StreamableHttp - update docs (#664)

Author: ihrpr

README.md

@@ -66,7 +66,7 @@ The Model Context Protocol allows applications to provide context for LLMs in a
 
 - Build MCP clients that can connect to any MCP server
 - Create MCP servers that expose resources, prompts and tools
-- Use standard transports like stdio and SSE
+- Use standard transports like stdio, SSE, and Streamable HTTP
 - Handle all MCP protocol messages and lifecycle events
 
 ## Installation
@@ -387,8 +387,81 @@ python server.py
 mcp run server.py
 ```
 
+### Streamable HTTP Transport
+
+> **Note**: Streamable HTTP transport is superseding SSE transport for production deployments.
+
+```python
+from mcp.server.fastmcp import FastMCP
+
+# Stateful server (maintains session state)
+mcp = FastMCP("StatefulServer")
+
+# Stateless server (no session persistence)
+mcp = FastMCP("StatelessServer", stateless_http=True)
+
+# Run server with streamable_http transport
+mcp.run(transport="streamable-http")
+```
+
+You can mount multiple FastMCP servers in a FastAPI application:
+
+```python
+# echo.py
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP(name="EchoServer", stateless_http=True)
+
+
+@mcp.tool(description="A simple echo tool")
+def echo(message: str) -> str:
+    return f"Echo: {message}"
+```
+
+```python
+# math.py
+from mcp.server.fastmcp import FastMCP
+
+mcp = FastMCP(name="MathServer", stateless_http=True)
+
+
+@mcp.tool(description="A simple add tool")
+def add_two(n: int) -> str:
+    return n + 2
+```
+
+```python
+# main.py
+from fastapi import FastAPI
+from mcp.echo import echo
+from mcp.math import math
+
+
+app = FastAPI()
+
+# Use the session manager's lifespan
+app = FastAPI(lifespan=lambda app: echo.mcp.session_manager.run())
+app.mount("/echo", echo.mcp.streamable_http_app())
+app.mount("/math", math.mcp.streamable_http_app())
+```
+
+For low level server with Streamable HTTP implementations, see:
+- Stateful server: [`examples/servers/simple-streamablehttp/`](examples/servers/simple-streamablehttp/)
+- Stateless server: [`examples/servers/simple-streamablehttp-stateless/`](examples/servers/simple-streamablehttp-stateless/)
+
+
+
+The streamable HTTP transport supports:
+- Stateful and stateless operation modes
+- Resumability with event stores
+- JSON or SSE response formats  
+- Better scalability for multi-node deployments
+
+
 ### Mounting to an Existing ASGI Server
 
+> **Note**: SSE transport is being superseded by [Streamable HTTP transport](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http).
+
 You can mount the SSE server to an existing ASGI server using the `sse_app` method. This allows you to integrate the SSE server with other ASGI applications.
 
 ```python
@@ -621,7 +694,7 @@ if __name__ == "__main__":
 
 ### Writing MCP Clients
 
-The SDK provides a high-level client interface for connecting to MCP servers:
+The SDK provides a high-level client interface for connecting to MCP servers using various [transports](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports):
 
 ```python
 from mcp import ClientSession, StdioServerParameters, types
@@ -685,6 +758,28 @@ if __name__ == "__main__":
     asyncio.run(run())
 ```
 
+Clients can also connect using [Streamable HTTP transport](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports#streamable-http):
+
+```python
+from mcp.client.streamable_http import streamablehttp_client
+from mcp import ClientSession
+
+
+async def main():
+    # Connect to a streamable HTTP server
+    async with streamablehttp_client("example/mcp") as (
+        read_stream,
+        write_stream,
+        _,
+    ):
+        # Create a session using the client streams
+        async with ClientSession(read_stream, write_stream) as session:
+            # Initialize the connection
+            await session.initialize()
+            # Call a tool
+            tool_result = await session.call_tool("echo", {"message": "hello"})
+```
+
 ### MCP Primitives
 
 The MCP protocol defines three core primitives that servers can implement: