Add generated runtime cleanup after workflow execution. Exported scripts now run best-effort ComfyUI cache cleanup in a finally block and support opt-in model unloading for embedded repeated-call use cases. Document the supported VRAM-related runtime flags and lock the behavior in focused exporter and runtime cleanup tests.

comfyui_to_python/generator/generated_helpers.py

@@ -2,6 +2,7 @@ from ..node_runtime import (
     add_comfyui_directory_to_sys_path,
     add_extra_model_paths,
     bootstrap_comfyui_runtime,
+    cleanup_comfyui_runtime,
     find_path,
     get_comfyui_path,
     get_value_at_index,
@@ -11,6 +12,7 @@ __all__ = [
     "add_comfyui_directory_to_sys_path",
     "add_extra_model_paths",
     "bootstrap_comfyui_runtime",
+    "cleanup_comfyui_runtime",
     "find_path",
     "get_comfyui_path",
     "get_value_at_index",

comfyui_to_python/generator/render.py

@@ -9,6 +9,7 @@ from .generated_helpers import (
     add_comfyui_directory_to_sys_path,
     add_extra_model_paths,
     bootstrap_comfyui_runtime,
+    cleanup_comfyui_runtime,
     find_path,
     get_comfyui_path,
     get_value_at_index,
@@ -36,6 +37,7 @@ class WorkflowRenderer:
             add_comfyui_directory_to_sys_path,
             add_extra_model_paths,
             bootstrap_comfyui_runtime,
+            cleanup_comfyui_runtime,
         ]:
             func_strings.append(f"\n{inspect.getsource(func)}")
 
@@ -74,7 +76,7 @@ class WorkflowRenderer:
 
         execution_section = [
             "# Workflow execution",
-            "def main():",
+            "def main(unload_models: bool | None = None):",
             "    bootstrap_comfyui_runtime()",
             "    add_extra_model_paths()",
         ]
@@ -88,20 +90,27 @@ class WorkflowRenderer:
                 "",
                 "    import torch",
                 "",
-                "    with torch.inference_mode():",
+                "    try:",
+                "        with torch.inference_mode():",
             ]
         )
         execution_section.extend(
             self.build_function_body(
-                plan.special_functions_code, "pass", indentation="        "
+                plan.special_functions_code, "pass", indentation="            "
             ).splitlines()
         )
-        execution_section.append(f"        for q in range({plan.queue_size}):")
+        execution_section.append(f"            for q in range({plan.queue_size}):")
         execution_section.extend(
             self.build_function_body(
-                plan.loop_code, "pass", indentation="            "
+                plan.loop_code, "pass", indentation="                "
             ).splitlines()
         )
+        execution_section.extend(
+            [
+                "    finally:",
+                "        cleanup_comfyui_runtime(unload_models=unload_models)",
+            ]
+        )
 
         entrypoint_section = [
             "# Entrypoint",

comfyui_to_python/node_runtime.py

@@ -94,6 +94,34 @@ def bootstrap_comfyui_runtime() -> None:
         os.environ["OCL_SET_SVM_SIZE"] = "262144"
 
 
+def cleanup_comfyui_runtime(unload_models: bool | None = None) -> None:
+    """Best-effort cleanup for embedded or repeated generated-script execution."""
+    import gc
+
+    should_unload = unload_models
+    if should_unload is None:
+        should_unload = os.environ.get("COMFYUI_TOPYTHON_UNLOAD_MODELS", "").lower() in {
+            "1",
+            "true",
+            "yes",
+            "on",
+        }
+
+    try:
+        import comfy.model_management as model_management
+    except ModuleNotFoundError:
+        gc.collect()
+        return
+
+    if hasattr(model_management, "cleanup_models_gc"):
+        model_management.cleanup_models_gc()
+    if should_unload and hasattr(model_management, "unload_all_models"):
+        model_management.unload_all_models()
+    if hasattr(model_management, "soft_empty_cache"):
+        model_management.soft_empty_cache()
+    gc.collect()
+
+
 def import_custom_nodes() -> None:
     """Initialize ComfyUI custom nodes in the exporter runtime."""
     comfyui_path = get_comfyui_path()