feat: mcp tool late binding (#468)

Author: edis-uipath

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "uipath-langchain"
-version = "0.5.1"
+version = "0.5.2"
 description = "Python SDK that enables developers to build and deploy LangGraph agents to the UiPath Cloud Platform"
 readme = { file = "README.md", content-type = "text/markdown" }
 requires-python = ">=3.11"

src/uipath_langchain/agent/tools/mcp_tool.py

@@ -110,18 +110,6 @@ async def create_mcp_tools_from_metadata(
     if config.is_enabled is False:
         return []
 
-    sdk = UiPath()
-    mcpServer: McpServer = await sdk.mcp.retrieve_async(
-        slug=config.slug, folder_path=config.folder_path
-    )
-
-    default_client_kwargs = get_httpx_client_kwargs()
-    client_kwargs = {
-        **default_client_kwargs,
-        "headers": {"Authorization": f"Bearer {sdk._config.secret}"},
-        "timeout": httpx.Timeout(600),
-    }
-
     # Lazy import to improve cold start time
     from mcp import ClientSession
     from mcp.client.streamable_http import streamable_http_client
@@ -132,7 +120,7 @@ async def create_mcp_tools_from_metadata(
         tool_name = sanitize_tool_name(mcp_tool.name)
         input_model: Any = create_model(mcp_tool.input_schema)
 
-        def get_tool_coroutine(mcp_tool: AgentMcpTool, input_model: Any) -> Any:
+        def build_mcp_tool(mcp_tool: AgentMcpTool, input_model: Any) -> Any:
             output_schema: Any
             if mcp_tool.output_schema:
                 output_schema = create_model(mcp_tool.output_schema)
@@ -148,6 +136,18 @@ def get_tool_coroutine(mcp_tool: AgentMcpTool, input_model: Any) -> Any:
             async def tool_fn(**kwargs: Any) -> Any:
                 """Execute MCP tool call with ephemeral session."""
                 async with AsyncExitStack() as stack:
+                    sdk = UiPath()
+                    mcpServer: McpServer = await sdk.mcp.retrieve_async(
+                        slug=config.slug, folder_path=config.folder_path
+                    )
+
+                    default_client_kwargs = get_httpx_client_kwargs()
+                    client_kwargs = {
+                        **default_client_kwargs,
+                        "headers": {"Authorization": f"Bearer {sdk._config.secret}"},
+                        "timeout": httpx.Timeout(600),
+                    }
+
                     # Create HTTP client
                     http_client = await stack.enter_async_context(
                         httpx.AsyncClient(**client_kwargs)
@@ -176,7 +176,7 @@ async def tool_fn(**kwargs: Any) -> Any:
             name=tool_name,
             description=mcp_tool.description,
             args_schema=input_model,
-            coroutine=get_tool_coroutine(mcp_tool, input_model),
+            coroutine=build_mcp_tool(mcp_tool, input_model),
             metadata={
                 "tool_type": "mcp",
                 "display_name": mcp_tool.name,