRANSPORT=streamable-http  # For web deployments (default)
+```
+
+Default Behavior
+
+- **Default**: `streamable-http` (if no TRANSPORT is set)
+- **Port**: 8080 (configurable via PORT environment variable)
 
 ## Installation
 
+Build the server:
+
+```bash
+go build -o mcp-calculator-server server.go
+```
+
+## Usage
+
+### Local Development (stdio)
+
 ```bash
-go install github.com/yinebebt/mcp-calculator-server
+TRANSPORT=stdio ./mcp-calculator-server
 ```
 
-## Configuration
+### Web Deployment (streamable-http, default)
 
-### Claude Desktop Configuration
+```bash
+./mcp-calculator-server
+# or explicitly:
+TRANSPORT=streamable-http PORT=8080 ./mcp-calculator-server
+```
 
-Add this server to your Claude Desktop configuration file:
+### MCP Inspector Configuration
 
-```json
-{
-  "mcpServers": {
-    "calculator": {
-      "command": "/path/to/mcp-calculator-server"
-    }
-  }
-}
+```bash
+Command: /path/to/calculator-server
+Environment: TRANSPORT=stdio
 ```
 
-### Restart Claude Desktop
+### Testing with Client
 
-After updating the configuration, restart Claude Desktop to load the new server.
+```bash
+go run -tags=client client.go ./calculator-server
+```
 
-## Usage
+## HTTP Endpoints (streamable-http mode)
 
-Once configured, you can ask Claude to perform calculations like "Can you calculate 2 + 3?"
+- **MCP Endpoint**: `http://localhost:8080/mcp`
+- **Health Check**: `http://localhost:8080/health`
 
 ## Tool Reference
 
 ### calculate
 
-Performs basic mathematical operations.
+Performs mathematical operations with proper operator precedence and implicit multiplication.
 
 **Parameters:**
-- `expression` (string, required): A mathematical expression to evaluate
 
-**Supported operations:**
+- `expression` (string, required): Mathematical expression to evaluate
+
+**Supported Operations:**
+
 - Addition: `+`
 - Subtraction: `-`
 - Multiplication: `*`
 - Division: `/`
 - Parentheses: `()` for grouping
-- Negative numbers: `-5`, `(-3 + 2)`
+- Negative numbers: `-5`, `(-3 + 2)`

client.go

@@ -45,7 +45,7 @@ type Client struct {
 func main() {
 	if len(os.Args) < 2 {
 		fmt.Println("Usage: go run -tags=client client.go <your-mcp-server-binary> [args...]")
-		fmt.Println("Example: go run -tags=client client.go ./mcp-calculator-server")
+		fmt.Println("Example: go run -tags=client client.go ./calculator-server")
 		os.Exit(1)
 	}
 
@@ -55,6 +55,9 @@ func main() {
 	args := os.Args[2:] // Skip program name and server binary
 	cmd := exec.Command(os.Args[1], args...)
 
+	// Set environment to force stdio transport mode
+	cmd.Env = append(os.Environ(), "TRANSPORT=stdio")
+
 	stdin, err := cmd.StdinPipe()
 	if err != nil {
 		fmt.Printf("Error creating stdin pipe: %v\n", err)
@@ -262,8 +265,9 @@ func (c *Client) printMenu() {
 
 func (c *Client) testBasicCalculation() {
 	fmt.Println("\nRunning calculation test...")
+
 	expr := "((2 + 3) * -4) / 2"
-	result, err := c.callCalculator("((2 + 3) * -4) / 2")
+	result, err := c.callCalculator(expr)
 	if err != nil {
 		fmt.Printf(" %s = ERROR: %v\n", expr, err)
 	} else {