Upgrade mcp-agent to mcp v1.8.0, plus a few fixes

Author: saqadri

examples/mcp/mcp_sse/main.py

@@ -2,7 +2,7 @@
 
 from dotenv import load_dotenv
 from rich import print
-
+from mcp.types import CallToolResult
 from mcp_agent.agents.agent import Agent
 from mcp_agent.app import MCPApp
 
@@ -22,10 +22,12 @@ async def test_sse():
 
         async with agent:
             print(await agent.list_tools())
-            # call_tool_result: CallToolResult = await agent.call_tool('mcp_test_server_sse-get-magic-number')
-            #
-            # assert call_tool_result.text == "42"
-            # print("SSE test passed!")
+            call_tool_result: CallToolResult = await agent.call_tool(
+                "mcp_test_server_sse_get-magic-number"
+            )
+
+            assert call_tool_result.content[0].text == "42"
+            print("SSE test passed!")
 
 
 if __name__ == "__main__":

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "mcp-agent"
-version = "0.0.20"
+version = "0.0.21"
 description = "Build effective agents with Model Context Protocol (MCP) using simple, composable patterns."
 readme = "README.md"
 license = { file = "LICENSE" }
@@ -16,7 +16,7 @@ requires-python = ">=3.10"
 dependencies = [
     "fastapi>=0.115.6",
     "instructor>=1.7.9",
-    "mcp>=1.7.1",
+    "mcp>=1.8.0",
     "opentelemetry-distro>=0.50b0",
     "opentelemetry-exporter-otlp-proto-http>=1.29.0",
     "pydantic-settings>=2.7.0",

src/mcp_agent/config.py

@@ -7,7 +7,7 @@
 from typing import Dict, List, Literal, Optional
 
 from httpx import Client
-from pydantic import BaseModel, ConfigDict, field_validator
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
@@ -61,7 +61,7 @@ class MCPServerSettings(BaseModel):
     command: str | None = None
     """The command to execute the server (e.g. npx)."""
 
-    args: List[str] | None = None
+    args: List[str] = Field(default_factory=list)
     """The arguments for the server command."""
 
     read_timeout_seconds: int | None = None
@@ -76,7 +76,7 @@ class MCPServerSettings(BaseModel):
     headers: Dict[str, str] | None = None
     """HTTP headers for sse or websocket requests."""
 
-    roots: Optional[List[MCPRootSettings]] = None
+    roots: List[MCPRootSettings] | None = None
     """Root directories this server has access to."""
 
     env: Dict[str, str] | None = None
@@ -86,7 +86,7 @@ class MCPServerSettings(BaseModel):
 class MCPSettings(BaseModel):
     """Configuration for all MCP servers."""
 
-    servers: Dict[str, MCPServerSettings] = {}
+    servers: Dict[str, MCPServerSettings] = Field(default_factory=dict)
     model_config = ConfigDict(extra="allow", arbitrary_types_allowed=True)
 
 

src/mcp_agent/mcp/mcp_connection_manager.py

@@ -23,14 +23,14 @@
 )
 from mcp.client.sse import sse_client
 from mcp.client.stdio import stdio_client
+from mcp.client.websocket import websocket_client
 from mcp.types import JSONRPCMessage, ServerCapabilities
 
 from mcp_agent.config import MCPServerSettings
 from mcp_agent.core.exceptions import ServerInitializationError
 from mcp_agent.event_progress import ProgressAction
 from mcp_agent.logging.logger import get_logger
 from mcp_agent.mcp.mcp_agent_client_session import MCPAgentClientSession
-from mcp_agent.mcp.websocket import websocket_client
 from mcp_agent.context_dependent import ContextDependent
 
 if TYPE_CHECKING:
@@ -272,15 +272,15 @@ def transport_context_factory():
             if config.transport == "stdio":
                 server_params = StdioServerParameters(
                     command=config.command,
-                    args=config.args,
+                    args=config.args or [],
                     env={**get_default_environment(), **(config.env or {})},
                 )
                 # Create stdio client config with redirected stderr
                 return stdio_client(server_params)
             elif config.transport == "sse":
                 return sse_client(config.url, config.headers)
             elif config.transport == "websocket":
-                return websocket_client(config.url, config.headers)
+                return websocket_client(config.url)
             else:
                 raise ValueError(f"Unsupported transport: {config.transport}")
 

src/mcp_agent/mcp/websocket.py

@@ -19,6 +19,7 @@
     get_default_environment,
 )
 from mcp.client.sse import sse_client
+from mcp.client.websocket import websocket_client
 
 from mcp_agent.config import (
     get_settings,
@@ -29,7 +30,6 @@
 
 from mcp_agent.logging.logger import get_logger
 from mcp_agent.mcp.mcp_connection_manager import MCPConnectionManager
-from mcp_agent.mcp.websocket import websocket_client
 
 logger = get_logger(__name__)
 
@@ -125,14 +125,14 @@ async def start_server(
         )
 
         if config.transport == "stdio":
-            if not config.command or not config.args:
+            if not config.command and not config.args:
                 raise ValueError(
                     f"Command and args are required for stdio transport: {server_name}"
                 )
 
             server_params = StdioServerParameters(
                 command=config.command,
-                args=config.args,
+                args=config.args or [],
                 env={**get_default_environment(), **(config.env or {})},
             )
 
@@ -180,7 +180,7 @@ async def start_server(
                     f"URL is required for websocket transport: {server_name}"
                 )
 
-            async with websocket_client(url=config.url, headers=config.headers) as (
+            async with websocket_client(url=config.url) as (  # pylint: disable=W0135
                 read_stream,
                 write_stream,
             ):