KiCad MCP Server

Instructions

Implementation Reference

• kicad_mcp/tools/drc_tools.py:22-63 (handler)

  The primary handler function for the 'get_drc_history_tool' MCP tool. It is decorated with @mcp.tool() for registration and implements the core logic: validates project path, retrieves DRC history using helper function, computes improvement trend over time, and returns structured JSON response.
  @mcp.tool() def get_drc_history_tool(project_path: str) -> Dict[str, Any]: """Get the DRC check history for a KiCad project. Args: project_path: Path to the KiCad project file (.kicad_pro) Returns: Dictionary with DRC history entries """ print(f"Getting DRC history for project: {project_path}") if not os.path.exists(project_path): print(f"Project not found: {project_path}") return {"success": False, "error": f"Project not found: {project_path}"} # Get history entries history_entries = get_drc_history(project_path) # Calculate trend information trend = None if len(history_entries) >= 2: first = history_entries[-1] # Oldest entry last = history_entries[0] # Newest entry first_violations = first.get("total_violations", 0) last_violations = last.get("total_violations", 0) if first_violations > last_violations: trend = "improving" elif first_violations < last_violations: trend = "degrading" else: trend = "stable" return { "success": True, "project_path": project_path, "history_entries": history_entries, "entry_count": len(history_entries), "trend": trend }
• kicad_mcp/server.py:152-152 (registration)

  Top-level registration call in the MCP server setup that invokes register_drc_tools(mcp), which in turn defines and registers the get_drc_history_tool using FastMCP's @mcp.tool() decorator.
  register_drc_tools(mcp)
• kicad_mcp/utils/drc_history.py:94-123 (helper)

  Key helper utility function that loads the project's DRC history from a JSON file (stored in user-specific directory), sorts entries by timestamp (newest first), and returns the list of history entries used by the tool handler.
  def get_drc_history(project_path: str) -> List[Dict[str, Any]]: """Get the DRC history for a project. Args: project_path: Path to the KiCad project file Returns: List of DRC history entries, sorted by timestamp (newest first) """ history_path = get_project_history_path(project_path) if not os.path.exists(history_path): print(f"No DRC history found for {project_path}") return [] try: with open(history_path, 'r') as f: history = json.load(f) # Sort entries by timestamp (newest first) entries = sorted( history.get("entries", []), key=lambda x: x.get("timestamp", 0), reverse=True ) return entries except (json.JSONDecodeError, IOError) as e: print(f"Error reading DRC history: {str(e)}") return []
• kicad_mcp/tools/drc_tools.py:15-64 (registration)

  The register_drc_tools function that defines and registers both DRC tools (get_drc_history_tool and run_drc_check) using @mcp.tool() decorators when called from server.py.
  def register_drc_tools(mcp: FastMCP) -> None: """Register DRC tools with the MCP server. Args: mcp: The FastMCP server instance """ @mcp.tool() def get_drc_history_tool(project_path: str) -> Dict[str, Any]: """Get the DRC check history for a KiCad project. Args: project_path: Path to the KiCad project file (.kicad_pro) Returns: Dictionary with DRC history entries """ print(f"Getting DRC history for project: {project_path}") if not os.path.exists(project_path): print(f"Project not found: {project_path}") return {"success": False, "error": f"Project not found: {project_path}"} # Get history entries history_entries = get_drc_history(project_path) # Calculate trend information trend = None if len(history_entries) >= 2: first = history_entries[-1] # Oldest entry last = history_entries[0] # Newest entry first_violations = first.get("total_violations", 0) last_violations = last.get("total_violations", 0) if first_violations > last_violations: trend = "improving" elif first_violations < last_violations: trend = "degrading" else: trend = "stable" return { "success": True, "project_path": project_path, "history_entries": history_entries, "entry_count": len(history_entries), "trend": trend }