"""Blender Add-on to run MCP Server inside Blender"""
bl_info = {
"name": "Blender MCP Server",
"author": "Gajan Mohan Raj",
"version": (1, 0),
"blender": (4, 0, 0),
"location": "View3D > Sidebar > BlenderMCP",
"description": "Connect Blender to Claude via MCP",
"category": "Interface",
}
import bpy # type: ignore
import sys
import threading
from pathlib import Path
# Module-level variable to track the server thread
mcp_server_thread = None
# Flag to signal server to stop
mcp_server_stop_flag = threading.Event()
# Add your project to path
project_path = Path("/Users/gajanmohanraj/Documents/afterquery/candidate-1767282743/blender_takehome")
if str(project_path) not in sys.path:
sys.path.insert(0, str(project_path))
print(f"Added to sys.path: {project_path}")
# Add src directory to path for new structure
src_path = project_path / "src"
if str(src_path) not in sys.path:
sys.path.insert(0, str(src_path))
print(f"Added to sys.path: {src_path}")
# Add user site-packages to path (where fastmcp is installed)
import site
user_site = site.getusersitepackages()
if user_site not in sys.path:
sys.path.insert(0, user_site)
print(f"Added user site-packages to sys.path: {user_site}")
def run_mcp_server():
"""Run MCP server directly inside Blender (in a separate thread)"""
print("=" * 60)
print("MCP Server Thread Starting...")
print(f"Python executable: {sys.executable}")
print(f"Python version: {sys.version}")
print(f"Blender version: {bpy.app.version_string}")
print("=" * 60)
try:
# Import the server module directly
# The paths are already set up at module level
from src.server import run
print("✓ Successfully imported MCP server")
print("Starting MCP server...")
print("Note: Server uses stdio for JSON-RPC communication")
print("Make sure Blender is launched from terminal or with stdout available")
print("=" * 60)
# Run the server - this will block until stopped
# FastMCP handles JSON-RPC via stdout
run()
except ImportError as e:
print(f"✗ Import error: {e}")
print("Make sure fastmcp is installed: pip install fastmcp")
import traceback
traceback.print_exc()
except Exception as e:
print(f"✗ MCP Server error: {e}")
import traceback
traceback.print_exc()
class BLENDERMCP_PT_Panel(bpy.types.Panel):
"""Blender MCP Control Panel"""
bl_label = "Blender MCP"
bl_idname = "BLENDERMCP_PT_Panel"
bl_space_type = 'VIEW_3D'
bl_region_type = 'UI'
bl_category = 'BlenderMCP'
def draw(self, context):
layout = self.layout
scene = context.scene
# Show current Blender file path
filepath = bpy.data.filepath
if filepath:
# Show just the filename for cleaner display
import os
filename = os.path.basename(filepath)
layout.label(text=f"File: {filename}", icon='FILE_BLEND')
# Show full path in a box (collapsed by default)
box = layout.box()
box.scale_y = 0.8
box.label(text=filepath, icon='NONE')
else:
layout.label(text="File: Unsaved", icon='FILE_BLEND')
layout.separator()
# Check both property and actual thread status
server_running_prop = getattr(scene, 'mcp_server_running', False)
server_running_thread = mcp_server_thread is not None and mcp_server_thread.is_alive()
server_running = server_running_prop or server_running_thread
# Sync property with actual thread status if they differ
if server_running_prop != server_running_thread:
scene.mcp_server_running = server_running_thread
if not server_running:
layout.operator("blendermcp.start_server", text="Connect to Claude")
else:
layout.operator("blendermcp.stop_server", text="Disconnect from Claude")
layout.label(text="Server: Running", icon='CHECKMARK')
class BLENDERMCP_OT_StartServer(bpy.types.Operator):
"""Start MCP Server"""
bl_idname = "blendermcp.start_server"
bl_label = "Connect to Claude"
bl_description = "Start the BlenderMCP server to connect with Claude"
def execute(self, context): # type: ignore[override]
global mcp_server_thread
# Check if server is already running
if mcp_server_thread is not None and mcp_server_thread.is_alive():
self.report({'WARNING'}, "MCP Server already running")
return {'CANCELLED'}
# Start server in background thread
mcp_server_thread = threading.Thread(target=run_mcp_server, daemon=True)
mcp_server_thread.start()
# Update scene property
scene = context.scene
scene.mcp_server_running = True
# Force UI to refresh
for area in context.screen.areas:
if area.type == 'VIEW_3D':
area.tag_redraw()
self.report({'INFO'}, "MCP Server started - check console for output")
return {'FINISHED'}
class BLENDERMCP_OT_StopServer(bpy.types.Operator):
"""Stop MCP Server"""
bl_idname = "blendermcp.stop_server"
bl_label = "Disconnect from Claude"
bl_description = "Stop the connection to Claude"
def execute(self, context): # type: ignore[override]
global mcp_server_thread, mcp_server_stop_flag
# Signal the server to stop
mcp_server_stop_flag.set()
# Wait for thread to finish (with timeout)
if mcp_server_thread is not None and mcp_server_thread.is_alive():
mcp_server_thread.join(timeout=2)
if mcp_server_thread.is_alive():
print("Warning: Server thread did not stop gracefully")
# Reset flag and thread
mcp_server_stop_flag.clear()
mcp_server_thread = None
# Update scene property
scene = context.scene
scene.mcp_server_running = False
# Force UI to refresh
for area in context.screen.areas:
if area.type == 'VIEW_3D':
area.tag_redraw()
print("✓ MCP Server stopped")
self.report({'INFO'}, "MCP Server stopped")
return {'FINISHED'}
def update_server_status(self, context): # type: ignore
"""Callback to refresh UI when server status changes"""
# Redraw all 3D viewport areas
if context and hasattr(context, 'screen') and context.screen:
for area in context.screen.areas:
if area.type == 'VIEW_3D':
area.tag_redraw()
def register():
# Register properties with update callback
bpy.types.Scene.mcp_server_running = bpy.props.BoolProperty( # type: ignore[attr-defined]
name="Server Running",
default=False,
update=update_server_status
)
# Register classes
bpy.utils.register_class(BLENDERMCP_PT_Panel)
bpy.utils.register_class(BLENDERMCP_OT_StartServer)
bpy.utils.register_class(BLENDERMCP_OT_StopServer)
def unregister():
global mcp_server_thread, mcp_server_stop_flag
# Stop the server if it's running
mcp_server_stop_flag.set()
if mcp_server_thread is not None and mcp_server_thread.is_alive():
mcp_server_thread.join(timeout=2)
mcp_server_thread = None
mcp_server_stop_flag.clear()
# Unregister classes
bpy.utils.unregister_class(BLENDERMCP_PT_Panel)
bpy.utils.unregister_class(BLENDERMCP_OT_StartServer)
bpy.utils.unregister_class(BLENDERMCP_OT_StopServer)
# Clean up properties
if hasattr(bpy.types.Scene, 'mcp_server_running'):
del bpy.types.Scene.mcp_server_running # type: ignore[attr-defined]
if __name__ == "__main__":
register()
