test: isolation test suite and workflows

execution.py

@@ -42,7 +42,6 @@ from comfy_execution.progress import get_progress_state, reset_progress_state, a
 from comfy_execution.utils import CurrentNodeContext
 from comfy_api.internal import _ComfyNodeInternal, _NodeOutputInternal, first_real_override, is_class, make_locked_method_func
 from comfy_api.latest import io, _io
-from comfy_execution.cache_provider import _has_cache_providers, _get_cache_providers, _logger as _cache_logger
 
 _AIMDO_VBAR_RESET_UNAVAILABLE_LOGGED = False
 
@@ -131,15 +130,15 @@ class CacheSet:
 
     # Performs like the old cache -- dump data ASAP
     def init_classic_cache(self):
-        self.outputs = HierarchicalCache(CacheKeySetInputSignature, enable_providers=True)
+        self.outputs = HierarchicalCache(CacheKeySetInputSignature)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_lru_cache(self, cache_size):
-        self.outputs = LRUCache(CacheKeySetInputSignature, max_size=cache_size, enable_providers=True)
+        self.outputs = LRUCache(CacheKeySetInputSignature, max_size=cache_size)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_ram_cache(self, min_headroom):
-        self.outputs = RAMPressureCache(CacheKeySetInputSignature, enable_providers=True)
+        self.outputs = RAMPressureCache(CacheKeySetInputSignature)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_null_cache(self):
@@ -434,7 +433,7 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
     inputs = dynprompt.get_node(unique_id)['inputs']
     class_type = dynprompt.get_node(unique_id)['class_type']
     class_def = nodes.NODE_CLASS_MAPPINGS[class_type]
-    cached = await caches.outputs.get(unique_id)
+    cached = caches.outputs.get(unique_id)
     if cached is not None:
         if server.client_id is not None:
             cached_ui = cached.ui or {}
@@ -490,10 +489,10 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                 server.last_node_id = display_node_id
                 server.send_sync("executing", { "node": unique_id, "display_node": display_node_id, "prompt_id": prompt_id }, server.client_id)
 
-            obj = await caches.objects.get(unique_id)
+            obj = caches.objects.get(unique_id)
             if obj is None:
                 obj = class_def()
-                await caches.objects.set(unique_id, obj)
+                caches.objects.set(unique_id, obj)
 
             if issubclass(class_def, _ComfyNodeInternal):
                 lazy_status_present = first_real_override(class_def, "check_lazy_status") is not None
@@ -537,15 +536,7 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                 GraphBuilder.set_default_prefix(unique_id, call_index, 0)
 
             try:
-                output_data, output_ui, has_subgraph, has_pending_tasks = await get_output_data(
-                    prompt_id,
-                    unique_id,
-                    obj,
-                    input_data_all,
-                    execution_block_cb=execution_block_cb,
-                    pre_execute_cb=pre_execute_cb,
-                    v3_data=v3_data,
-                )
+                output_data, output_ui, has_subgraph, has_pending_tasks = await get_output_data(prompt_id, unique_id, obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, v3_data=v3_data)
             finally:
                 if comfy.memory_management.aimdo_enabled:
                     if args.verbose == "DEBUG":
@@ -630,7 +621,7 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
 
         cache_entry = CacheEntry(ui=ui_outputs.get(unique_id), outputs=output_data)
         execution_list.cache_update(unique_id, cache_entry)
-        await caches.outputs.set(unique_id, cache_entry)
+        caches.outputs.set(unique_id, cache_entry)
 
     except comfy.model_management.InterruptProcessingException as iex:
         logging.info("Processing interrupted")
@@ -766,19 +757,6 @@ class PromptExecutor:
             }
             self.add_message("execution_error", mes, broadcast=False)
 
-    def _notify_prompt_lifecycle(self, event: str, prompt_id: str):
-        if not _has_cache_providers():
-            return
-
-        for provider in _get_cache_providers():
-            try:
-                if event == "start":
-                    provider.on_prompt_start(prompt_id)
-                elif event == "end":
-                    provider.on_prompt_end(prompt_id)
-            except Exception as e:
-                _cache_logger.warning(f"Cache provider {provider.__class__.__name__} error on {event}: {e}")
-
     def execute(self, prompt, prompt_id, extra_data={}, execute_outputs=[]):
         asyncio.run(self.execute_async(prompt, prompt_id, extra_data, execute_outputs))
 
@@ -826,87 +804,79 @@ class PromptExecutor:
             except Exception:
                 logging.debug("][ EX:isolation_boundary_cleanup_start failed", exc_info=True)
 
-        self._notify_prompt_lifecycle("start", prompt_id)
+        with torch.inference_mode():
+            dynamic_prompt = DynamicPrompt(prompt)
+            reset_progress_state(prompt_id, dynamic_prompt)
+            add_progress_handler(WebUIProgressHandler(self.server))
+            is_changed_cache = IsChangedCache(prompt_id, dynamic_prompt, self.caches.outputs)
+            for cache in self.caches.all:
+                await cache.set_prompt(dynamic_prompt, prompt.keys(), is_changed_cache)
+                cache.clean_unused()
 
-        try:
-            with torch.inference_mode():
-                dynamic_prompt = DynamicPrompt(prompt)
-                reset_progress_state(prompt_id, dynamic_prompt)
-                add_progress_handler(WebUIProgressHandler(self.server))
-                is_changed_cache = IsChangedCache(prompt_id, dynamic_prompt, self.caches.outputs)
-                for cache in self.caches.all:
-                    await cache.set_prompt(dynamic_prompt, prompt.keys(), is_changed_cache)
-                    cache.clean_unused()
+            cached_nodes = []
+            for node_id in prompt:
+                if self.caches.outputs.get(node_id) is not None:
+                    cached_nodes.append(node_id)
 
-                node_ids = list(prompt.keys())
-                cache_results = await asyncio.gather(
-                    *(self.caches.outputs.get(node_id) for node_id in node_ids)
+            comfy.model_management.cleanup_models_gc()
+            self.add_message("execution_cached",
+                          { "nodes": cached_nodes, "prompt_id": prompt_id},
+                          broadcast=False)
+            pending_subgraph_results = {}
+            pending_async_nodes = {} # TODO - Unify this with pending_subgraph_results
+            ui_node_outputs = {}
+            executed = set()
+            execution_list = ExecutionList(dynamic_prompt, self.caches.outputs)
+            current_outputs = self.caches.outputs.all_node_ids()
+            for node_id in list(execute_outputs):
+                execution_list.add_node(node_id)
+
+            if args.use_process_isolation:
+                pending_class_types = set()
+                for node_id in execution_list.pendingNodes.keys():
+                    class_type = dynamic_prompt.get_node(node_id)["class_type"]
+                    pending_class_types.add(class_type)
+                await self._wait_model_patcher_quiescence_safe(
+                    fail_loud=True,
+                    timeout_ms=120000,
+                    marker="EX:notify_graph_wait_idle",
                 )
-                cached_nodes = [
-                    node_id for node_id, result in zip(node_ids, cache_results)
-                    if result is not None
-                ]
+                await self._notify_execution_graph_safe(pending_class_types, fail_loud=True)
 
-                comfy.model_management.cleanup_models_gc()
-                self.add_message("execution_cached",
-                              { "nodes": cached_nodes, "prompt_id": prompt_id},
-                              broadcast=False)
-                pending_subgraph_results = {}
-                pending_async_nodes = {} # TODO - Unify this with pending_subgraph_results
-                ui_node_outputs = {}
-                executed = set()
-                execution_list = ExecutionList(dynamic_prompt, self.caches.outputs)
-                current_outputs = self.caches.outputs.all_node_ids()
-                for node_id in list(execute_outputs):
-                    execution_list.add_node(node_id)
+            while not execution_list.is_empty():
+                node_id, error, ex = await execution_list.stage_node_execution()
+                if error is not None:
+                    self.handle_execution_error(prompt_id, dynamic_prompt.original_prompt, current_outputs, executed, error, ex)
+                    break
 
-                if args.use_process_isolation:
-                    pending_class_types = set()
-                    for node_id in execution_list.pendingNodes.keys():
-                        class_type = dynamic_prompt.get_node(node_id)["class_type"]
-                        pending_class_types.add(class_type)
-                    await self._wait_model_patcher_quiescence_safe(
-                        fail_loud=True,
-                        timeout_ms=120000,
-                        marker="EX:notify_graph_wait_idle",
-                    )
-                    await self._notify_execution_graph_safe(pending_class_types, fail_loud=True)
+                assert node_id is not None, "Node ID should not be None at this point"
+                result, error, ex = await execute(self.server, dynamic_prompt, self.caches, node_id, extra_data, executed, prompt_id, execution_list, pending_subgraph_results, pending_async_nodes, ui_node_outputs)
+                self.success = result != ExecutionResult.FAILURE
+                if result == ExecutionResult.FAILURE:
+                    self.handle_execution_error(prompt_id, dynamic_prompt.original_prompt, current_outputs, executed, error, ex)
+                    break
+                elif result == ExecutionResult.PENDING:
+                    execution_list.unstage_node_execution()
+                else: # result == ExecutionResult.SUCCESS:
+                    execution_list.complete_node_execution()
+                self.caches.outputs.poll(ram_headroom=self.cache_args["ram"])
+            else:
+                # Only execute when the while-loop ends without break
+                self.add_message("execution_success", { "prompt_id": prompt_id }, broadcast=False)
 
-                while not execution_list.is_empty():
-                    node_id, error, ex = await execution_list.stage_node_execution()
-                    if error is not None:
-                        self.handle_execution_error(prompt_id, dynamic_prompt.original_prompt, current_outputs, executed, error, ex)
-                        break
-
-                    assert node_id is not None, "Node ID should not be None at this point"
-                    result, error, ex = await execute(self.server, dynamic_prompt, self.caches, node_id, extra_data, executed, prompt_id, execution_list, pending_subgraph_results, pending_async_nodes, ui_node_outputs)
-                    self.success = result != ExecutionResult.FAILURE
-                    if result == ExecutionResult.FAILURE:
-                        self.handle_execution_error(prompt_id, dynamic_prompt.original_prompt, current_outputs, executed, error, ex)
-                        break
-                    elif result == ExecutionResult.PENDING:
-                        execution_list.unstage_node_execution()
-                    else: # result == ExecutionResult.SUCCESS:
-                        execution_list.complete_node_execution()
-                    self.caches.outputs.poll(ram_headroom=self.cache_args["ram"])
-                else:
-                    # Only execute when the while-loop ends without break
-                    self.add_message("execution_success", { "prompt_id": prompt_id }, broadcast=False)
-
-                ui_outputs = {}
-                meta_outputs = {}
-                for node_id, ui_info in ui_node_outputs.items():
-                    ui_outputs[node_id] = ui_info["output"]
-                    meta_outputs[node_id] = ui_info["meta"]
-                self.history_result = {
-                    "outputs": ui_outputs,
-                    "meta": meta_outputs,
-                }
-                self.server.last_node_id = None
-                if comfy.model_management.DISABLE_SMART_MEMORY:
-                    comfy.model_management.unload_all_models()
-        finally:
-            self._notify_prompt_lifecycle("end", prompt_id)
+            ui_outputs = {}
+            meta_outputs = {}
+            for node_id, ui_info in ui_node_outputs.items():
+                ui_outputs[node_id] = ui_info["output"]
+                meta_outputs[node_id] = ui_info["meta"]
+            self.history_result = {
+                "outputs": ui_outputs,
+                "meta": meta_outputs,
+            }
+            comfy.model_management.cleanup_models_gc()
+            self.server.last_node_id = None
+            if comfy.model_management.DISABLE_SMART_MEMORY:
+                comfy.model_management.unload_all_models()
 
 
 async def validate_inputs(prompt_id, prompt, item, validated):

server.py

@@ -34,8 +34,6 @@ from app.frontend_management import FrontendManager, parse_version
 from comfy_api.internal import _ComfyNodeInternal
 from app.assets.seeder import asset_seeder
 from app.assets.api.routes import register_assets_routes
-from app.assets.services.ingest import register_file_in_place
-from app.assets.services.asset_management import resolve_hash_to_path
 
 from app.user_manager import UserManager
 from app.model_manager import ModelFileManager
@@ -313,7 +311,7 @@ class PromptServer():
         @routes.get("/")
         async def get_root(request):
             response = web.FileResponse(os.path.join(self.web_root, "index.html"))
-            response.headers['Cache-Control'] = 'no-store, must-revalidate'
+            response.headers['Cache-Control'] = 'no-cache'
             response.headers["Pragma"] = "no-cache"
             response.headers["Expires"] = "0"
             return response
@@ -357,8 +355,7 @@ class PromptServer():
                     for entry in cache.list_files(ext_name):
                         if entry["relative_path"].endswith(".js"):
                             extensions.append(
-                                "/extensions/" + urllib.parse.quote(ext_name)
-                                + "/" + entry["relative_path"]
+                                "/extensions/" + urllib.parse.quote(ext_name) + "/" + entry["relative_path"]
                             )
 
             return web.json_response(extensions)
@@ -434,24 +431,7 @@ class PromptServer():
                         with open(filepath, "wb") as f:
                             f.write(image.file.read())
 
-                resp = {"name" : filename, "subfolder": subfolder, "type": image_upload_type}
-
-                if args.enable_assets:
-                    try:
-                        tag = image_upload_type if image_upload_type in ("input", "output") else "input"
-                        result = register_file_in_place(abs_path=filepath, name=filename, tags=[tag])
-                        resp["asset"] = {
-                            "id": result.ref.id,
-                            "name": result.ref.name,
-                            "asset_hash": result.asset.hash,
-                            "size": result.asset.size_bytes,
-                            "mime_type": result.asset.mime_type,
-                            "tags": result.tags,
-                        }
-                    except Exception:
-                        logging.warning("Failed to register uploaded image as asset", exc_info=True)
-
-                return web.json_response(resp)
+                return web.json_response({"name" : filename, "subfolder": subfolder, "type": image_upload_type})
             else:
                 return web.Response(status=400)
 
@@ -511,43 +491,30 @@ class PromptServer():
         async def view_image(request):
             if "filename" in request.rel_url.query:
                 filename = request.rel_url.query["filename"]
+                filename, output_dir = folder_paths.annotated_filepath(filename)
 
-                # The frontend's LoadImage combo widget uses asset_hash values
-                # (e.g. "blake3:...") as widget values. When litegraph renders the
-                # node preview, it constructs /view?filename=<asset_hash>, so this
-                # endpoint must resolve blake3 hashes to their on-disk file paths.
-                if filename.startswith("blake3:"):
-                    owner_id = self.user_manager.get_request_user_id(request)
-                    result = resolve_hash_to_path(filename, owner_id=owner_id)
-                    if result is None:
-                        return web.Response(status=404)
-                    file, filename, resolved_content_type = result.abs_path, result.download_name, result.content_type
-                else:
-                    resolved_content_type = None
-                    filename, output_dir = folder_paths.annotated_filepath(filename)
+                if not filename:
+                    return web.Response(status=400)
 
-                    if not filename:
-                        return web.Response(status=400)
+                # validation for security: prevent accessing arbitrary path
+                if filename[0] == '/' or '..' in filename:
+                    return web.Response(status=400)
 
-                    # validation for security: prevent accessing arbitrary path
-                    if filename[0] == '/' or '..' in filename:
-                        return web.Response(status=400)
+                if output_dir is None:
+                    type = request.rel_url.query.get("type", "output")
+                    output_dir = folder_paths.get_directory_by_type(type)
 
-                    if output_dir is None:
-                        type = request.rel_url.query.get("type", "output")
-                        output_dir = folder_paths.get_directory_by_type(type)
+                if output_dir is None:
+                    return web.Response(status=400)
 
-                    if output_dir is None:
-                        return web.Response(status=400)
+                if "subfolder" in request.rel_url.query:
+                    full_output_dir = os.path.join(output_dir, request.rel_url.query["subfolder"])
+                    if os.path.commonpath((os.path.abspath(full_output_dir), output_dir)) != output_dir:
+                        return web.Response(status=403)
+                    output_dir = full_output_dir
 
-                    if "subfolder" in request.rel_url.query:
-                        full_output_dir = os.path.join(output_dir, request.rel_url.query["subfolder"])
-                        if os.path.commonpath((os.path.abspath(full_output_dir), output_dir)) != output_dir:
-                            return web.Response(status=403)
-                        output_dir = full_output_dir
-
-                    filename = os.path.basename(filename)
-                    file = os.path.join(output_dir, filename)
+                filename = os.path.basename(filename)
+                file = os.path.join(output_dir, filename)
 
                 if os.path.isfile(file):
                     if 'preview' in request.rel_url.query:
@@ -607,13 +574,8 @@ class PromptServer():
                             return web.Response(body=alpha_buffer.read(), content_type='image/png',
                                                 headers={"Content-Disposition": f"filename=\"{filename}\""})
                     else:
-                        # Use the content type from asset resolution if available,
-                        # otherwise guess from the filename.
-                        content_type = (
-                            resolved_content_type
-                            or mimetypes.guess_type(filename)[0]
-                            or 'application/octet-stream'
-                        )
+                        # Get content type from mimetype, defaulting to 'application/octet-stream'
+                        content_type = mimetypes.guess_type(filename)[0] or 'application/octet-stream'
 
                         # For security, force certain mimetypes to download instead of display
                         if content_type in {'text/html', 'text/html-sandboxed', 'application/xhtml+xml', 'text/javascript', 'text/css'}:
@@ -1078,11 +1040,11 @@ class PromptServer():
                 ALLOWED_EXTENSIONS,
             )
 
-            async def serve_proxied_web_file(request):
-                ext_name = request.match_info["extension_name"]
-                file_path = request.match_info["path"]
-                suffix = os.path.splitext(file_path)[1].lower()
+            async def proxied_web_handler(request):
+                ext_name = request.match_info["ext_name"]
+                file_path = request.match_info["file_path"]
 
+                suffix = os.path.splitext(file_path)[1].lower()
                 if suffix not in ALLOWED_EXTENSIONS:
                     return web.Response(status=403, text="Forbidden file type")
 
@@ -1091,14 +1053,18 @@ class PromptServer():
                 if result is None:
                     return web.Response(status=404, text="Not found")
 
-                return web.Response(
-                    body=result["content"],
-                    content_type=result["content_type"],
-                )
+                content_type = {
+                    ".js": "application/javascript",
+                    ".css": "text/css",
+                    ".html": "text/html",
+                    ".json": "application/json",
+                }.get(suffix, "application/octet-stream")
+
+                return web.Response(body=result, content_type=content_type)
 
             self.app.router.add_get(
-                "/extensions/{extension_name}/{path:.+}",
-                serve_proxied_web_file,
+                "/extensions/{ext_name}/{file_path:.*}",
+                proxied_web_handler,
             )
 
         installed_templates_version = FrontendManager.get_installed_templates_version()

tests/isolation/conda_sealed_worker/__init__.py

@@ -0,0 +1,209 @@
+# pylint: disable=import-outside-toplevel,import-error
+from __future__ import annotations
+
+import logging
+import os
+import sys
+from pathlib import Path
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+
+def _artifact_dir() -> Path | None:
+    raw = os.environ.get("PYISOLATE_ARTIFACT_DIR")
+    if not raw:
+        return None
+    path = Path(raw)
+    path.mkdir(parents=True, exist_ok=True)
+    return path
+
+
+def _write_artifact(name: str, content: str) -> None:
+    artifact_dir = _artifact_dir()
+    if artifact_dir is None:
+        return
+    (artifact_dir / name).write_text(content, encoding="utf-8")
+
+
+def _contains_tensor_marker(value: Any) -> bool:
+    if isinstance(value, dict):
+        if value.get("__type__") == "TensorValue":
+            return True
+        return any(_contains_tensor_marker(v) for v in value.values())
+    if isinstance(value, (list, tuple)):
+        return any(_contains_tensor_marker(v) for v in value)
+    return False
+
+
+class InspectRuntimeNode:
+    RETURN_TYPES = (
+        "STRING",
+        "STRING",
+        "BOOLEAN",
+        "BOOLEAN",
+        "STRING",
+        "STRING",
+        "BOOLEAN",
+    )
+    RETURN_NAMES = (
+        "path_dump",
+        "runtime_report",
+        "saw_comfy_root",
+        "imported_comfy_wrapper",
+        "comfy_module_dump",
+        "python_exe",
+        "saw_user_site",
+    )
+    FUNCTION = "inspect"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {}}
+
+    def inspect(self) -> tuple[str, str, bool, bool, str, str, bool]:
+        import cfgrib
+        import eccodes
+        import xarray as xr
+
+        path_dump = "\n".join(sys.path)
+        comfy_root = "/home/johnj/ComfyUI"
+        saw_comfy_root = any(
+            entry == comfy_root
+            or entry.startswith(f"{comfy_root}/comfy")
+            or entry.startswith(f"{comfy_root}/.venv")
+            for entry in sys.path
+        )
+        imported_comfy_wrapper = "comfy.isolation.extension_wrapper" in sys.modules
+        comfy_module_dump = "\n".join(
+            sorted(name for name in sys.modules if name.startswith("comfy"))
+        )
+        saw_user_site = any("/.local/lib/" in entry for entry in sys.path)
+        python_exe = sys.executable
+
+        runtime_lines = [
+            "Conda sealed worker runtime probe",
+            f"python_exe={python_exe}",
+            f"xarray_origin={getattr(xr, '__file__', '<missing>')}",
+            f"cfgrib_origin={getattr(cfgrib, '__file__', '<missing>')}",
+            f"eccodes_origin={getattr(eccodes, '__file__', '<missing>')}",
+            f"saw_comfy_root={saw_comfy_root}",
+            f"imported_comfy_wrapper={imported_comfy_wrapper}",
+            f"saw_user_site={saw_user_site}",
+        ]
+        runtime_report = "\n".join(runtime_lines)
+
+        _write_artifact("child_bootstrap_paths.txt", path_dump)
+        _write_artifact("child_import_trace.txt", comfy_module_dump)
+        _write_artifact("child_dependency_dump.txt", runtime_report)
+        logger.warning("][ Conda sealed runtime probe executed")
+        logger.warning("][ conda python executable: %s", python_exe)
+        logger.warning(
+            "][ conda dependency origins: xarray=%s cfgrib=%s eccodes=%s",
+            getattr(xr, "__file__", "<missing>"),
+            getattr(cfgrib, "__file__", "<missing>"),
+            getattr(eccodes, "__file__", "<missing>"),
+        )
+
+        return (
+            path_dump,
+            runtime_report,
+            saw_comfy_root,
+            imported_comfy_wrapper,
+            comfy_module_dump,
+            python_exe,
+            saw_user_site,
+        )
+
+
+class OpenWeatherDatasetNode:
+    RETURN_TYPES = ("FLOAT", "STRING", "STRING")
+    RETURN_NAMES = ("sum_value", "grib_path", "dependency_report")
+    FUNCTION = "open_dataset"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {}}
+
+    def open_dataset(self) -> tuple[float, str, str]:
+        import eccodes
+        import xarray as xr
+
+        artifact_dir = _artifact_dir()
+        if artifact_dir is None:
+            artifact_dir = Path(os.environ.get("HOME", ".")) / "pyisolate_artifacts"
+            artifact_dir.mkdir(parents=True, exist_ok=True)
+
+        grib_path = artifact_dir / "toolkit_weather_fixture.grib2"
+
+        gid = eccodes.codes_grib_new_from_samples("GRIB2")
+        for key, value in [
+            ("gridType", "regular_ll"),
+            ("Nx", 2),
+            ("Ny", 2),
+            ("latitudeOfFirstGridPointInDegrees", 1.0),
+            ("longitudeOfFirstGridPointInDegrees", 0.0),
+            ("latitudeOfLastGridPointInDegrees", 0.0),
+            ("longitudeOfLastGridPointInDegrees", 1.0),
+            ("iDirectionIncrementInDegrees", 1.0),
+            ("jDirectionIncrementInDegrees", 1.0),
+            ("jScansPositively", 0),
+            ("shortName", "t"),
+            ("typeOfLevel", "surface"),
+            ("level", 0),
+            ("date", 20260315),
+            ("time", 0),
+            ("step", 0),
+        ]:
+            eccodes.codes_set(gid, key, value)
+
+        eccodes.codes_set_values(gid, [1.0, 2.0, 3.0, 4.0])
+        with grib_path.open("wb") as handle:
+            eccodes.codes_write(gid, handle)
+        eccodes.codes_release(gid)
+
+        dataset = xr.open_dataset(grib_path, engine="cfgrib")
+        sum_value = float(dataset["t"].sum().item())
+        dependency_report = "\n".join(
+            [
+                f"dataset_sum={sum_value}",
+                f"grib_path={grib_path}",
+                "xarray_engine=cfgrib",
+            ]
+        )
+        _write_artifact("weather_dependency_report.txt", dependency_report)
+        logger.warning("][ cfgrib import ok")
+        logger.warning("][ xarray open_dataset engine=cfgrib path=%s", grib_path)
+        logger.warning("][ conda weather dataset sum=%s", sum_value)
+        return sum_value, str(grib_path), dependency_report
+
+
+class EchoLatentNode:
+    RETURN_TYPES = ("LATENT", "BOOLEAN")
+    RETURN_NAMES = ("latent", "saw_json_tensor")
+    FUNCTION = "echo_latent"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {"latent": ("LATENT",)}}
+
+    def echo_latent(self, latent: Any) -> tuple[Any, bool]:
+        saw_json_tensor = _contains_tensor_marker(latent)
+        logger.warning("][ conda latent echo json_marker=%s", saw_json_tensor)
+        return latent, saw_json_tensor
+
+
+NODE_CLASS_MAPPINGS = {
+    "CondaSealedRuntimeProbe": InspectRuntimeNode,
+    "CondaSealedOpenWeatherDataset": OpenWeatherDatasetNode,
+    "CondaSealedLatentEcho": EchoLatentNode,
+}
+
+NODE_DISPLAY_NAME_MAPPINGS = {
+    "CondaSealedRuntimeProbe": "Conda Sealed Runtime Probe",
+    "CondaSealedOpenWeatherDataset": "Conda Sealed Open Weather Dataset",
+    "CondaSealedLatentEcho": "Conda Sealed Latent Echo",
+}

tests/isolation/conda_sealed_worker/pyproject.toml

@@ -0,0 +1,13 @@
+[project]
+name = "comfyui-toolkit-conda-sealed-worker"
+version = "0.1.0"
+dependencies = ["xarray", "cfgrib"]
+
+[tool.comfy.isolation]
+can_isolate = true
+share_torch = false
+package_manager = "conda"
+execution_model = "sealed_worker"
+standalone = true
+conda_channels = ["conda-forge"]
+conda_dependencies = ["eccodes", "cfgrib"]

tests/isolation/internal_probe_host_policy.toml

@@ -0,0 +1,7 @@
+[tool.comfy.host]
+sandbox_mode = "required"
+allow_network = false
+writable_paths = [
+  "/dev/shm",
+  "/home/johnj/ComfyUI/output",
+]

tests/isolation/internal_probe_node/__init__.py

@@ -0,0 +1,6 @@
+from .probe_nodes import (
+    NODE_CLASS_MAPPINGS as NODE_CLASS_MAPPINGS,
+    NODE_DISPLAY_NAME_MAPPINGS as NODE_DISPLAY_NAME_MAPPINGS,
+)
+
+__all__ = ["NODE_CLASS_MAPPINGS", "NODE_DISPLAY_NAME_MAPPINGS"]

tests/isolation/internal_probe_node/probe_nodes.py

@@ -0,0 +1,75 @@
+from __future__ import annotations
+
+
+class InternalIsolationProbeImage:
+    CATEGORY = "tests/isolation"
+    RETURN_TYPES = ()
+    FUNCTION = "run"
+    OUTPUT_NODE = True
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {}}
+
+    def run(self):
+        from comfy_api.latest import UI
+        import torch
+
+        image = torch.zeros((1, 2, 2, 3), dtype=torch.float32)
+        image[:, :, :, 0] = 1.0
+        ui = UI.PreviewImage(image)
+        return {"ui": ui.as_dict(), "result": ()}
+
+
+class InternalIsolationProbeAudio:
+    CATEGORY = "tests/isolation"
+    RETURN_TYPES = ()
+    FUNCTION = "run"
+    OUTPUT_NODE = True
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {}}
+
+    def run(self):
+        from comfy_api.latest import UI
+        import torch
+
+        waveform = torch.zeros((1, 1, 32), dtype=torch.float32)
+        audio = {"waveform": waveform, "sample_rate": 44100}
+        ui = UI.PreviewAudio(audio)
+        return {"ui": ui.as_dict(), "result": ()}
+
+
+class InternalIsolationProbeUI3D:
+    CATEGORY = "tests/isolation"
+    RETURN_TYPES = ()
+    FUNCTION = "run"
+    OUTPUT_NODE = True
+
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {"required": {}}
+
+    def run(self):
+        from comfy_api.latest import UI
+        import torch
+
+        bg_image = torch.zeros((1, 2, 2, 3), dtype=torch.float32)
+        bg_image[:, :, :, 1] = 1.0
+        camera_info = {"distance": 1.0}
+        ui = UI.PreviewUI3D("internal_probe_preview.obj", camera_info, bg_image=bg_image)
+        return {"ui": ui.as_dict(), "result": ()}
+
+
+NODE_CLASS_MAPPINGS = {
+    "InternalIsolationProbeImage": InternalIsolationProbeImage,
+    "InternalIsolationProbeAudio": InternalIsolationProbeAudio,
+    "InternalIsolationProbeUI3D": InternalIsolationProbeUI3D,
+}
+
+NODE_DISPLAY_NAME_MAPPINGS = {
+    "InternalIsolationProbeImage": "Internal Isolation Probe Image",
+    "InternalIsolationProbeAudio": "Internal Isolation Probe Audio",
+    "InternalIsolationProbeUI3D": "Internal Isolation Probe UI3D",
+}

tests/isolation/singleton_boundary_helpers.py

@@ -0,0 +1,955 @@
+from __future__ import annotations
+
+import asyncio
+import importlib.util
+import os
+import sys
+from pathlib import Path
+from typing import Any
+
+
+COMFYUI_ROOT = Path(__file__).resolve().parents[2]
+UV_SEALED_WORKER_MODULE = COMFYUI_ROOT / "tests" / "isolation" / "uv_sealed_worker" / "__init__.py"
+FORBIDDEN_MINIMAL_SEALED_MODULES = (
+    "torch",
+    "folder_paths",
+    "comfy.utils",
+    "comfy.model_management",
+    "main",
+    "comfy.isolation.extension_wrapper",
+)
+FORBIDDEN_SEALED_SINGLETON_MODULES = (
+    "torch",
+    "folder_paths",
+    "comfy.utils",
+    "comfy_execution.progress",
+)
+FORBIDDEN_EXACT_SMALL_PROXY_MODULES = FORBIDDEN_SEALED_SINGLETON_MODULES
+FORBIDDEN_MODEL_MANAGEMENT_MODULES = (
+    "comfy.model_management",
+)
+
+
+def _load_module_from_path(module_name: str, module_path: Path):
+    spec = importlib.util.spec_from_file_location(module_name, module_path)
+    if spec is None or spec.loader is None:
+        raise RuntimeError(f"unable to build import spec for {module_path}")
+    module = importlib.util.module_from_spec(spec)
+    sys.modules[module_name] = module
+    try:
+        spec.loader.exec_module(module)
+    except Exception:
+        sys.modules.pop(module_name, None)
+        raise
+    return module
+
+
+def matching_modules(prefixes: tuple[str, ...], modules: set[str]) -> list[str]:
+    return sorted(
+        module_name
+        for module_name in modules
+        if any(
+            module_name == prefix or module_name.startswith(f"{prefix}.")
+            for prefix in prefixes
+        )
+    )
+
+
+def _load_helper_proxy_service() -> Any | None:
+    try:
+        from comfy.isolation.proxies.helper_proxies import HelperProxiesService
+    except (ImportError, AttributeError):
+        return None
+    return HelperProxiesService
+
+
+def _load_model_management_proxy() -> Any | None:
+    try:
+        from comfy.isolation.proxies.model_management_proxy import ModelManagementProxy
+    except (ImportError, AttributeError):
+        return None
+    return ModelManagementProxy
+
+
+async def _capture_minimal_sealed_worker_imports() -> dict[str, object]:
+    from pyisolate.sealed import SealedNodeExtension
+
+    module_name = "tests.isolation.uv_sealed_worker_boundary_probe"
+    before = set(sys.modules)
+    extension = SealedNodeExtension()
+    module = _load_module_from_path(module_name, UV_SEALED_WORKER_MODULE)
+    try:
+        await extension.on_module_loaded(module)
+        node_list = await extension.list_nodes()
+        node_details = await extension.get_node_details("UVSealedRuntimeProbe")
+        imported = set(sys.modules) - before
+        return {
+            "mode": "minimal_sealed_worker",
+            "node_names": sorted(node_list),
+            "runtime_probe_function": node_details["function"],
+            "modules": sorted(imported),
+            "forbidden_matches": matching_modules(FORBIDDEN_MINIMAL_SEALED_MODULES, imported),
+        }
+    finally:
+        sys.modules.pop(module_name, None)
+
+
+def capture_minimal_sealed_worker_imports() -> dict[str, object]:
+    return asyncio.run(_capture_minimal_sealed_worker_imports())
+
+
+class FakeSingletonCaller:
+    def __init__(self, methods: dict[str, Any], calls: list[dict[str, Any]], object_id: str):
+        self._methods = methods
+        self._calls = calls
+        self._object_id = object_id
+
+    def __getattr__(self, name: str):
+        if name not in self._methods:
+            raise AttributeError(name)
+
+        async def method(*args: Any, **kwargs: Any) -> Any:
+            self._calls.append(
+                {
+                    "object_id": self._object_id,
+                    "method": name,
+                    "args": list(args),
+                    "kwargs": dict(kwargs),
+                }
+            )
+            result = self._methods[name]
+            return result(*args, **kwargs) if callable(result) else result
+
+        return method
+
+
+class FakeSingletonRPC:
+    def __init__(self) -> None:
+        self.calls: list[dict[str, Any]] = []
+        self._device = {"__pyisolate_torch_device__": "cpu"}
+        self._services: dict[str, dict[str, Any]] = {
+            "FolderPathsProxy": {
+                "rpc_get_models_dir": lambda: "/sandbox/models",
+                "rpc_get_folder_names_and_paths": lambda: {
+                    "checkpoints": {
+                        "paths": ["/sandbox/models/checkpoints"],
+                        "extensions": [".ckpt", ".safetensors"],
+                    }
+                },
+                "rpc_get_extension_mimetypes_cache": lambda: {"webp": "image"},
+                "rpc_get_filename_list_cache": lambda: {},
+                "rpc_get_temp_directory": lambda: "/sandbox/temp",
+                "rpc_get_input_directory": lambda: "/sandbox/input",
+                "rpc_get_output_directory": lambda: "/sandbox/output",
+                "rpc_get_user_directory": lambda: "/sandbox/user",
+                "rpc_get_annotated_filepath": self._get_annotated_filepath,
+                "rpc_exists_annotated_filepath": lambda _name: False,
+                "rpc_add_model_folder_path": lambda *_args, **_kwargs: None,
+                "rpc_get_folder_paths": lambda folder_name: [f"/sandbox/models/{folder_name}"],
+                "rpc_get_filename_list": lambda folder_name: [f"{folder_name}_fixture.safetensors"],
+                "rpc_get_full_path": lambda folder_name, filename: f"/sandbox/models/{folder_name}/{filename}",
+            },
+            "UtilsProxy": {
+                "progress_bar_hook": lambda value, total, preview=None, node_id=None: {
+                    "value": value,
+                    "total": total,
+                    "preview": preview,
+                    "node_id": node_id,
+                }
+            },
+            "ProgressProxy": {
+                "rpc_set_progress": lambda value, max_value, node_id=None, image=None: {
+                    "value": value,
+                    "max_value": max_value,
+                    "node_id": node_id,
+                    "image": image,
+                }
+            },
+            "HelperProxiesService": {
+                "rpc_restore_input_types": lambda raw: raw,
+            },
+            "ModelManagementProxy": {
+                "rpc_call": self._model_management_rpc_call,
+            },
+        }
+
+    def _model_management_rpc_call(self, method_name: str, args: Any = None, kwargs: Any = None) -> Any:
+        if method_name == "get_torch_device":
+            return self._device
+        elif method_name == "get_torch_device_name":
+            return "cpu"
+        elif method_name == "get_free_memory":
+            return 34359738368
+        raise AssertionError(f"unexpected model_management method {method_name}")
+
+    @staticmethod
+    def _get_annotated_filepath(name: str, default_dir: str | None = None) -> str:
+        if name.endswith("[output]"):
+            return f"/sandbox/output/{name[:-8]}"
+        if name.endswith("[input]"):
+            return f"/sandbox/input/{name[:-7]}"
+        if name.endswith("[temp]"):
+            return f"/sandbox/temp/{name[:-6]}"
+        base_dir = default_dir or "/sandbox/input"
+        return f"{base_dir}/{name}"
+
+    def create_caller(self, cls: Any, object_id: str):
+        methods = self._services.get(object_id) or self._services.get(getattr(cls, "__name__", object_id))
+        if methods is None:
+            raise KeyError(object_id)
+        return FakeSingletonCaller(methods, self.calls, object_id)
+
+
+def _clear_proxy_rpcs() -> None:
+    from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+    from comfy.isolation.proxies.progress_proxy import ProgressProxy
+    from comfy.isolation.proxies.utils_proxy import UtilsProxy
+
+    FolderPathsProxy.clear_rpc()
+    ProgressProxy.clear_rpc()
+    UtilsProxy.clear_rpc()
+    helper_proxy_service = _load_helper_proxy_service()
+    if helper_proxy_service is not None:
+        helper_proxy_service.clear_rpc()
+    model_management_proxy = _load_model_management_proxy()
+    if model_management_proxy is not None and hasattr(model_management_proxy, "clear_rpc"):
+        model_management_proxy.clear_rpc()
+
+
+def prepare_sealed_singleton_proxies(fake_rpc: FakeSingletonRPC) -> None:
+    os.environ["PYISOLATE_CHILD"] = "1"
+    os.environ["PYISOLATE_IMPORT_TORCH"] = "0"
+    _clear_proxy_rpcs()
+
+    from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+    from comfy.isolation.proxies.progress_proxy import ProgressProxy
+    from comfy.isolation.proxies.utils_proxy import UtilsProxy
+
+    FolderPathsProxy.set_rpc(fake_rpc)
+    ProgressProxy.set_rpc(fake_rpc)
+    UtilsProxy.set_rpc(fake_rpc)
+    helper_proxy_service = _load_helper_proxy_service()
+    if helper_proxy_service is not None:
+        helper_proxy_service.set_rpc(fake_rpc)
+    model_management_proxy = _load_model_management_proxy()
+    if model_management_proxy is not None and hasattr(model_management_proxy, "set_rpc"):
+        model_management_proxy.set_rpc(fake_rpc)
+
+
+def reset_forbidden_singleton_modules() -> None:
+    for module_name in (
+        "folder_paths",
+        "comfy.utils",
+        "comfy_execution.progress",
+    ):
+        sys.modules.pop(module_name, None)
+
+
+class FakeExactRelayCaller:
+    def __init__(self, methods: dict[str, Any], transcripts: list[dict[str, Any]], object_id: str):
+        self._methods = methods
+        self._transcripts = transcripts
+        self._object_id = object_id
+
+    def __getattr__(self, name: str):
+        if name not in self._methods:
+            raise AttributeError(name)
+
+        async def method(*args: Any, **kwargs: Any) -> Any:
+            self._transcripts.append(
+                {
+                    "phase": "child_call",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "args": list(args),
+                    "kwargs": dict(kwargs),
+                }
+            )
+            impl = self._methods[name]
+            self._transcripts.append(
+                {
+                    "phase": "host_invocation",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "target": impl["target"],
+                    "args": list(args),
+                    "kwargs": dict(kwargs),
+                }
+            )
+            result = impl["result"](*args, **kwargs) if callable(impl["result"]) else impl["result"]
+            self._transcripts.append(
+                {
+                    "phase": "result",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "result": result,
+                }
+            )
+            return result
+
+        return method
+
+
+class FakeExactRelayRPC:
+    def __init__(self) -> None:
+        self.transcripts: list[dict[str, Any]] = []
+        self._device = {"__pyisolate_torch_device__": "cpu"}
+        self._services: dict[str, dict[str, Any]] = {
+            "FolderPathsProxy": {
+                "rpc_get_models_dir": {
+                    "target": "folder_paths.models_dir",
+                    "result": "/sandbox/models",
+                },
+                "rpc_get_temp_directory": {
+                    "target": "folder_paths.get_temp_directory",
+                    "result": "/sandbox/temp",
+                },
+                "rpc_get_input_directory": {
+                    "target": "folder_paths.get_input_directory",
+                    "result": "/sandbox/input",
+                },
+                "rpc_get_output_directory": {
+                    "target": "folder_paths.get_output_directory",
+                    "result": "/sandbox/output",
+                },
+                "rpc_get_user_directory": {
+                    "target": "folder_paths.get_user_directory",
+                    "result": "/sandbox/user",
+                },
+                "rpc_get_folder_names_and_paths": {
+                    "target": "folder_paths.folder_names_and_paths",
+                    "result": {
+                        "checkpoints": {
+                            "paths": ["/sandbox/models/checkpoints"],
+                            "extensions": [".ckpt", ".safetensors"],
+                        }
+                    },
+                },
+                "rpc_get_extension_mimetypes_cache": {
+                    "target": "folder_paths.extension_mimetypes_cache",
+                    "result": {"webp": "image"},
+                },
+                "rpc_get_filename_list_cache": {
+                    "target": "folder_paths.filename_list_cache",
+                    "result": {},
+                },
+                "rpc_get_annotated_filepath": {
+                    "target": "folder_paths.get_annotated_filepath",
+                    "result": lambda name, default_dir=None: FakeSingletonRPC._get_annotated_filepath(name, default_dir),
+                },
+                "rpc_exists_annotated_filepath": {
+                    "target": "folder_paths.exists_annotated_filepath",
+                    "result": False,
+                },
+                "rpc_add_model_folder_path": {
+                    "target": "folder_paths.add_model_folder_path",
+                    "result": None,
+                },
+                "rpc_get_folder_paths": {
+                    "target": "folder_paths.get_folder_paths",
+                    "result": lambda folder_name: [f"/sandbox/models/{folder_name}"],
+                },
+                "rpc_get_filename_list": {
+                    "target": "folder_paths.get_filename_list",
+                    "result": lambda folder_name: [f"{folder_name}_fixture.safetensors"],
+                },
+                "rpc_get_full_path": {
+                    "target": "folder_paths.get_full_path",
+                    "result": lambda folder_name, filename: f"/sandbox/models/{folder_name}/{filename}",
+                },
+            },
+            "UtilsProxy": {
+                "progress_bar_hook": {
+                    "target": "comfy.utils.PROGRESS_BAR_HOOK",
+                    "result": lambda value, total, preview=None, node_id=None: {
+                        "value": value,
+                        "total": total,
+                        "preview": preview,
+                        "node_id": node_id,
+                    },
+                },
+            },
+            "ProgressProxy": {
+                "rpc_set_progress": {
+                    "target": "comfy_execution.progress.get_progress_state().update_progress",
+                    "result": None,
+                },
+            },
+            "HelperProxiesService": {
+                "rpc_restore_input_types": {
+                    "target": "comfy.isolation.proxies.helper_proxies.restore_input_types",
+                    "result": lambda raw: raw,
+                }
+            },
+            "ModelManagementProxy": {
+                "rpc_call": {
+                    "target": "comfy.model_management.*",
+                    "result": self._model_management_rpc_call,
+                },
+            },
+        }
+
+    def _model_management_rpc_call(self, method_name: str, args: Any = None, kwargs: Any = None) -> Any:
+        device = {"__pyisolate_torch_device__": "cpu"}
+        if method_name == "get_torch_device":
+            return device
+        elif method_name == "get_torch_device_name":
+            return "cpu"
+        elif method_name == "get_free_memory":
+            return 34359738368
+        raise AssertionError(f"unexpected exact-relay method {method_name}")
+
+    def create_caller(self, cls: Any, object_id: str):
+        methods = self._services.get(object_id) or self._services.get(getattr(cls, "__name__", object_id))
+        if methods is None:
+            raise KeyError(object_id)
+        return FakeExactRelayCaller(methods, self.transcripts, object_id)
+
+
+def capture_exact_small_proxy_relay() -> dict[str, object]:
+    reset_forbidden_singleton_modules()
+    fake_rpc = FakeExactRelayRPC()
+    previous_child = os.environ.get("PYISOLATE_CHILD")
+    previous_import_torch = os.environ.get("PYISOLATE_IMPORT_TORCH")
+    try:
+        prepare_sealed_singleton_proxies(fake_rpc)
+
+        from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+        from comfy.isolation.proxies.helper_proxies import restore_input_types
+        from comfy.isolation.proxies.progress_proxy import ProgressProxy
+        from comfy.isolation.proxies.utils_proxy import UtilsProxy
+
+        folder_proxy = FolderPathsProxy()
+        utils_proxy = UtilsProxy()
+        progress_proxy = ProgressProxy()
+        before = set(sys.modules)
+
+        restored = restore_input_types(
+            {
+                "required": {
+                    "image": {"__pyisolate_any_type__": True, "value": "*"},
+                }
+            }
+        )
+        folder_path = folder_proxy.get_annotated_filepath("demo.png[input]")
+        models_dir = folder_proxy.models_dir
+        folder_names_and_paths = folder_proxy.folder_names_and_paths
+        asyncio.run(utils_proxy.progress_bar_hook(2, 5, node_id="node-17"))
+        progress_proxy.set_progress(1.5, 5.0, node_id="node-17")
+
+        imported = set(sys.modules) - before
+        return {
+            "mode": "exact_small_proxy_relay",
+            "folder_path": folder_path,
+            "models_dir": models_dir,
+            "folder_names_and_paths": folder_names_and_paths,
+            "restored_any_type": str(restored["required"]["image"]),
+            "transcripts": fake_rpc.transcripts,
+            "modules": sorted(imported),
+            "forbidden_matches": matching_modules(FORBIDDEN_EXACT_SMALL_PROXY_MODULES, imported),
+        }
+    finally:
+        _clear_proxy_rpcs()
+        if previous_child is None:
+            os.environ.pop("PYISOLATE_CHILD", None)
+        else:
+            os.environ["PYISOLATE_CHILD"] = previous_child
+        if previous_import_torch is None:
+            os.environ.pop("PYISOLATE_IMPORT_TORCH", None)
+        else:
+            os.environ["PYISOLATE_IMPORT_TORCH"] = previous_import_torch
+
+
+class FakeModelManagementExactRelayRPC:
+    def __init__(self) -> None:
+        self.transcripts: list[dict[str, object]] = []
+        self._device = {"__pyisolate_torch_device__": "cpu"}
+        self._services: dict[str, dict[str, Any]] = {
+            "ModelManagementProxy": {
+                "rpc_call": self._rpc_call,
+            }
+        }
+
+    def create_caller(self, cls: Any, object_id: str):
+        methods = self._services.get(object_id) or self._services.get(getattr(cls, "__name__", object_id))
+        if methods is None:
+            raise KeyError(object_id)
+        return _ModelManagementExactRelayCaller(methods)
+
+    def _rpc_call(self, method_name: str, args: Any, kwargs: Any) -> Any:
+        self.transcripts.append(
+            {
+                "phase": "child_call",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "args": _json_safe(args),
+                "kwargs": _json_safe(kwargs),
+            }
+        )
+        target = f"comfy.model_management.{method_name}"
+        self.transcripts.append(
+            {
+                "phase": "host_invocation",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "target": target,
+                "args": _json_safe(args),
+                "kwargs": _json_safe(kwargs),
+            }
+        )
+        if method_name == "get_torch_device":
+            result = self._device
+        elif method_name == "get_torch_device_name":
+            result = "cpu"
+        elif method_name == "get_free_memory":
+            result = 34359738368
+        else:
+            raise AssertionError(f"unexpected exact-relay method {method_name}")
+        self.transcripts.append(
+            {
+                "phase": "result",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "result": _json_safe(result),
+            }
+        )
+        return result
+
+
+class _ModelManagementExactRelayCaller:
+    def __init__(self, methods: dict[str, Any]):
+        self._methods = methods
+
+    def __getattr__(self, name: str):
+        if name not in self._methods:
+            raise AttributeError(name)
+
+        async def method(*args: Any, **kwargs: Any) -> Any:
+            impl = self._methods[name]
+            return impl(*args, **kwargs) if callable(impl) else impl
+
+        return method
+
+
+def _json_safe(value: Any) -> Any:
+    if callable(value):
+        return f"<callable {getattr(value, '__name__', 'anonymous')}>"
+    if isinstance(value, tuple):
+        return [_json_safe(item) for item in value]
+    if isinstance(value, list):
+        return [_json_safe(item) for item in value]
+    if isinstance(value, dict):
+        return {key: _json_safe(inner) for key, inner in value.items()}
+    return value
+
+
+def capture_model_management_exact_relay() -> dict[str, object]:
+    for module_name in FORBIDDEN_MODEL_MANAGEMENT_MODULES:
+        sys.modules.pop(module_name, None)
+
+    fake_rpc = FakeModelManagementExactRelayRPC()
+    previous_child = os.environ.get("PYISOLATE_CHILD")
+    previous_import_torch = os.environ.get("PYISOLATE_IMPORT_TORCH")
+    try:
+        os.environ["PYISOLATE_CHILD"] = "1"
+        os.environ["PYISOLATE_IMPORT_TORCH"] = "0"
+
+        from comfy.isolation.proxies.model_management_proxy import ModelManagementProxy
+
+        if hasattr(ModelManagementProxy, "clear_rpc"):
+            ModelManagementProxy.clear_rpc()
+        if hasattr(ModelManagementProxy, "set_rpc"):
+            ModelManagementProxy.set_rpc(fake_rpc)
+
+        proxy = ModelManagementProxy()
+        before = set(sys.modules)
+        device = proxy.get_torch_device()
+        device_name = proxy.get_torch_device_name(device)
+        free_memory = proxy.get_free_memory(device)
+        imported = set(sys.modules) - before
+        return {
+            "mode": "model_management_exact_relay",
+            "device": str(device),
+            "device_type": getattr(device, "type", None),
+            "device_name": device_name,
+            "free_memory": free_memory,
+            "transcripts": fake_rpc.transcripts,
+            "modules": sorted(imported),
+            "forbidden_matches": matching_modules(FORBIDDEN_MODEL_MANAGEMENT_MODULES, imported),
+        }
+    finally:
+        model_management_proxy = _load_model_management_proxy()
+        if model_management_proxy is not None and hasattr(model_management_proxy, "clear_rpc"):
+            model_management_proxy.clear_rpc()
+        if previous_child is None:
+            os.environ.pop("PYISOLATE_CHILD", None)
+        else:
+            os.environ["PYISOLATE_CHILD"] = previous_child
+        if previous_import_torch is None:
+            os.environ.pop("PYISOLATE_IMPORT_TORCH", None)
+        else:
+            os.environ["PYISOLATE_IMPORT_TORCH"] = previous_import_torch
+
+
+FORBIDDEN_PROMPT_WEB_MODULES = (
+    "server",
+    "aiohttp",
+    "comfy.isolation.extension_wrapper",
+)
+FORBIDDEN_EXACT_BOOTSTRAP_MODULES = (
+    "comfy.isolation.adapter",
+    "folder_paths",
+    "comfy.utils",
+    "comfy.model_management",
+    "server",
+    "main",
+    "comfy.isolation.extension_wrapper",
+)
+
+
+class _PromptServiceExactRelayCaller:
+    def __init__(self, methods: dict[str, Any], transcripts: list[dict[str, Any]], object_id: str):
+        self._methods = methods
+        self._transcripts = transcripts
+        self._object_id = object_id
+
+    def __getattr__(self, name: str):
+        if name not in self._methods:
+            raise AttributeError(name)
+
+        async def method(*args: Any, **kwargs: Any) -> Any:
+            self._transcripts.append(
+                {
+                    "phase": "child_call",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "args": _json_safe(args),
+                    "kwargs": _json_safe(kwargs),
+                }
+            )
+            impl = self._methods[name]
+            self._transcripts.append(
+                {
+                    "phase": "host_invocation",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "target": impl["target"],
+                    "args": _json_safe(args),
+                    "kwargs": _json_safe(kwargs),
+                }
+            )
+            result = impl["result"](*args, **kwargs) if callable(impl["result"]) else impl["result"]
+            self._transcripts.append(
+                {
+                    "phase": "result",
+                    "object_id": self._object_id,
+                    "method": name,
+                    "result": _json_safe(result),
+                }
+            )
+            return result
+
+        return method
+
+
+class FakePromptWebRPC:
+    def __init__(self) -> None:
+        self.transcripts: list[dict[str, Any]] = []
+        self._services = {
+            "PromptServerService": {
+                "ui_send_progress_text": {
+                    "target": "server.PromptServer.instance.send_progress_text",
+                    "result": None,
+                },
+                "register_route_rpc": {
+                    "target": "server.PromptServer.instance.routes.add_route",
+                    "result": None,
+                },
+            }
+        }
+
+    def create_caller(self, cls: Any, object_id: str):
+        methods = self._services.get(object_id) or self._services.get(getattr(cls, "__name__", object_id))
+        if methods is None:
+            raise KeyError(object_id)
+        return _PromptServiceExactRelayCaller(methods, self.transcripts, object_id)
+
+
+class FakeWebDirectoryProxy:
+    def __init__(self, transcripts: list[dict[str, Any]]):
+        self._transcripts = transcripts
+
+    def get_web_file(self, extension_name: str, relative_path: str) -> dict[str, Any]:
+        self._transcripts.append(
+            {
+                "phase": "child_call",
+                "object_id": "WebDirectoryProxy",
+                "method": "get_web_file",
+                "args": [extension_name, relative_path],
+                "kwargs": {},
+            }
+        )
+        self._transcripts.append(
+            {
+                "phase": "host_invocation",
+                "object_id": "WebDirectoryProxy",
+                "method": "get_web_file",
+                "target": "comfy.isolation.proxies.web_directory_proxy.WebDirectoryProxy.get_web_file",
+                "args": [extension_name, relative_path],
+                "kwargs": {},
+            }
+        )
+        result = {
+            "content": "Y29uc29sZS5sb2coJ2RlbycpOw==",
+            "content_type": "application/javascript",
+        }
+        self._transcripts.append(
+            {
+                "phase": "result",
+                "object_id": "WebDirectoryProxy",
+                "method": "get_web_file",
+                "result": result,
+            }
+        )
+        return result
+
+
+def capture_prompt_web_exact_relay() -> dict[str, object]:
+    for module_name in FORBIDDEN_PROMPT_WEB_MODULES:
+        sys.modules.pop(module_name, None)
+
+    fake_rpc = FakePromptWebRPC()
+
+    from comfy.isolation.proxies.prompt_server_impl import PromptServerStub
+    from comfy.isolation.proxies.web_directory_proxy import WebDirectoryCache
+
+    PromptServerStub.set_rpc(fake_rpc)
+    stub = PromptServerStub()
+    cache = WebDirectoryCache()
+    cache.register_proxy("demo_ext", FakeWebDirectoryProxy(fake_rpc.transcripts))
+
+    before = set(sys.modules)
+
+    def demo_handler(_request):
+        return {"ok": True}
+
+    stub.send_progress_text("hello", "node-17")
+    stub.routes.get("/demo")(demo_handler)
+    web_file = cache.get_file("demo_ext", "js/app.js")
+    imported = set(sys.modules) - before
+    return {
+        "mode": "prompt_web_exact_relay",
+        "web_file": {
+            "content_type": web_file["content_type"] if web_file else None,
+            "content": web_file["content"].decode("utf-8") if web_file else None,
+        },
+        "transcripts": fake_rpc.transcripts,
+        "modules": sorted(imported),
+        "forbidden_matches": matching_modules(FORBIDDEN_PROMPT_WEB_MODULES, imported),
+    }
+
+
+class FakeExactBootstrapRPC:
+    def __init__(self) -> None:
+        self.transcripts: list[dict[str, Any]] = []
+        self._device = {"__pyisolate_torch_device__": "cpu"}
+        self._services: dict[str, dict[str, Any]] = {
+            "FolderPathsProxy": FakeExactRelayRPC()._services["FolderPathsProxy"],
+            "HelperProxiesService": FakeExactRelayRPC()._services["HelperProxiesService"],
+            "ProgressProxy": FakeExactRelayRPC()._services["ProgressProxy"],
+            "UtilsProxy": FakeExactRelayRPC()._services["UtilsProxy"],
+            "PromptServerService": {
+                "ui_send_sync": {
+                    "target": "server.PromptServer.instance.send_sync",
+                    "result": None,
+                },
+                "ui_send": {
+                    "target": "server.PromptServer.instance.send",
+                    "result": None,
+                },
+                "ui_send_progress_text": {
+                    "target": "server.PromptServer.instance.send_progress_text",
+                    "result": None,
+                },
+                "register_route_rpc": {
+                    "target": "server.PromptServer.instance.routes.add_route",
+                    "result": None,
+                },
+            },
+            "ModelManagementProxy": {
+                "rpc_call": self._rpc_call,
+            },
+        }
+
+    def create_caller(self, cls: Any, object_id: str):
+        methods = self._services.get(object_id) or self._services.get(getattr(cls, "__name__", object_id))
+        if methods is None:
+            raise KeyError(object_id)
+        if object_id == "ModelManagementProxy":
+            return _ModelManagementExactRelayCaller(methods)
+        return _PromptServiceExactRelayCaller(methods, self.transcripts, object_id)
+
+    def _rpc_call(self, method_name: str, args: Any, kwargs: Any) -> Any:
+        self.transcripts.append(
+            {
+                "phase": "child_call",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "args": _json_safe(args),
+                "kwargs": _json_safe(kwargs),
+            }
+        )
+        self.transcripts.append(
+            {
+                "phase": "host_invocation",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "target": f"comfy.model_management.{method_name}",
+                "args": _json_safe(args),
+                "kwargs": _json_safe(kwargs),
+            }
+        )
+        result = self._device if method_name == "get_torch_device" else None
+        self.transcripts.append(
+            {
+                "phase": "result",
+                "object_id": "ModelManagementProxy",
+                "method": method_name,
+                "result": _json_safe(result),
+            }
+        )
+        return result
+
+
+def capture_exact_proxy_bootstrap_contract() -> dict[str, object]:
+    from pyisolate._internal.rpc_protocol import get_child_rpc_instance, set_child_rpc_instance
+
+    from comfy.isolation.adapter import ComfyUIAdapter
+    from comfy.isolation.child_hooks import initialize_child_process
+    from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+    from comfy.isolation.proxies.helper_proxies import HelperProxiesService
+    from comfy.isolation.proxies.model_management_proxy import ModelManagementProxy
+    from comfy.isolation.proxies.progress_proxy import ProgressProxy
+    from comfy.isolation.proxies.prompt_server_impl import PromptServerStub
+    from comfy.isolation.proxies.utils_proxy import UtilsProxy
+
+    host_services = sorted(cls.__name__ for cls in ComfyUIAdapter().provide_rpc_services())
+
+    for module_name in FORBIDDEN_EXACT_BOOTSTRAP_MODULES:
+        sys.modules.pop(module_name, None)
+
+    previous_child = os.environ.get("PYISOLATE_CHILD")
+    previous_import_torch = os.environ.get("PYISOLATE_IMPORT_TORCH")
+    os.environ["PYISOLATE_CHILD"] = "1"
+    os.environ["PYISOLATE_IMPORT_TORCH"] = "0"
+
+    _clear_proxy_rpcs()
+    if hasattr(PromptServerStub, "clear_rpc"):
+        PromptServerStub.clear_rpc()
+    else:
+        PromptServerStub._rpc = None  # type: ignore[attr-defined]
+    fake_rpc = FakeExactBootstrapRPC()
+    set_child_rpc_instance(fake_rpc)
+
+    before = set(sys.modules)
+    try:
+        initialize_child_process()
+        imported = set(sys.modules) - before
+        matrix = {
+            "base.py": {
+                "bound": get_child_rpc_instance() is fake_rpc,
+                "details": {"child_rpc_instance": get_child_rpc_instance() is fake_rpc},
+            },
+            "folder_paths_proxy.py": {
+                "bound": "FolderPathsProxy" in host_services and FolderPathsProxy._rpc is not None,
+                "details": {"host_service": "FolderPathsProxy" in host_services, "child_rpc": FolderPathsProxy._rpc is not None},
+            },
+            "helper_proxies.py": {
+                "bound": "HelperProxiesService" in host_services and HelperProxiesService._rpc is not None,
+                "details": {"host_service": "HelperProxiesService" in host_services, "child_rpc": HelperProxiesService._rpc is not None},
+            },
+            "model_management_proxy.py": {
+                "bound": "ModelManagementProxy" in host_services and ModelManagementProxy._rpc is not None,
+                "details": {"host_service": "ModelManagementProxy" in host_services, "child_rpc": ModelManagementProxy._rpc is not None},
+            },
+            "progress_proxy.py": {
+                "bound": "ProgressProxy" in host_services and ProgressProxy._rpc is not None,
+                "details": {"host_service": "ProgressProxy" in host_services, "child_rpc": ProgressProxy._rpc is not None},
+            },
+            "prompt_server_impl.py": {
+                "bound": "PromptServerService" in host_services and PromptServerStub._rpc is not None,
+                "details": {"host_service": "PromptServerService" in host_services, "child_rpc": PromptServerStub._rpc is not None},
+            },
+            "utils_proxy.py": {
+                "bound": "UtilsProxy" in host_services and UtilsProxy._rpc is not None,
+                "details": {"host_service": "UtilsProxy" in host_services, "child_rpc": UtilsProxy._rpc is not None},
+            },
+            "web_directory_proxy.py": {
+                "bound": "WebDirectoryProxy" in host_services,
+                "details": {"host_service": "WebDirectoryProxy" in host_services},
+            },
+        }
+    finally:
+        set_child_rpc_instance(None)
+        if previous_child is None:
+            os.environ.pop("PYISOLATE_CHILD", None)
+        else:
+            os.environ["PYISOLATE_CHILD"] = previous_child
+        if previous_import_torch is None:
+            os.environ.pop("PYISOLATE_IMPORT_TORCH", None)
+        else:
+            os.environ["PYISOLATE_IMPORT_TORCH"] = previous_import_torch
+
+    omitted = sorted(name for name, status in matrix.items() if not status["bound"])
+    return {
+        "mode": "exact_proxy_bootstrap_contract",
+        "host_services": host_services,
+        "matrix": matrix,
+        "omitted_proxies": omitted,
+        "modules": sorted(imported),
+        "forbidden_matches": matching_modules(FORBIDDEN_EXACT_BOOTSTRAP_MODULES, imported),
+    }
+
+def capture_sealed_singleton_imports() -> dict[str, object]:
+    reset_forbidden_singleton_modules()
+    fake_rpc = FakeSingletonRPC()
+    previous_child = os.environ.get("PYISOLATE_CHILD")
+    previous_import_torch = os.environ.get("PYISOLATE_IMPORT_TORCH")
+    before = set(sys.modules)
+    try:
+        prepare_sealed_singleton_proxies(fake_rpc)
+
+        from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+        from comfy.isolation.proxies.progress_proxy import ProgressProxy
+        from comfy.isolation.proxies.utils_proxy import UtilsProxy
+
+        folder_proxy = FolderPathsProxy()
+        progress_proxy = ProgressProxy()
+        utils_proxy = UtilsProxy()
+
+        folder_path = folder_proxy.get_annotated_filepath("demo.png[input]")
+        temp_dir = folder_proxy.get_temp_directory()
+        models_dir = folder_proxy.models_dir
+        asyncio.run(utils_proxy.progress_bar_hook(2, 5, node_id="node-17"))
+        progress_proxy.set_progress(1.5, 5.0, node_id="node-17")
+
+        imported = set(sys.modules) - before
+        return {
+            "mode": "sealed_singletons",
+            "folder_path": folder_path,
+            "temp_dir": temp_dir,
+            "models_dir": models_dir,
+            "rpc_calls": fake_rpc.calls,
+            "modules": sorted(imported),
+            "forbidden_matches": matching_modules(FORBIDDEN_SEALED_SINGLETON_MODULES, imported),
+        }
+    finally:
+        _clear_proxy_rpcs()
+        if previous_child is None:
+            os.environ.pop("PYISOLATE_CHILD", None)
+        else:
+            os.environ["PYISOLATE_CHILD"] = previous_child
+        if previous_import_torch is None:
+            os.environ.pop("PYISOLATE_IMPORT_TORCH", None)
+        else:
+            os.environ["PYISOLATE_IMPORT_TORCH"] = previous_import_torch

tests/isolation/stage_internal_probe_node.py

@@ -0,0 +1,69 @@
+from __future__ import annotations
+
+import argparse
+import shutil
+import sys
+import tempfile
+from contextlib import contextmanager
+from pathlib import Path
+from typing import Iterator
+
+
+COMFYUI_ROOT = Path(__file__).resolve().parents[2]
+PROBE_SOURCE_ROOT = COMFYUI_ROOT / "tests" / "isolation" / "internal_probe_node"
+PROBE_NODE_NAME = "InternalIsolationProbeNode"
+
+PYPROJECT_CONTENT = """[project]
+name = "InternalIsolationProbeNode"
+version = "0.0.1"
+
+[tool.comfy.isolation]
+can_isolate = true
+share_torch = true
+"""
+
+
+def _probe_target_root(comfy_root: Path) -> Path:
+    return Path(comfy_root) / "custom_nodes" / PROBE_NODE_NAME
+
+
+def stage_probe_node(comfy_root: Path) -> Path:
+    if not PROBE_SOURCE_ROOT.is_dir():
+        raise RuntimeError(f"Missing probe source directory: {PROBE_SOURCE_ROOT}")
+
+    target_root = _probe_target_root(comfy_root)
+    target_root.mkdir(parents=True, exist_ok=True)
+    for source_path in PROBE_SOURCE_ROOT.iterdir():
+        destination_path = target_root / source_path.name
+        if source_path.is_dir():
+            shutil.copytree(source_path, destination_path, dirs_exist_ok=True)
+        else:
+            shutil.copy2(source_path, destination_path)
+
+    (target_root / "pyproject.toml").write_text(PYPROJECT_CONTENT, encoding="utf-8")
+    return target_root
+
+
+@contextmanager
+def staged_probe_node() -> Iterator[Path]:
+    staging_root = Path(tempfile.mkdtemp(prefix="comfyui_internal_probe_"))
+    try:
+        yield stage_probe_node(staging_root)
+    finally:
+        shutil.rmtree(staging_root, ignore_errors=True)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(
+        description="Stage the internal isolation probe node under an explicit ComfyUI root."
+    )
+    parser.add_argument(
+        "--target-root",
+        type=Path,
+        required=True,
+        help="Explicit ComfyUI root to stage under. Caller owns cleanup.",
+    )
+    args = parser.parse_args()
+
+    staged = stage_probe_node(args.target_root)
+    sys.stdout.write(f"{staged}\n")

tests/isolation/test_client_snapshot.py

@@ -25,7 +25,7 @@ def _run_client_process(env):
     existing = env.get("PYTHONPATH", "")
     if existing:
         pythonpath_parts.append(existing)
-    env["PYTHONPATH"] = ":".join(pythonpath_parts)
+    env["PYTHONPATH"] = os.pathsep.join(pythonpath_parts)
 
     result = subprocess.run(  # noqa: S603
         [sys.executable, "-c", SCRIPT],

tests/isolation/test_cuda_wheels_and_env_flags.py

@@ -8,13 +8,19 @@ import logging
 import os
 import sys
 from types import SimpleNamespace
+from typing import Any, cast
 
 import pytest
 
+import comfy.isolation as isolation_pkg
 from comfy.isolation import runtime_helpers
+from comfy.isolation import extension_loader as extension_loader_module
+from comfy.isolation import extension_wrapper as extension_wrapper_module
+from comfy.isolation import model_patcher_proxy_utils
 from comfy.isolation.extension_loader import ExtensionLoadError, load_isolated_node
 from comfy.isolation.extension_wrapper import ComfyNodeExtension
 from comfy.isolation.model_patcher_proxy_utils import maybe_wrap_model_for_isolation
+from pyisolate._internal.environment_conda import _generate_pixi_toml
 
 
 class _DummyExtension:
@@ -63,11 +69,10 @@ flash_attn = "flash-attn-special"
             captured.update(config)
             return _DummyExtension()
 
+    monkeypatch.setattr(extension_loader_module.pyisolate, "ExtensionManager", DummyManager)
     monkeypatch.setattr(
-        "comfy.isolation.extension_loader.pyisolate.ExtensionManager", DummyManager
-    )
-    monkeypatch.setattr(
-        "comfy.isolation.extension_loader.load_host_policy",
+        extension_loader_module,
+        "load_host_policy",
         lambda base_path: {
             "sandbox_mode": "required",
             "allow_network": False,
@@ -75,11 +80,10 @@ flash_attn = "flash-attn-special"
             "readonly_paths": [],
         },
     )
+    monkeypatch.setattr(extension_loader_module, "is_cache_valid", lambda *args, **kwargs: True)
     monkeypatch.setattr(
-        "comfy.isolation.extension_loader.is_cache_valid", lambda *args, **kwargs: True
-    )
-    monkeypatch.setattr(
-        "comfy.isolation.extension_loader.load_from_cache",
+        extension_loader_module,
+        "load_from_cache",
         lambda *args, **kwargs: {"Node": {"display_name": "Node", "schema_v1": {}}},
     )
     monkeypatch.setitem(sys.modules, "folder_paths", SimpleNamespace(base_path=str(tmp_path)))
@@ -141,6 +145,163 @@ packages = ["flash-attn"]
         )
 
 
+def test_conda_cuda_wheels_declared_packages_do_not_force_pixi_solve(tmp_path, monkeypatch):
+    node_dir = tmp_path / "node"
+    node_dir.mkdir()
+    manifest_path = node_dir / "pyproject.toml"
+    _write_manifest(
+        node_dir,
+        """
+[project]
+name = "demo-node"
+dependencies = ["numpy>=1.0", "spconv", "cumm", "flash-attn"]
+
+[tool.comfy.isolation]
+can_isolate = true
+package_manager = "conda"
+conda_channels = ["conda-forge"]
+
+[tool.comfy.isolation.cuda_wheels]
+index_url = "https://example.invalid/cuda-wheels"
+packages = ["spconv", "cumm", "flash-attn"]
+""".strip(),
+    )
+
+    captured: dict[str, object] = {}
+
+    class DummyManager:
+        def __init__(self, *args, **kwargs) -> None:
+            return None
+
+        def load_extension(self, config):
+            captured.update(config)
+            return _DummyExtension()
+
+    monkeypatch.setattr(extension_loader_module.pyisolate, "ExtensionManager", DummyManager)
+    monkeypatch.setattr(
+        extension_loader_module,
+        "load_host_policy",
+        lambda base_path: {
+            "sandbox_mode": "disabled",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+        },
+    )
+    monkeypatch.setattr(extension_loader_module, "is_cache_valid", lambda *args, **kwargs: True)
+    monkeypatch.setattr(
+        extension_loader_module,
+        "load_from_cache",
+        lambda *args, **kwargs: {"Node": {"display_name": "Node", "schema_v1": {}}},
+    )
+    monkeypatch.setitem(sys.modules, "folder_paths", SimpleNamespace(base_path=str(tmp_path)))
+
+    asyncio.run(
+        load_isolated_node(
+            node_dir,
+            manifest_path,
+            logging.getLogger("test"),
+            lambda *args, **kwargs: object,
+            tmp_path / "venvs",
+            [],
+        )
+    )
+
+    generated = _generate_pixi_toml(captured)
+    assert 'numpy = ">=1.0"' in generated
+    assert "spconv =" not in generated
+    assert "cumm =" not in generated
+    assert "flash-attn =" not in generated
+
+
+def test_conda_cuda_wheels_loader_accepts_sam3d_contract(tmp_path, monkeypatch):
+    node_dir = tmp_path / "node"
+    node_dir.mkdir()
+    manifest_path = node_dir / "pyproject.toml"
+    _write_manifest(
+        node_dir,
+        """
+[project]
+name = "demo-node"
+dependencies = [
+  "torch",
+  "torchvision",
+  "pytorch3d",
+  "gsplat",
+  "nvdiffrast",
+  "flash-attn",
+  "sageattention",
+  "spconv",
+  "cumm",
+]
+
+[tool.comfy.isolation]
+can_isolate = true
+package_manager = "conda"
+conda_channels = ["conda-forge"]
+
+[tool.comfy.isolation.cuda_wheels]
+index_url = "https://example.invalid/cuda-wheels"
+packages = ["pytorch3d", "gsplat", "nvdiffrast", "flash-attn", "sageattention", "spconv", "cumm"]
+""".strip(),
+    )
+
+    captured: dict[str, object] = {}
+
+    class DummyManager:
+        def __init__(self, *args, **kwargs) -> None:
+            return None
+
+        def load_extension(self, config):
+            captured.update(config)
+            return _DummyExtension()
+
+    monkeypatch.setattr(extension_loader_module.pyisolate, "ExtensionManager", DummyManager)
+    monkeypatch.setattr(
+        extension_loader_module,
+        "load_host_policy",
+        lambda base_path: {
+            "sandbox_mode": "disabled",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+        },
+    )
+    monkeypatch.setattr(extension_loader_module, "is_cache_valid", lambda *args, **kwargs: True)
+    monkeypatch.setattr(
+        extension_loader_module,
+        "load_from_cache",
+        lambda *args, **kwargs: {"Node": {"display_name": "Node", "schema_v1": {}}},
+    )
+    monkeypatch.setitem(sys.modules, "folder_paths", SimpleNamespace(base_path=str(tmp_path)))
+
+    asyncio.run(
+        load_isolated_node(
+            node_dir,
+            manifest_path,
+            logging.getLogger("test"),
+            lambda *args, **kwargs: object,
+            tmp_path / "venvs",
+            [],
+        )
+    )
+
+    assert captured["package_manager"] == "conda"
+    assert captured["cuda_wheels"] == {
+        "index_url": "https://example.invalid/cuda-wheels/",
+        "packages": [
+            "pytorch3d",
+            "gsplat",
+            "nvdiffrast",
+            "flash-attn",
+            "sageattention",
+            "spconv",
+            "cumm",
+        ],
+        "package_map": {},
+    }
+
+
 def test_load_isolated_node_omits_cuda_wheels_when_not_configured(tmp_path, monkeypatch):
     node_dir = tmp_path / "node"
     node_dir.mkdir()
@@ -167,11 +328,10 @@ can_isolate = true
             captured.update(config)
             return _DummyExtension()
 
+    monkeypatch.setattr(extension_loader_module.pyisolate, "ExtensionManager", DummyManager)
     monkeypatch.setattr(
-        "comfy.isolation.extension_loader.pyisolate.ExtensionManager", DummyManager
-    )
-    monkeypatch.setattr(
-        "comfy.isolation.extension_loader.load_host_policy",
+        extension_loader_module,
+        "load_host_policy",
         lambda base_path: {
             "sandbox_mode": "disabled",
             "allow_network": False,
@@ -179,11 +339,10 @@ can_isolate = true
             "readonly_paths": [],
         },
     )
+    monkeypatch.setattr(extension_loader_module, "is_cache_valid", lambda *args, **kwargs: True)
     monkeypatch.setattr(
-        "comfy.isolation.extension_loader.is_cache_valid", lambda *args, **kwargs: True
-    )
-    monkeypatch.setattr(
-        "comfy.isolation.extension_loader.load_from_cache",
+        extension_loader_module,
+        "load_from_cache",
         lambda *args, **kwargs: {"Node": {"display_name": "Node", "schema_v1": {}}},
     )
     monkeypatch.setitem(sys.modules, "folder_paths", SimpleNamespace(base_path=str(tmp_path)))
@@ -214,7 +373,7 @@ def test_maybe_wrap_model_for_isolation_uses_runtime_flag(monkeypatch):
             self.registry = registry
             self.manage_lifecycle = manage_lifecycle
 
-    monkeypatch.setattr("comfy.isolation.model_patcher_proxy_utils.args.use_process_isolation", True)
+    monkeypatch.setattr(model_patcher_proxy_utils.args, "use_process_isolation", True)
     monkeypatch.delenv("PYISOLATE_ISOLATION_ACTIVE", raising=False)
     monkeypatch.delenv("PYISOLATE_CHILD", raising=False)
     monkeypatch.setitem(
@@ -228,20 +387,17 @@ def test_maybe_wrap_model_for_isolation_uses_runtime_flag(monkeypatch):
         SimpleNamespace(ModelPatcherProxy=DummyProxy),
     )
 
-    wrapped = maybe_wrap_model_for_isolation(object())
+    wrapped = cast(Any, maybe_wrap_model_for_isolation(object()))
 
     assert isinstance(wrapped, DummyProxy)
-    assert wrapped.model_id == "model-123"
-    assert wrapped.manage_lifecycle is True
+    assert getattr(wrapped, "model_id") == "model-123"
+    assert getattr(wrapped, "manage_lifecycle") is True
 
 
 def test_flush_transport_state_uses_child_env_without_legacy_flag(monkeypatch):
     monkeypatch.setenv("PYISOLATE_CHILD", "1")
     monkeypatch.delenv("PYISOLATE_ISOLATION_ACTIVE", raising=False)
-    monkeypatch.setattr(
-        "comfy.isolation.extension_wrapper._flush_tensor_transport_state",
-        lambda marker: 3,
-    )
+    monkeypatch.setattr(extension_wrapper_module, "_flush_tensor_transport_state", lambda marker: 3)
     monkeypatch.setitem(
         sys.modules,
         "comfy.isolation.model_patcher_proxy_registry",
@@ -260,8 +416,6 @@ def test_flush_transport_state_uses_child_env_without_legacy_flag(monkeypatch):
 
 
 def test_build_stub_class_relieves_host_vram_without_legacy_flag(monkeypatch):
-    import comfy.isolation as isolation_pkg
-
     relieve_calls: list[str] = []
 
     async def deserialize_from_isolation(result, extension):

tests/isolation/test_exact_proxy_bootstrap_contract.py

@@ -0,0 +1,22 @@
+from __future__ import annotations
+
+from tests.isolation.singleton_boundary_helpers import (
+    capture_exact_proxy_bootstrap_contract,
+)
+
+
+def test_no_proxy_omission_allowed() -> None:
+    payload = capture_exact_proxy_bootstrap_contract()
+
+    assert payload["omitted_proxies"] == []
+    assert payload["forbidden_matches"] == []
+
+    matrix = payload["matrix"]
+    assert matrix["base.py"]["bound"] is True
+    assert matrix["folder_paths_proxy.py"]["bound"] is True
+    assert matrix["helper_proxies.py"]["bound"] is True
+    assert matrix["model_management_proxy.py"]["bound"] is True
+    assert matrix["progress_proxy.py"]["bound"] is True
+    assert matrix["prompt_server_impl.py"]["bound"] is True
+    assert matrix["utils_proxy.py"]["bound"] is True
+    assert matrix["web_directory_proxy.py"]["bound"] is True

tests/isolation/test_exact_proxy_relay_matrix.py

@@ -0,0 +1,128 @@
+from __future__ import annotations
+
+from tests.isolation.singleton_boundary_helpers import (
+    capture_exact_small_proxy_relay,
+    capture_model_management_exact_relay,
+    capture_prompt_web_exact_relay,
+)
+
+
+def _transcripts_for(payload: dict[str, object], object_id: str, method: str) -> list[dict[str, object]]:
+    return [
+        entry
+        for entry in payload["transcripts"]
+        if entry["object_id"] == object_id and entry["method"] == method
+    ]
+
+
+def test_folder_paths_exact_relay() -> None:
+    payload = capture_exact_small_proxy_relay()
+
+    assert payload["forbidden_matches"] == []
+    assert payload["models_dir"] == "/sandbox/models"
+    assert payload["folder_path"] == "/sandbox/input/demo.png"
+
+    models_dir_calls = _transcripts_for(payload, "FolderPathsProxy", "rpc_get_models_dir")
+    annotated_calls = _transcripts_for(payload, "FolderPathsProxy", "rpc_get_annotated_filepath")
+
+    assert models_dir_calls
+    assert annotated_calls
+    assert all(entry["phase"] != "child_call" or entry["method"] != "rpc_snapshot" for entry in payload["transcripts"])
+
+
+def test_progress_exact_relay() -> None:
+    payload = capture_exact_small_proxy_relay()
+
+    progress_calls = _transcripts_for(payload, "ProgressProxy", "rpc_set_progress")
+
+    assert progress_calls
+    host_targets = [entry["target"] for entry in progress_calls if entry["phase"] == "host_invocation"]
+    assert host_targets == ["comfy_execution.progress.get_progress_state().update_progress"]
+    result_entries = [entry for entry in progress_calls if entry["phase"] == "result"]
+    assert result_entries == [{"phase": "result", "object_id": "ProgressProxy", "method": "rpc_set_progress", "result": None}]
+
+
+def test_utils_exact_relay() -> None:
+    payload = capture_exact_small_proxy_relay()
+
+    utils_calls = _transcripts_for(payload, "UtilsProxy", "progress_bar_hook")
+
+    assert utils_calls
+    host_targets = [entry["target"] for entry in utils_calls if entry["phase"] == "host_invocation"]
+    assert host_targets == ["comfy.utils.PROGRESS_BAR_HOOK"]
+    result_entries = [entry for entry in utils_calls if entry["phase"] == "result"]
+    assert result_entries
+    assert result_entries[0]["result"]["value"] == 2
+    assert result_entries[0]["result"]["total"] == 5
+
+
+def test_helper_proxy_exact_relay() -> None:
+    payload = capture_exact_small_proxy_relay()
+
+    helper_calls = _transcripts_for(payload, "HelperProxiesService", "rpc_restore_input_types")
+
+    assert helper_calls
+    host_targets = [entry["target"] for entry in helper_calls if entry["phase"] == "host_invocation"]
+    assert host_targets == ["comfy.isolation.proxies.helper_proxies.restore_input_types"]
+    assert payload["restored_any_type"] == "*"
+
+
+def test_model_management_exact_relay() -> None:
+    payload = capture_model_management_exact_relay()
+
+    model_calls = _transcripts_for(payload, "ModelManagementProxy", "get_torch_device")
+    model_calls += _transcripts_for(payload, "ModelManagementProxy", "get_torch_device_name")
+    model_calls += _transcripts_for(payload, "ModelManagementProxy", "get_free_memory")
+
+    assert payload["forbidden_matches"] == []
+    assert model_calls
+    host_targets = [
+        entry["target"]
+        for entry in payload["transcripts"]
+        if entry["phase"] == "host_invocation"
+    ]
+    assert host_targets == [
+        "comfy.model_management.get_torch_device",
+        "comfy.model_management.get_torch_device_name",
+        "comfy.model_management.get_free_memory",
+    ]
+
+
+def test_model_management_capability_preserved() -> None:
+    payload = capture_model_management_exact_relay()
+
+    assert payload["device"] == "cpu"
+    assert payload["device_type"] == "cpu"
+    assert payload["device_name"] == "cpu"
+    assert payload["free_memory"] == 34359738368
+
+
+def test_prompt_server_exact_relay() -> None:
+    payload = capture_prompt_web_exact_relay()
+
+    prompt_calls = _transcripts_for(payload, "PromptServerService", "ui_send_progress_text")
+    prompt_calls += _transcripts_for(payload, "PromptServerService", "register_route_rpc")
+
+    assert payload["forbidden_matches"] == []
+    assert prompt_calls
+    host_targets = [
+        entry["target"]
+        for entry in payload["transcripts"]
+        if entry["object_id"] == "PromptServerService" and entry["phase"] == "host_invocation"
+    ]
+    assert host_targets == [
+        "server.PromptServer.instance.send_progress_text",
+        "server.PromptServer.instance.routes.add_route",
+    ]
+
+
+def test_web_directory_exact_relay() -> None:
+    payload = capture_prompt_web_exact_relay()
+
+    web_calls = _transcripts_for(payload, "WebDirectoryProxy", "get_web_file")
+
+    assert web_calls
+    host_targets = [entry["target"] for entry in web_calls if entry["phase"] == "host_invocation"]
+    assert host_targets == ["comfy.isolation.proxies.web_directory_proxy.WebDirectoryProxy.get_web_file"]
+    assert payload["web_file"]["content_type"] == "application/javascript"
+    assert payload["web_file"]["content"] == "console.log('deo');"

tests/isolation/test_extension_loader_conda.py

@@ -0,0 +1,428 @@
+"""Tests for conda config parsing in extension_loader.py (Slice 5).
+
+These tests verify that extension_loader.py correctly parses conda-related
+fields from pyproject.toml manifests and passes them into the extension config
+dict given to pyisolate. The torch import chain is broken by pre-mocking
+extension_wrapper before importing extension_loader.
+"""
+
+from __future__ import annotations
+
+import importlib
+import sys
+import types
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+
+def _make_manifest(
+    *,
+    package_manager: str = "uv",
+    conda_channels: list[str] | None = None,
+    conda_dependencies: list[str] | None = None,
+    conda_platforms: list[str] | None = None,
+    share_torch: bool = False,
+    can_isolate: bool = True,
+    dependencies: list[str] | None = None,
+    cuda_wheels: list[str] | None = None,
+) -> dict:
+    """Build a manifest dict matching tomllib.load() output."""
+    isolation: dict = {"can_isolate": can_isolate}
+    if package_manager != "uv":
+        isolation["package_manager"] = package_manager
+    if conda_channels is not None:
+        isolation["conda_channels"] = conda_channels
+    if conda_dependencies is not None:
+        isolation["conda_dependencies"] = conda_dependencies
+    if conda_platforms is not None:
+        isolation["conda_platforms"] = conda_platforms
+    if share_torch:
+        isolation["share_torch"] = True
+    if cuda_wheels is not None:
+        isolation["cuda_wheels"] = cuda_wheels
+
+    return {
+        "project": {
+            "name": "test-extension",
+            "dependencies": dependencies or ["numpy"],
+        },
+        "tool": {"comfy": {"isolation": isolation}},
+    }
+
+
+@pytest.fixture
+def manifest_file(tmp_path):
+    """Create a dummy pyproject.toml so manifest_path.open('rb') succeeds."""
+    path = tmp_path / "pyproject.toml"
+    path.write_bytes(b"")  # content is overridden by tomllib mock
+    return path
+
+
+@pytest.fixture
+def loader_module(monkeypatch):
+    """Import extension_loader under a mocked isolation package for this test only."""
+    mock_wrapper = MagicMock()
+    mock_wrapper.ComfyNodeExtension = type("ComfyNodeExtension", (), {})
+
+    iso_mod = types.ModuleType("comfy.isolation")
+    iso_mod.__path__ = [  # type: ignore[attr-defined]
+        str(Path(__file__).resolve().parent.parent.parent / "comfy" / "isolation")
+    ]
+    iso_mod.__package__ = "comfy.isolation"
+
+    manifest_loader = types.SimpleNamespace(
+        is_cache_valid=lambda *args, **kwargs: False,
+        load_from_cache=lambda *args, **kwargs: None,
+        save_to_cache=lambda *args, **kwargs: None,
+    )
+    host_policy = types.SimpleNamespace(
+        load_host_policy=lambda base_path: {
+            "sandbox_mode": "required",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+        }
+    )
+    folder_paths = types.SimpleNamespace(base_path="/fake/comfyui")
+
+    monkeypatch.setitem(sys.modules, "comfy.isolation", iso_mod)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.extension_wrapper", mock_wrapper)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.runtime_helpers", MagicMock())
+    monkeypatch.setitem(sys.modules, "comfy.isolation.manifest_loader", manifest_loader)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.host_policy", host_policy)
+    monkeypatch.setitem(sys.modules, "folder_paths", folder_paths)
+    sys.modules.pop("comfy.isolation.extension_loader", None)
+
+    module = importlib.import_module("comfy.isolation.extension_loader")
+    try:
+        yield module, mock_wrapper
+    finally:
+        sys.modules.pop("comfy.isolation.extension_loader", None)
+        comfy_pkg = sys.modules.get("comfy")
+        if comfy_pkg is not None and hasattr(comfy_pkg, "isolation"):
+            delattr(comfy_pkg, "isolation")
+
+
+@pytest.fixture
+def mock_pyisolate(loader_module):
+    """Mock pyisolate to avoid real venv creation."""
+    module, mock_wrapper = loader_module
+    mock_ext = AsyncMock()
+    mock_ext.list_nodes = AsyncMock(return_value={})
+
+    mock_manager = MagicMock()
+    mock_manager.load_extension = MagicMock(return_value=mock_ext)
+    sealed_type = type("SealedNodeExtension", (), {})
+
+    with patch.object(module, "pyisolate") as mock_pi:
+        mock_pi.ExtensionManager = MagicMock(return_value=mock_manager)
+        mock_pi.SealedNodeExtension = sealed_type
+        yield module, mock_pi, mock_manager, mock_ext, mock_wrapper
+
+
+def load_isolated_node(*args, **kwargs):
+    return sys.modules["comfy.isolation.extension_loader"].load_isolated_node(
+        *args, **kwargs
+    )
+
+
+class TestCondaPackageManagerParsing:
+    """Verify extension_loader.py parses conda config from pyproject.toml."""
+
+    @pytest.mark.asyncio
+    async def test_conda_package_manager_in_config(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """package_manager='conda' must appear in extension_config."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["package_manager"] == "conda"
+
+    @pytest.mark.asyncio
+    async def test_conda_channels_in_config(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """conda_channels must be passed through to extension_config."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge", "nvidia"],
+            conda_dependencies=["eccodes"],
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["conda_channels"] == ["conda-forge", "nvidia"]
+
+    @pytest.mark.asyncio
+    async def test_conda_dependencies_in_config(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """conda_dependencies must be passed through to extension_config."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes", "cfgrib"],
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["conda_dependencies"] == ["eccodes", "cfgrib"]
+
+    @pytest.mark.asyncio
+    async def test_conda_platforms_in_config(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """conda_platforms must be passed through to extension_config."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+            conda_platforms=["linux-64"],
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["conda_platforms"] == ["linux-64"]
+
+
+class TestCondaForcedOverrides:
+    """Verify conda forces share_torch=False, share_cuda_ipc=False."""
+
+    @pytest.mark.asyncio
+    async def test_conda_forces_share_torch_false(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """share_torch must be forced False for conda, even if manifest says True."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+            share_torch=True,  # manifest requests True — must be overridden
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["share_torch"] is False
+
+    @pytest.mark.asyncio
+    async def test_conda_forces_share_cuda_ipc_false(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """share_cuda_ipc must be forced False for conda."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+            share_torch=True,
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["share_cuda_ipc"] is False
+
+    @pytest.mark.asyncio
+    async def test_conda_sealed_worker_uses_host_policy_sandbox_config(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """Conda sealed_worker must carry the host-policy sandbox config on Linux."""
+
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+        )
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with (
+            patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib,
+            patch(
+                "comfy.isolation.extension_loader.platform.system",
+                return_value="Linux",
+            ),
+        ):
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        assert config["sandbox"] == {
+            "network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+        }
+
+    @pytest.mark.asyncio
+    async def test_conda_uses_sealed_extension_type(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """Conda must not launch through ComfyNodeExtension."""
+
+        _, mock_pi, _, _, mock_wrapper = mock_pyisolate
+        manifest = _make_manifest(
+            package_manager="conda",
+            conda_channels=["conda-forge"],
+            conda_dependencies=["eccodes"],
+        )
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        extension_type = mock_pi.ExtensionManager.call_args[0][0]
+        assert extension_type.__name__ == "SealedNodeExtension"
+        assert extension_type is not mock_wrapper.ComfyNodeExtension
+
+
+class TestUvUnchanged:
+    """Verify uv extensions are NOT affected by conda changes."""
+
+    @pytest.mark.asyncio
+    async def test_uv_default_no_conda_keys(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """Default uv extension must NOT have package_manager or conda keys."""
+
+        manifest = _make_manifest()  # defaults: uv, no conda fields
+
+        _, _, mock_manager, _, _ = mock_pyisolate
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        config = mock_manager.load_extension.call_args[0][0]
+        # uv extensions should not have conda-specific keys
+        assert config.get("package_manager", "uv") == "uv"
+        assert "conda_channels" not in config
+        assert "conda_dependencies" not in config
+
+    @pytest.mark.asyncio
+    async def test_uv_keeps_comfy_extension_type(
+        self, mock_pyisolate, manifest_file, tmp_path
+    ):
+        """uv keeps the existing ComfyNodeExtension path."""
+
+        _, mock_pi, _, _, _ = mock_pyisolate
+        manifest = _make_manifest()
+
+        with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+            mock_tomllib.load.return_value = manifest
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )
+
+        extension_type = mock_pi.ExtensionManager.call_args[0][0]
+        assert extension_type.__name__ == "ComfyNodeExtension"
+        assert extension_type is not mock_pi.SealedNodeExtension

tests/isolation/test_extension_loader_sealed_worker.py

@@ -0,0 +1,281 @@
+"""Tests for execution_model parsing and sealed-worker loader selection."""
+
+from __future__ import annotations
+
+import importlib
+import sys
+import types
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+
+def _make_manifest(
+    *,
+    package_manager: str = "uv",
+    execution_model: str | None = None,
+    can_isolate: bool = True,
+    dependencies: list[str] | None = None,
+    sealed_host_ro_paths: list[str] | None = None,
+) -> dict:
+    isolation: dict = {"can_isolate": can_isolate}
+    if package_manager != "uv":
+        isolation["package_manager"] = package_manager
+    if execution_model is not None:
+        isolation["execution_model"] = execution_model
+    if sealed_host_ro_paths is not None:
+        isolation["sealed_host_ro_paths"] = sealed_host_ro_paths
+
+    return {
+        "project": {
+            "name": "test-extension",
+            "dependencies": dependencies or ["numpy"],
+        },
+        "tool": {"comfy": {"isolation": isolation}},
+    }
+
+
+@pytest.fixture
+def manifest_file(tmp_path):
+    path = tmp_path / "pyproject.toml"
+    path.write_bytes(b"")
+    return path
+
+
+@pytest.fixture
+def loader_module(monkeypatch):
+    mock_wrapper = MagicMock()
+    mock_wrapper.ComfyNodeExtension = type("ComfyNodeExtension", (), {})
+
+    iso_mod = types.ModuleType("comfy.isolation")
+    iso_mod.__path__ = [  # type: ignore[attr-defined]
+        str(Path(__file__).resolve().parent.parent.parent / "comfy" / "isolation")
+    ]
+    iso_mod.__package__ = "comfy.isolation"
+
+    manifest_loader = types.SimpleNamespace(
+        is_cache_valid=lambda *args, **kwargs: False,
+        load_from_cache=lambda *args, **kwargs: None,
+        save_to_cache=lambda *args, **kwargs: None,
+    )
+    host_policy = types.SimpleNamespace(
+        load_host_policy=lambda base_path: {
+            "sandbox_mode": "required",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+            "sealed_worker_ro_import_paths": [],
+        }
+    )
+    folder_paths = types.SimpleNamespace(base_path="/fake/comfyui")
+
+    monkeypatch.setitem(sys.modules, "comfy.isolation", iso_mod)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.extension_wrapper", mock_wrapper)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.runtime_helpers", MagicMock())
+    monkeypatch.setitem(sys.modules, "comfy.isolation.manifest_loader", manifest_loader)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.host_policy", host_policy)
+    monkeypatch.setitem(sys.modules, "folder_paths", folder_paths)
+    sys.modules.pop("comfy.isolation.extension_loader", None)
+
+    module = importlib.import_module("comfy.isolation.extension_loader")
+    try:
+        yield module
+    finally:
+        sys.modules.pop("comfy.isolation.extension_loader", None)
+        comfy_pkg = sys.modules.get("comfy")
+        if comfy_pkg is not None and hasattr(comfy_pkg, "isolation"):
+            delattr(comfy_pkg, "isolation")
+
+
+@pytest.fixture
+def mock_pyisolate(loader_module):
+    mock_ext = AsyncMock()
+    mock_ext.list_nodes = AsyncMock(return_value={})
+
+    mock_manager = MagicMock()
+    mock_manager.load_extension = MagicMock(return_value=mock_ext)
+    sealed_type = type("SealedNodeExtension", (), {})
+
+    with patch.object(loader_module, "pyisolate") as mock_pi:
+        mock_pi.ExtensionManager = MagicMock(return_value=mock_manager)
+        mock_pi.SealedNodeExtension = sealed_type
+        yield loader_module, mock_pi, mock_manager, mock_ext, sealed_type
+
+
+def load_isolated_node(*args, **kwargs):
+    return sys.modules["comfy.isolation.extension_loader"].load_isolated_node(*args, **kwargs)
+
+
+@pytest.mark.asyncio
+async def test_uv_sealed_worker_selects_sealed_extension_type(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest(execution_model="sealed_worker")
+
+    _, mock_pi, mock_manager, _, sealed_type = mock_pyisolate
+
+    with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+        mock_tomllib.load.return_value = manifest
+        await load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_file,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    config = mock_manager.load_extension.call_args[0][0]
+    assert extension_type is sealed_type
+    assert config["execution_model"] == "sealed_worker"
+    assert "apis" not in config
+
+
+@pytest.mark.asyncio
+async def test_default_uv_keeps_host_coupled_extension_type(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest()
+
+    _, mock_pi, mock_manager, _, sealed_type = mock_pyisolate
+
+    with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+        mock_tomllib.load.return_value = manifest
+        await load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_file,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    config = mock_manager.load_extension.call_args[0][0]
+    assert extension_type is not sealed_type
+    assert "execution_model" not in config
+
+
+@pytest.mark.asyncio
+async def test_conda_without_execution_model_remains_sealed_worker(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest(package_manager="conda")
+    manifest["tool"]["comfy"]["isolation"]["conda_channels"] = ["conda-forge"]
+    manifest["tool"]["comfy"]["isolation"]["conda_dependencies"] = ["eccodes"]
+
+    _, mock_pi, mock_manager, _, sealed_type = mock_pyisolate
+
+    with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+        mock_tomllib.load.return_value = manifest
+        await load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_file,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    config = mock_manager.load_extension.call_args[0][0]
+    assert extension_type is sealed_type
+    assert config["execution_model"] == "sealed_worker"
+
+
+@pytest.mark.asyncio
+async def test_sealed_worker_uses_host_policy_ro_import_paths(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest(execution_model="sealed_worker")
+
+    module, _, mock_manager, _, _ = mock_pyisolate
+
+    with (
+        patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib,
+        patch.object(
+            module,
+            "load_host_policy",
+            return_value={
+                "sandbox_mode": "required",
+                "allow_network": False,
+                "writable_paths": [],
+                "readonly_paths": [],
+                "sealed_worker_ro_import_paths": ["/home/johnj/ComfyUI"],
+            },
+        ),
+    ):
+        mock_tomllib.load.return_value = manifest
+        await load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_file,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+
+    config = mock_manager.load_extension.call_args[0][0]
+    assert config["sealed_host_ro_paths"] == ["/home/johnj/ComfyUI"]
+
+
+@pytest.mark.asyncio
+async def test_host_coupled_does_not_emit_sealed_host_ro_paths(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest(execution_model="host-coupled")
+
+    module, _, mock_manager, _, _ = mock_pyisolate
+
+    with (
+        patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib,
+        patch.object(
+            module,
+            "load_host_policy",
+            return_value={
+                "sandbox_mode": "required",
+                "allow_network": False,
+                "writable_paths": [],
+                "readonly_paths": [],
+                "sealed_worker_ro_import_paths": ["/home/johnj/ComfyUI"],
+            },
+        ),
+    ):
+        mock_tomllib.load.return_value = manifest
+        await load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_file,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+
+    config = mock_manager.load_extension.call_args[0][0]
+    assert "sealed_host_ro_paths" not in config
+
+
+@pytest.mark.asyncio
+async def test_sealed_worker_manifest_ro_import_paths_blocked(
+    mock_pyisolate, manifest_file, tmp_path
+):
+    manifest = _make_manifest(
+        execution_model="sealed_worker",
+        sealed_host_ro_paths=["/home/johnj/ComfyUI"],
+    )
+
+    _, _, _mock_manager, _, _ = mock_pyisolate
+
+    with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+        mock_tomllib.load.return_value = manifest
+        with pytest.raises(ValueError, match="Manifest field 'sealed_host_ro_paths' is not allowed"):
+            await load_isolated_node(
+                node_dir=tmp_path,
+                manifest_path=manifest_file,
+                logger=MagicMock(),
+                build_stub_class=MagicMock(),
+                venv_root=tmp_path / "venvs",
+                extension_managers=[],
+            )

tests/isolation/test_folder_paths_proxy.py

@@ -4,6 +4,7 @@ import pytest
 from pathlib import Path
 
 from comfy.isolation.proxies.folder_paths_proxy import FolderPathsProxy
+from tests.isolation.singleton_boundary_helpers import capture_sealed_singleton_imports
 
 
 class TestFolderPathsProxy:
@@ -109,3 +110,13 @@ class TestFolderPathsProxy:
         result = proxy.get_folder_paths("checkpoints")
         # Should have at least one checkpoint path registered
         assert len(result) > 0, "Checkpoints folder paths is empty"
+
+    def test_sealed_child_safe_uses_rpc_without_importing_folder_paths(self, monkeypatch):
+        monkeypatch.setenv("PYISOLATE_CHILD", "1")
+        monkeypatch.setenv("PYISOLATE_IMPORT_TORCH", "0")
+
+        payload = capture_sealed_singleton_imports()
+
+        assert payload["temp_dir"] == "/sandbox/temp"
+        assert payload["models_dir"] == "/sandbox/models"
+        assert "folder_paths" not in payload["modules"]

tests/isolation/test_host_policy.py

@@ -1,5 +1,7 @@
 from pathlib import Path
 
+import pytest
+
 
 def _write_pyproject(path: Path, content: str) -> None:
     path.write_text(content, encoding="utf-8")
@@ -111,3 +113,97 @@ allow_network = true
 
     assert policy["sandbox_mode"] == "disabled"
     assert policy["allow_network"] is True
+
+
+def test_disallows_host_tmp_default_or_override_defaults(tmp_path):
+    from comfy.isolation.host_policy import DEFAULT_POLICY, load_host_policy
+
+    policy = load_host_policy(tmp_path)
+
+    assert "/tmp" not in DEFAULT_POLICY["writable_paths"]
+    assert "/tmp" not in policy["writable_paths"]
+
+
+def test_disallows_host_tmp_default_or_override_config(tmp_path):
+    from comfy.isolation.host_policy import load_host_policy
+
+    _write_pyproject(
+        tmp_path / "pyproject.toml",
+        """
+[tool.comfy.host]
+writable_paths = ["/dev/shm", "/tmp", "/tmp/", "/work/cache"]
+""".strip(),
+    )
+
+    policy = load_host_policy(tmp_path)
+
+    assert policy["writable_paths"] == ["/dev/shm", "/work/cache"]
+
+
+def test_sealed_worker_ro_import_paths_defaults_off_and_parse(tmp_path):
+    from comfy.isolation.host_policy import load_host_policy
+
+    policy = load_host_policy(tmp_path)
+    assert policy["sealed_worker_ro_import_paths"] == []
+
+    _write_pyproject(
+        tmp_path / "pyproject.toml",
+        """
+[tool.comfy.host]
+sealed_worker_ro_import_paths = ["/home/johnj/ComfyUI", "/opt/comfy-shared"]
+""".strip(),
+    )
+
+    policy = load_host_policy(tmp_path)
+    assert policy["sealed_worker_ro_import_paths"] == [
+        "/home/johnj/ComfyUI",
+        "/opt/comfy-shared",
+    ]
+
+
+def test_sealed_worker_ro_import_paths_rejects_non_list_or_relative(tmp_path):
+    from comfy.isolation.host_policy import load_host_policy
+
+    _write_pyproject(
+        tmp_path / "pyproject.toml",
+        """
+[tool.comfy.host]
+sealed_worker_ro_import_paths = "/home/johnj/ComfyUI"
+""".strip(),
+    )
+    with pytest.raises(ValueError, match="must be a list of absolute paths"):
+        load_host_policy(tmp_path)
+
+    _write_pyproject(
+        tmp_path / "pyproject.toml",
+        """
+[tool.comfy.host]
+sealed_worker_ro_import_paths = ["relative/path"]
+""".strip(),
+    )
+    with pytest.raises(ValueError, match="entries must be absolute paths"):
+        load_host_policy(tmp_path)
+
+
+def test_host_policy_path_override_controls_ro_import_paths(tmp_path, monkeypatch):
+    from comfy.isolation.host_policy import load_host_policy
+
+    _write_pyproject(
+        tmp_path / "pyproject.toml",
+        """
+[tool.comfy.host]
+sealed_worker_ro_import_paths = ["/ignored/base/path"]
+""".strip(),
+    )
+    override_path = tmp_path / "host_policy_override.toml"
+    _write_pyproject(
+        override_path,
+        """
+[tool.comfy.host]
+sealed_worker_ro_import_paths = ["/override/ro/path"]
+""".strip(),
+    )
+    monkeypatch.setenv("COMFY_HOST_POLICY_PATH", str(override_path))
+
+    policy = load_host_policy(tmp_path)
+    assert policy["sealed_worker_ro_import_paths"] == ["/override/ro/path"]

tests/isolation/test_init.py

@@ -1,5 +1,12 @@
 """Unit tests for PyIsolate isolation system initialization."""
 
+import importlib
+import sys
+
+from tests.isolation.singleton_boundary_helpers import (
+    FakeSingletonRPC,
+    reset_forbidden_singleton_modules,
+)
 
 
 def test_log_prefix():
@@ -11,9 +18,9 @@ def test_log_prefix():
 
 def test_module_initialization():
     """Verify module initializes without errors."""
-    import comfy.isolation
-    assert hasattr(comfy.isolation, 'LOG_PREFIX')
-    assert hasattr(comfy.isolation, 'initialize_proxies')
+    isolation_pkg = importlib.import_module("comfy.isolation")
+    assert hasattr(isolation_pkg, "LOG_PREFIX")
+    assert hasattr(isolation_pkg, "initialize_proxies")
 
 
 class TestInitializeProxies:
@@ -54,3 +61,20 @@ class TestInitializeProxies:
         utils_proxy = UtilsProxy()
         assert folder_proxy is not None
         assert utils_proxy is not None
+
+    def test_sealed_child_safe_initialize_proxies_avoids_real_utils_import(self, monkeypatch):
+        monkeypatch.setenv("PYISOLATE_CHILD", "1")
+        monkeypatch.setenv("PYISOLATE_IMPORT_TORCH", "0")
+        reset_forbidden_singleton_modules()
+
+        from pyisolate._internal import rpc_protocol
+        from comfy.isolation import initialize_proxies
+
+        fake_rpc = FakeSingletonRPC()
+        monkeypatch.setattr(rpc_protocol, "get_child_rpc_instance", lambda: fake_rpc)
+
+        initialize_proxies()
+
+        assert "comfy.utils" not in sys.modules
+        assert "folder_paths" not in sys.modules
+        assert "comfy_execution.progress" not in sys.modules

tests/isolation/test_internal_probe_node_assets.py

@@ -0,0 +1,105 @@
+from __future__ import annotations
+
+import importlib.util
+import json
+from pathlib import Path
+
+
+COMFYUI_ROOT = Path(__file__).resolve().parents[2]
+ISOLATION_ROOT = COMFYUI_ROOT / "tests" / "isolation"
+PROBE_ROOT = ISOLATION_ROOT / "internal_probe_node"
+WORKFLOW_ROOT = ISOLATION_ROOT / "workflows"
+TOOLKIT_ROOT = COMFYUI_ROOT / "custom_nodes" / "ComfyUI-IsolationToolkit"
+
+EXPECTED_PROBE_FILES = {
+    "__init__.py",
+    "probe_nodes.py",
+}
+EXPECTED_WORKFLOWS = {
+    "internal_probe_preview_image_audio.json",
+    "internal_probe_ui3d.json",
+}
+BANNED_REFERENCES = (
+    "ComfyUI-IsolationToolkit",
+    "toolkit_smoke_playlist",
+    "run_isolation_toolkit_smoke.sh",
+)
+
+
+def _text_assets() -> list[Path]:
+    return sorted(list(PROBE_ROOT.rglob("*.py")) + list(WORKFLOW_ROOT.glob("internal_probe_*.json")))
+
+
+def _load_probe_package():
+    spec = importlib.util.spec_from_file_location(
+        "internal_probe_node",
+        PROBE_ROOT / "__init__.py",
+        submodule_search_locations=[str(PROBE_ROOT)],
+    )
+    module = importlib.util.module_from_spec(spec)
+    assert spec is not None
+    assert spec.loader is not None
+    spec.loader.exec_module(module)
+    return module
+
+
+def test_inventory_is_minimal_and_isolation_owned():
+    assert PROBE_ROOT.is_dir()
+    assert WORKFLOW_ROOT.is_dir()
+    assert PROBE_ROOT.is_relative_to(ISOLATION_ROOT)
+    assert WORKFLOW_ROOT.is_relative_to(ISOLATION_ROOT)
+    assert not PROBE_ROOT.is_relative_to(TOOLKIT_ROOT)
+
+    probe_files = {path.name for path in PROBE_ROOT.iterdir() if path.is_file()}
+    workflow_files = {path.name for path in WORKFLOW_ROOT.glob("internal_probe_*.json")}
+
+    assert probe_files == EXPECTED_PROBE_FILES
+    assert workflow_files == EXPECTED_WORKFLOWS
+
+    module = _load_probe_package()
+    mappings = module.NODE_CLASS_MAPPINGS
+
+    assert sorted(mappings.keys()) == [
+        "InternalIsolationProbeAudio",
+        "InternalIsolationProbeImage",
+        "InternalIsolationProbeUI3D",
+    ]
+
+    preview_workflow = json.loads(
+        (WORKFLOW_ROOT / "internal_probe_preview_image_audio.json").read_text(
+            encoding="utf-8"
+        )
+    )
+    ui3d_workflow = json.loads(
+        (WORKFLOW_ROOT / "internal_probe_ui3d.json").read_text(encoding="utf-8")
+    )
+
+    assert [preview_workflow[node_id]["class_type"] for node_id in ("1", "2")] == [
+        "InternalIsolationProbeImage",
+        "InternalIsolationProbeAudio",
+    ]
+    assert [ui3d_workflow[node_id]["class_type"] for node_id in ("1",)] == [
+        "InternalIsolationProbeUI3D",
+    ]
+
+
+def test_zero_toolkit_references_in_probe_assets():
+    for asset in _text_assets():
+        content = asset.read_text(encoding="utf-8")
+        for banned in BANNED_REFERENCES:
+            assert banned not in content, f"{asset} unexpectedly references {banned}"
+
+
+def test_replacement_contract_has_zero_toolkit_references():
+    contract_assets = [
+        *(PROBE_ROOT.rglob("*.py")),
+        *WORKFLOW_ROOT.glob("internal_probe_*.json"),
+        ISOLATION_ROOT / "stage_internal_probe_node.py",
+        ISOLATION_ROOT / "internal_probe_host_policy.toml",
+    ]
+
+    for asset in sorted(contract_assets):
+        assert asset.exists(), f"Missing replacement-contract asset: {asset}"
+        content = asset.read_text(encoding="utf-8")
+        for banned in BANNED_REFERENCES:
+            assert banned not in content, f"{asset} unexpectedly references {banned}"

tests/isolation/test_internal_probe_node_loading.py

@@ -0,0 +1,180 @@
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+import sys
+from pathlib import Path
+
+import pytest
+
+import nodes
+from tests.isolation.stage_internal_probe_node import (
+    PROBE_NODE_NAME,
+    stage_probe_node,
+    staged_probe_node,
+)
+
+
+COMFYUI_ROOT = Path(__file__).resolve().parents[2]
+ISOLATION_ROOT = COMFYUI_ROOT / "tests" / "isolation"
+PROBE_SOURCE_ROOT = ISOLATION_ROOT / "internal_probe_node"
+EXPECTED_NODE_IDS = [
+    "InternalIsolationProbeAudio",
+    "InternalIsolationProbeImage",
+    "InternalIsolationProbeUI3D",
+]
+
+CLIENT_SCRIPT = """
+import importlib.util
+import json
+import os
+import sys
+
+import pyisolate._internal.client  # noqa: F401  # triggers snapshot bootstrap
+
+module_path = os.environ["PYISOLATE_MODULE_PATH"]
+spec = importlib.util.spec_from_file_location(
+    "internal_probe_node",
+    os.path.join(module_path, "__init__.py"),
+    submodule_search_locations=[module_path],
+)
+module = importlib.util.module_from_spec(spec)
+assert spec is not None
+assert spec.loader is not None
+sys.modules["internal_probe_node"] = module
+spec.loader.exec_module(module)
+print(
+    json.dumps(
+        {
+            "sys_path": list(sys.path),
+            "module_path": module_path,
+            "node_ids": sorted(module.NODE_CLASS_MAPPINGS.keys()),
+        }
+    )
+)
+"""
+
+
+def _run_client_process(env: dict[str, str]) -> dict:
+    pythonpath_parts = [str(COMFYUI_ROOT)]
+    existing = env.get("PYTHONPATH", "")
+    if existing:
+        pythonpath_parts.append(existing)
+    env["PYTHONPATH"] = ":".join(pythonpath_parts)
+
+    result = subprocess.run(  # noqa: S603
+        [sys.executable, "-c", CLIENT_SCRIPT],
+        capture_output=True,
+        text=True,
+        env=env,
+        check=True,
+    )
+    return json.loads(result.stdout.strip().splitlines()[-1])
+
+
+@pytest.fixture()
+def staged_probe_module(tmp_path: Path) -> tuple[Path, Path]:
+    staged_comfy_root = tmp_path / "ComfyUI"
+    module_path = staged_comfy_root / "custom_nodes" / "InternalIsolationProbeNode"
+    shutil.copytree(PROBE_SOURCE_ROOT, module_path)
+    return staged_comfy_root, module_path
+
+
+@pytest.mark.asyncio
+async def test_staged_probe_node_discovered(staged_probe_module: tuple[Path, Path]) -> None:
+    _, module_path = staged_probe_module
+    class_mappings_snapshot = dict(nodes.NODE_CLASS_MAPPINGS)
+    display_name_snapshot = dict(nodes.NODE_DISPLAY_NAME_MAPPINGS)
+    loaded_module_dirs_snapshot = dict(nodes.LOADED_MODULE_DIRS)
+
+    try:
+        ignore = set(nodes.NODE_CLASS_MAPPINGS.keys())
+        loaded = await nodes.load_custom_node(
+            str(module_path), ignore=ignore, module_parent="custom_nodes"
+        )
+
+        assert loaded is True
+        assert nodes.LOADED_MODULE_DIRS["InternalIsolationProbeNode"] == str(
+            module_path.resolve()
+        )
+
+        for node_id in EXPECTED_NODE_IDS:
+            assert node_id in nodes.NODE_CLASS_MAPPINGS
+            node_cls = nodes.NODE_CLASS_MAPPINGS[node_id]
+            assert (
+                getattr(node_cls, "RELATIVE_PYTHON_MODULE", None)
+                == "custom_nodes.InternalIsolationProbeNode"
+            )
+    finally:
+        nodes.NODE_CLASS_MAPPINGS.clear()
+        nodes.NODE_CLASS_MAPPINGS.update(class_mappings_snapshot)
+        nodes.NODE_DISPLAY_NAME_MAPPINGS.clear()
+        nodes.NODE_DISPLAY_NAME_MAPPINGS.update(display_name_snapshot)
+        nodes.LOADED_MODULE_DIRS.clear()
+        nodes.LOADED_MODULE_DIRS.update(loaded_module_dirs_snapshot)
+
+
+def test_staged_probe_node_module_path_is_valid_for_child_bootstrap(
+    tmp_path: Path, staged_probe_module: tuple[Path, Path]
+) -> None:
+    staged_comfy_root, module_path = staged_probe_module
+    snapshot = {
+        "sys_path": [str(COMFYUI_ROOT), "/host/lib1", "/host/lib2"],
+        "sys_executable": sys.executable,
+        "sys_prefix": sys.prefix,
+        "environment": {},
+    }
+    snapshot_path = tmp_path / "snapshot.json"
+    snapshot_path.write_text(json.dumps(snapshot), encoding="utf-8")
+
+    env = os.environ.copy()
+    env.update(
+        {
+            "PYISOLATE_CHILD": "1",
+            "PYISOLATE_HOST_SNAPSHOT": str(snapshot_path),
+            "PYISOLATE_MODULE_PATH": str(module_path),
+        }
+    )
+
+    payload = _run_client_process(env)
+
+    assert payload["module_path"] == str(module_path)
+    assert payload["node_ids"] == EXPECTED_NODE_IDS
+    assert str(COMFYUI_ROOT) in payload["sys_path"]
+    assert str(staged_comfy_root) not in payload["sys_path"]
+
+
+def test_stage_probe_node_stages_only_under_explicit_root(tmp_path: Path) -> None:
+    comfy_root = tmp_path / "sandbox-root"
+
+    module_path = stage_probe_node(comfy_root)
+
+    assert module_path == comfy_root / "custom_nodes" / PROBE_NODE_NAME
+    assert module_path.is_dir()
+    assert (module_path / "__init__.py").is_file()
+    assert (module_path / "probe_nodes.py").is_file()
+    assert (module_path / "pyproject.toml").is_file()
+
+
+def test_staged_probe_node_context_cleans_up_temp_root() -> None:
+    with staged_probe_node() as module_path:
+        staging_root = module_path.parents[1]
+        assert module_path.name == PROBE_NODE_NAME
+        assert module_path.is_dir()
+        assert staging_root.is_dir()
+
+    assert not staging_root.exists()
+
+
+def test_stage_script_requires_explicit_target_root() -> None:
+    result = subprocess.run(  # noqa: S603
+        [sys.executable, str(ISOLATION_ROOT / "stage_internal_probe_node.py")],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+
+    assert result.returncode != 0
+    assert "--target-root" in result.stderr

tests/isolation/test_manifest_loader_discovery.py

@@ -0,0 +1,86 @@
+from __future__ import annotations
+
+import importlib
+import sys
+from pathlib import Path
+from types import ModuleType
+
+
+def _write_manifest(path: Path, *, standalone: bool = False) -> None:
+    lines = [
+        "[project]",
+        'name = "test-node"',
+        'version = "0.1.0"',
+        "",
+        "[tool.comfy.isolation]",
+        "can_isolate = true",
+        "share_torch = false",
+    ]
+    if standalone:
+        lines.append("standalone = true")
+    path.write_text("\n".join(lines) + "\n", encoding="utf-8")
+
+
+def _load_manifest_loader(custom_nodes_root: Path):
+    folder_paths = ModuleType("folder_paths")
+    folder_paths.base_path = str(custom_nodes_root)
+    folder_paths.get_folder_paths = lambda kind: [str(custom_nodes_root)] if kind == "custom_nodes" else []
+    sys.modules["folder_paths"] = folder_paths
+
+    if "comfy.isolation" not in sys.modules:
+        iso_mod = ModuleType("comfy.isolation")
+        iso_mod.__path__ = [  # type: ignore[attr-defined]
+            str(Path(__file__).resolve().parent.parent.parent / "comfy" / "isolation")
+        ]
+        iso_mod.__package__ = "comfy.isolation"
+        sys.modules["comfy.isolation"] = iso_mod
+
+    sys.modules.pop("comfy.isolation.manifest_loader", None)
+
+    import comfy.isolation.manifest_loader as manifest_loader
+
+    return importlib.reload(manifest_loader)
+
+
+def test_finds_top_level_isolation_manifest(tmp_path: Path) -> None:
+    node_dir = tmp_path / "TopLevelNode"
+    node_dir.mkdir(parents=True)
+    _write_manifest(node_dir / "pyproject.toml")
+
+    manifest_loader = _load_manifest_loader(tmp_path)
+    manifests = manifest_loader.find_manifest_directories()
+
+    assert manifests == [(node_dir, node_dir / "pyproject.toml")]
+
+
+def test_ignores_nested_manifest_without_standalone_flag(tmp_path: Path) -> None:
+    toolkit_dir = tmp_path / "ToolkitNode"
+    toolkit_dir.mkdir(parents=True)
+    _write_manifest(toolkit_dir / "pyproject.toml")
+
+    nested_dir = toolkit_dir / "packages" / "nested_fixture"
+    nested_dir.mkdir(parents=True)
+    _write_manifest(nested_dir / "pyproject.toml", standalone=False)
+
+    manifest_loader = _load_manifest_loader(tmp_path)
+    manifests = manifest_loader.find_manifest_directories()
+
+    assert manifests == [(toolkit_dir, toolkit_dir / "pyproject.toml")]
+
+
+def test_finds_nested_standalone_manifest(tmp_path: Path) -> None:
+    toolkit_dir = tmp_path / "ToolkitNode"
+    toolkit_dir.mkdir(parents=True)
+    _write_manifest(toolkit_dir / "pyproject.toml")
+
+    nested_dir = toolkit_dir / "packages" / "uv_sealed_worker"
+    nested_dir.mkdir(parents=True)
+    _write_manifest(nested_dir / "pyproject.toml", standalone=True)
+
+    manifest_loader = _load_manifest_loader(tmp_path)
+    manifests = manifest_loader.find_manifest_directories()
+
+    assert manifests == [
+        (toolkit_dir, toolkit_dir / "pyproject.toml"),
+        (nested_dir, nested_dir / "pyproject.toml"),
+    ]

tests/isolation/test_runtime_helpers_stub_contract.py

@@ -0,0 +1,125 @@
+"""Generic runtime-helper stub contract tests."""
+
+from __future__ import annotations
+
+import asyncio
+import logging
+import os
+import subprocess
+import sys
+from pathlib import Path
+from types import SimpleNamespace
+from typing import Any, cast
+
+from comfy.isolation import runtime_helpers
+from comfy_api.latest import io as latest_io
+from tests.isolation.stage_internal_probe_node import PROBE_NODE_NAME, staged_probe_node
+
+
+class _DummyExtension:
+    def __init__(self, *, name: str, module_path: str):
+        self.name = name
+        self.module_path = module_path
+
+    async def execute_node(self, _node_name: str, **inputs):
+        return {
+            "__node_output__": True,
+            "args": (inputs,),
+            "ui": {"status": "ok"},
+            "expand": False,
+            "block_execution": False,
+        }
+
+
+def _install_model_serialization_stub(monkeypatch):
+    async def deserialize_from_isolation(payload, _extension):
+        return payload
+
+    monkeypatch.setitem(
+        sys.modules,
+        "pyisolate._internal.model_serialization",
+        SimpleNamespace(
+            serialize_for_isolation=lambda payload: payload,
+            deserialize_from_isolation=deserialize_from_isolation,
+        ),
+    )
+
+
+def test_stub_sets_relative_python_module(monkeypatch):
+    _install_model_serialization_stub(monkeypatch)
+    monkeypatch.setattr(runtime_helpers, "scan_shm_forensics", lambda *args, **kwargs: None)
+    monkeypatch.setattr(runtime_helpers, "_relieve_host_vram_pressure", lambda *args, **kwargs: None)
+
+    extension = _DummyExtension(name="internal_probe", module_path=os.getcwd())
+    stub = cast(Any, runtime_helpers.build_stub_class(
+        "ProbeNode",
+        {
+            "is_v3": True,
+            "schema_v1": {},
+            "input_types": {},
+        },
+        extension,
+        {},
+        logging.getLogger("test"),
+    ))
+
+    info = getattr(stub, "GET_NODE_INFO_V1")()
+    assert info["python_module"] == "custom_nodes.internal_probe"
+
+
+def test_stub_ui_dispatch_roundtrip(monkeypatch):
+    _install_model_serialization_stub(monkeypatch)
+    monkeypatch.setattr(runtime_helpers, "scan_shm_forensics", lambda *args, **kwargs: None)
+    monkeypatch.setattr(runtime_helpers, "_relieve_host_vram_pressure", lambda *args, **kwargs: None)
+
+    extension = _DummyExtension(name="internal_probe", module_path=os.getcwd())
+    stub = runtime_helpers.build_stub_class(
+        "ProbeNode",
+        {
+            "is_v3": True,
+            "schema_v1": {"python_module": "custom_nodes.internal_probe"},
+            "input_types": {},
+        },
+        extension,
+        {},
+        logging.getLogger("test"),
+    )
+
+    result = asyncio.run(getattr(stub, "_pyisolate_execute")(SimpleNamespace(), token="value"))
+
+    assert isinstance(result, latest_io.NodeOutput)
+    assert result.ui == {"status": "ok"}
+
+
+def test_stub_class_types_align_with_extension():
+    extension = SimpleNamespace(name="internal_probe", module_path="/sandbox/probe")
+    running_extensions = {"internal_probe": extension}
+
+    specs = [
+        SimpleNamespace(module_path=Path("/sandbox/probe"), node_name="ProbeImage"),
+        SimpleNamespace(module_path=Path("/sandbox/probe"), node_name="ProbeAudio"),
+        SimpleNamespace(module_path=Path("/sandbox/other"), node_name="OtherNode"),
+    ]
+
+    class_types = runtime_helpers.get_class_types_for_extension(
+        "internal_probe", running_extensions, specs
+    )
+
+    assert class_types == {"ProbeImage", "ProbeAudio"}
+
+
+def test_probe_stage_requires_explicit_root():
+    script = Path(__file__).resolve().parent / "stage_internal_probe_node.py"
+    result = subprocess.run([sys.executable, str(script)], capture_output=True, text=True, check=False)
+
+    assert result.returncode != 0
+    assert "--target-root" in result.stderr
+
+
+def test_probe_stage_cleans_up_context():
+    with staged_probe_node() as module_path:
+        staged_root = module_path.parents[1]
+        assert module_path.name == PROBE_NODE_NAME
+        assert staged_root.exists()
+
+    assert not staged_root.exists()

tests/isolation/test_savedimages_serialization.py

@@ -0,0 +1,53 @@
+import logging
+import socket
+import sys
+from pathlib import Path
+
+repo_root = Path(__file__).resolve().parents[2]
+pyisolate_root = repo_root.parent / "pyisolate"
+if pyisolate_root.exists():
+    sys.path.insert(0, str(pyisolate_root))
+
+from comfy.isolation.adapter import ComfyUIAdapter
+from comfy_api.latest._io import FolderType
+from comfy_api.latest._ui import SavedImages, SavedResult
+from pyisolate._internal.rpc_transports import JSONSocketTransport
+from pyisolate._internal.serialization_registry import SerializerRegistry
+
+
+def test_savedimages_roundtrip(caplog):
+    registry = SerializerRegistry.get_instance()
+    registry.clear()
+    ComfyUIAdapter().register_serializers(registry)
+
+    payload = SavedImages(
+        results=[SavedResult("issue82.png", "slice2", FolderType.output)],
+        is_animated=True,
+    )
+
+    a, b = socket.socketpair()
+    sender = JSONSocketTransport(a)
+    receiver = JSONSocketTransport(b)
+    try:
+        with caplog.at_level(logging.WARNING, logger="pyisolate._internal.rpc_transports"):
+            sender.send({"ui": payload})
+            result = receiver.recv()
+    finally:
+        sender.close()
+        receiver.close()
+        registry.clear()
+
+    ui = result["ui"]
+    assert isinstance(ui, SavedImages)
+    assert ui.is_animated is True
+    assert len(ui.results) == 1
+    assert isinstance(ui.results[0], SavedResult)
+    assert ui.results[0].filename == "issue82.png"
+    assert ui.results[0].subfolder == "slice2"
+    assert ui.results[0].type == FolderType.output
+    assert ui.as_dict() == {
+        "images": [SavedResult("issue82.png", "slice2", FolderType.output)],
+        "animated": (True,),
+    }
+    assert not any("GENERIC SERIALIZER USED" in record.message for record in caplog.records)
+    assert not any("GENERIC DESERIALIZER USED" in record.message for record in caplog.records)

tests/isolation/test_sealed_worker_contract_matrix.py

@@ -0,0 +1,368 @@
+"""Generic sealed-worker loader contract matrix tests."""
+
+from __future__ import annotations
+
+import importlib
+import json
+import sys
+import types
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+COMFYUI_ROOT = Path(__file__).resolve().parents[2]
+TEST_WORKFLOW_ROOT = COMFYUI_ROOT / "tests" / "isolation" / "workflows"
+SEALED_WORKFLOW_CLASS_TYPES: dict[str, set[str]] = {
+    "quick_6_uv_sealed_worker.json": {
+        "EmptyLatentImage",
+        "ProxyTestSealedWorker",
+        "UVSealedBoltonsSlugify",
+        "UVSealedLatentEcho",
+        "UVSealedRuntimeProbe",
+    },
+    "isolation_7_uv_sealed_worker.json": {
+        "EmptyLatentImage",
+        "ProxyTestSealedWorker",
+        "UVSealedBoltonsSlugify",
+        "UVSealedLatentEcho",
+        "UVSealedRuntimeProbe",
+    },
+    "quick_8_conda_sealed_worker.json": {
+        "CondaSealedLatentEcho",
+        "CondaSealedOpenWeatherDataset",
+        "CondaSealedRuntimeProbe",
+        "EmptyLatentImage",
+        "ProxyTestCondaSealedWorker",
+    },
+    "isolation_9_conda_sealed_worker.json": {
+        "CondaSealedLatentEcho",
+        "CondaSealedOpenWeatherDataset",
+        "CondaSealedRuntimeProbe",
+        "EmptyLatentImage",
+        "ProxyTestCondaSealedWorker",
+    },
+}
+
+
+def _workflow_class_types(path: Path) -> set[str]:
+    payload = json.loads(path.read_text(encoding="utf-8"))
+    return {
+        node["class_type"]
+        for node in payload.values()
+        if isinstance(node, dict) and "class_type" in node
+    }
+
+
+def _make_manifest(
+    *,
+    package_manager: str = "uv",
+    execution_model: str | None = None,
+    can_isolate: bool = True,
+    dependencies: list[str] | None = None,
+    share_torch: bool = False,
+    sealed_host_ro_paths: list[str] | None = None,
+) -> dict:
+    isolation: dict[str, object] = {
+        "can_isolate": can_isolate,
+    }
+    if package_manager != "uv":
+        isolation["package_manager"] = package_manager
+    if execution_model is not None:
+        isolation["execution_model"] = execution_model
+    if share_torch:
+        isolation["share_torch"] = True
+    if sealed_host_ro_paths is not None:
+        isolation["sealed_host_ro_paths"] = sealed_host_ro_paths
+
+    if package_manager == "conda":
+        isolation["conda_channels"] = ["conda-forge"]
+        isolation["conda_dependencies"] = ["numpy"]
+
+    return {
+        "project": {
+            "name": "contract-extension",
+            "dependencies": dependencies or ["numpy"],
+        },
+        "tool": {"comfy": {"isolation": isolation}},
+    }
+
+
+@pytest.fixture
+def manifest_file(tmp_path: Path) -> Path:
+    path = tmp_path / "pyproject.toml"
+    path.write_bytes(b"")
+    return path
+
+
+def _loader_module(
+    monkeypatch: pytest.MonkeyPatch, *, preload_extension_wrapper: bool
+):
+    mock_wrapper = MagicMock()
+    mock_wrapper.ComfyNodeExtension = type("ComfyNodeExtension", (), {})
+
+    iso_mod = types.ModuleType("comfy.isolation")
+    iso_mod.__path__ = [
+        str(Path(__file__).resolve().parent.parent.parent / "comfy" / "isolation")
+    ]
+    iso_mod.__package__ = "comfy.isolation"
+
+    manifest_loader = types.SimpleNamespace(
+        is_cache_valid=lambda *args, **kwargs: False,
+        load_from_cache=lambda *args, **kwargs: None,
+        save_to_cache=lambda *args, **kwargs: None,
+    )
+    host_policy = types.SimpleNamespace(
+        load_host_policy=lambda base_path: {
+            "sandbox_mode": "required",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+            "sealed_worker_ro_import_paths": [],
+        }
+    )
+    folder_paths = types.SimpleNamespace(base_path="/fake/comfyui")
+
+    monkeypatch.setitem(sys.modules, "comfy.isolation", iso_mod)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.runtime_helpers", MagicMock())
+    monkeypatch.setitem(sys.modules, "comfy.isolation.manifest_loader", manifest_loader)
+    monkeypatch.setitem(sys.modules, "comfy.isolation.host_policy", host_policy)
+    monkeypatch.setitem(sys.modules, "folder_paths", folder_paths)
+    if preload_extension_wrapper:
+        monkeypatch.setitem(sys.modules, "comfy.isolation.extension_wrapper", mock_wrapper)
+    else:
+        sys.modules.pop("comfy.isolation.extension_wrapper", None)
+    sys.modules.pop("comfy.isolation.extension_loader", None)
+
+    module = importlib.import_module("comfy.isolation.extension_loader")
+    try:
+        yield module, mock_wrapper
+    finally:
+        sys.modules.pop("comfy.isolation.extension_loader", None)
+        comfy_pkg = sys.modules.get("comfy")
+        if comfy_pkg is not None and hasattr(comfy_pkg, "isolation"):
+            delattr(comfy_pkg, "isolation")
+
+
+@pytest.fixture
+def loader_module(monkeypatch: pytest.MonkeyPatch):
+    yield from _loader_module(monkeypatch, preload_extension_wrapper=True)
+
+
+@pytest.fixture
+def sealed_loader_module(monkeypatch: pytest.MonkeyPatch):
+    yield from _loader_module(monkeypatch, preload_extension_wrapper=False)
+
+
+@pytest.fixture
+def mocked_loader(loader_module):
+    module, mock_wrapper = loader_module
+    mock_ext = AsyncMock()
+    mock_ext.list_nodes = AsyncMock(return_value={})
+
+    mock_manager = MagicMock()
+    mock_manager.load_extension = MagicMock(return_value=mock_ext)
+    sealed_type = type("SealedNodeExtension", (), {})
+
+    with patch.object(module, "pyisolate") as mock_pi:
+        mock_pi.ExtensionManager = MagicMock(return_value=mock_manager)
+        mock_pi.SealedNodeExtension = sealed_type
+        yield module, mock_pi, mock_manager, sealed_type, mock_wrapper
+
+
+@pytest.fixture
+def sealed_mocked_loader(sealed_loader_module):
+    module, mock_wrapper = sealed_loader_module
+    mock_ext = AsyncMock()
+    mock_ext.list_nodes = AsyncMock(return_value={})
+
+    mock_manager = MagicMock()
+    mock_manager.load_extension = MagicMock(return_value=mock_ext)
+    sealed_type = type("SealedNodeExtension", (), {})
+
+    with patch.object(module, "pyisolate") as mock_pi:
+        mock_pi.ExtensionManager = MagicMock(return_value=mock_manager)
+        mock_pi.SealedNodeExtension = sealed_type
+        yield module, mock_pi, mock_manager, sealed_type, mock_wrapper
+
+
+async def _load_node(module, manifest: dict, manifest_path: Path, tmp_path: Path) -> dict:
+    with patch("comfy.isolation.extension_loader.tomllib") as mock_tomllib:
+        mock_tomllib.load.return_value = manifest
+        await module.load_isolated_node(
+            node_dir=tmp_path,
+            manifest_path=manifest_path,
+            logger=MagicMock(),
+            build_stub_class=MagicMock(),
+            venv_root=tmp_path / "venvs",
+            extension_managers=[],
+        )
+    manager = module.pyisolate.ExtensionManager.return_value
+    return manager.load_extension.call_args[0][0]
+
+
+@pytest.mark.asyncio
+async def test_uv_host_coupled_default(mocked_loader, manifest_file: Path, tmp_path: Path):
+    module, mock_pi, _mock_manager, sealed_type, _ = mocked_loader
+    manifest = _make_manifest(package_manager="uv")
+
+    config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    assert extension_type is not sealed_type
+    assert "execution_model" not in config
+
+
+@pytest.mark.asyncio
+async def test_uv_sealed_worker_opt_in(
+    sealed_mocked_loader, manifest_file: Path, tmp_path: Path
+):
+    module, mock_pi, _mock_manager, sealed_type, _ = sealed_mocked_loader
+    manifest = _make_manifest(package_manager="uv", execution_model="sealed_worker")
+
+    config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    assert extension_type is sealed_type
+    assert config["execution_model"] == "sealed_worker"
+    assert "apis" not in config
+    assert "comfy.isolation.extension_wrapper" not in sys.modules
+
+
+@pytest.mark.asyncio
+async def test_conda_defaults_to_sealed_worker(
+    sealed_mocked_loader, manifest_file: Path, tmp_path: Path
+):
+    module, mock_pi, _mock_manager, sealed_type, _ = sealed_mocked_loader
+    manifest = _make_manifest(package_manager="conda")
+
+    config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    assert extension_type is sealed_type
+    assert config["execution_model"] == "sealed_worker"
+    assert config["package_manager"] == "conda"
+    assert "comfy.isolation.extension_wrapper" not in sys.modules
+
+
+@pytest.mark.asyncio
+async def test_conda_never_uses_comfy_extension_type(
+    mocked_loader, manifest_file: Path, tmp_path: Path
+):
+    module, mock_pi, _mock_manager, sealed_type, mock_wrapper = mocked_loader
+    manifest = _make_manifest(package_manager="conda")
+
+    await _load_node(module, manifest, manifest_file, tmp_path)
+
+    extension_type = mock_pi.ExtensionManager.call_args[0][0]
+    assert extension_type is sealed_type
+    assert extension_type is not mock_wrapper.ComfyNodeExtension
+
+
+@pytest.mark.asyncio
+async def test_conda_forces_share_torch_false(mocked_loader, manifest_file: Path, tmp_path: Path):
+    module, _mock_pi, _mock_manager, _sealed_type, _ = mocked_loader
+    manifest = _make_manifest(package_manager="conda", share_torch=True)
+
+    config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    assert config["share_torch"] is False
+
+
+@pytest.mark.asyncio
+async def test_conda_forces_share_cuda_ipc_false(
+    mocked_loader, manifest_file: Path, tmp_path: Path
+):
+    module, _mock_pi, _mock_manager, _sealed_type, _ = mocked_loader
+    manifest = _make_manifest(package_manager="conda", share_torch=True)
+
+    config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    assert config["share_cuda_ipc"] is False
+
+
+@pytest.mark.asyncio
+async def test_conda_sandbox_policy_applied(mocked_loader, manifest_file: Path, tmp_path: Path):
+    module, _mock_pi, _mock_manager, _sealed_type, _ = mocked_loader
+    manifest = _make_manifest(package_manager="conda")
+
+    custom_policy = {
+        "sandbox_mode": "required",
+        "allow_network": True,
+        "writable_paths": ["/data/write"],
+        "readonly_paths": ["/data/read"],
+    }
+
+    with patch("platform.system", return_value="Linux"):
+        with patch.object(module, "load_host_policy", return_value=custom_policy):
+            config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    assert config["sandbox_mode"] == "required"
+    assert config["sandbox"] == {
+        "network": True,
+        "writable_paths": ["/data/write"],
+        "readonly_paths": ["/data/read"],
+    }
+
+
+def test_sealed_worker_workflow_templates_present() -> None:
+    missing = [
+        filename
+        for filename in SEALED_WORKFLOW_CLASS_TYPES
+        if not (TEST_WORKFLOW_ROOT / filename).is_file()
+    ]
+    assert not missing, f"missing sealed-worker workflow templates: {missing}"
+
+
+@pytest.mark.parametrize(
+    "workflow_name,expected_class_types",
+    SEALED_WORKFLOW_CLASS_TYPES.items(),
+)
+def test_sealed_worker_workflow_class_type_contract(
+    workflow_name: str, expected_class_types: set[str]
+) -> None:
+    workflow_path = TEST_WORKFLOW_ROOT / workflow_name
+    assert workflow_path.is_file(), f"workflow missing: {workflow_path}"
+
+    assert _workflow_class_types(workflow_path) == expected_class_types
+
+
+@pytest.mark.asyncio
+async def test_sealed_worker_host_policy_ro_import_matrix(
+    mocked_loader, manifest_file: Path, tmp_path: Path
+):
+    module, _mock_pi, _mock_manager, _sealed_type, _ = mocked_loader
+    manifest = _make_manifest(package_manager="uv", execution_model="sealed_worker")
+
+    with patch.object(
+        module,
+        "load_host_policy",
+        return_value={
+            "sandbox_mode": "required",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+            "sealed_worker_ro_import_paths": [],
+        },
+    ):
+        default_config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    with patch.object(
+        module,
+        "load_host_policy",
+        return_value={
+            "sandbox_mode": "required",
+            "allow_network": False,
+            "writable_paths": [],
+            "readonly_paths": [],
+            "sealed_worker_ro_import_paths": ["/home/johnj/ComfyUI"],
+        },
+    ):
+        opt_in_config = await _load_node(module, manifest, manifest_file, tmp_path)
+
+    assert default_config["execution_model"] == "sealed_worker"
+    assert "sealed_host_ro_paths" not in default_config
+
+    assert opt_in_config["execution_model"] == "sealed_worker"
+    assert opt_in_config["sealed_host_ro_paths"] == ["/home/johnj/ComfyUI"]
+    assert "apis" not in opt_in_config

tests/isolation/test_shared_model_proxy_contract.py

@@ -0,0 +1,44 @@
+import asyncio
+import sys
+from pathlib import Path
+
+repo_root = Path(__file__).resolve().parents[2]
+pyisolate_root = repo_root.parent / "pyisolate"
+if pyisolate_root.exists():
+    sys.path.insert(0, str(pyisolate_root))
+
+from comfy.isolation.adapter import ComfyUIAdapter
+from comfy.isolation.runtime_helpers import _wrap_remote_handles_as_host_proxies
+from pyisolate._internal.model_serialization import deserialize_from_isolation
+from pyisolate._internal.remote_handle import RemoteObjectHandle
+from pyisolate._internal.serialization_registry import SerializerRegistry
+
+
+def test_shared_model_ksampler_contract():
+    registry = SerializerRegistry.get_instance()
+    registry.clear()
+    ComfyUIAdapter().register_serializers(registry)
+
+    handle = RemoteObjectHandle("model_0", "ModelPatcher")
+
+    class FakeExtension:
+        async def call_remote_object_method(self, object_id, method_name, *args, **kwargs):
+            assert object_id == "model_0"
+            assert method_name == "get_model_object"
+            assert args == ("latent_format",)
+            assert kwargs == {}
+            return "resolved:latent_format"
+
+    wrapped = (handle,)
+    assert isinstance(wrapped, tuple)
+    assert isinstance(wrapped[0], RemoteObjectHandle)
+
+    deserialized = asyncio.run(deserialize_from_isolation(wrapped))
+    proxied = _wrap_remote_handles_as_host_proxies(deserialized, FakeExtension())
+    model_for_host = proxied[0]
+
+    assert not isinstance(model_for_host, RemoteObjectHandle)
+    assert hasattr(model_for_host, "get_model_object")
+    assert model_for_host.get_model_object("latent_format") == "resolved:latent_format"
+
+    registry.clear()

tests/isolation/test_singleton_proxy_boundary_matrix.py

@@ -0,0 +1,78 @@
+from __future__ import annotations
+
+import json
+
+from tests.isolation.singleton_boundary_helpers import (
+    capture_minimal_sealed_worker_imports,
+    capture_sealed_singleton_imports,
+)
+
+
+def test_minimal_sealed_worker_forbidden_imports() -> None:
+    payload = capture_minimal_sealed_worker_imports()
+
+    assert payload["mode"] == "minimal_sealed_worker"
+    assert payload["runtime_probe_function"] == "inspect"
+    assert payload["forbidden_matches"] == []
+
+
+def test_torch_share_subset_scope() -> None:
+    minimal = capture_minimal_sealed_worker_imports()
+
+    allowed_torch_share_only = {
+        "torch",
+        "folder_paths",
+        "comfy.utils",
+        "comfy.model_management",
+        "main",
+        "comfy.isolation.extension_wrapper",
+    }
+
+    assert minimal["forbidden_matches"] == []
+    assert all(
+        module_name not in minimal["modules"] for module_name in sorted(allowed_torch_share_only)
+    )
+
+
+def test_capture_payload_is_json_serializable() -> None:
+    payload = capture_minimal_sealed_worker_imports()
+
+    encoded = json.dumps(payload, sort_keys=True)
+
+    assert "\"minimal_sealed_worker\"" in encoded
+
+
+def test_folder_paths_child_safe() -> None:
+    payload = capture_sealed_singleton_imports()
+
+    assert payload["mode"] == "sealed_singletons"
+    assert payload["folder_path"] == "/sandbox/input/demo.png"
+    assert payload["temp_dir"] == "/sandbox/temp"
+    assert payload["models_dir"] == "/sandbox/models"
+    assert payload["forbidden_matches"] == []
+
+
+def test_utils_child_safe() -> None:
+    payload = capture_sealed_singleton_imports()
+
+    progress_calls = [
+        call
+        for call in payload["rpc_calls"]
+        if call["object_id"] == "UtilsProxy" and call["method"] == "progress_bar_hook"
+    ]
+
+    assert progress_calls
+    assert payload["forbidden_matches"] == []
+
+
+def test_progress_child_safe() -> None:
+    payload = capture_sealed_singleton_imports()
+
+    progress_calls = [
+        call
+        for call in payload["rpc_calls"]
+        if call["object_id"] == "ProgressProxy" and call["method"] == "rpc_set_progress"
+    ]
+
+    assert progress_calls
+    assert payload["forbidden_matches"] == []

tests/isolation/test_web_directory_handler.py

@@ -0,0 +1,129 @@
+"""Tests for WebDirectoryProxy host-side cache and aiohttp handler integration."""
+
+from __future__ import annotations
+
+import base64
+import sys
+from unittest.mock import MagicMock
+
+import pytest
+
+from comfy.isolation.proxies.web_directory_proxy import (
+    ALLOWED_EXTENSIONS,
+    WebDirectoryCache,
+)
+
+
+@pytest.fixture()
+def mock_proxy() -> MagicMock:
+    """Create a mock WebDirectoryProxy RPC proxy."""
+    proxy = MagicMock()
+    proxy.list_web_files.return_value = [
+        {"relative_path": "js/app.js", "content_type": "application/javascript"},
+        {"relative_path": "js/utils.js", "content_type": "application/javascript"},
+        {"relative_path": "index.html", "content_type": "text/html"},
+        {"relative_path": "style.css", "content_type": "text/css"},
+    ]
+    proxy.get_web_file.return_value = {
+        "content": base64.b64encode(b"console.log('hello');").decode("ascii"),
+        "content_type": "application/javascript",
+    }
+    return proxy
+
+
+@pytest.fixture()
+def cache_with_proxy(mock_proxy: MagicMock) -> WebDirectoryCache:
+    """Create a WebDirectoryCache with a registered mock proxy."""
+    cache = WebDirectoryCache()
+    cache.register_proxy("test-extension", mock_proxy)
+    return cache
+
+
+class TestExtensionsListing:
+    """AC-2: /extensions endpoint lists proxied JS files in URL format."""
+
+    def test_extensions_listing_produces_url_format_paths(
+        self, cache_with_proxy: WebDirectoryCache
+    ) -> None:
+        """Simulate what server.py does: build /extensions/{name}/{path} URLs."""
+        import urllib.parse
+
+        ext_name = "test-extension"
+        urls = []
+        for entry in cache_with_proxy.list_files(ext_name):
+            if entry["relative_path"].endswith(".js"):
+                urls.append(
+                    "/extensions/" + urllib.parse.quote(ext_name)
+                    + "/" + entry["relative_path"]
+                )
+
+        # Emit the actual URL list so it appears in test log output.
+        sys.stdout.write(f"\n--- Proxied JS URLs ({len(urls)}) ---\n")
+        for url in urls:
+            sys.stdout.write(f"  {url}\n")
+        sys.stdout.write("--- End URLs ---\n")
+
+        # At least one proxied JS URL in /extensions/{name}/{path} format
+        assert len(urls) >= 1, f"Expected >= 1 proxied JS URL, got {len(urls)}"
+        assert "/extensions/test-extension/js/app.js" in urls, (
+            f"Expected /extensions/test-extension/js/app.js in {urls}"
+        )
+
+
+class TestCacheHit:
+    """AC-3: Cache populated on first request, reused on second."""
+
+    def test_cache_hit_single_rpc_call(
+        self, cache_with_proxy: WebDirectoryCache, mock_proxy: MagicMock
+    ) -> None:
+        # First call — RPC
+        result1 = cache_with_proxy.get_file("test-extension", "js/app.js")
+        assert result1 is not None
+        assert result1["content"] == b"console.log('hello');"
+
+        # Second call — cache hit
+        result2 = cache_with_proxy.get_file("test-extension", "js/app.js")
+        assert result2 is not None
+        assert result2["content"] == b"console.log('hello');"
+
+        # Proxy was called exactly once
+        assert mock_proxy.get_web_file.call_count == 1
+
+    def test_cache_returns_none_for_unknown_extension(
+        self, cache_with_proxy: WebDirectoryCache
+    ) -> None:
+        result = cache_with_proxy.get_file("nonexistent", "js/app.js")
+        assert result is None
+
+
+class TestForbiddenType:
+    """AC-4: Disallowed file types return HTTP 403 Forbidden."""
+
+    @pytest.mark.parametrize(
+        "disallowed_path,expected_status",
+        [
+            ("backdoor.py", 403),
+            ("malware.exe", 403),
+            ("exploit.sh", 403),
+        ],
+    )
+    def test_forbidden_file_type_returns_403(
+        self, disallowed_path: str, expected_status: int
+    ) -> None:
+        """Simulate the aiohttp handler's file-type check and verify 403."""
+        import os
+        suffix = os.path.splitext(disallowed_path)[1].lower()
+
+        # This mirrors the handler logic in server.py:
+        # if suffix not in ALLOWED_EXTENSIONS: return web.Response(status=403)
+        if suffix not in ALLOWED_EXTENSIONS:
+            status = 403
+        else:
+            status = 200
+
+        sys.stdout.write(
+            f"\n--- HTTP status for {disallowed_path} (suffix={suffix}): {status} ---\n"
+        )
+        assert status == expected_status, (
+            f"Expected HTTP {expected_status} for {disallowed_path}, got {status}"
+        )

tests/isolation/test_web_directory_proxy.py

@@ -0,0 +1,130 @@
+"""Tests for WebDirectoryProxy — allow-list, traversal prevention, content serving."""
+
+from __future__ import annotations
+
+import base64
+from pathlib import Path
+
+import pytest
+
+from comfy.isolation.proxies.web_directory_proxy import WebDirectoryProxy
+
+
+@pytest.fixture()
+def web_dir_with_mixed_files(tmp_path: Path) -> Path:
+    """Create a temp web directory with allowed and disallowed file types."""
+    web = tmp_path / "web"
+    js_dir = web / "js"
+    js_dir.mkdir(parents=True)
+
+    # Allowed types
+    (js_dir / "app.js").write_text("console.log('hello');")
+    (web / "index.html").write_text("<html></html>")
+    (web / "style.css").write_text("body { margin: 0; }")
+
+    # Disallowed types
+    (web / "backdoor.py").write_text("import os; os.system('rm -rf /')")
+    (web / "malware.exe").write_bytes(b"\x00" * 16)
+    (web / "exploit.sh").write_text("#!/bin/bash\nrm -rf /")
+
+    return web
+
+
+@pytest.fixture()
+def proxy_with_web_dir(web_dir_with_mixed_files: Path) -> WebDirectoryProxy:
+    """Create a WebDirectoryProxy with a registered test web directory."""
+    proxy = WebDirectoryProxy()
+    # Clear class-level state to avoid cross-test pollution
+    WebDirectoryProxy._web_dirs = {}
+    WebDirectoryProxy.register_web_dir("test-extension", str(web_dir_with_mixed_files))
+    return proxy
+
+
+class TestAllowList:
+    """AC-2: list_web_files returns only allowed file types."""
+
+    def test_allowlist_only_safe_types(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        files = proxy_with_web_dir.list_web_files("test-extension")
+        extensions = {Path(f["relative_path"]).suffix for f in files}
+
+        # Only .js, .html, .css should appear
+        assert extensions == {".js", ".html", ".css"}
+
+    def test_allowlist_excludes_dangerous_types(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        files = proxy_with_web_dir.list_web_files("test-extension")
+        paths = [f["relative_path"] for f in files]
+
+        assert not any(p.endswith(".py") for p in paths)
+        assert not any(p.endswith(".exe") for p in paths)
+        assert not any(p.endswith(".sh") for p in paths)
+
+    def test_allowlist_correct_count(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        files = proxy_with_web_dir.list_web_files("test-extension")
+        # 3 allowed files: app.js, index.html, style.css
+        assert len(files) == 3
+
+    def test_allowlist_unknown_extension_returns_empty(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        files = proxy_with_web_dir.list_web_files("nonexistent-extension")
+        assert files == []
+
+
+class TestTraversal:
+    """AC-3: get_web_file rejects directory traversal attempts."""
+
+    @pytest.mark.parametrize(
+        "malicious_path",
+        [
+            "../../../etc/passwd",
+            "/etc/passwd",
+            "../../__init__.py",
+        ],
+    )
+    def test_traversal_rejected(
+        self, proxy_with_web_dir: WebDirectoryProxy, malicious_path: str
+    ) -> None:
+        with pytest.raises(ValueError):
+            proxy_with_web_dir.get_web_file("test-extension", malicious_path)
+
+
+class TestContent:
+    """AC-4: get_web_file returns base64 content with correct MIME types."""
+
+    def test_content_js_mime_type(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        result = proxy_with_web_dir.get_web_file("test-extension", "js/app.js")
+        assert result["content_type"] == "application/javascript"
+
+    def test_content_html_mime_type(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        result = proxy_with_web_dir.get_web_file("test-extension", "index.html")
+        assert result["content_type"] == "text/html"
+
+    def test_content_css_mime_type(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        result = proxy_with_web_dir.get_web_file("test-extension", "style.css")
+        assert result["content_type"] == "text/css"
+
+    def test_content_base64_roundtrip(
+        self, proxy_with_web_dir: WebDirectoryProxy, web_dir_with_mixed_files: Path
+    ) -> None:
+        result = proxy_with_web_dir.get_web_file("test-extension", "js/app.js")
+        decoded = base64.b64decode(result["content"])
+        source = (web_dir_with_mixed_files / "js" / "app.js").read_bytes()
+        assert decoded == source
+
+    def test_content_disallowed_type_rejected(
+        self, proxy_with_web_dir: WebDirectoryProxy
+    ) -> None:
+        with pytest.raises(ValueError, match="Disallowed file type"):
+            proxy_with_web_dir.get_web_file("test-extension", "backdoor.py")

tests/isolation/uv_sealed_worker/__init__.py

@@ -0,0 +1,230 @@
+# pylint: disable=import-outside-toplevel,import-error
+from __future__ import annotations
+
+import os
+import sys
+import logging
+from pathlib import Path
+from typing import Any
+
+logger = logging.getLogger(__name__)
+
+
+def _artifact_dir() -> Path | None:
+    raw = os.environ.get("PYISOLATE_ARTIFACT_DIR")
+    if not raw:
+        return None
+    path = Path(raw)
+    path.mkdir(parents=True, exist_ok=True)
+    return path
+
+
+def _write_artifact(name: str, content: str) -> None:
+    artifact_dir = _artifact_dir()
+    if artifact_dir is None:
+        return
+    (artifact_dir / name).write_text(content, encoding="utf-8")
+
+
+def _contains_tensor_marker(value: Any) -> bool:
+    if isinstance(value, dict):
+        if value.get("__type__") == "TensorValue":
+            return True
+        return any(_contains_tensor_marker(v) for v in value.values())
+    if isinstance(value, (list, tuple)):
+        return any(_contains_tensor_marker(v) for v in value)
+    return False
+
+
+class InspectRuntimeNode:
+    RETURN_TYPES = (
+        "STRING",
+        "STRING",
+        "BOOLEAN",
+        "BOOLEAN",
+        "STRING",
+        "STRING",
+        "BOOLEAN",
+    )
+    RETURN_NAMES = (
+        "path_dump",
+        "boltons_origin",
+        "saw_comfy_root",
+        "imported_comfy_wrapper",
+        "comfy_module_dump",
+        "report",
+        "saw_user_site",
+    )
+    FUNCTION = "inspect"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {}}
+
+    def inspect(self) -> tuple[str, str, bool, bool, str, str, bool]:
+        import boltons
+
+        path_dump = "\n".join(sys.path)
+        comfy_root = "/home/johnj/ComfyUI"
+        saw_comfy_root = any(
+            entry == comfy_root
+            or entry.startswith(f"{comfy_root}/comfy")
+            or entry.startswith(f"{comfy_root}/.venv")
+            for entry in sys.path
+        )
+        imported_comfy_wrapper = "comfy.isolation.extension_wrapper" in sys.modules
+        comfy_module_dump = "\n".join(
+            sorted(name for name in sys.modules if name.startswith("comfy"))
+        )
+        saw_user_site = any("/.local/lib/" in entry for entry in sys.path)
+        boltons_origin = getattr(boltons, "__file__", "<missing>")
+
+        report_lines = [
+            "UV sealed worker runtime probe",
+            f"boltons_origin={boltons_origin}",
+            f"saw_comfy_root={saw_comfy_root}",
+            f"imported_comfy_wrapper={imported_comfy_wrapper}",
+            f"saw_user_site={saw_user_site}",
+        ]
+        report = "\n".join(report_lines)
+
+        _write_artifact("child_bootstrap_paths.txt", path_dump)
+        _write_artifact("child_import_trace.txt", comfy_module_dump)
+        _write_artifact("child_dependency_dump.txt", boltons_origin)
+        logger.warning("][ UV sealed runtime probe executed")
+        logger.warning("][ boltons origin: %s", boltons_origin)
+
+        return (
+            path_dump,
+            boltons_origin,
+            saw_comfy_root,
+            imported_comfy_wrapper,
+            comfy_module_dump,
+            report,
+            saw_user_site,
+        )
+
+
+class BoltonsSlugifyNode:
+    RETURN_TYPES = ("STRING", "STRING")
+    RETURN_NAMES = ("slug", "boltons_origin")
+    FUNCTION = "slugify_text"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {"text": ("STRING", {"default": "Sealed Worker Rocks"})}}
+
+    def slugify_text(self, text: str) -> tuple[str, str]:
+        import boltons
+        from boltons.strutils import slugify
+
+        slug = slugify(text)
+        origin = getattr(boltons, "__file__", "<missing>")
+        logger.warning("][ boltons slugify: %r -> %r", text, slug)
+        return slug, origin
+
+
+class FilesystemBarrierNode:
+    RETURN_TYPES = ("STRING", "BOOLEAN", "BOOLEAN", "BOOLEAN")
+    RETURN_NAMES = (
+        "report",
+        "outside_blocked",
+        "module_mutation_blocked",
+        "artifact_write_ok",
+    )
+    FUNCTION = "probe"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {}}
+
+    def probe(self) -> tuple[str, bool, bool, bool]:
+        artifact_dir = _artifact_dir()
+        artifact_write_ok = False
+        if artifact_dir is not None:
+            probe_path = artifact_dir / "filesystem_barrier_probe.txt"
+            probe_path.write_text("artifact write ok\n", encoding="utf-8")
+            artifact_write_ok = probe_path.exists()
+
+        module_target = Path(__file__).with_name(
+            "mutated_from_child_should_not_exist.txt"
+        )
+        module_mutation_blocked = False
+        try:
+            module_target.write_text("mutation should fail\n", encoding="utf-8")
+        except Exception:
+            module_mutation_blocked = True
+        else:
+            module_target.unlink(missing_ok=True)
+
+        outside_target = Path("/home/johnj/mysolate/.uv_sealed_worker_escape_probe")
+        outside_blocked = False
+        try:
+            outside_target.write_text("escape should fail\n", encoding="utf-8")
+        except Exception:
+            outside_blocked = True
+        else:
+            outside_target.unlink(missing_ok=True)
+
+        report_lines = [
+            "UV sealed worker filesystem barrier probe",
+            f"artifact_write_ok={artifact_write_ok}",
+            f"module_mutation_blocked={module_mutation_blocked}",
+            f"outside_blocked={outside_blocked}",
+        ]
+        report = "\n".join(report_lines)
+        _write_artifact("filesystem_barrier_report.txt", report)
+        logger.warning("][ filesystem barrier probe executed")
+        return report, outside_blocked, module_mutation_blocked, artifact_write_ok
+
+
+class EchoTensorNode:
+    RETURN_TYPES = ("TENSOR", "BOOLEAN")
+    RETURN_NAMES = ("tensor", "saw_json_tensor")
+    FUNCTION = "echo"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {"tensor": ("TENSOR",)}}
+
+    def echo(self, tensor: Any) -> tuple[Any, bool]:
+        saw_json_tensor = _contains_tensor_marker(tensor)
+        logger.warning("][ tensor echo json_marker=%s", saw_json_tensor)
+        return tensor, saw_json_tensor
+
+
+class EchoLatentNode:
+    RETURN_TYPES = ("LATENT", "BOOLEAN")
+    RETURN_NAMES = ("latent", "saw_json_tensor")
+    FUNCTION = "echo_latent"
+    CATEGORY = "PyIsolated/SealedWorker"
+
+    @classmethod
+    def INPUT_TYPES(cls) -> dict[str, Any]:  # noqa: N802
+        return {"required": {"latent": ("LATENT",)}}
+
+    def echo_latent(self, latent: Any) -> tuple[Any, bool]:
+        saw_json_tensor = _contains_tensor_marker(latent)
+        logger.warning("][ latent echo json_marker=%s", saw_json_tensor)
+        return latent, saw_json_tensor
+
+
+NODE_CLASS_MAPPINGS = {
+    "UVSealedRuntimeProbe": InspectRuntimeNode,
+    "UVSealedBoltonsSlugify": BoltonsSlugifyNode,
+    "UVSealedFilesystemBarrier": FilesystemBarrierNode,
+    "UVSealedTensorEcho": EchoTensorNode,
+    "UVSealedLatentEcho": EchoLatentNode,
+}
+
+NODE_DISPLAY_NAME_MAPPINGS = {
+    "UVSealedRuntimeProbe": "UV Sealed Runtime Probe",
+    "UVSealedBoltonsSlugify": "UV Sealed Boltons Slugify",
+    "UVSealedFilesystemBarrier": "UV Sealed Filesystem Barrier",
+    "UVSealedTensorEcho": "UV Sealed Tensor Echo",
+    "UVSealedLatentEcho": "UV Sealed Latent Echo",
+}

tests/isolation/uv_sealed_worker/pyproject.toml

@@ -0,0 +1,11 @@
+[project]
+name = "comfyui-toolkit-uv-sealed-worker"
+version = "0.1.0"
+dependencies = ["boltons"]
+
+[tool.comfy.isolation]
+can_isolate = true
+share_torch = false
+package_manager = "uv"
+execution_model = "sealed_worker"
+standalone = true

tests/isolation/workflows/internal_probe_preview_image_audio.json

@@ -0,0 +1,10 @@
+{
+  "1": {
+    "class_type": "InternalIsolationProbeImage",
+    "inputs": {}
+  },
+  "2": {
+    "class_type": "InternalIsolationProbeAudio",
+    "inputs": {}
+  }
+}

tests/isolation/workflows/internal_probe_ui3d.json

@@ -0,0 +1,6 @@
+{
+  "1": {
+    "class_type": "InternalIsolationProbeUI3D",
+    "inputs": {}
+  }
+}

tests/isolation/workflows/isolation_7_uv_sealed_worker.json

@@ -0,0 +1,22 @@
+{
+  "1": {
+    "class_type": "EmptyLatentImage",
+    "inputs": {}
+  },
+  "2": {
+    "class_type": "ProxyTestSealedWorker",
+    "inputs": {}
+  },
+  "3": {
+    "class_type": "UVSealedBoltonsSlugify",
+    "inputs": {}
+  },
+  "4": {
+    "class_type": "UVSealedLatentEcho",
+    "inputs": {}
+  },
+  "5": {
+    "class_type": "UVSealedRuntimeProbe",
+    "inputs": {}
+  }
+}

tests/isolation/workflows/isolation_9_conda_sealed_worker.json

@@ -0,0 +1,22 @@
+{
+  "1": {
+    "class_type": "CondaSealedLatentEcho",
+    "inputs": {}
+  },
+  "2": {
+    "class_type": "CondaSealedOpenWeatherDataset",
+    "inputs": {}
+  },
+  "3": {
+    "class_type": "CondaSealedRuntimeProbe",
+    "inputs": {}
+  },
+  "4": {
+    "class_type": "EmptyLatentImage",
+    "inputs": {}
+  },
+  "5": {
+    "class_type": "ProxyTestCondaSealedWorker",
+    "inputs": {}
+  }
+}

tests/isolation/workflows/quick_6_uv_sealed_worker.json

@@ -0,0 +1,22 @@
+{
+  "1": {
+    "class_type": "EmptyLatentImage",
+    "inputs": {}
+  },
+  "2": {
+    "class_type": "ProxyTestSealedWorker",
+    "inputs": {}
+  },
+  "3": {
+    "class_type": "UVSealedBoltonsSlugify",
+    "inputs": {}
+  },
+  "4": {
+    "class_type": "UVSealedLatentEcho",
+    "inputs": {}
+  },
+  "5": {
+    "class_type": "UVSealedRuntimeProbe",
+    "inputs": {}
+  }
+}

tests/isolation/workflows/quick_8_conda_sealed_worker.json

@@ -0,0 +1,22 @@
+{
+  "1": {
+    "class_type": "CondaSealedLatentEcho",
+    "inputs": {}
+  },
+  "2": {
+    "class_type": "CondaSealedOpenWeatherDataset",
+    "inputs": {}
+  },
+  "3": {
+    "class_type": "CondaSealedRuntimeProbe",
+    "inputs": {}
+  },
+  "4": {
+    "class_type": "EmptyLatentImage",
+    "inputs": {}
+  },
+  "5": {
+    "class_type": "ProxyTestCondaSealedWorker",
+    "inputs": {}
+  }
+}

tests/test_adapter.py

@@ -1,5 +1,8 @@
 import os
+import subprocess
 import sys
+import textwrap
+import types
 from pathlib import Path
 
 repo_root = Path(__file__).resolve().parents[1]
@@ -8,6 +11,8 @@ if pyisolate_root.exists():
     sys.path.insert(0, str(pyisolate_root))
 
 from comfy.isolation.adapter import ComfyUIAdapter
+from pyisolate._internal.sandbox import build_bwrap_command
+from pyisolate._internal.sandbox_detect import RestrictionModel
 from pyisolate._internal.serialization_registry import SerializerRegistry
 
 
@@ -49,3 +54,69 @@ def test_register_serializers():
     assert registry.has_handler("VAE")
 
     registry.clear()
+
+
+def test_child_temp_directory_fence_uses_private_tmp(tmp_path):
+    adapter = ComfyUIAdapter()
+    child_script = textwrap.dedent(
+        """
+        from pathlib import Path
+
+        child_temp = Path("/tmp/comfyui_temp")
+        child_temp.mkdir(parents=True, exist_ok=True)
+        scratch = child_temp / "child_only.txt"
+        scratch.write_text("child-only", encoding="utf-8")
+        print(f"CHILD_TEMP={child_temp}")
+        print(f"CHILD_FILE={scratch}")
+        """
+    )
+    fake_folder_paths = types.SimpleNamespace(
+        temp_directory="/host/tmp/should_not_survive",
+        folder_names_and_paths={},
+        extension_mimetypes_cache={},
+        filename_list_cache={},
+    )
+
+    class FolderPathsProxy:
+        def get_temp_directory(self):
+            return "/host/tmp/should_not_survive"
+
+    original_folder_paths = sys.modules.get("folder_paths")
+    sys.modules["folder_paths"] = fake_folder_paths
+    try:
+        os.environ["PYISOLATE_CHILD"] = "1"
+        adapter.handle_api_registration(FolderPathsProxy, rpc=None)
+    finally:
+        os.environ.pop("PYISOLATE_CHILD", None)
+        if original_folder_paths is not None:
+            sys.modules["folder_paths"] = original_folder_paths
+        else:
+            sys.modules.pop("folder_paths", None)
+
+    assert fake_folder_paths.temp_directory == "/tmp/comfyui_temp"
+
+    host_child_file = Path("/tmp/comfyui_temp/child_only.txt")
+    if host_child_file.exists():
+        host_child_file.unlink()
+
+    cmd = build_bwrap_command(
+        python_exe=sys.executable,
+        module_path=str(repo_root / "custom_nodes" / "ComfyUI-IsolationToolkit"),
+        venv_path=str(repo_root / ".venv"),
+        uds_address=str(tmp_path / "adapter.sock"),
+        allow_gpu=False,
+        restriction_model=RestrictionModel.NONE,
+        sandbox_config={"writable_paths": ["/dev/shm"], "readonly_paths": [], "network": False},
+        adapter=adapter,
+    )
+    assert "--tmpfs" in cmd and "/tmp" in cmd
+    assert ["--bind", "/tmp", "/tmp"] not in [cmd[i : i + 3] for i in range(len(cmd) - 2)]
+
+    command_tail = cmd[-3:]
+    assert command_tail[1:] == ["-m", "pyisolate._internal.uds_client"]
+    cmd = cmd[:-3] + [sys.executable, "-c", child_script]
+
+    completed = subprocess.run(cmd, check=True, capture_output=True, text=True)
+
+    assert "CHILD_TEMP=/tmp/comfyui_temp" in completed.stdout
+    assert not host_child_file.exists(), "Child temp file leaked into host /tmp"