fix: schematic pin connection reliability

- add_schematic_net_label: warn in description that coords must be exact pin endpoints; recommend connect_to_net instead
- connect_to_net: stub wire direction now follows pin angle (was hardcoded +X)
- pin_locator.py: add get_pin_angle() and _get_lib_id() helpers
- new tool: get_schematic_pin_locations(schematicPath, reference) → returns exact x/y of every pin endpoint, so Claude can place labels correctly

python/commands/connection_schematic.py

@@ -256,7 +256,16 @@ class ConnectionManager:
                 return False
 
             # Add a small wire stub from the pin (2.54mm = 0.1 inch, standard grid spacing)
-            stub_end = [pin_loc[0] + 2.54, pin_loc[1]]
+            # Stub direction follows the pin's outward angle from the PinLocator
+            pin_angle_deg = getattr(locator, '_last_pin_angle', 0)
+            try:
+                pin_angle_deg = locator.get_pin_angle(schematic_path, component_ref, pin_name) or 0
+            except Exception:
+                pin_angle_deg = 0
+            import math as _math
+            angle_rad = _math.radians(pin_angle_deg)
+            stub_end = [round(pin_loc[0] + 2.54 * _math.cos(angle_rad), 4),
+                        round(pin_loc[1] - 2.54 * _math.sin(angle_rad), 4)]
 
             # Create wire stub using WireManager
             wire_success = WireManager.add_wire(schematic_path, pin_loc, stub_end)

python/commands/pin_locator.py

@@ -179,6 +179,63 @@ class PinLocator:
 
         return (rotated_x, rotated_y)
 
+    def _get_lib_id(self, schematic_path: Path, symbol_reference: str) -> Optional[str]:
+        """Helper: return the lib_id string for a placed symbol"""
+        try:
+            sch_key = str(schematic_path)
+            if sch_key not in self._schematic_cache:
+                self._schematic_cache[sch_key] = Schematic(sch_key)
+            sch = self._schematic_cache[sch_key]
+            for symbol in sch.symbol:
+                if symbol.property.Reference.value == symbol_reference:
+                    return symbol.lib_id.value if hasattr(symbol, "lib_id") else None
+        except Exception:
+            pass
+        return None
+
+    def get_pin_angle(
+        self, schematic_path: Path, symbol_reference: str, pin_number: str
+    ) -> Optional[float]:
+        """
+        Get the outward angle of a pin endpoint in degrees (0=right, 90=up, 180=left, 270=down).
+        This is the direction a wire stub must extend to stay connected to the pin.
+
+        Returns angle in degrees, or None if pin not found.
+        """
+        try:
+            sch_key = str(schematic_path)
+            if sch_key not in self._schematic_cache:
+                self._schematic_cache[sch_key] = Schematic(sch_key)
+            sch = self._schematic_cache[sch_key]
+
+            target_symbol = None
+            for symbol in sch.symbol:
+                if symbol.property.Reference.value == symbol_reference:
+                    target_symbol = symbol
+                    break
+
+            if not target_symbol:
+                return None
+
+            symbol_at = target_symbol.at.value
+            symbol_rotation = float(symbol_at[2]) if len(symbol_at) > 2 else 0.0
+
+            lib_id = target_symbol.lib_id.value if hasattr(target_symbol, "lib_id") else None
+            if not lib_id:
+                return None
+
+            pins = self.get_symbol_pins(schematic_path, lib_id)
+            if pin_number not in pins:
+                return None
+
+            # Pin definition angle + symbol rotation = absolute outward direction
+            pin_def_angle = pins[pin_number].get("angle", 0)
+            absolute_angle = (pin_def_angle + symbol_rotation) % 360
+            return absolute_angle
+
+        except Exception:
+            return None
+
     def get_pin_location(
         self, schematic_path: Path, symbol_reference: str, pin_number: str
     ) -> Optional[List[float]]:

python/kicad_interface.py

@@ -375,6 +375,7 @@ class KiCADInterface:
             "add_schematic_connection": self._handle_add_schematic_connection,
             "add_schematic_net_label": self._handle_add_schematic_net_label,
             "connect_to_net": self._handle_connect_to_net,
+            "get_schematic_pin_locations": self._handle_get_schematic_pin_locations,
             "get_net_connections": self._handle_get_net_connections,
             "generate_netlist": self._handle_generate_netlist,
             "list_schematic_libraries": self._handle_list_schematic_libraries,
@@ -1271,6 +1272,47 @@ class KiCADInterface:
                 "errorDetails": traceback.format_exc(),
             }
 
+    def _handle_get_schematic_pin_locations(self, params):
+        """Return exact pin endpoint coordinates for a schematic component"""
+        logger.info("Getting schematic pin locations")
+        try:
+            from pathlib import Path
+            from commands.pin_locator import PinLocator
+
+            schematic_path = params.get("schematicPath")
+            reference = params.get("reference")
+
+            if not all([schematic_path, reference]):
+                return {"success": False, "message": "Missing required parameters: schematicPath, reference"}
+
+            locator = PinLocator()
+            all_pins = locator.get_all_symbol_pins(Path(schematic_path), reference)
+
+            if not all_pins:
+                return {"success": False, "message": f"No pins found for {reference} — check reference and schematic path"}
+
+            # Enrich with pin names and angles from the symbol definition
+            pins_def = locator.get_symbol_pins(
+                Path(schematic_path),
+                locator._get_lib_id(Path(schematic_path), reference),
+            ) if hasattr(locator, "_get_lib_id") else {}
+
+            result = {}
+            for pin_num, coords in all_pins.items():
+                entry = {"x": coords[0], "y": coords[1]}
+                if pin_num in pins_def:
+                    entry["name"] = pins_def[pin_num].get("name", pin_num)
+                    entry["angle"] = locator.get_pin_angle(Path(schematic_path), reference, pin_num) or 0
+                result[pin_num] = entry
+
+            return {"success": True, "reference": reference, "pins": result}
+
+        except Exception as e:
+            logger.error(f"Error getting pin locations: {e}")
+            import traceback
+            logger.error(traceback.format_exc())
+            return {"success": False, "message": str(e)}
+
     def _handle_get_net_connections(self, params):
         """Get all connections for a named net"""
         logger.info("Getting net connections")

python/schemas/tool_schemas.py

@@ -1388,7 +1388,7 @@ SCHEMATIC_TOOLS = [
     {
         "name": "add_schematic_net_label",
         "title": "Add Net Label",
-        "description": "Adds a net label to assign a name to a wire/net on the schematic.",
+        "description": "Adds a net label at exact coordinates on a schematic wire or pin endpoint. WARNING: x/y must match an existing wire endpoint or pin endpoint exactly — placing the label even 0.01mm away from a pin will result in an unconnected pin ERC error. To connect a component pin to a net by reference and pin number (recommended), use connect_to_net instead.",
         "inputSchema": {
             "type": "object",
             "properties": {
@@ -1463,6 +1463,25 @@ SCHEMATIC_TOOLS = [
             "required": ["schematicPath", "netName"]
         }
     },
+    {
+        "name": "get_schematic_pin_locations",
+        "title": "Get Schematic Pin Locations",
+        "description": "Returns the exact absolute coordinates of all pins on a schematic component. Use this BEFORE placing net labels with add_schematic_net_label to get the correct x/y position for each pin endpoint.",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "schematicPath": {
+                    "type": "string",
+                    "description": "Path to the schematic file"
+                },
+                "reference": {
+                    "type": "string",
+                    "description": "Component reference designator (e.g., U1, R1, J2)"
+                }
+            },
+            "required": ["schematicPath", "reference"]
+        }
+    },
     {
         "name": "generate_netlist",
         "title": "Generate Netlist",