KiCad MCP Server

Instructions

Implementation Reference

• kicad_mcp/tools/netlist_tools.py:278-442 (handler)

  The primary handler function for the 'find_component_connections' tool. It locates the schematic file, extracts the netlist, identifies the component's pins and connected nets, categorizes pin types, and returns detailed connection information.
  @mcp.tool() async def find_component_connections(project_path: str, component_ref: str, ctx: Context | None) -> Dict[str, Any]: """Find all connections for a specific component in a KiCad project. This tool extracts information about how a specific component is connected to other components in the schematic. Args: project_path: Path to the KiCad project file (.kicad_pro) component_ref: Component reference (e.g., "R1", "U3") ctx: MCP context for progress reporting Returns: Dictionary with component connection information """ print(f"Finding connections for component {component_ref} in project: {project_path}") if not os.path.exists(project_path): print(f"Project not found: {project_path}") if ctx: ctx.info(f"Project not found: {project_path}") return {"success": False, "error": f"Project not found: {project_path}"} # Report progress if ctx: await ctx.report_progress(10, 100) # Get the schematic file try: files = get_project_files(project_path) if "schematic" not in files: print("Schematic file not found in project") if ctx: ctx.info("Schematic file not found in project") return {"success": False, "error": "Schematic file not found in project"} schematic_path = files["schematic"] print(f"Found schematic file: {schematic_path}") if ctx: ctx.info(f"Found schematic file: {os.path.basename(schematic_path)}") # Extract netlist if ctx: await ctx.report_progress(30, 100) ctx.info(f"Extracting netlist to find connections for {component_ref}...") netlist_data = extract_netlist(schematic_path) if "error" in netlist_data: print(f"Failed to extract netlist: {netlist_data['error']}") if ctx: ctx.info(f"Failed to extract netlist: {netlist_data['error']}") return {"success": False, "error": netlist_data['error']} # Check if component exists in the netlist components = netlist_data.get("components", {}) if component_ref not in components: print(f"Component {component_ref} not found in schematic") if ctx: ctx.info(f"Component {component_ref} not found in schematic") return { "success": False, "error": f"Component {component_ref} not found in schematic", "available_components": list(components.keys()) } # Get component information component_info = components[component_ref] # Find connections if ctx: await ctx.report_progress(50, 100) ctx.info("Finding connections...") nets = netlist_data.get("nets", {}) connections = [] connected_nets = [] for net_name, pins in nets.items(): # Check if any pin belongs to our component component_pins = [] for pin in pins: if pin.get('component') == component_ref: component_pins.append(pin) if component_pins: # This net has connections to our component net_connections = [] for pin in component_pins: pin_num = pin.get('pin', 'Unknown') # Find other components connected to this pin connected_components = [] for other_pin in pins: other_comp = other_pin.get('component') if other_comp and other_comp != component_ref: connected_components.append({ "component": other_comp, "pin": other_pin.get('pin', 'Unknown') }) net_connections.append({ "pin": pin_num, "net": net_name, "connected_to": connected_components }) connections.extend(net_connections) connected_nets.append(net_name) # Analyze the connections if ctx: await ctx.report_progress(70, 100) ctx.info("Analyzing connections...") # Categorize connections by pin function (if possible) pin_functions = {} if "pins" in component_info: for pin in component_info["pins"]: pin_num = pin.get('num') pin_name = pin.get('name', '') # Try to categorize based on pin name pin_type = "unknown" if any(power_term in pin_name.upper() for power_term in ["VCC", "VDD", "VEE", "VSS", "GND", "PWR", "POWER"]): pin_type = "power" elif any(io_term in pin_name.upper() for io_term in ["IO", "I/O", "GPIO"]): pin_type = "io" elif any(input_term in pin_name.upper() for input_term in ["IN", "INPUT"]): pin_type = "input" elif any(output_term in pin_name.upper() for output_term in ["OUT", "OUTPUT"]): pin_type = "output" pin_functions[pin_num] = { "name": pin_name, "type": pin_type } # Build result result = { "success": True, "project_path": project_path, "schematic_path": schematic_path, "component": component_ref, "component_info": component_info, "connections": connections, "connected_nets": connected_nets, "pin_functions": pin_functions, "total_connections": len(connections) } if ctx: await ctx.report_progress(100, 100) ctx.info(f"Found {len(connections)} connections for component {component_ref}") return result except Exception as e: print(f"Error finding component connections: {str(e)}", exc_info=True) if ctx: ctx.info(f"Error finding component connections: {str(e)}") return {"success": False, "error": str(e)}
• kicad_mcp/server.py:154-154 (registration)

  The server initialization calls register_netlist_tools(mcp), which defines and registers the find_component_connections tool using @mcp.tool() decorator.
  register_netlist_tools(mcp)
• kicad_mcp/utils/netlist_parser.py:393-393 (helper)

  Helper function used by the tool to parse the schematic and extract netlist data including components and nets.
  def extract_netlist(schematic_path: str) -> Dict[str, Any]: