Add HTTP Stream Transport

aider/args.py

@@ -804,6 +804,13 @@ def get_parser(default_config_files, git_root):
         help="Specify a file path with MCP server configurations",
         default=None,
     )
+    group.add_argument(
+        "--mcp-transport",
+        metavar="MCP_TRANSPORT",
+        help="Specify the transport for MCP servers (default: stdio)",
+        default="stdio",
+        choices=["stdio", "http"],
+    )
     group.add_argument(
         "-c",
         "--config",

aider/main.py

@@ -972,7 +972,9 @@ def get_io(pretty):
 
     try:
         # Load MCP servers from config string or file
-        mcp_servers = load_mcp_servers(args.mcp_servers, args.mcp_servers_file, io, args.verbose)
+        mcp_servers = load_mcp_servers(
+            args.mcp_servers, args.mcp_servers_file, io, args.verbose, args.mcp_transport
+        )
 
         if not mcp_servers:
             mcp_servers = []

aider/mcp/__init__.py

@@ -1,9 +1,9 @@
 import json
 
-from aider.mcp.server import McpServer
+from aider.mcp.server import McpServer, HttpStreamingServer
 
 
-def _parse_mcp_servers_from_json_string(json_string, io, verbose=False):
+def _parse_mcp_servers_from_json_string(json_string, io, verbose=False, mcp_transport="stdio"):
     """Parse MCP servers from a JSON string."""
     servers = []
 
@@ -19,7 +19,11 @@ def _parse_mcp_servers_from_json_string(json_string, io, verbose=False):
 
                 # Create a server config with name included
                 server_config["name"] = name
-                servers.append(McpServer(server_config))
+                transport = server_config.get("transport", mcp_transport)
+                if transport == "stdio":
+                    servers.append(McpServer(server_config))
+                elif transport == "http":
+                    servers.append(HttpStreamingServer(server_config))
 
             if verbose:
                 io.tool_output(f"Loaded {len(servers)} MCP servers from JSON string")
@@ -34,7 +38,7 @@ def _parse_mcp_servers_from_json_string(json_string, io, verbose=False):
     return servers
 
 
-def _parse_mcp_servers_from_file(file_path, io, verbose=False):
+def _parse_mcp_servers_from_file(file_path, io, verbose=False, mcp_transport="stdio"):
     """Parse MCP servers from a JSON file."""
     servers = []
 
@@ -52,7 +56,11 @@ def _parse_mcp_servers_from_file(file_path, io, verbose=False):
 
                 # Create a server config with name included
                 server_config["name"] = name
-                servers.append(McpServer(server_config))
+                transport = server_config.get("transport", mcp_transport)
+                if transport == "stdio":
+                    servers.append(McpServer(server_config))
+                elif transport == "http":
+                    servers.append(HttpStreamingServer(server_config))
 
             if verbose:
                 io.tool_output(f"Loaded {len(servers)} MCP servers from {file_path}")
@@ -69,18 +77,18 @@ def _parse_mcp_servers_from_file(file_path, io, verbose=False):
     return servers
 
 
-def load_mcp_servers(mcp_servers, mcp_servers_file, io, verbose=False):
+def load_mcp_servers(mcp_servers, mcp_servers_file, io, verbose=False, mcp_transport="stdio"):
     """Load MCP servers from a JSON string or file."""
     servers = []
 
     # First try to load from the JSON string (preferred)
     if mcp_servers:
-        servers = _parse_mcp_servers_from_json_string(mcp_servers, io, verbose)
+        servers = _parse_mcp_servers_from_json_string(mcp_servers, io, verbose, mcp_transport)
         if servers:
             return servers
 
     # If JSON string failed or wasn't provided, try the file
     if mcp_servers_file:
-        servers = _parse_mcp_servers_from_file(mcp_servers_file, io, verbose)
+        servers = _parse_mcp_servers_from_file(mcp_servers_file, io, verbose, mcp_transport)
 
     return servers

aider/mcp/server.py

@@ -5,6 +5,7 @@
 
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.stdio import stdio_client
+from mcp.client.streamable_http import streamablehttp_client
 
 
 class McpServer:
@@ -74,3 +75,25 @@ async def disconnect(self):
                 self.stdio_context = None
             except Exception as e:
                 logging.error(f"Error during cleanup of server {self.name}: {e}")
+
+class HttpStreamingServer(McpServer):
+    async def connect(self):
+        if self.session is not None:
+            logging.info(f"Using existing session for MCP server: {self.name}")
+            return self.session
+
+        logging.info(f"Establishing new connection to MCP server: {self.name}")
+        try:
+            url = self.config["url"]
+            http_transport = await self.exit_stack.enter_async_context(streamablehttp_client(url))
+            read, write, _ = http_transport
+
+            session = await self.exit_stack.enter_async_context(ClientSession(read, write))
+            await session.initialize()
+            self.session = session
+            return session
+        except Exception as e:
+            logging.error(f"Error initializing server {self.name}: {e}")
+            await self.disconnect()
+            raise
+

aider/website/docs/config/mcp.md

@@ -17,7 +17,8 @@ for more information.
 You have two ways of sharing your MCP server configuration with Aider.
 
 {: .note }
-Today, Aider only supports connecting to MCP servers using the stdio transport
+
+> Today, Aider supports connecting to MCP servers using stdio and http transports.
 
 ### Config Files
 
@@ -28,8 +29,8 @@ mcp-servers: |
   {
     "mcpServers": {
       "git": {
-        "command": "uvx",
-        "args": ["mcp-server-git"]
+        "transport": "http",
+        "url": "http://localhost:8000"
       }
     }
   }
@@ -50,7 +51,7 @@ You can specify MCP servers directly on the command line using the `--mcp-server
 #### Using a JSON String
 
 ```bash
-aider --mcp-servers '{"mcpServers":{"git":{"command":"uvx","args":["mcp-server-git"]}}}'
+aider --mcp-servers '{"mcpServers":{"git":{"transport":"http","url":"http://localhost:8000"}}}'
 ```
 
 #### Using a configuration file
@@ -61,6 +62,14 @@ Alternatively, you can store your MCP server configurations in a JSON file and r
 aider --mcp-servers-file mcp.json
 ```
 
+#### Specifying the transport
+
+You can use the `--mcp-transport` flag to specify the transport for all configured MCP servers that do not have a transport specified.
+
+```bash
+aider --mcp-transport http
+```
+
 ### Environment Variables
 
 You can also configure MCP servers using environment variables in your `.env` file:

requirements.txt

@@ -239,7 +239,7 @@ mccabe==0.7.0
     # via
     #   -c requirements/common-constraints.txt
     #   flake8
-mcp==1.6.0
+mcp==1.12.3
     # via
     #   -c requirements/common-constraints.txt
     #   -r requirements/requirements.in

requirements/common-constraints.txt

@@ -262,7 +262,7 @@ matplotlib==3.10.3
     # via -r requirements/requirements-dev.in
 mccabe==0.7.0
     # via flake8
-mcp==1.6.0
+mcp==1.12.3
     # via -r requirements/requirements.in
 mdurl==0.1.2
     # via markdown-it-py

requirements/requirements.in

@@ -30,7 +30,7 @@ pillow
 shtab
 oslex
 google-generativeai
-mcp>=1.0.0
+mcp==1.12.3
 
 # The proper dependency is networkx[default], but this brings
 # in matplotlib and a bunch of other deps