feat: Modernize to Streamable HTTP transport with JSON-RPC 2.0

CLAUDE.md

@@ -8,16 +8,16 @@ WebCat is a **Model Context Protocol (MCP) server** that provides web search and
 
 1. **Web Search Tool**: Search the web using Serper API or DuckDuckGo fallback
 2. **Content Extraction**: Full webpage scraping with markdown conversion using Readability
-3. **MCP Compliance**: SSE transport for compatibility with Claude Desktop and LiteLLM
+3. **MCP Compliance**: Streamable HTTP transport with JSON-RPC 2.0 for compatibility with all MCP clients
 
-**Tech Stack**: Python, FastAPI, FastMCP, BeautifulSoup, Readability, html2text, Serper/DuckDuckGo
+**Tech Stack**: Python, FastMCP, BeautifulSoup, Readability, html2text, Serper/DuckDuckGo
 
 ## Architecture
 
 ### High-Level Flow
 
 ```
-MCP Client → FastMCP Server (SSE) → Search Tool Decision
+MCP Client → FastMCP Server (Streamable HTTP + JSON-RPC 2.0) → Search Tool Decision
 │
 ├─ Serper API (premium): Google-powered search with better ranking
 │
@@ -28,8 +28,8 @@ MCP Client → FastMCP Server (SSE) → Search Tool Decision
 
 ### Key Components
 
-**MCP Server (Python/FastAPI)**:
-- `docker/mcp_server.py` - FastMCP server with SSE transport
+**MCP Server (Python/FastMCP)**:
+- `docker/mcp_server.py` - FastMCP server with Streamable HTTP transport
 - `docker/health.py` - Health check and status endpoints
 - `docker/demo_server.py` - Demo client interface
 - `docker/api_tools.py` - Additional API tooling
@@ -418,8 +418,8 @@ def fetch_newsource_search_results(query: str) -> List[Dict[str, Any]]:
 
 ## Important Notes
 
-- **MCP Protocol**: Uses SSE (Server-Sent Events) transport for LiteLLM compatibility
-- **No Authentication**: Simplified setup - no API keys required for basic functionality
+- **MCP Protocol**: Uses Streamable HTTP transport with JSON-RPC 2.0 (modern, future-proof)
+- **Optional Authentication**: Bearer token auth available but not required for basic functionality
 - **Automatic Fallback**: Serper API → DuckDuckGo if no key or if Serper fails
 - **Content Processing**: Readability + html2text for clean markdown conversion
 - **Rate Limiting**: Default 10 requests per 60 seconds (configurable via env vars)

README.md

@@ -41,10 +41,10 @@ python mcp_server.py
 WebCat is an **MCP (Model Context Protocol) server** that provides AI models with:
 - 🔍 **Web Search** - Serper API (premium) or DuckDuckGo (free fallback)
 - 📄 **Content Extraction** - Clean markdown conversion with Readability + html2text
-- 🌐 **SSE Streaming** - Real-time results via Server-Sent Events
+- 🌐 **Modern HTTP Transport** - Streamable HTTP with JSON-RPC 2.0
 - 🐳 **Multi-Platform Docker** - Works on Intel, ARM, and Apple Silicon
 
-Built with **FastAPI**, **FastMCP**, and **Readability** for seamless AI integration.
+Built with **FastMCP**, **Readability**, and **html2text** for seamless AI integration.
 
 ## Features
 
@@ -96,8 +96,7 @@ make mcp        # Start MCP server
 |----------|-------------|
 | `http://localhost:8000/health` | 💗 Health check |
 | `http://localhost:8000/status` | 📊 Server status |
-| `http://localhost:8000/mcp` | 🛠️ MCP protocol endpoint |
-| `http://localhost:8000/sse` | 🔗 SSE streaming |
+| `http://localhost:8000/mcp` | 🛠️ MCP protocol endpoint (Streamable HTTP with JSON-RPC 2.0) |
 
 ## Configuration
 
@@ -144,7 +143,7 @@ WebCat exposes these tools via MCP:
 ```
 MCP Client (Claude, LiteLLM)
     ↓
-FastMCP Server (SSE Transport)
+FastMCP Server (Streamable HTTP with JSON-RPC 2.0)
     ↓
 Authentication (optional bearer token)
     ↓
@@ -158,8 +157,8 @@ Search Decision
 ```
 
 **Tech Stack:**
-- **FastAPI** - High-performance async web framework
-- **FastMCP** - MCP protocol implementation with SSE transport
+- **FastMCP** - MCP protocol implementation with modern HTTP transport
+- **JSON-RPC 2.0** - Standard protocol for client-server communication
 - **Readability** - Content extraction (removes navigation/ads)
 - **html2text** - HTML to markdown conversion
 - **Serper/DuckDuckGo** - Search APIs with automatic fallback

docker/cli.py

@@ -78,8 +78,10 @@ def main():
             print(f"📡 WebCat MCP Server: http://{args.host}:{args.port}/mcp")
             print("✨ Ready for MCP connections!")
 
-            # Run the FastMCP server
-            mcp_server.run(transport="sse", host=args.host, port=args.port, path="/mcp")
+            # Run the FastMCP server with modern HTTP transport
+            mcp_server.run(
+                transport="http", host=args.host, port=args.port, path="/mcp"
+            )
         except ImportError as e:
             print(f"❌ Error importing MCP server: {e}")
             print("Make sure all dependencies are installed.")

docker/mcp_server.py

@@ -79,9 +79,9 @@ async def search_tool() -> dict:
     port = int(os.environ.get("PORT", 8000))
     logging.info(f"Starting FastMCP server on port {port}")
 
-    # Run the server with SSE transport for LiteLLM compatibility
+    # Run the server with modern HTTP transport (Streamable HTTP with JSON-RPC 2.0)
     mcp_server.run(
-        transport="sse",
+        transport="http",
         host="0.0.0.0",
         port=port,
         path="/mcp",  # Explicit path for MCP endpoint