scripts/mcp_interaction_server.gd

@@ -14,9 +14,18 @@ const BUSY_TIMEOUT: float = 30.0
 var _key_map: Dictionary
 var _held_keys: Dictionary = {}
 
+var _debugger_safe: bool = false
+
 func _ready() -> void:
-	# Ensure MCP server keeps processing even when game is paused
 	process_mode = Node.PROCESS_MODE_ALWAYS
+	if EngineDebugger.is_active():
+		EngineDebugger.send_message("core:set_skip_breakpoints", [true])
+		EngineDebugger.send_message("core:set_ignore_error_breaks", [true])
+		_debugger_safe = EngineDebugger.is_skipping_breakpoints()
+		if _debugger_safe:
+			print("McpInteractionServer: Debugger breakpoints safely disabled")
+		else:
+			push_warning("McpInteractionServer: Could not disable debugger breakpoints (LocalDebugger?). Eval with invalid code may hang the game.")
 	_init_key_map()
 	_server = TCPServer.new()
 	var err: int = _server.listen(PORT, "127.0.0.1")
@@ -544,17 +553,18 @@ func _cmd_eval(params: Dictionary) -> void:
 		_send_response({"error": "No code provided"})
 		return
 
-	# Wrap user code in a function so we can capture the return value
+	var script_source: String = _build_eval_script(code)
-	var script_source: String = """extends Node
 
-func execute():
+	if EngineDebugger.is_active() and not _debugger_safe:
-	var __result = null
+		var ext_validation: Dictionary = _validate_script_external(script_source)
-	__result = await _run()
+		if not ext_validation.get("valid", false):
-	return __result
+			_send_response({"error": "Script validation failed: %s" % ext_validation.get("error", "unknown error")})
+			return
 
-func _run():
+	var validation: Dictionary = _validate_script_source(script_source)
-%s
+	if not validation.get("valid", false):
-""" % [_indent_code(code)]
+		_send_response({"error": "Script validation failed: %s" % validation.get("error", "unknown error"), "error_code": validation.get("error_code", -1)})
+		return
 
 	var script: GDScript = GDScript.new()
 	script.source_code = script_source
@@ -565,7 +575,6 @@ func _run():
 
 	var temp_node: Node = Node.new()
 	temp_node.set_script(script)
-	# Allow eval to work even when game is paused
 	temp_node.process_mode = Node.PROCESS_MODE_ALWAYS
 	add_child(temp_node)
 
@@ -577,6 +586,69 @@ func _run():
 	_send_response({"success": true, "result": _variant_to_json(result)})
 
 
+func _build_eval_script(code: String) -> String:
+	return """extends Node
+
+func execute():
+	var __result = null
+	__result = await _run()
+	return __result
+
+func _run():
+%s
+""" % [_indent_code(code)]
+
+
+func _validate_script_source(source: String) -> Dictionary:
+	var test_script: GDScript = GDScript.new()
+	test_script.source_code = source
+	var err: int = test_script.reload()
+	if err != OK:
+		var error_name: String = ""
+		match err:
+			ERR_PARSE_ERROR:
+				error_name = "Parse error"
+			ERR_COMPILATION_FAILED:
+				error_name = "Compilation failed"
+			_:
+				error_name = "Error code %d" % err
+		return {"valid": false, "error": error_name, "error_code": err}
+	return {"valid": true}
+
+
+func _validate_script_external(source: String) -> Dictionary:
+	var temp_path: String = "user://_mcp_eval_validate_%d.gd" % Time.get_ticks_msec()
+	var file: FileAccess = FileAccess.open(temp_path, FileAccess.WRITE)
+	if file == null:
+		return {"valid": true}
+	file.store_string(source)
+	file.close()
+
+	var godot_path: String = OS.get_executable_path()
+	var project_path: String = ProjectSettings.globalize_path("res://")
+	var global_temp: String = ProjectSettings.globalize_path(temp_path)
+	var output: Array = []
+	var exit_code: int = OS.execute(godot_path, [
+		"--headless",
+		"--check-only",
+		"--script", global_temp,
+		"--path", project_path
+	], output)
+
+	DirAccess.remove_absolute(global_temp)
+
+	if exit_code != 0:
+		var error_detail: String = ""
+		for line in output:
+			error_detail += line + "\n"
+		error_detail = error_detail.strip_edges()
+		var msg: String = "Syntax error in eval code (external validation)"
+		if not error_detail.is_empty():
+			msg += ": " + error_detail
+		return {"valid": false, "error": msg}
+	return {"valid": true}
+
+
 func _indent_code(code: String) -> String:
 	var lines: PackedStringArray = code.split("\n")
 	var indented: String = ""