Merge branch 'master' into feat/string-min-max-length

* Implement seek and read for pins

Source pins from an mmap is pad because its its a CPU->CPU copy that
attempts to fully buffer the same data twice. Instead, use seek and
read which avoids the mmap buffering while usually being a faster
read in the first place (avoiding mmap faulting etc).

* pinned_memory: Use Aimdo pinner

The aimdo pinner bypasses pytorches CPU allocator which can leak
windows commit charge.

* ops: bypass init() of weight for embedding layer

This similarly consumes large commit charge especially for TEs. It can
cause a permanement leaked commit charge which can destabilize on
systems close to the commit ceiling and generally confuses the RAM
stats.

* model_patcher: implement pinned memory counter

Implement a pinned memory counter for better accounting of what volume
of memory pins have.

* implement touch accounting

Implement accounting of touching mmapped tensors.

* mm+mp: add residency mmap getter

* utils: use the aimdo mmap to load sft files

* model_management: Implement tigher RAM pressure semantics

Implement a pressure release on entire MMAPs as windows does perform
faster when mmaps are unloaded and model loads free ramp into fully
unallocated RAM.

Make the concept of freeing for pins a completely separate concept.
Now that pins are loadable directly from original file and don' touch
the mmap, tighten the freeing budget to just the current loaded model
- what you have left over. This still over-frees pins, but its a lot
better than before.

So after the pins are freed with that algorithm, bounce entire MMAPs
to free RAM based on what the model needs, deducting off any known
resident-in-mmap tensors to the free quota to keep it as tight as
possible.

* comfy-aimdo 0.2.11

Comfy aimdo 0.2.11

* mm: Implement file_slice path for QT

* ruff

* ops: put meta-tensors in place to allow custom nodes to check geo

README.md

@@ -38,6 +38,8 @@ ComfyUI lets you design and execute advanced stable diffusion pipelines using a
 
 ## Get Started
 
+### Local
+
 #### [Desktop Application](https://www.comfy.org/download)
 - The easiest way to get started.
 - Available on Windows & macOS.
@@ -49,8 +51,13 @@ ComfyUI lets you design and execute advanced stable diffusion pipelines using a
 #### [Manual Install](#manual-install-windows-linux)
 Supports all operating systems and GPU types (NVIDIA, AMD, Intel, Apple Silicon, Ascend).
 
-## [Examples](https://comfyanonymous.github.io/ComfyUI_examples/)
-See what ComfyUI can do with the [example workflows](https://comfyanonymous.github.io/ComfyUI_examples/).
+### Cloud
+
+#### [Comfy Cloud](https://www.comfy.org/cloud)
+- Our official paid cloud version for those who can't afford local hardware.
+
+## Examples
+See what ComfyUI can do with the [newer template workflows](https://comfy.org/workflows) or old [example workflows](https://comfyanonymous.github.io/ComfyUI_examples/).
 
 ## Features
 - Nodes/graph/flowchart interface to experiment and create complex Stable Diffusion workflows without needing to code anything.

comfy/memory_management.py

@@ -1,9 +1,68 @@
 import math
+import ctypes
+import threading
+import dataclasses
 import torch
 from typing import NamedTuple
 
 from comfy.quant_ops import QuantizedTensor
 
+
+class TensorFileSlice(NamedTuple):
+    file_ref: object
+    thread_id: int
+    offset: int
+    size: int
+
+
+def read_tensor_file_slice_into(tensor, destination):
+
+    if isinstance(tensor, QuantizedTensor):
+        if not isinstance(destination, QuantizedTensor):
+            return False
+        if tensor._layout_cls != destination._layout_cls:
+            return False
+
+        if not read_tensor_file_slice_into(tensor._qdata, destination._qdata):
+            return False
+
+        dst_orig_dtype = destination._params.orig_dtype
+        destination._params.copy_from(tensor._params, non_blocking=False)
+        destination._params = dataclasses.replace(destination._params, orig_dtype=dst_orig_dtype)
+        return True
+
+    info = getattr(tensor.untyped_storage(), "_comfy_tensor_file_slice", None)
+    if info is None:
+        return False
+
+    file_obj = info.file_ref
+    if (destination.device.type != "cpu"
+            or file_obj is None
+            or threading.get_ident() != info.thread_id
+            or destination.numel() * destination.element_size() < info.size):
+        return False
+
+    if info.size == 0:
+        return True
+
+    buf_type = ctypes.c_ubyte * info.size
+    view = memoryview(buf_type.from_address(destination.data_ptr()))
+
+    try:
+        file_obj.seek(info.offset)
+        done = 0
+        while done < info.size:
+            try:
+                n = file_obj.readinto(view[done:])
+            except OSError:
+                return False
+            if n <= 0:
+                return False
+            done += n
+        return True
+    finally:
+        view.release()
+
 class TensorGeometry(NamedTuple):
     shape: any
     dtype: torch.dtype

comfy/model_management.py

@@ -505,6 +505,28 @@ def module_size(module):
         module_mem += t.nbytes
     return module_mem
 
+def module_mmap_residency(module, free=False):
+    mmap_touched_mem = 0
+    module_mem = 0
+    bounced_mmaps = set()
+    sd = module.state_dict()
+    for k in sd:
+        t = sd[k]
+        module_mem += t.nbytes
+        storage = t._qdata.untyped_storage() if isinstance(t, comfy.quant_ops.QuantizedTensor) else t.untyped_storage()
+        if not getattr(storage, "_comfy_tensor_mmap_touched", False):
+            continue
+        mmap_touched_mem += t.nbytes
+        if not free:
+            continue
+        storage._comfy_tensor_mmap_touched = False
+        mmap_obj = storage._comfy_tensor_mmap_refs[0]
+        if mmap_obj in bounced_mmaps:
+            continue
+        mmap_obj.bounce()
+        bounced_mmaps.add(mmap_obj)
+    return mmap_touched_mem, module_mem
+
 class LoadedModel:
     def __init__(self, model):
         self._set_model(model)
@@ -532,6 +554,9 @@ class LoadedModel:
     def model_memory(self):
         return self.model.model_size()
 
+    def model_mmap_residency(self, free=False):
+        return self.model.model_mmap_residency(free=free)
+
     def model_loaded_memory(self):
         return self.model.loaded_size()
 
@@ -633,7 +658,7 @@ def extra_reserved_memory():
 def minimum_inference_memory():
     return (1024 * 1024 * 1024) * 0.8 + extra_reserved_memory()
 
-def free_memory(memory_required, device, keep_loaded=[], for_dynamic=False, ram_required=0):
+def free_memory(memory_required, device, keep_loaded=[], for_dynamic=False, pins_required=0, ram_required=0):
     cleanup_models_gc()
     unloaded_model = []
     can_unload = []
@@ -646,13 +671,14 @@ def free_memory(memory_required, device, keep_loaded=[], for_dynamic=False, ram_
                 can_unload.append((-shift_model.model_offloaded_memory(), sys.getrefcount(shift_model.model), shift_model.model_memory(), i))
                 shift_model.currently_used = False
 
-    for x in sorted(can_unload):
+    can_unload_sorted = sorted(can_unload)
+    for x in can_unload_sorted:
         i = x[-1]
         memory_to_free = 1e32
-        ram_to_free = 1e32
+        pins_to_free = 1e32
         if not DISABLE_SMART_MEMORY:
             memory_to_free = memory_required - get_free_memory(device)
-            ram_to_free = ram_required - get_free_ram()
+            pins_to_free = pins_required - get_free_ram()
             if current_loaded_models[i].model.is_dynamic() and for_dynamic:
                 #don't actually unload dynamic models for the sake of other dynamic models
                 #as that works on-demand.
@@ -661,9 +687,18 @@ def free_memory(memory_required, device, keep_loaded=[], for_dynamic=False, ram_
         if memory_to_free > 0 and current_loaded_models[i].model_unload(memory_to_free):
             logging.debug(f"Unloading {current_loaded_models[i].model.model.__class__.__name__}")
             unloaded_model.append(i)
-        if ram_to_free > 0:
+        if pins_to_free > 0:
+            logging.debug(f"PIN Unloading {current_loaded_models[i].model.model.__class__.__name__}")
+            current_loaded_models[i].model.partially_unload_ram(pins_to_free)
+
+    for x in can_unload_sorted:
+        i = x[-1]
+        ram_to_free = ram_required - psutil.virtual_memory().available
+        if ram_to_free <= 0 and i not in unloaded_model:
+            continue
+        resident_memory, _ = current_loaded_models[i].model_mmap_residency(free=True)
+        if resident_memory > 0:
             logging.debug(f"RAM Unloading {current_loaded_models[i].model.model.__class__.__name__}")
-            current_loaded_models[i].model.partially_unload_ram(ram_to_free)
 
     for i in sorted(unloaded_model, reverse=True):
         unloaded_models.append(current_loaded_models.pop(i))
@@ -729,17 +764,27 @@ def load_models_gpu(models, memory_required=0, force_patch_weights=False, minimu
 
 
     total_memory_required = {}
+    total_pins_required = {}
     total_ram_required = {}
     for loaded_model in models_to_load:
-        total_memory_required[loaded_model.device] = total_memory_required.get(loaded_model.device, 0) + loaded_model.model_memory_required(loaded_model.device)
-        #x2, one to make sure the OS can fit the model for loading in disk cache, and for us to do any pinning we
-        #want to do.
-        #FIXME: This should subtract off the to_load current pin consumption.
-        total_ram_required[loaded_model.device] = total_ram_required.get(loaded_model.device, 0) + loaded_model.model_memory() * 2
+        device = loaded_model.device
+        total_memory_required[device] = total_memory_required.get(device, 0) + loaded_model.model_memory_required(device)
+        resident_memory, model_memory = loaded_model.model_mmap_residency()
+        pinned_memory = loaded_model.model.pinned_memory_size()
+        #FIXME: This can over-free the pins as it budgets to pin the entire model. We should
+        #make this JIT to keep as much pinned as possible.
+        pins_required = model_memory - pinned_memory
+        ram_required = model_memory - resident_memory
+        total_pins_required[device] = total_pins_required.get(device, 0) + pins_required
+        total_ram_required[device] = total_ram_required.get(device, 0) + ram_required
 
     for device in total_memory_required:
         if device != torch.device("cpu"):
-            free_memory(total_memory_required[device] * 1.1 + extra_mem, device, for_dynamic=free_for_dynamic, ram_required=total_ram_required[device])
+            free_memory(total_memory_required[device] * 1.1 + extra_mem,
+                        device,
+                        for_dynamic=free_for_dynamic,
+                        pins_required=total_pins_required[device],
+                        ram_required=total_ram_required[device])
 
     for device in total_memory_required:
         if device != torch.device("cpu"):
@@ -1225,6 +1270,11 @@ def cast_to_gathered(tensors, r, non_blocking=False, stream=None):
             dest_view = dest_views.pop(0)
             if tensor is None:
                 continue
+            if comfy.memory_management.read_tensor_file_slice_into(tensor, dest_view):
+                continue
+            storage = tensor._qdata.untyped_storage() if isinstance(tensor, comfy.quant_ops.QuantizedTensor) else tensor.untyped_storage()
+            if hasattr(storage, "_comfy_tensor_mmap_touched"):
+                storage._comfy_tensor_mmap_touched = True
             dest_view.copy_(tensor, non_blocking=non_blocking)
 
 

comfy/model_patcher.py

@@ -297,6 +297,9 @@ class ModelPatcher:
         self.size = comfy.model_management.module_size(self.model)
         return self.size
 
+    def model_mmap_residency(self, free=False):
+        return comfy.model_management.module_mmap_residency(self.model, free=free)
+
     def get_ram_usage(self):
         return self.model_size()
 
@@ -1063,6 +1066,10 @@ class ModelPatcher:
 
             return self.model.model_loaded_weight_memory - current_used
 
+    def pinned_memory_size(self):
+        # Pinned memory pressure tracking is only implemented for DynamicVram loading
+        return 0
+
     def partially_unload_ram(self, ram_to_unload):
         pass
 
@@ -1653,6 +1660,16 @@ class ModelPatcherDynamic(ModelPatcher):
 
         return freed
 
+    def pinned_memory_size(self):
+        total = 0
+        loading = self._load_list(for_dynamic=True)
+        for x in loading:
+            _, _, _, _, m, _ = x
+            pin = comfy.pinned_memory.get_pin(m)
+            if pin is not None:
+                total += pin.numel() * pin.element_size()
+        return total
+
     def partially_unload_ram(self, ram_to_unload):
         loading = self._load_list(for_dynamic=True, default_device=self.offload_device)
         for x in loading:

comfy/ops.py

@@ -306,6 +306,33 @@ class CastWeightBiasOp:
     bias_function = []
 
 class disable_weight_init:
+    @staticmethod
+    def _lazy_load_from_state_dict(module, state_dict, prefix, local_metadata,
+                                   missing_keys, unexpected_keys, weight_shape,
+                                   bias_shape=None):
+        assign_to_params_buffers = local_metadata.get("assign_to_params_buffers", False)
+        prefix_len = len(prefix)
+        for k, v in state_dict.items():
+            key = k[prefix_len:]
+            if key == "weight":
+                if not assign_to_params_buffers:
+                    v = v.clone()
+                module.weight = torch.nn.Parameter(v, requires_grad=False)
+            elif bias_shape is not None and key == "bias" and v is not None:
+                if not assign_to_params_buffers:
+                    v = v.clone()
+                module.bias = torch.nn.Parameter(v, requires_grad=False)
+            else:
+                unexpected_keys.append(k)
+
+        if module.weight is None:
+            module.weight = torch.nn.Parameter(torch.zeros(weight_shape), requires_grad=False)
+            missing_keys.append(prefix + "weight")
+
+        if bias_shape is not None and module.bias is None and getattr(module, "comfy_need_lazy_init_bias", False):
+            module.bias = torch.nn.Parameter(torch.zeros(bias_shape), requires_grad=False)
+            missing_keys.append(prefix + "bias")
+
     class Linear(torch.nn.Linear, CastWeightBiasOp):
 
         def __init__(self, in_features, out_features, bias=True, device=None, dtype=None):
@@ -333,29 +360,16 @@ class disable_weight_init:
             if not comfy.model_management.WINDOWS or not comfy.memory_management.aimdo_enabled:
                 return super()._load_from_state_dict(state_dict, prefix, local_metadata, strict,
                                                      missing_keys, unexpected_keys, error_msgs)
-            assign_to_params_buffers = local_metadata.get("assign_to_params_buffers", False)
-            prefix_len = len(prefix)
-            for k,v in state_dict.items():
-                if k[prefix_len:] == "weight":
-                    if not assign_to_params_buffers:
-                        v = v.clone()
-                    self.weight = torch.nn.Parameter(v, requires_grad=False)
-                elif k[prefix_len:] == "bias" and v is not None:
-                    if not assign_to_params_buffers:
-                        v = v.clone()
-                    self.bias = torch.nn.Parameter(v, requires_grad=False)
-                else:
-                    unexpected_keys.append(k)
-
-            #Reconcile default construction of the weight if its missing.
-            if self.weight is None:
-                v = torch.zeros(self.in_features, self.out_features)
-                self.weight = torch.nn.Parameter(v, requires_grad=False)
-                missing_keys.append(prefix+"weight")
-            if self.bias is None and self.comfy_need_lazy_init_bias:
-                v = torch.zeros(self.out_features,)
-                self.bias = torch.nn.Parameter(v, requires_grad=False)
-                missing_keys.append(prefix+"bias")
+            disable_weight_init._lazy_load_from_state_dict(
+                self,
+                state_dict,
+                prefix,
+                local_metadata,
+                missing_keys,
+                unexpected_keys,
+                weight_shape=(self.in_features, self.out_features),
+                bias_shape=(self.out_features,),
+            )
 
 
         def reset_parameters(self):
@@ -547,6 +561,48 @@ class disable_weight_init:
                 return super().forward(*args, **kwargs)
 
     class Embedding(torch.nn.Embedding, CastWeightBiasOp):
+        def __init__(self, num_embeddings, embedding_dim, padding_idx=None, max_norm=None,
+                     norm_type=2.0, scale_grad_by_freq=False, sparse=False, _weight=None,
+                     _freeze=False, device=None, dtype=None):
+            if not comfy.model_management.WINDOWS or not comfy.memory_management.aimdo_enabled:
+                super().__init__(num_embeddings, embedding_dim, padding_idx, max_norm,
+                                 norm_type, scale_grad_by_freq, sparse, _weight,
+                                 _freeze, device, dtype)
+                return
+
+            torch.nn.Module.__init__(self)
+            self.num_embeddings = num_embeddings
+            self.embedding_dim = embedding_dim
+            self.padding_idx = padding_idx
+            self.max_norm = max_norm
+            self.norm_type = norm_type
+            self.scale_grad_by_freq = scale_grad_by_freq
+            self.sparse = sparse
+            # Keep shape/dtype visible for module introspection without reserving storage.
+            embedding_dtype = dtype if dtype is not None else torch.get_default_dtype()
+            self.weight = torch.nn.Parameter(
+                torch.empty((num_embeddings, embedding_dim), device="meta", dtype=embedding_dtype),
+                requires_grad=False,
+            )
+            self.bias = None
+            self.weight_comfy_model_dtype = dtype
+
+        def _load_from_state_dict(self, state_dict, prefix, local_metadata,
+                                strict, missing_keys, unexpected_keys, error_msgs):
+
+            if not comfy.model_management.WINDOWS or not comfy.memory_management.aimdo_enabled:
+                return super()._load_from_state_dict(state_dict, prefix, local_metadata, strict,
+                                                     missing_keys, unexpected_keys, error_msgs)
+            disable_weight_init._lazy_load_from_state_dict(
+                self,
+                state_dict,
+                prefix,
+                local_metadata,
+                missing_keys,
+                unexpected_keys,
+                weight_shape=(self.num_embeddings, self.embedding_dim),
+            )
+
         def reset_parameters(self):
             self.bias = None
             return None

comfy/pinned_memory.py

@@ -1,6 +1,7 @@
-import torch
 import comfy.model_management
 import comfy.memory_management
+import comfy_aimdo.host_buffer
+import comfy_aimdo.torch
 
 from comfy.cli_args import args
 
@@ -12,18 +13,31 @@ def pin_memory(module):
         return
     #FIXME: This is a RAM cache trigger event
     size = comfy.memory_management.vram_aligned_size([ module.weight, module.bias ])
-    pin = torch.empty((size,), dtype=torch.uint8)
-    if comfy.model_management.pin_memory(pin):
-        module._pin = pin
-    else:
+
+    if comfy.model_management.MAX_PINNED_MEMORY <= 0 or (comfy.model_management.TOTAL_PINNED_MEMORY + size) > comfy.model_management.MAX_PINNED_MEMORY:
         module.pin_failed = True
         return False
+
+    try:
+        hostbuf = comfy_aimdo.host_buffer.HostBuffer(size)
+    except RuntimeError:
+        module.pin_failed = True
+        return False
+
+    module._pin = comfy_aimdo.torch.hostbuf_to_tensor(hostbuf)
+    module._pin_hostbuf = hostbuf
+    comfy.model_management.TOTAL_PINNED_MEMORY += size
     return True
 
 def unpin_memory(module):
     if get_pin(module) is None:
         return 0
     size = module._pin.numel() * module._pin.element_size()
-    comfy.model_management.unpin_memory(module._pin)
+
+    comfy.model_management.TOTAL_PINNED_MEMORY -= size
+    if comfy.model_management.TOTAL_PINNED_MEMORY < 0:
+        comfy.model_management.TOTAL_PINNED_MEMORY = 0
+
     del module._pin
+    del module._pin_hostbuf
     return size

comfy/utils.py

@@ -20,6 +20,8 @@
 import torch
 import math
 import struct
+import ctypes
+import os
 import comfy.memory_management
 import safetensors.torch
 import numpy as np
@@ -32,7 +34,7 @@ from einops import rearrange
 from comfy.cli_args import args
 import json
 import time
-import mmap
+import threading
 import warnings
 
 MMAP_TORCH_FILES = args.mmap_torch_files
@@ -81,14 +83,17 @@ _TYPES = {
 }
 
 def load_safetensors(ckpt):
-    f = open(ckpt, "rb")
-    mapping = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)
-    mv = memoryview(mapping)
+    import comfy_aimdo.model_mmap
 
-    header_size = struct.unpack("<Q", mapping[:8])[0]
-    header = json.loads(mapping[8:8+header_size].decode("utf-8"))
+    f = open(ckpt, "rb", buffering=0)
+    model_mmap = comfy_aimdo.model_mmap.ModelMMAP(ckpt)
+    file_size = os.path.getsize(ckpt)
+    mv = memoryview((ctypes.c_uint8 * file_size).from_address(model_mmap.get()))
 
-    mv = mv[8 + header_size:]
+    header_size = struct.unpack("<Q", mv[:8])[0]
+    header = json.loads(mv[8:8 + header_size].tobytes().decode("utf-8"))
+
+    mv = mv[(data_base_offset := 8 + header_size):]
 
     sd = {}
     for name, info in header.items():
@@ -102,7 +107,14 @@ def load_safetensors(ckpt):
             with warnings.catch_warnings():
                 #We are working with read-only RAM by design
                 warnings.filterwarnings("ignore", message="The given buffer is not writable")
-                sd[name] = torch.frombuffer(mv[start:end], dtype=_TYPES[info["dtype"]]).view(info["shape"])
+                tensor = torch.frombuffer(mv[start:end], dtype=_TYPES[info["dtype"]]).view(info["shape"])
+                storage = tensor.untyped_storage()
+                setattr(storage,
+                        "_comfy_tensor_file_slice",
+                        comfy.memory_management.TensorFileSlice(f, threading.get_ident(), data_base_offset + start, end - start))
+                setattr(storage, "_comfy_tensor_mmap_refs", (model_mmap, mv))
+                setattr(storage, "_comfy_tensor_mmap_touched", False)
+                sd[name] = tensor
 
     return sd, header.get("__metadata__", {}),
 

comfy_api/latest/__init__.py

@@ -25,6 +25,7 @@ class ComfyAPI_latest(ComfyAPIBase):
         super().__init__()
         self.node_replacement = self.NodeReplacement()
         self.execution = self.Execution()
+        self.caching = self.Caching()
 
     class NodeReplacement(ProxiedSingleton):
         async def register(self, node_replace: io.NodeReplace) -> None:
@@ -84,6 +85,36 @@ class ComfyAPI_latest(ComfyAPIBase):
                 image=to_display,
             )
 
+    class Caching(ProxiedSingleton):
+        """
+        External cache provider API for sharing cached node outputs
+        across ComfyUI instances.
+
+        Example::
+
+            from comfy_api.latest import Caching
+
+            class MyCacheProvider(Caching.CacheProvider):
+                async def on_lookup(self, context):
+                    ...  # check external storage
+
+                async def on_store(self, context, value):
+                    ...  # store to external storage
+
+            Caching.register_provider(MyCacheProvider())
+        """
+        from ._caching import CacheProvider, CacheContext, CacheValue
+
+        async def register_provider(self, provider: "ComfyAPI_latest.Caching.CacheProvider") -> None:
+            """Register an external cache provider. Providers are called in registration order."""
+            from comfy_execution.cache_provider import register_cache_provider
+            register_cache_provider(provider)
+
+        async def unregister_provider(self, provider: "ComfyAPI_latest.Caching.CacheProvider") -> None:
+            """Unregister a previously registered cache provider."""
+            from comfy_execution.cache_provider import unregister_cache_provider
+            unregister_cache_provider(provider)
+
 class ComfyExtension(ABC):
     async def on_load(self) -> None:
         """
@@ -116,6 +147,9 @@ class Types:
     VOXEL = VOXEL
     File3D = File3D
 
+
+Caching = ComfyAPI_latest.Caching
+
 ComfyAPI = ComfyAPI_latest
 
 # Create a synchronous version of the API
@@ -135,6 +169,7 @@ __all__ = [
     "Input",
     "InputImpl",
     "Types",
+    "Caching",
     "ComfyExtension",
     "io",
     "IO",

comfy_api/latest/_caching.py

@@ -0,0 +1,42 @@
+from abc import ABC, abstractmethod
+from typing import Optional
+from dataclasses import dataclass
+
+
+@dataclass
+class CacheContext:
+    node_id: str
+    class_type: str
+    cache_key_hash: str  # SHA256 hex digest
+
+
+@dataclass
+class CacheValue:
+    outputs: list
+    ui: dict = None
+
+
+class CacheProvider(ABC):
+    """Abstract base class for external cache providers.
+    Exceptions from provider methods are caught by the caller and never break execution.
+    """
+
+    @abstractmethod
+    async def on_lookup(self, context: CacheContext) -> Optional[CacheValue]:
+        """Called on local cache miss. Return CacheValue if found, None otherwise."""
+        pass
+
+    @abstractmethod
+    async def on_store(self, context: CacheContext, value: CacheValue) -> None:
+        """Called after local store. Dispatched via asyncio.create_task."""
+        pass
+
+    def should_cache(self, context: CacheContext, value: Optional[CacheValue] = None) -> bool:
+        """Return False to skip external caching for this node. Default: True."""
+        return True
+
+    def on_prompt_start(self, prompt_id: str) -> None:
+        pass
+
+    def on_prompt_end(self, prompt_id: str) -> None:
+        pass

comfy_api/latest/_io.py

@@ -326,11 +326,14 @@ class String(ComfyTypeIO):
         '''String input.'''
         def __init__(self, id: str, display_name: str=None, optional=False, tooltip: str=None, lazy: bool=None,
                     multiline=False, placeholder: str=None, default: str=None, dynamic_prompts: bool=None,
-                    socketless: bool=None, force_input: bool=None, extra_dict=None, raw_link: bool=None, advanced: bool=None):
+                    socketless: bool=None, force_input: bool=None, extra_dict=None, raw_link: bool=None, advanced: bool=None,
+                    min_length: int=None, max_length: int=None):
             super().__init__(id, display_name, optional, tooltip, lazy, default, socketless, None, force_input, extra_dict, raw_link, advanced)
             self.multiline = multiline
             self.placeholder = placeholder
             self.dynamic_prompts = dynamic_prompts
+            self.min_length = min_length
+            self.max_length = max_length
             self.default: str
 
         def as_dict(self):
@@ -338,6 +341,8 @@ class String(ComfyTypeIO):
                 "multiline": self.multiline,
                 "placeholder": self.placeholder,
                 "dynamicPrompts": self.dynamic_prompts,
+                "minLength": self.min_length,
+                "maxLength": self.max_length,
             })
 
 @comfytype(io_type="COMBO")

comfy_api_nodes/nodes_hunyuan3d.py

@@ -1,3 +1,7 @@
+import zipfile
+from io import BytesIO
+
+import torch
 from typing_extensions import override
 
 from comfy_api.latest import IO, ComfyExtension, Input, Types
@@ -17,7 +21,10 @@ from comfy_api_nodes.apis.hunyuan3d import (
 )
 from comfy_api_nodes.util import (
     ApiEndpoint,
+    bytesio_to_image_tensor,
+    download_url_to_bytesio,
     download_url_to_file_3d,
+    download_url_to_image_tensor,
     downscale_image_tensor_by_max_side,
     poll_op,
     sync_op,
@@ -36,6 +43,68 @@ def _is_tencent_rate_limited(status: int, body: object) -> bool:
     )
 
 
+class ObjZipResult:
+    __slots__ = ("obj", "texture", "metallic", "normal", "roughness")
+
+    def __init__(
+        self,
+        obj: Types.File3D,
+        texture: Input.Image | None = None,
+        metallic: Input.Image | None = None,
+        normal: Input.Image | None = None,
+        roughness: Input.Image | None = None,
+    ):
+        self.obj = obj
+        self.texture = texture
+        self.metallic = metallic
+        self.normal = normal
+        self.roughness = roughness
+
+
+async def download_and_extract_obj_zip(url: str) -> ObjZipResult:
+    """The Tencent API returns OBJ results as ZIP archives containing the .obj mesh, and texture images.
+
+    When PBR is enabled, the ZIP may contain additional metallic, normal, and roughness maps
+    identified by their filename suffixes.
+    """
+    data = BytesIO()
+    await download_url_to_bytesio(url, data)
+    data.seek(0)
+    if not zipfile.is_zipfile(data):
+        data.seek(0)
+        return ObjZipResult(obj=Types.File3D(source=data, file_format="obj"))
+    data.seek(0)
+    obj_bytes = None
+    textures: dict[str, Input.Image] = {}
+    with zipfile.ZipFile(data) as zf:
+        for name in zf.namelist():
+            lower = name.lower()
+            if lower.endswith(".obj"):
+                obj_bytes = zf.read(name)
+            elif any(lower.endswith(ext) for ext in (".png", ".jpg", ".jpeg", ".bmp", ".tiff", ".webp")):
+                stem = lower.rsplit(".", 1)[0]
+                tensor = bytesio_to_image_tensor(BytesIO(zf.read(name)), mode="RGB")
+                matched_key = "texture"
+                for suffix, key in {
+                    "_metallic": "metallic",
+                    "_normal": "normal",
+                    "_roughness": "roughness",
+                }.items():
+                    if stem.endswith(suffix):
+                        matched_key = key
+                        break
+                textures[matched_key] = tensor
+    if obj_bytes is None:
+        raise ValueError("ZIP archive does not contain an OBJ file.")
+    return ObjZipResult(
+        obj=Types.File3D(source=BytesIO(obj_bytes), file_format="obj"),
+        texture=textures.get("texture"),
+        metallic=textures.get("metallic"),
+        normal=textures.get("normal"),
+        roughness=textures.get("roughness"),
+    )
+
+
 def get_file_from_response(
     response_objs: list[ResultFile3D], file_type: str, raise_if_not_found: bool = True
 ) -> ResultFile3D | None:
@@ -93,6 +162,7 @@ class TencentTextToModelNode(IO.ComfyNode):
                 IO.String.Output(display_name="model_file"),  # for backward compatibility only
                 IO.File3DGLB.Output(display_name="GLB"),
                 IO.File3DOBJ.Output(display_name="OBJ"),
+                IO.Image.Output(display_name="texture_image"),
             ],
             hidden=[
                 IO.Hidden.auth_token_comfy_org,
@@ -151,14 +221,14 @@ class TencentTextToModelNode(IO.ComfyNode):
             response_model=To3DProTaskResultResponse,
             status_extractor=lambda r: r.Status,
         )
+        obj_result = await download_and_extract_obj_zip(get_file_from_response(result.ResultFile3Ds, "obj").Url)
         return IO.NodeOutput(
             f"{task_id}.glb",
             await download_url_to_file_3d(
                 get_file_from_response(result.ResultFile3Ds, "glb").Url, "glb", task_id=task_id
             ),
-            await download_url_to_file_3d(
-                get_file_from_response(result.ResultFile3Ds, "obj").Url, "obj", task_id=task_id
-            ),
+            obj_result.obj,
+            obj_result.texture,
         )
 
 
@@ -211,6 +281,10 @@ class TencentImageToModelNode(IO.ComfyNode):
                 IO.String.Output(display_name="model_file"),  # for backward compatibility only
                 IO.File3DGLB.Output(display_name="GLB"),
                 IO.File3DOBJ.Output(display_name="OBJ"),
+                IO.Image.Output(display_name="texture_image"),
+                IO.Image.Output(display_name="optional_metallic"),
+                IO.Image.Output(display_name="optional_normal"),
+                IO.Image.Output(display_name="optional_roughness"),
             ],
             hidden=[
                 IO.Hidden.auth_token_comfy_org,
@@ -304,14 +378,17 @@ class TencentImageToModelNode(IO.ComfyNode):
             response_model=To3DProTaskResultResponse,
             status_extractor=lambda r: r.Status,
         )
+        obj_result = await download_and_extract_obj_zip(get_file_from_response(result.ResultFile3Ds, "obj").Url)
         return IO.NodeOutput(
             f"{task_id}.glb",
             await download_url_to_file_3d(
                 get_file_from_response(result.ResultFile3Ds, "glb").Url, "glb", task_id=task_id
             ),
-            await download_url_to_file_3d(
-                get_file_from_response(result.ResultFile3Ds, "obj").Url, "obj", task_id=task_id
-            ),
+            obj_result.obj,
+            obj_result.texture,
+            obj_result.metallic if obj_result.metallic is not None else torch.zeros(1, 1, 1, 3),
+            obj_result.normal if obj_result.normal is not None else torch.zeros(1, 1, 1, 3),
+            obj_result.roughness if obj_result.roughness is not None else torch.zeros(1, 1, 1, 3),
         )
 
 
@@ -431,7 +508,8 @@ class Tencent3DTextureEditNode(IO.ComfyNode):
             ],
             outputs=[
                 IO.File3DGLB.Output(display_name="GLB"),
-                IO.File3DFBX.Output(display_name="FBX"),
+                IO.File3DOBJ.Output(display_name="OBJ"),
+                IO.Image.Output(display_name="texture_image"),
             ],
             hidden=[
                 IO.Hidden.auth_token_comfy_org,
@@ -480,7 +558,8 @@ class Tencent3DTextureEditNode(IO.ComfyNode):
         )
         return IO.NodeOutput(
             await download_url_to_file_3d(get_file_from_response(result.ResultFile3Ds, "glb").Url, "glb"),
-            await download_url_to_file_3d(get_file_from_response(result.ResultFile3Ds, "fbx").Url, "fbx"),
+            await download_url_to_file_3d(get_file_from_response(result.ResultFile3Ds, "obj").Url, "obj"),
+            await download_url_to_image_tensor(get_file_from_response(result.ResultFile3Ds, "texture_image").Url),
         )
 
 
@@ -654,7 +733,7 @@ class TencentHunyuan3DExtension(ComfyExtension):
             TencentTextToModelNode,
             TencentImageToModelNode,
             TencentModelTo3DUVNode,
-            # Tencent3DTextureEditNode,
+            Tencent3DTextureEditNode,
             Tencent3DPartNode,
             TencentSmartTopologyNode,
         ]

comfy_execution/cache_provider.py

@@ -0,0 +1,138 @@
+from typing import Any, Optional, Tuple, List
+import hashlib
+import json
+import logging
+import threading
+
+# Public types — source of truth is comfy_api.latest._caching
+from comfy_api.latest._caching import CacheProvider, CacheContext, CacheValue  # noqa: F401 (re-exported)
+
+_logger = logging.getLogger(__name__)
+
+
+_providers: List[CacheProvider] = []
+_providers_lock = threading.Lock()
+_providers_snapshot: Tuple[CacheProvider, ...] = ()
+
+
+def register_cache_provider(provider: CacheProvider) -> None:
+    """Register an external cache provider. Providers are called in registration order."""
+    global _providers_snapshot
+    with _providers_lock:
+        if provider in _providers:
+            _logger.warning(f"Provider {provider.__class__.__name__} already registered")
+            return
+        _providers.append(provider)
+        _providers_snapshot = tuple(_providers)
+        _logger.debug(f"Registered cache provider: {provider.__class__.__name__}")
+
+
+def unregister_cache_provider(provider: CacheProvider) -> None:
+    global _providers_snapshot
+    with _providers_lock:
+        try:
+            _providers.remove(provider)
+            _providers_snapshot = tuple(_providers)
+            _logger.debug(f"Unregistered cache provider: {provider.__class__.__name__}")
+        except ValueError:
+            _logger.warning(f"Provider {provider.__class__.__name__} was not registered")
+
+
+def _get_cache_providers() -> Tuple[CacheProvider, ...]:
+    return _providers_snapshot
+
+
+def _has_cache_providers() -> bool:
+    return bool(_providers_snapshot)
+
+
+def _clear_cache_providers() -> None:
+    global _providers_snapshot
+    with _providers_lock:
+        _providers.clear()
+        _providers_snapshot = ()
+
+
+def _canonicalize(obj: Any) -> Any:
+    # Convert to canonical JSON-serializable form with deterministic ordering.
+    # Frozensets have non-deterministic iteration order between Python sessions.
+    # Raises ValueError for non-cacheable types (Unhashable, unknown) so that
+    # _serialize_cache_key returns None and external caching is skipped.
+    if isinstance(obj, frozenset):
+        return ("__frozenset__", sorted(
+            [_canonicalize(item) for item in obj],
+            key=lambda x: json.dumps(x, sort_keys=True)
+        ))
+    elif isinstance(obj, set):
+        return ("__set__", sorted(
+            [_canonicalize(item) for item in obj],
+            key=lambda x: json.dumps(x, sort_keys=True)
+        ))
+    elif isinstance(obj, tuple):
+        return ("__tuple__", [_canonicalize(item) for item in obj])
+    elif isinstance(obj, list):
+        return [_canonicalize(item) for item in obj]
+    elif isinstance(obj, dict):
+        return {"__dict__": sorted(
+            [[_canonicalize(k), _canonicalize(v)] for k, v in obj.items()],
+            key=lambda x: json.dumps(x, sort_keys=True)
+        )}
+    elif isinstance(obj, (int, float, str, bool, type(None))):
+        return (type(obj).__name__, obj)
+    elif isinstance(obj, bytes):
+        return ("__bytes__", obj.hex())
+    else:
+        raise ValueError(f"Cannot canonicalize type: {type(obj).__name__}")
+
+
+def _serialize_cache_key(cache_key: Any) -> Optional[str]:
+    # Returns deterministic SHA256 hex digest, or None on failure.
+    # Uses JSON (not pickle) because pickle is non-deterministic across sessions.
+    try:
+        canonical = _canonicalize(cache_key)
+        json_str = json.dumps(canonical, sort_keys=True, separators=(',', ':'))
+        return hashlib.sha256(json_str.encode('utf-8')).hexdigest()
+    except Exception as e:
+        _logger.warning(f"Failed to serialize cache key: {e}")
+        return None
+
+
+def _contains_self_unequal(obj: Any) -> bool:
+    # Local cache matches by ==. Values where not (x == x) (NaN, etc.) will
+    # never hit locally, but serialized form would match externally. Skip these.
+    try:
+        if not (obj == obj):
+            return True
+    except Exception:
+        return True
+    if isinstance(obj, (frozenset, tuple, list, set)):
+        return any(_contains_self_unequal(item) for item in obj)
+    if isinstance(obj, dict):
+        return any(_contains_self_unequal(k) or _contains_self_unequal(v) for k, v in obj.items())
+    if hasattr(obj, 'value'):
+        return _contains_self_unequal(obj.value)
+    return False
+
+
+def _estimate_value_size(value: CacheValue) -> int:
+    try:
+        import torch
+    except ImportError:
+        return 0
+
+    total = 0
+
+    def estimate(obj):
+        nonlocal total
+        if isinstance(obj, torch.Tensor):
+            total += obj.numel() * obj.element_size()
+        elif isinstance(obj, dict):
+            for v in obj.values():
+                estimate(v)
+        elif isinstance(obj, (list, tuple)):
+            for item in obj:
+                estimate(item)
+
+    for output in value.outputs:
+        estimate(output)
+    return total

comfy_execution/caching.py

@@ -1,3 +1,4 @@
+import asyncio
 import bisect
 import gc
 import itertools
@@ -147,13 +148,15 @@ class CacheKeySetInputSignature(CacheKeySet):
                     self.get_ordered_ancestry_internal(dynprompt, ancestor_id, ancestors, order_mapping)
 
 class BasicCache:
-    def __init__(self, key_class):
+    def __init__(self, key_class, enable_providers=False):
         self.key_class = key_class
         self.initialized = False
+        self.enable_providers = enable_providers
         self.dynprompt: DynamicPrompt
         self.cache_key_set: CacheKeySet
         self.cache = {}
         self.subcaches = {}
+        self._pending_store_tasks: set = set()
 
     async def set_prompt(self, dynprompt, node_ids, is_changed_cache):
         self.dynprompt = dynprompt
@@ -196,18 +199,138 @@ class BasicCache:
     def poll(self, **kwargs):
         pass
 
-    def _set_immediate(self, node_id, value):
-        assert self.initialized
-        cache_key = self.cache_key_set.get_data_key(node_id)
-        self.cache[cache_key] = value
-
-    def _get_immediate(self, node_id):
+    def get_local(self, node_id):
         if not self.initialized:
             return None
         cache_key = self.cache_key_set.get_data_key(node_id)
         if cache_key in self.cache:
             return self.cache[cache_key]
-        else:
+        return None
+
+    def set_local(self, node_id, value):
+        assert self.initialized
+        cache_key = self.cache_key_set.get_data_key(node_id)
+        self.cache[cache_key] = value
+
+    async def _set_immediate(self, node_id, value):
+        assert self.initialized
+        cache_key = self.cache_key_set.get_data_key(node_id)
+        self.cache[cache_key] = value
+
+        await self._notify_providers_store(node_id, cache_key, value)
+
+    async def _get_immediate(self, node_id):
+        if not self.initialized:
+            return None
+        cache_key = self.cache_key_set.get_data_key(node_id)
+
+        if cache_key in self.cache:
+            return self.cache[cache_key]
+
+        external_result = await self._check_providers_lookup(node_id, cache_key)
+        if external_result is not None:
+            self.cache[cache_key] = external_result
+            return external_result
+
+        return None
+
+    async def _notify_providers_store(self, node_id, cache_key, value):
+        from comfy_execution.cache_provider import (
+            _has_cache_providers, _get_cache_providers,
+            CacheValue, _contains_self_unequal, _logger
+        )
+
+        if not self.enable_providers:
+            return
+        if not _has_cache_providers():
+            return
+        if not self._is_external_cacheable_value(value):
+            return
+        if _contains_self_unequal(cache_key):
+            return
+
+        context = self._build_context(node_id, cache_key)
+        if context is None:
+            return
+        cache_value = CacheValue(outputs=value.outputs, ui=value.ui)
+
+        for provider in _get_cache_providers():
+            try:
+                if provider.should_cache(context, cache_value):
+                    task = asyncio.create_task(self._safe_provider_store(provider, context, cache_value))
+                    self._pending_store_tasks.add(task)
+                    task.add_done_callback(self._pending_store_tasks.discard)
+            except Exception as e:
+                _logger.warning(f"Cache provider {provider.__class__.__name__} error on store: {e}")
+
+    @staticmethod
+    async def _safe_provider_store(provider, context, cache_value):
+        from comfy_execution.cache_provider import _logger
+        try:
+            await provider.on_store(context, cache_value)
+        except Exception as e:
+            _logger.warning(f"Cache provider {provider.__class__.__name__} async store error: {e}")
+
+    async def _check_providers_lookup(self, node_id, cache_key):
+        from comfy_execution.cache_provider import (
+            _has_cache_providers, _get_cache_providers,
+            CacheValue, _contains_self_unequal, _logger
+        )
+
+        if not self.enable_providers:
+            return None
+        if not _has_cache_providers():
+            return None
+        if _contains_self_unequal(cache_key):
+            return None
+
+        context = self._build_context(node_id, cache_key)
+        if context is None:
+            return None
+
+        for provider in _get_cache_providers():
+            try:
+                if not provider.should_cache(context):
+                    continue
+                result = await provider.on_lookup(context)
+                if result is not None:
+                    if not isinstance(result, CacheValue):
+                        _logger.warning(f"Provider {provider.__class__.__name__} returned invalid type")
+                        continue
+                    if not isinstance(result.outputs, (list, tuple)):
+                        _logger.warning(f"Provider {provider.__class__.__name__} returned invalid outputs")
+                        continue
+                    from execution import CacheEntry
+                    return CacheEntry(ui=result.ui, outputs=list(result.outputs))
+            except Exception as e:
+                _logger.warning(f"Cache provider {provider.__class__.__name__} error on lookup: {e}")
+
+        return None
+
+    def _is_external_cacheable_value(self, value):
+        return hasattr(value, 'outputs') and hasattr(value, 'ui')
+
+    def _get_class_type(self, node_id):
+        if not self.initialized or not self.dynprompt:
+            return ''
+        try:
+            return self.dynprompt.get_node(node_id).get('class_type', '')
+        except Exception:
+            return ''
+
+    def _build_context(self, node_id, cache_key):
+        from comfy_execution.cache_provider import CacheContext, _serialize_cache_key, _logger
+        try:
+            cache_key_hash = _serialize_cache_key(cache_key)
+            if cache_key_hash is None:
+                return None
+            return CacheContext(
+                node_id=node_id,
+                class_type=self._get_class_type(node_id),
+                cache_key_hash=cache_key_hash,
+            )
+        except Exception as e:
+            _logger.warning(f"Failed to build cache context for node {node_id}: {e}")
             return None
 
     async def _ensure_subcache(self, node_id, children_ids):
@@ -236,8 +359,8 @@ class BasicCache:
         return result
 
 class HierarchicalCache(BasicCache):
-    def __init__(self, key_class):
-        super().__init__(key_class)
+    def __init__(self, key_class, enable_providers=False):
+        super().__init__(key_class, enable_providers=enable_providers)
 
     def _get_cache_for(self, node_id):
         assert self.dynprompt is not None
@@ -257,16 +380,27 @@ class HierarchicalCache(BasicCache):
                 return None
         return cache
 
-    def get(self, node_id):
+    async def get(self, node_id):
         cache = self._get_cache_for(node_id)
         if cache is None:
             return None
-        return cache._get_immediate(node_id)
+        return await cache._get_immediate(node_id)
 
-    def set(self, node_id, value):
+    def get_local(self, node_id):
+        cache = self._get_cache_for(node_id)
+        if cache is None:
+            return None
+        return BasicCache.get_local(cache, node_id)
+
+    async def set(self, node_id, value):
         cache = self._get_cache_for(node_id)
         assert cache is not None
-        cache._set_immediate(node_id, value)
+        await cache._set_immediate(node_id, value)
+
+    def set_local(self, node_id, value):
+        cache = self._get_cache_for(node_id)
+        assert cache is not None
+        BasicCache.set_local(cache, node_id, value)
 
     async def ensure_subcache_for(self, node_id, children_ids):
         cache = self._get_cache_for(node_id)
@@ -287,18 +421,24 @@ class NullCache:
     def poll(self, **kwargs):
         pass
 
-    def get(self, node_id):
+    async def get(self, node_id):
         return None
 
-    def set(self, node_id, value):
+    def get_local(self, node_id):
+        return None
+
+    async def set(self, node_id, value):
+        pass
+
+    def set_local(self, node_id, value):
         pass
 
     async def ensure_subcache_for(self, node_id, children_ids):
         return self
 
 class LRUCache(BasicCache):
-    def __init__(self, key_class, max_size=100):
-        super().__init__(key_class)
+    def __init__(self, key_class, max_size=100, enable_providers=False):
+        super().__init__(key_class, enable_providers=enable_providers)
         self.max_size = max_size
         self.min_generation = 0
         self.generation = 0
@@ -322,18 +462,18 @@ class LRUCache(BasicCache):
                     del self.children[key]
         self._clean_subcaches()
 
-    def get(self, node_id):
+    async def get(self, node_id):
         self._mark_used(node_id)
-        return self._get_immediate(node_id)
+        return await self._get_immediate(node_id)
 
     def _mark_used(self, node_id):
         cache_key = self.cache_key_set.get_data_key(node_id)
         if cache_key is not None:
             self.used_generation[cache_key] = self.generation
 
-    def set(self, node_id, value):
+    async def set(self, node_id, value):
         self._mark_used(node_id)
-        return self._set_immediate(node_id, value)
+        return await self._set_immediate(node_id, value)
 
     async def ensure_subcache_for(self, node_id, children_ids):
         # Just uses subcaches for tracking 'live' nodes
@@ -366,20 +506,20 @@ RAM_CACHE_OLD_WORKFLOW_OOM_MULTIPLIER = 1.3
 
 class RAMPressureCache(LRUCache):
 
-    def __init__(self, key_class):
-        super().__init__(key_class, 0)
+    def __init__(self, key_class, enable_providers=False):
+        super().__init__(key_class, 0, enable_providers=enable_providers)
         self.timestamps = {}
 
     def clean_unused(self):
         self._clean_subcaches()
 
-    def set(self, node_id, value):
+    async def set(self, node_id, value):
         self.timestamps[self.cache_key_set.get_data_key(node_id)] = time.time()
-        super().set(node_id, value)
+        await super().set(node_id, value)
 
-    def get(self, node_id):
+    async def get(self, node_id):
         self.timestamps[self.cache_key_set.get_data_key(node_id)] = time.time()
-        return super().get(node_id)
+        return await super().get(node_id)
 
     def poll(self, ram_headroom):
         def _ram_gb():

comfy_execution/graph.py

@@ -204,12 +204,12 @@ class ExecutionList(TopologicalSort):
         self.execution_cache_listeners = {}
 
     def is_cached(self, node_id):
-        return self.output_cache.get(node_id) is not None
+        return self.output_cache.get_local(node_id) is not None
 
     def cache_link(self, from_node_id, to_node_id):
         if to_node_id not in self.execution_cache:
             self.execution_cache[to_node_id] = {}
-        self.execution_cache[to_node_id][from_node_id] = self.output_cache.get(from_node_id)
+        self.execution_cache[to_node_id][from_node_id] = self.output_cache.get_local(from_node_id)
         if from_node_id not in self.execution_cache_listeners:
             self.execution_cache_listeners[from_node_id] = set()
         self.execution_cache_listeners[from_node_id].add(to_node_id)
@@ -221,7 +221,7 @@ class ExecutionList(TopologicalSort):
         if value is None:
             return None
         #Write back to the main cache on touch.
-        self.output_cache.set(from_node_id, value)
+        self.output_cache.set_local(from_node_id, value)
         return value
 
     def cache_update(self, node_id, value):

execution.py

@@ -40,6 +40,7 @@ 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
 
 
 class ExecutionResult(Enum):
@@ -81,7 +82,7 @@ class IsChangedCache:
             return self.is_changed[node_id]
 
         # Intentionally do not use cached outputs here. We only want constants in IS_CHANGED
-        input_data_all, _, v3_data = get_input_data(node["inputs"], class_def, node_id, None)
+        input_data_all, _, v3_data, _ = get_input_data(node["inputs"], class_def, node_id, None)
         try:
             is_changed = await _async_map_node_over_list(self.prompt_id, node_id, class_def, input_data_all, is_changed_name, v3_data=v3_data)
             is_changed = await resolve_map_node_over_list_results(is_changed)
@@ -126,15 +127,15 @@ class CacheSet:
 
     # Performs like the old cache -- dump data ASAP
     def init_classic_cache(self):
-        self.outputs = HierarchicalCache(CacheKeySetInputSignature)
+        self.outputs = HierarchicalCache(CacheKeySetInputSignature, enable_providers=True)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_lru_cache(self, cache_size):
-        self.outputs = LRUCache(CacheKeySetInputSignature, max_size=cache_size)
+        self.outputs = LRUCache(CacheKeySetInputSignature, max_size=cache_size, enable_providers=True)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_ram_cache(self, min_headroom):
-        self.outputs = RAMPressureCache(CacheKeySetInputSignature)
+        self.outputs = RAMPressureCache(CacheKeySetInputSignature, enable_providers=True)
         self.objects = HierarchicalCache(CacheKeySetID)
 
     def init_null_cache(self):
@@ -213,7 +214,35 @@ def get_input_data(inputs, class_def, unique_id, execution_list=None, dynprompt=
                 if h[x] == "API_KEY_COMFY_ORG":
                     input_data_all[x] = [extra_data.get("api_key_comfy_org", None)]
     v3_data["hidden_inputs"] = hidden_inputs_v3
-    return input_data_all, missing_keys, v3_data
+    return input_data_all, missing_keys, v3_data, valid_inputs
+
+def validate_resolved_inputs(input_data_all, class_def, valid_inputs):
+    """Validate resolved input values against schema constraints.
+
+    This is needed because validate_inputs() only sees direct widget values.
+    Linked inputs aren't resolved during validate_inputs(), so this runs after resolution to catch any violations.
+    """
+    for x, values in input_data_all.items():
+        input_type, input_category, extra_info = get_input_info(class_def, x, valid_inputs)
+        if input_type != "STRING":
+            continue
+        min_length = extra_info.get("minLength")
+        max_length = extra_info.get("maxLength")
+        if min_length is None and max_length is None:
+            continue
+        for val in values:
+            if val is None or not isinstance(val, str):
+                continue
+            if min_length is not None and len(val) < min_length:
+                raise ValueError(
+                    f"Input '{x}': value length {len(val)} is shorter than "
+                    f"minimum length of {min_length}"
+                )
+            if max_length is not None and len(val) > max_length:
+                raise ValueError(
+                    f"Input '{x}': value length {len(val)} is longer than "
+                    f"maximum length of {max_length}"
+                )
 
 map_node_over_list = None #Don't hook this please
 
@@ -418,7 +447,7 @@ 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 = caches.outputs.get(unique_id)
+    cached = await caches.outputs.get(unique_id)
     if cached is not None:
         if server.client_id is not None:
             cached_ui = cached.ui or {}
@@ -469,15 +498,15 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
             has_subgraph = False
         else:
             get_progress_state().start_progress(unique_id)
-            input_data_all, missing_keys, v3_data = get_input_data(inputs, class_def, unique_id, execution_list, dynprompt, extra_data)
+            input_data_all, missing_keys, v3_data, valid_inputs = get_input_data(inputs, class_def, unique_id, execution_list, dynprompt, extra_data)
             if server.client_id is not None:
                 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 = caches.objects.get(unique_id)
+            obj = await caches.objects.get(unique_id)
             if obj is None:
                 obj = class_def()
-                caches.objects.set(unique_id, obj)
+                await 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
@@ -498,6 +527,8 @@ async def execute(server, dynprompt, caches, current_item, extra_data, executed,
                         execution_list.make_input_strong_link(unique_id, i)
                     return (ExecutionResult.PENDING, None, None)
 
+            validate_resolved_inputs(input_data_all, class_def, valid_inputs)
+
             def execution_block_cb(block):
                 if block.message is not None:
                     mes = {
@@ -588,7 +619,7 @@ 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)
-        caches.outputs.set(unique_id, cache_entry)
+        await caches.outputs.set(unique_id, cache_entry)
 
     except comfy.model_management.InterruptProcessingException as iex:
         logging.info("Processing interrupted")
@@ -684,6 +715,19 @@ 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))
 
@@ -700,66 +744,75 @@ class PromptExecutor:
         self.status_messages = []
         self.add_message("execution_start", { "prompt_id": prompt_id}, broadcast=False)
 
-        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()
+        self._notify_prompt_lifecycle("start", prompt_id)
 
-            cached_nodes = []
-            for node_id in prompt:
-                if self.caches.outputs.get(node_id) is not None:
-                    cached_nodes.append(node_id)
+        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()
 
-            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)
+                node_ids = list(prompt.keys())
+                cache_results = await asyncio.gather(
+                    *(self.caches.outputs.get(node_id) for node_id in node_ids)
+                )
+                cached_nodes = [
+                    node_id for node_id, result in zip(node_ids, cache_results)
+                    if result is not None
+                ]
 
-            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
+                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)
 
-                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
 
-            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()
+                    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)
 
 
 async def validate_inputs(prompt_id, prompt, item, validated):
@@ -940,6 +993,34 @@ async def validate_inputs(prompt_id, prompt, item, validated):
                     errors.append(error)
                     continue
 
+                if input_type == "STRING":
+                    if "minLength" in extra_info and len(val) < extra_info["minLength"]:
+                        error = {
+                            "type": "value_shorter_than_min_length",
+                            "message": "Value length {} shorter than min length of {}".format(len(val), extra_info["minLength"]),
+                            "details": f"{x}",
+                            "extra_info": {
+                                "input_name": x,
+                                "input_config": info,
+                                "received_value": val,
+                            }
+                        }
+                        errors.append(error)
+                        continue
+                    if "maxLength" in extra_info and len(val) > extra_info["maxLength"]:
+                        error = {
+                            "type": "value_longer_than_max_length",
+                            "message": "Value length {} longer than max length of {}".format(len(val), extra_info["maxLength"]),
+                            "details": f"{x}",
+                            "extra_info": {
+                                "input_name": x,
+                                "input_config": info,
+                                "received_value": val,
+                            }
+                        }
+                        errors.append(error)
+                        continue
+
                 if isinstance(input_type, list) or input_type == io.Combo.io_type:
                     if input_type == io.Combo.io_type:
                         combo_options = extra_info.get("options", [])
@@ -971,7 +1052,7 @@ async def validate_inputs(prompt_id, prompt, item, validated):
                         continue
 
     if len(validate_function_inputs) > 0 or validate_has_kwargs:
-        input_data_all, _, v3_data = get_input_data(inputs, obj_class, unique_id)
+        input_data_all, _, v3_data, _ = get_input_data(inputs, obj_class, unique_id)
         input_filtered = {}
         for x in input_data_all:
             if x in validate_function_inputs or validate_has_kwargs:

manager_requirements.txt

@@ -1 +1 @@
-comfyui_manager==4.1b2
+comfyui_manager==4.1b4

requirements.txt

@@ -1,4 +1,4 @@
-comfyui-frontend-package==1.41.18
+comfyui-frontend-package==1.41.19
 comfyui-workflow-templates==0.9.21
 comfyui-embedded-docs==0.4.3
 torch
@@ -23,7 +23,7 @@ SQLAlchemy
 filelock
 av>=14.2.0
 comfy-kitchen>=0.2.8
-comfy-aimdo>=0.2.10
+comfy-aimdo>=0.2.11
 requests
 simpleeval>=1.0.0
 blake3

tests-unit/execution_test/test_cache_provider.py

@@ -0,0 +1,403 @@
+"""Tests for external cache provider API."""
+
+import importlib.util
+import pytest
+from typing import Optional
+
+
+def _torch_available() -> bool:
+    """Check if PyTorch is available."""
+    return importlib.util.find_spec("torch") is not None
+
+
+from comfy_execution.cache_provider import (
+    CacheProvider,
+    CacheContext,
+    CacheValue,
+    register_cache_provider,
+    unregister_cache_provider,
+    _get_cache_providers,
+    _has_cache_providers,
+    _clear_cache_providers,
+    _serialize_cache_key,
+    _contains_self_unequal,
+    _estimate_value_size,
+    _canonicalize,
+)
+
+
+class TestCanonicalize:
+    """Test _canonicalize function for deterministic ordering."""
+
+    def test_frozenset_ordering_is_deterministic(self):
+        """Frozensets should produce consistent canonical form regardless of iteration order."""
+        # Create two frozensets with same content
+        fs1 = frozenset([("a", 1), ("b", 2), ("c", 3)])
+        fs2 = frozenset([("c", 3), ("a", 1), ("b", 2)])
+
+        result1 = _canonicalize(fs1)
+        result2 = _canonicalize(fs2)
+
+        assert result1 == result2
+
+    def test_nested_frozenset_ordering(self):
+        """Nested frozensets should also be deterministically ordered."""
+        inner1 = frozenset([1, 2, 3])
+        inner2 = frozenset([3, 2, 1])
+
+        fs1 = frozenset([("key", inner1)])
+        fs2 = frozenset([("key", inner2)])
+
+        result1 = _canonicalize(fs1)
+        result2 = _canonicalize(fs2)
+
+        assert result1 == result2
+
+    def test_dict_ordering(self):
+        """Dicts should be sorted by key."""
+        d1 = {"z": 1, "a": 2, "m": 3}
+        d2 = {"a": 2, "m": 3, "z": 1}
+
+        result1 = _canonicalize(d1)
+        result2 = _canonicalize(d2)
+
+        assert result1 == result2
+
+    def test_tuple_preserved(self):
+        """Tuples should be marked and preserved."""
+        t = (1, 2, 3)
+        result = _canonicalize(t)
+
+        assert result[0] == "__tuple__"
+
+    def test_list_preserved(self):
+        """Lists should be recursively canonicalized."""
+        lst = [{"b": 2, "a": 1}, frozenset([3, 2, 1])]
+        result = _canonicalize(lst)
+
+        # First element should be canonicalized dict
+        assert "__dict__" in result[0]
+        # Second element should be canonicalized frozenset
+        assert result[1][0] == "__frozenset__"
+
+    def test_primitives_include_type(self):
+        """Primitive types should include type name for disambiguation."""
+        assert _canonicalize(42) == ("int", 42)
+        assert _canonicalize(3.14) == ("float", 3.14)
+        assert _canonicalize("hello") == ("str", "hello")
+        assert _canonicalize(True) == ("bool", True)
+        assert _canonicalize(None) == ("NoneType", None)
+
+    def test_int_and_str_distinguished(self):
+        """int 7 and str '7' must produce different canonical forms."""
+        assert _canonicalize(7) != _canonicalize("7")
+
+    def test_bytes_converted(self):
+        """Bytes should be converted to hex string."""
+        b = b"\x00\xff"
+        result = _canonicalize(b)
+
+        assert result[0] == "__bytes__"
+        assert result[1] == "00ff"
+
+    def test_set_ordering(self):
+        """Sets should be sorted like frozensets."""
+        s1 = {3, 1, 2}
+        s2 = {1, 2, 3}
+
+        result1 = _canonicalize(s1)
+        result2 = _canonicalize(s2)
+
+        assert result1 == result2
+        assert result1[0] == "__set__"
+
+    def test_unknown_type_raises(self):
+        """Unknown types should raise ValueError (fail-closed)."""
+        class CustomObj:
+            pass
+        with pytest.raises(ValueError):
+            _canonicalize(CustomObj())
+
+    def test_object_with_value_attr_raises(self):
+        """Objects with .value attribute (Unhashable-like) should raise ValueError."""
+        class FakeUnhashable:
+            def __init__(self):
+                self.value = float('nan')
+        with pytest.raises(ValueError):
+            _canonicalize(FakeUnhashable())
+
+
+class TestSerializeCacheKey:
+    """Test _serialize_cache_key for deterministic hashing."""
+
+    def test_same_content_same_hash(self):
+        """Same content should produce same hash."""
+        key1 = frozenset([("node_1", frozenset([("input", "value")]))])
+        key2 = frozenset([("node_1", frozenset([("input", "value")]))])
+
+        hash1 = _serialize_cache_key(key1)
+        hash2 = _serialize_cache_key(key2)
+
+        assert hash1 == hash2
+
+    def test_different_content_different_hash(self):
+        """Different content should produce different hash."""
+        key1 = frozenset([("node_1", "value_a")])
+        key2 = frozenset([("node_1", "value_b")])
+
+        hash1 = _serialize_cache_key(key1)
+        hash2 = _serialize_cache_key(key2)
+
+        assert hash1 != hash2
+
+    def test_returns_hex_string(self):
+        """Should return hex string (SHA256 hex digest)."""
+        key = frozenset([("test", 123)])
+        result = _serialize_cache_key(key)
+
+        assert isinstance(result, str)
+        assert len(result) == 64  # SHA256 hex digest is 64 chars
+
+    def test_complex_nested_structure(self):
+        """Complex nested structures should hash deterministically."""
+        # Note: frozensets can only contain hashable types, so we use
+        # nested frozensets of tuples to represent dict-like structures
+        key = frozenset([
+            ("node_1", frozenset([
+                ("input_a", ("tuple", "value")),
+                ("input_b", frozenset([("nested", "dict")])),
+            ])),
+            ("node_2", frozenset([
+                ("param", 42),
+            ])),
+        ])
+
+        # Hash twice to verify determinism
+        hash1 = _serialize_cache_key(key)
+        hash2 = _serialize_cache_key(key)
+
+        assert hash1 == hash2
+
+    def test_dict_in_cache_key(self):
+        """Dicts passed directly to _serialize_cache_key should work."""
+        key = {"node_1": {"input": "value"}, "node_2": 42}
+
+        hash1 = _serialize_cache_key(key)
+        hash2 = _serialize_cache_key(key)
+
+        assert hash1 == hash2
+        assert isinstance(hash1, str)
+        assert len(hash1) == 64
+
+    def test_unknown_type_returns_none(self):
+        """Non-cacheable types should return None (fail-closed)."""
+        class CustomObj:
+            pass
+        assert _serialize_cache_key(CustomObj()) is None
+
+
+class TestContainsSelfUnequal:
+    """Test _contains_self_unequal utility function."""
+
+    def test_nan_float_detected(self):
+        """NaN floats should be detected (not equal to itself)."""
+        assert _contains_self_unequal(float('nan')) is True
+
+    def test_regular_float_not_detected(self):
+        """Regular floats are equal to themselves."""
+        assert _contains_self_unequal(3.14) is False
+        assert _contains_self_unequal(0.0) is False
+        assert _contains_self_unequal(-1.5) is False
+
+    def test_infinity_not_detected(self):
+        """Infinity is equal to itself."""
+        assert _contains_self_unequal(float('inf')) is False
+        assert _contains_self_unequal(float('-inf')) is False
+
+    def test_nan_in_list(self):
+        """NaN in list should be detected."""
+        assert _contains_self_unequal([1, 2, float('nan'), 4]) is True
+        assert _contains_self_unequal([1, 2, 3, 4]) is False
+
+    def test_nan_in_tuple(self):
+        """NaN in tuple should be detected."""
+        assert _contains_self_unequal((1, float('nan'))) is True
+        assert _contains_self_unequal((1, 2, 3)) is False
+
+    def test_nan_in_frozenset(self):
+        """NaN in frozenset should be detected."""
+        assert _contains_self_unequal(frozenset([1, float('nan')])) is True
+        assert _contains_self_unequal(frozenset([1, 2, 3])) is False
+
+    def test_nan_in_dict_value(self):
+        """NaN in dict value should be detected."""
+        assert _contains_self_unequal({"key": float('nan')}) is True
+        assert _contains_self_unequal({"key": 42}) is False
+
+    def test_nan_in_nested_structure(self):
+        """NaN in deeply nested structure should be detected."""
+        nested = {"level1": [{"level2": (1, 2, float('nan'))}]}
+        assert _contains_self_unequal(nested) is True
+
+    def test_non_numeric_types(self):
+        """Non-numeric types should not be self-unequal."""
+        assert _contains_self_unequal("string") is False
+        assert _contains_self_unequal(None) is False
+        assert _contains_self_unequal(True) is False
+
+    def test_object_with_nan_value_attribute(self):
+        """Objects wrapping NaN in .value should be detected."""
+        class NanWrapper:
+            def __init__(self):
+                self.value = float('nan')
+        assert _contains_self_unequal(NanWrapper()) is True
+
+    def test_custom_self_unequal_object(self):
+        """Custom objects where not (x == x) should be detected."""
+        class NeverEqual:
+            def __eq__(self, other):
+                return False
+        assert _contains_self_unequal(NeverEqual()) is True
+
+
+class TestEstimateValueSize:
+    """Test _estimate_value_size utility function."""
+
+    def test_empty_outputs(self):
+        """Empty outputs should have zero size."""
+        value = CacheValue(outputs=[])
+        assert _estimate_value_size(value) == 0
+
+    @pytest.mark.skipif(
+        not _torch_available(),
+        reason="PyTorch not available"
+    )
+    def test_tensor_size_estimation(self):
+        """Tensor size should be estimated correctly."""
+        import torch
+
+        # 1000 float32 elements = 4000 bytes
+        tensor = torch.zeros(1000, dtype=torch.float32)
+        value = CacheValue(outputs=[[tensor]])
+
+        size = _estimate_value_size(value)
+        assert size == 4000
+
+    @pytest.mark.skipif(
+        not _torch_available(),
+        reason="PyTorch not available"
+    )
+    def test_nested_tensor_in_dict(self):
+        """Tensors nested in dicts should be counted."""
+        import torch
+
+        tensor = torch.zeros(100, dtype=torch.float32)  # 400 bytes
+        value = CacheValue(outputs=[[{"samples": tensor}]])
+
+        size = _estimate_value_size(value)
+        assert size == 400
+
+
+class TestProviderRegistry:
+    """Test cache provider registration and retrieval."""
+
+    def setup_method(self):
+        """Clear providers before each test."""
+        _clear_cache_providers()
+
+    def teardown_method(self):
+        """Clear providers after each test."""
+        _clear_cache_providers()
+
+    def test_register_provider(self):
+        """Provider should be registered successfully."""
+        provider = MockCacheProvider()
+        register_cache_provider(provider)
+
+        assert _has_cache_providers() is True
+        providers = _get_cache_providers()
+        assert len(providers) == 1
+        assert providers[0] is provider
+
+    def test_unregister_provider(self):
+        """Provider should be unregistered successfully."""
+        provider = MockCacheProvider()
+        register_cache_provider(provider)
+        unregister_cache_provider(provider)
+
+        assert _has_cache_providers() is False
+
+    def test_multiple_providers(self):
+        """Multiple providers can be registered."""
+        provider1 = MockCacheProvider()
+        provider2 = MockCacheProvider()
+
+        register_cache_provider(provider1)
+        register_cache_provider(provider2)
+
+        providers = _get_cache_providers()
+        assert len(providers) == 2
+
+    def test_duplicate_registration_ignored(self):
+        """Registering same provider twice should be ignored."""
+        provider = MockCacheProvider()
+
+        register_cache_provider(provider)
+        register_cache_provider(provider)  # Should be ignored
+
+        providers = _get_cache_providers()
+        assert len(providers) == 1
+
+    def test_clear_providers(self):
+        """_clear_cache_providers should remove all providers."""
+        provider1 = MockCacheProvider()
+        provider2 = MockCacheProvider()
+
+        register_cache_provider(provider1)
+        register_cache_provider(provider2)
+        _clear_cache_providers()
+
+        assert _has_cache_providers() is False
+        assert len(_get_cache_providers()) == 0
+
+
+class TestCacheContext:
+    """Test CacheContext dataclass."""
+
+    def test_context_creation(self):
+        """CacheContext should be created with all fields."""
+        context = CacheContext(
+            node_id="node-456",
+            class_type="KSampler",
+            cache_key_hash="a" * 64,
+        )
+
+        assert context.node_id == "node-456"
+        assert context.class_type == "KSampler"
+        assert context.cache_key_hash == "a" * 64
+
+
+class TestCacheValue:
+    """Test CacheValue dataclass."""
+
+    def test_value_creation(self):
+        """CacheValue should be created with outputs."""
+        outputs = [[{"samples": "tensor_data"}]]
+        value = CacheValue(outputs=outputs)
+
+        assert value.outputs == outputs
+
+
+class MockCacheProvider(CacheProvider):
+    """Mock cache provider for testing."""
+
+    def __init__(self):
+        self.lookups = []
+        self.stores = []
+
+    async def on_lookup(self, context: CacheContext) -> Optional[CacheValue]:
+        self.lookups.append(context)
+        return None
+
+    async def on_store(self, context: CacheContext, value: CacheValue) -> None:
+        self.stores.append((context, value))

tests/execution/test_execution.py

@@ -1011,3 +1011,49 @@ class TestExecution:
         """Test getting a non-existent job returns 404"""
         job = client.get_job("nonexistent-job-id")
         assert job is None, "Non-existent job should return None"
+
+
+    @pytest.mark.parametrize("text, expect_error", [
+        ("hello", False),       # 5 chars, within [3, 10]
+        ("abc", False),         # 3 chars, exact min boundary
+        ("abcdefghij", False),  # 10 chars, exact max boundary
+        ("ab", True),           # 2 chars, below min
+        ("abcdefghijk", True),  # 11 chars, above max
+        ("", True),             # 0 chars, below min
+    ])
+    def test_string_length_widget_validation(self, text, expect_error, client: ComfyClient, builder: GraphBuilder):
+        """Test minLength/maxLength validation for direct widget values (validate_inputs path)."""
+        g = builder
+        node = g.node("StubStringWithLength", text=text)
+        g.node("SaveImage", images=node.out(0))
+        if expect_error:
+            with pytest.raises(urllib.error.HTTPError) as exc_info:
+                client.run(g)
+            assert exc_info.value.code == 400
+        else:
+            client.run(g)
+
+
+    @pytest.mark.parametrize("text, expect_error", [
+        ("hello", False),       # 5 chars, within [3, 10]
+        ("abc", False),         # 3 chars, exact min boundary
+        ("abcdefghij", False),  # 10 chars, exact max boundary
+        ("ab", True),           # 2 chars, below min
+        ("abcdefghijk", True),  # 11 chars, above max
+        ("", True),             # 0 chars, below min
+    ])
+    def test_string_length_linked_validation(self, text, expect_error, client: ComfyClient, builder: GraphBuilder):
+        """Test minLength/maxLength validation for linked inputs (validate_resolved_inputs path)."""
+        g = builder
+        str_node = g.node("StubStringOutput", value=text)
+        node = g.node("StubStringWithLength", text=str_node.out(0))
+        g.node("SaveImage", images=node.out(0))
+
+        if expect_error:
+            try:
+                client.run(g)
+                assert False, "Should have raised an error"
+            except Exception as e:
+                assert 'prompt_id' in e.args[0], f"Did not get proper error message: {e}"
+        else:
+            client.run(g)

tests/execution/testing_nodes/testing-pack/stubs.py

@@ -113,12 +113,48 @@ class StubFloat:
     def stub_float(self, value):
         return (value,)
 
+class StubStringOutput:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "value": ("STRING", {"default": ""}),
+            },
+        }
+
+    RETURN_TYPES = ("STRING",)
+    FUNCTION = "stub_string"
+
+    CATEGORY = "Testing/Stub Nodes"
+
+    def stub_string(self, value):
+        return (value,)
+
+class StubStringWithLength:
+    @classmethod
+    def INPUT_TYPES(cls):
+        return {
+            "required": {
+                "text": ("STRING", {"default": "hello", "minLength": 3, "maxLength": 10}),
+            },
+        }
+
+    RETURN_TYPES = ("IMAGE",)
+    FUNCTION = "stub_string_with_length"
+
+    CATEGORY = "Testing/Stub Nodes"
+
+    def stub_string_with_length(self, text):
+        return (torch.zeros(1, 64, 64, 3),)
+
 TEST_STUB_NODE_CLASS_MAPPINGS = {
     "StubImage": StubImage,
     "StubConstantImage": StubConstantImage,
     "StubMask": StubMask,
     "StubInt": StubInt,
     "StubFloat": StubFloat,
+    "StubStringOutput": StubStringOutput,
+    "StubStringWithLength": StubStringWithLength,
 }
 TEST_STUB_NODE_DISPLAY_NAME_MAPPINGS = {
     "StubImage": "Stub Image",
@@ -126,4 +162,6 @@ TEST_STUB_NODE_DISPLAY_NAME_MAPPINGS = {
     "StubMask": "Stub Mask",
     "StubInt": "Stub Int",
     "StubFloat": "Stub Float",
+    "StubStringOutput": "Stub String Output",
+    "StubStringWithLength": "Stub String With Length",
 }