The HTTP transport provides standard MCP JSON-RPC over HTTP POST requests. This is the default transport and offers maximum compatibility with existing MCP clients and tools.

Overview

The HTTP transport implements a basic HTTP/1.1 server that:

• Listens on TCP port 8080 (configurable via MCP_HTTP_PORT)
• Accepts POST requests with JSON-RPC payloads
• Returns JSON-RPC responses in the HTTP body
• Uses one request per connection (connection closes after reply)

This is a minimal implementation focused on MCP compliance, not a full-featured HTTP server.

Supported Platforms

• Linux (native BSD sockets)
• Zephyr RTOS (native_sim, ESP32 with WiFi)

Usage

Linux

# Build with HTTP transport (default)
mkdir -p build && cd build
cmake .. -DMCP_ENABLE_EXAMPLES=ON
cmake --build .

# Run server
./examples/linux/mcp_server/mcp-linux-mcp_server
# Server listens on http://0.0.0.0:8080

Zephyr

# Build for ESP32
./scripts/build-zephyr.sh -b esp32_devkitc/esp32/procpu \
  --wifi-ssid "YOUR_SSID" --wifi-pass "YOUR_PASSWORD"

# Flash and monitor
cd examples/zephyr/mcp_server
west flash && west espressif monitor

Testing

# Initialize session
curl -X POST http://localhost:8080 \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":"1","method":"initialize","params":{}}'

# List tools
curl -X POST http://localhost:8080 \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":"2","method":"tools/list","params":{}}'

# Call tool
curl -X POST http://localhost:8080 \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":"3","method":"tools/call","params":{"name":"echo","arguments":{"text":"hello"}}}'

Configuration

typedef struct {
    uint16_t port;        // TCP port (default: 8080)
    const char *bind_addr; // Bind address (default: "0.0.0.0")
} mcp_http_config_t;