Update langgraph/mcp_output/mcp_plugin/mcp_service.py

langgraph/mcp_output/mcp_plugin/mcp_service.py

@@ -1,87 +1,443 @@
-from fastmcp import FastMCP, subprocess, ctypes
-
-class CppServiceWrapper:
-    def __init__(self, executable_path):
-        self.executable_path = executable_path
-
-    def call_executable(self, *args):
-        try:
-            result = subprocess.run([self.executable_path] + list(args), capture_output=True, text=True)
-            if result.returncode != 0:
-                return {"success": False, "error": result.stderr}
-            return {"success": True, "result": result.stdout}
-        except Exception as e:
-            return {"success": False, "error": str(e)}
-
-    def load_dynamic_library(self, lib_path):
-        try:
-            return ctypes.CDLL(lib_path)
-        except OSError as e:
-            return None
-
-def compile_project(build_system, source_dir):
+import os
+import sys
+from typing import Dict, Any, List, Optional, Union
+import json
+
+# Add the local source directory to sys.path
+source_path = os.path.join(os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__)))), "source")
+if source_path not in sys.path:
+    sys.path.insert(0, source_path)
+
+from fastmcp import FastMCP
+
+# Import LangGraph modules
+try:
+    from langgraph.graph import StateGraph, Graph, END
+    from langgraph.prebuilt import ToolExecutor, ToolInvocation
+    from typing_extensions import TypedDict
+except ImportError:
+    # Fallback for basic functionality
+    StateGraph = None
+    Graph = None
+    END = "__end__"
+
+# Create the FastMCP service application
+mcp = FastMCP("langgraph_service")
+
+# Storage for graphs
+_graphs: Dict[str, Any] = {}
+_compiled_graphs: Dict[str, Any] = {}
+
+
+@mcp.tool(name="create_state_graph", description="Create a new StateGraph")
+def create_state_graph(
+    graph_id: str,
+    state_schema: Optional[Dict[str, str]] = None
+) -> Dict[str, Any]:
+    """
+    Create a new StateGraph for building stateful workflows.
+
+    Args:
+        graph_id: Unique identifier for the graph
+        state_schema: Optional schema defining state structure (dict of field_name: type_name)
+
+    Returns:
+        Dictionary with success status and graph info
+    """
     try:
-        if build_system == "cmake":
-            subprocess.run(["cmake", source_dir], check=True)
-            subprocess.run(["make"], check=True)
-        elif build_system == "make":
-            subprocess.run(["make", "-C", source_dir], check=True)
-        elif build_system == "configure":
-            subprocess.run(["./configure"], cwd=source_dir, check=True)
-            subprocess.run(["make"], cwd=source_dir, check=True)
+        if StateGraph is None:
+            return {"success": False, "result": None, "error": "StateGraph not available"}
+        
+        # Create a simple state type
+        if state_schema:
+            # Create a TypedDict-like state class dynamically
+            state_fields = {k: str for k, v in state_schema.items()}
+            
+            class GraphState(TypedDict):
+                pass
+            
+            # Add fields
+            for field, ftype in state_fields.items():
+                GraphState.__annotations__[field] = Any
+            
+            graph = StateGraph(GraphState)
         else:
-            return {"success": False, "error": "Unsupported build system"}
-        return {"success": True}
-    except subprocess.CalledProcessError as e:
-        return {"success": False, "error": str(e)}
+            # Default state with messages
+            class DefaultState(TypedDict):
+                messages: List[str]
+            
+            graph = StateGraph(DefaultState)
+        
+        _graphs[graph_id] = {
+            "graph": graph,
+            "nodes": [],
+            "edges": [],
+            "compiled": False
+        }
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "state_schema": state_schema or {"messages": "List[str]"}
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
 
-mcp = FastMCP("cpp_service")
 
-@ mcp.tool(name="compile_project", description="Compile the C/C++ project using the specified build system.")
-def compile_project_tool(build_system: str, source_dir: str) -> dict:
+@mcp.tool(name="add_node", description="Add a node to a graph")
+def add_node(
+    graph_id: str,
+    node_name: str,
+    node_type: str = "function"
+) -> Dict[str, Any]:
     """
-    Compile the C/C++ project using the specified build system.
+    Add a node to a StateGraph.
 
-    Parameters:
-    - build_system (str): The build system to use (e.g., 'cmake', 'make', 'configure').
-    - source_dir (str): The directory containing the source code.
+    Args:
+        graph_id: ID of the graph
+        node_name: Name of the node
+        node_type: Type of node (function, tool, etc.)
 
     Returns:
-    - dict: A dictionary containing 'success' and 'error' fields.
+        Dictionary with success status
     """
-    return compile_project(build_system, source_dir)
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        if graph_data["compiled"]:
+            return {"success": False, "result": None, "error": "Cannot modify compiled graph"}
+        
+        # Create a simple node function
+        def node_function(state):
+            # Default: pass through state with a message
+            if "messages" in state:
+                messages = state.get("messages", [])
+                messages.append(f"Processed by {node_name}")
+                return {"messages": messages}
+            return state
+        
+        graph_data["graph"].add_node(node_name, node_function)
+        graph_data["nodes"].append(node_name)
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "node_name": node_name,
+                "node_type": node_type
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
 
-@ mcp.tool(name="execute_cpp_function", description="Execute a C++ function via the compiled executable.")
-def execute_cpp_function(executable_path: str, *args: str) -> dict:
+@mcp.tool(name="add_edge", description="Add an edge between two nodes")
+def add_edge(
+    graph_id: str,
+    from_node: str,
+    to_node: str
+) -> Dict[str, Any]:
     """
-    Execute a C++ function via the compiled executable.
+    Add an edge connecting two nodes in a graph.
 
-    Parameters:
-    - executable_path (str): Path to the compiled executable.
-    - args (str): Arguments to pass to the executable.
+    Args:
+        graph_id: ID of the graph
+        from_node: Source node name
+        to_node: Target node name (use "__end__" for terminal node)
 
     Returns:
-    - dict: A dictionary containing 'success', 'result', and 'error' fields.
+        Dictionary with success status
     """
-    wrapper = CppServiceWrapper(executable_path)
-    return wrapper.call_executable(*args)
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        if graph_data["compiled"]:
+            return {"success": False, "result": None, "error": "Cannot modify compiled graph"}
+        
+        graph_data["graph"].add_edge(from_node, to_node)
+        graph_data["edges"].append({"from": from_node, "to": to_node})
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "from_node": from_node,
+                "to_node": to_node
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
 
-@ mcp.tool(name="load_cpp_library", description="Load a C++ dynamic library and return its handle.")
-def load_cpp_library(lib_path: str) -> dict:
+@mcp.tool(name="add_conditional_edge", description="Add a conditional edge with routing logic")
+def add_conditional_edge(
+    graph_id: str,
+    from_node: str,
+    condition_type: str = "simple"
+) -> Dict[str, Any]:
     """
-    Load a C++ dynamic library and return its handle.
+    Add a conditional edge that routes based on state.
 
-    Parameters:
-    - lib_path (str): Path to the dynamic library.
+    Args:
+        graph_id: ID of the graph
+        from_node: Source node name
+        condition_type: Type of condition (simple, multi, etc.)
 
     Returns:
-    - dict: A dictionary containing 'success' and 'result' fields.
+        Dictionary with success status
     """
-    wrapper = CppServiceWrapper("")
-    lib = wrapper.load_dynamic_library(lib_path)
-    if lib is None:
-        return {"success": False, "error": "Failed to load library"}
-    return {"success": True, "result": "Library loaded successfully"}
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        if graph_data["compiled"]:
+            return {"success": False, "result": None, "error": "Cannot modify compiled graph"}
+        
+        # Simple routing function
+        def route_function(state):
+            # Default routing based on message count
+            messages = state.get("messages", [])
+            if len(messages) > 3:
+                return END
+            else:
+                # Route to first available node or END
+                nodes = graph_data["nodes"]
+                return nodes[0] if nodes else END
+        
+        graph_data["graph"].add_conditional_edges(
+            from_node,
+            route_function
+        )
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "from_node": from_node,
+                "condition_type": condition_type
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
 
-def create_app():
+@mcp.tool(name="set_entry_point", description="Set the entry point of the graph")
+def set_entry_point(
+    graph_id: str,
+    node_name: str
+) -> Dict[str, Any]:
+    """
+    Set the entry point (starting node) for a graph.
+
+    Args:
+        graph_id: ID of the graph
+        node_name: Name of the entry node
+
+    Returns:
+        Dictionary with success status
+    """
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        if graph_data["compiled"]:
+            return {"success": False, "result": None, "error": "Cannot modify compiled graph"}
+        
+        graph_data["graph"].set_entry_point(node_name)
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "entry_point": node_name
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+@mcp.tool(name="compile_graph", description="Compile a graph for execution")
+def compile_graph(
+    graph_id: str
+) -> Dict[str, Any]:
+    """
+    Compile a StateGraph into an executable workflow.
+
+    Args:
+        graph_id: ID of the graph to compile
+
+    Returns:
+        Dictionary with success status and compiled graph info
+    """
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        if graph_data["compiled"]:
+            return {"success": False, "result": None, "error": "Graph already compiled"}
+        
+        compiled = graph_data["graph"].compile()
+        _compiled_graphs[graph_id] = compiled
+        graph_data["compiled"] = True
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "num_nodes": len(graph_data["nodes"]),
+                "num_edges": len(graph_data["edges"]),
+                "compiled": True
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+@mcp.tool(name="invoke_graph", description="Execute a compiled graph with input")
+def invoke_graph(
+    graph_id: str,
+    input_data: Dict[str, Any]
+) -> Dict[str, Any]:
+    """
+    Execute a compiled graph with given input.
+
+    Args:
+        graph_id: ID of the compiled graph
+        input_data: Input state/data for the graph
+
+    Returns:
+        Dictionary with execution result
+    """
+    try:
+        if graph_id not in _compiled_graphs:
+            return {"success": False, "result": None, "error": f"Compiled graph '{graph_id}' not found"}
+        
+        compiled_graph = _compiled_graphs[graph_id]
+        result = compiled_graph.invoke(input_data)
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "output": result
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+@mcp.tool(name="get_graph_info", description="Get information about a graph")
+def get_graph_info(graph_id: str) -> Dict[str, Any]:
+    """
+    Get detailed information about a graph.
+
+    Args:
+        graph_id: ID of the graph
+
+    Returns:
+        Dictionary with graph details
+    """
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        graph_data = _graphs[graph_id]
+        
+        return {
+            "success": True,
+            "result": {
+                "graph_id": graph_id,
+                "nodes": graph_data["nodes"],
+                "edges": graph_data["edges"],
+                "compiled": graph_data["compiled"]
+            },
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+@mcp.tool(name="list_graphs", description="List all stored graphs")
+def list_graphs() -> Dict[str, Any]:
+    """
+    List all stored graphs.
+
+    Returns:
+        Dictionary with list of graph IDs
+    """
+    try:
+        graphs_info = []
+        for gid, gdata in _graphs.items():
+            graphs_info.append({
+                "graph_id": gid,
+                "num_nodes": len(gdata["nodes"]),
+                "num_edges": len(gdata["edges"]),
+                "compiled": gdata["compiled"]
+            })
+        
+        return {
+            "success": True,
+            "result": {"graphs": graphs_info},
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+@mcp.tool(name="delete_graph", description="Delete a graph")
+def delete_graph(graph_id: str) -> Dict[str, Any]:
+    """
+    Delete a stored graph.
+
+    Args:
+        graph_id: ID of the graph to delete
+
+    Returns:
+        Dictionary with success status
+    """
+    try:
+        if graph_id not in _graphs:
+            return {"success": False, "result": None, "error": f"Graph '{graph_id}' not found"}
+        
+        del _graphs[graph_id]
+        if graph_id in _compiled_graphs:
+            del _compiled_graphs[graph_id]
+        
+        return {
+            "success": True,
+            "result": {"deleted": graph_id},
+            "error": None
+        }
+    except Exception as e:
+        return {"success": False, "result": None, "error": str(e)}
+
+
+def create_app() -> FastMCP:
+    """
+    Create and return the FastMCP application instance.
+
+    Returns:
+        FastMCP: The FastMCP application instance.
+    """
     return mcp