Streamable HTTP MCP PoC + Browserbase Example

environments/mcp_env/mcp_env.py

@@ -19,6 +19,7 @@
 EXA_FETCH_TOOLS = [
     {
         "name": "exa",
+        "transport": "stdio",
         "command": "npx",
         "args": [
             "-y",
@@ -31,12 +32,22 @@
     },
     {
         "name": "fetch",
+        "transport": "stdio",
         "command": "uvx",
         "args": ["mcp-server-fetch"],
         "description": "Fetch MCP server",
     },
 ]
 
+BROWSERBASE_TOOLS = [
+    {
+        "name": "browserbase",
+        "transport": "http",
+        "url": os.getenv("BROWSERBASE_URL"),
+        "description": "Browserbase MCP",
+    },
+]
+
 
 class MCPEnv(ToolEnv):
     """Environment for MCP-based tools using the official MCP SDK."""

environments/mcp_env/src/mcp_server_connection.py

@@ -4,6 +4,7 @@
 
 from mcp import ClientSession, StdioServerParameters
 from mcp.client.stdio import stdio_client
+from mcp.client.streamable_http import streamablehttp_client
 from mcp.types import TextContent, Tool
 
 from .models import MCPServerConfig
@@ -35,27 +36,55 @@ async def connect(self):
 
     async def _get_connection(self):
         try:
-            server_params = StdioServerParameters(
-                command=self.config.command,
-                args=self.config.args or [],
-                env=self.config.env,
-            )
+            if self.config.transport == "stdio":
+                if not self.config.command:
+                    raise ValueError("stdio transport requires 'command'")
+                server_params = StdioServerParameters(
+                    command=self.config.command,
+                    args=self.config.args or [],
+                    env=self.config.env,
+                )
 
-            async with stdio_client(server_params) as (read, write):
-                async with ClientSession(read, write) as session:
-                    self.session = session
+                async with stdio_client(server_params) as (read, write):
+                    async with ClientSession(read, write) as session:
+                        self.session = session
 
-                    await session.initialize()
+                        await session.initialize()
 
-                    tools_response = await session.list_tools()
+                        tools_response = await session.list_tools()
 
-                    for tool in tools_response.tools:
-                        self.tools[tool.name] = tool
+                        for tool in tools_response.tools:
+                            self.tools[tool.name] = tool
 
-                    self._ready.set()
+                        self._ready.set()
 
-                    while True:
-                        await asyncio.sleep(1)
+                        while True:
+                            await asyncio.sleep(1)
+
+            elif self.config.transport == "http":
+                if not self.config.url:
+                    raise ValueError("http transport requires 'url'")
+
+                async with streamablehttp_client(
+                    self.config.url,
+                    headers=self.config.headers or {},
+                ) as (read, write, _get_session_id):
+                    async with ClientSession(read, write) as session:
+                        self.session = session
+
+                        await session.initialize()
+
+                        tools_response = await session.list_tools()
+
+                        for tool in tools_response.tools:
+                            self.tools[tool.name] = tool
+
+                        self._ready.set()
+
+                        while True:
+                            await asyncio.sleep(1)
+            else:
+                raise ValueError(f"Unknown transport: {self.config.transport}")
 
         except asyncio.CancelledError:
             raise

environments/mcp_env/src/models.py

@@ -1,11 +1,16 @@
 from dataclasses import dataclass
-from typing import Dict, List
+from typing import Dict, List, Literal, Optional
 
 
 @dataclass
 class MCPServerConfig:
     name: str
-    command: str
-    args: List[str] | None = None
-    env: Dict[str, str] | None = None
+    transport: Literal["stdio", "http"] = "stdio"
     description: str = ""
+    # stdio params
+    command: Optional[str] = None
+    args: Optional[List[str]] = None
+    env: Optional[Dict[str, str]] = None
+    # http params
+    url: Optional[str] = None
+    headers: Optional[Dict[str, str]] = None