fix(evo1): move LIBERO padding into policy processors

docs/source/evo1.mdx

@@ -139,6 +139,8 @@ every finetuning flag.
 | `policy.n_action_steps`                       | `50`                     | Number of actions consumed from a sampled chunk                   |
 | `policy.max_state_dim`                        | `24`                     | State padding dimension                                           |
 | `policy.max_action_dim`                       | `24`                     | Action padding dimension                                          |
+| `policy.postprocess_action_dim`               | `null`                   | Optional action dimension returned after EVO1 postprocessing      |
+| `policy.binarize_gripper`                     | `false`                  | Binarizes the postprocessed gripper channel for LIBERO-style eval |
 | `policy.task_field`                           | `task`                   | Batch field used as the language prompt                           |
 
 ## Results
@@ -161,16 +163,20 @@ pixel embeddings, VLM fused tokens, normalized actions, and denormalized actions
 The published checkpoint expects the raw LIBERO camera feature names
 `observation.images.agentview_image` and `observation.images.robot0_eye_in_hand_image`. The official EVO1 LIBERO
 rollout protocol also replans every 14 actions and binarizes the gripper command before stepping the simulator.
-The LIBERO environment postprocessor applies the gripper binarization automatically for EVO1 policies. To run the
-converted checkpoint with LeRobot LIBERO evaluation for the same one-episode-per-task setting, keep the raw camera
-names instead of the default `image`/`image2` mapping and override `policy.n_action_steps` to 14:
+The EVO1 policy postprocessor can crop the padded 24D action back to the 7D LIBERO action space and apply that
+gripper binarization. To run the converted checkpoint with LeRobot LIBERO evaluation for the same
+one-episode-per-task setting, keep the raw camera names instead of the default `image`/`image2` mapping, enable
+FlashAttention, and set the LIBERO action postprocessing flags:
 
 ```bash
 lerobot-eval \
   --policy.path=javadcc/evo1-libero-lerobot \
   --policy.vlm_model_name=OpenGVLab/InternVL3-1B \
   --policy.device=cuda \
+  --policy.use_flash_attn=true \
   --policy.n_action_steps=14 \
+  --policy.postprocess_action_dim=7 \
+  --policy.binarize_gripper=true \
   --env.type=libero \
   --env.task=libero_object \
   --env.camera_name_mapping="{agentview_image: agentview_image, robot0_eye_in_hand_image: robot0_eye_in_hand_image}" \

pyproject.toml

@@ -140,6 +140,7 @@ pyserial-dep = ["pyserial>=3.5,<4.0"]
 deepdiff-dep = ["deepdiff>=7.0.1,<9.0.0"]
 pynput-dep = ["pynput>=1.7.8,<1.9.0"]
 pyzmq-dep = ["pyzmq>=26.2.1,<28.0.0"]
+timm-dep = ["timm>=1.0.0,<1.1.0"]
 
 # Motors
 feetech = ["feetech-servo-sdk>=1.0.0,<2.0.0", "lerobot[pyserial-dep]", "lerobot[deepdiff-dep]"]
@@ -187,7 +188,7 @@ groot = [
     "lerobot[peft-dep]",
     "lerobot[diffusers-dep]",
     "dm-tree>=0.1.8,<1.0.0",
-    "timm>=1.0.0,<1.1.0",
+    "lerobot[timm-dep]",
     "decord>=0.6.0,<1.0.0; (platform_machine == 'AMD64' or platform_machine == 'x86_64')",
     "ninja>=1.11.1,<2.0.0",
     "flash-attn>=2.5.9,<3.0.0 ; sys_platform != 'darwin'"
@@ -195,7 +196,7 @@ groot = [
 sarm = ["lerobot[transformers-dep]", "pydantic>=2.0.0,<3.0.0", "faker>=33.0.0,<35.0.0", "lerobot[matplotlib-dep]", "lerobot[qwen-vl-utils-dep]"]
 xvla = ["lerobot[transformers-dep]"]
 eo1 = ["lerobot[transformers-dep]", "lerobot[qwen-vl-utils-dep]"]
-evo1 = ["lerobot[transformers-dep]", "timm>=1.0.0,<1.1.0"]
+evo1 = ["lerobot[transformers-dep]", "lerobot[timm-dep]"]
 hilserl = ["lerobot[transformers-dep]", "gym-hil>=0.1.13,<0.2.0", "lerobot[grpcio-dep]", "lerobot[placo-dep]"]
 
 # Features
@@ -350,7 +351,6 @@ ignore = [
 # E402: conditional-import guards (TYPE_CHECKING / is_package_available) must precede the imports they protect
 "src/lerobot/scripts/convert_dataset_v21_to_v30.py" = ["E402"]
 "src/lerobot/policies/wall_x/**" = ["N801", "N812", "SIM102", "SIM108", "SIM210", "SIM211", "B006", "B007", "SIM118"] # Supprese these as they are coming from original Qwen2_5_vl code TODO(pepijn): refactor original
-"src/lerobot/policies/evo1/**" = ["N801", "N812"]
 
 [tool.ruff.lint.isort]
 combine-as-imports = true

src/lerobot/envs/configs.py

@@ -26,7 +26,6 @@ from gymnasium.envs.registration import registry as gym_registry
 from lerobot.configs import FeatureType, PolicyFeature
 from lerobot.processor import (
     IsaaclabArenaProcessorStep,
-    LiberoActionProcessorStep,
     LiberoProcessorStep,
     PolicyProcessorPipeline,
 )
@@ -128,7 +127,7 @@ class EnvConfig(draccus.ChoiceRegistry, abc.ABC):
             vec = env_cls([_make_one for _ in range(n_envs)], **extra_kwargs)
         return {self.type: {0: vec}}
 
-    def get_env_processors(self, policy_cfg: Any | None = None):
+    def get_env_processors(self):
         """Return (preprocessor, postprocessor) for this env. Default: identity."""
         return PolicyProcessorPipeline(steps=[]), PolicyProcessorPipeline(steps=[])
 
@@ -357,7 +356,6 @@ class LiberoEnv(EnvConfig):
         }
     )
     control_mode: str = "relative"  # or "absolute"
-    binarize_gripper: bool | None = None
 
     def __post_init__(self):
         if self.obs_type == "pixels":
@@ -442,22 +440,10 @@ class LiberoEnv(EnvConfig):
             is_libero_plus=self.is_libero_plus,
         )
 
-    def get_env_processors(self, policy_cfg: Any | None = None):
-        is_evo1 = getattr(policy_cfg, "type", None) == "evo1"
-        max_state_dim = getattr(policy_cfg, "max_state_dim", None) if is_evo1 else None
-        action_feature = self.features.get(ACTION)
-        action_dim = int(action_feature.shape[0]) if action_feature is not None else 7
-        binarize_gripper = is_evo1 if self.binarize_gripper is None else self.binarize_gripper
+    def get_env_processors(self):
         return (
-            PolicyProcessorPipeline(steps=[LiberoProcessorStep(max_state_dim=max_state_dim)]),
-            PolicyProcessorPipeline(
-                steps=[
-                    LiberoActionProcessorStep(
-                        action_dim=action_dim,
-                        binarize_gripper=binarize_gripper,
-                    )
-                ]
-            ),
+            PolicyProcessorPipeline(steps=[LiberoProcessorStep()]),
+            PolicyProcessorPipeline(steps=[]),
         )
 
 
@@ -723,7 +709,7 @@ class IsaaclabArenaEnv(HubEnvConfig):
     def gym_kwargs(self) -> dict:
         return {}
 
-    def get_env_processors(self, policy_cfg: Any | None = None):
+    def get_env_processors(self):
         state_keys = tuple(k.strip() for k in (self.state_keys or "").split(",") if k.strip())
         camera_keys = tuple(k.strip() for k in (self.camera_keys or "").split(",") if k.strip())
         if not state_keys and not camera_keys:

src/lerobot/envs/factory.py

@@ -15,7 +15,6 @@
 # limitations under the License.
 from __future__ import annotations
 
-import inspect
 from typing import Any
 
 import gymnasium as gym
@@ -53,14 +52,7 @@ def make_env_pre_post_processors(
 
         return make_xvla_libero_pre_post_processors()
 
-    get_processors = env_cfg.get_env_processors
-    signature = inspect.signature(get_processors)
-    supports_policy_cfg = "policy_cfg" in signature.parameters or any(
-        param.kind is inspect.Parameter.VAR_KEYWORD for param in signature.parameters.values()
-    )
-    if supports_policy_cfg:
-        return get_processors(policy_cfg=policy_cfg)
-    return get_processors()
+    return env_cfg.get_env_processors()
 
 
 def make_env(

src/lerobot/policies/evo1/README.md

@@ -1 +0,0 @@
-../../../../docs/source/policy_evo1_README.md

src/lerobot/policies/evo1/README.md

@@ -0,0 +1,18 @@
+# EVO1
+
+EVO1 is a Vision-Language-Action policy for robot control. The LeRobot
+integration uses an InternVL3 vision-language backbone with a flow-matching
+action head, and supports staged training through the standard LeRobot policy
+APIs.
+
+The upstream EVO1 project is available at
+[MINT-SJTU/Evo-1](https://github.com/MINT-SJTU/Evo-1).
+
+```bibtex
+@misc{evo1,
+  title = {EVO1},
+  author = {{MINT-SJTU}},
+  year = {2026},
+  howpublished = {\url{https://github.com/MINT-SJTU/Evo-1}},
+}
+```

src/lerobot/policies/evo1/configuration_evo1.py

@@ -14,6 +14,7 @@
 
 from __future__ import annotations
 
+import logging
 import math
 from dataclasses import dataclass, field
 
@@ -26,6 +27,8 @@ from lerobot.optim.optimizers import AdamWConfig
 from lerobot.optim.schedulers import LRSchedulerConfig
 from lerobot.utils.constants import ACTION, OBS_IMAGES, OBS_STATE
 
+logger = logging.getLogger(__name__)
+
 
 @LRSchedulerConfig.register_subclass("evo1_exact")
 @dataclass
@@ -59,6 +62,12 @@ class Evo1Config(PreTrainedConfig):
     max_views: int = 3
     image_resolution: tuple[int, int] = (448, 448)
     empty_cameras: int = 0
+    postprocess_action_dim: int | None = None
+    binarize_gripper: bool = False
+    gripper_index: int = 6
+    gripper_threshold: float = 0.5
+    gripper_below_threshold_value: float = 1.0
+    gripper_above_threshold_value: float = -1.0
 
     normalization_mapping: dict[str, NormalizationMode] = field(
         default_factory=lambda: {
@@ -114,16 +123,32 @@ class Evo1Config(PreTrainedConfig):
             )
 
         if self.apply_training_stage_defaults:
-            if self.training_stage == "stage1":
-                self.finetune_vlm = False
-                self.finetune_language_model = False
-                self.finetune_vision_model = False
-                self.finetune_action_head = True
-            elif self.training_stage == "stage2":
-                self.finetune_vlm = True
-                self.finetune_language_model = True
-                self.finetune_vision_model = True
-                self.finetune_action_head = True
+            stage_defaults = {
+                "stage1": {
+                    "finetune_vlm": False,
+                    "finetune_language_model": False,
+                    "finetune_vision_model": False,
+                    "finetune_action_head": True,
+                },
+                "stage2": {
+                    "finetune_vlm": True,
+                    "finetune_language_model": True,
+                    "finetune_vision_model": True,
+                    "finetune_action_head": True,
+                },
+            }[self.training_stage]
+            for flag_name, default_value in stage_defaults.items():
+                current_value = getattr(self, flag_name)
+                if current_value is not None and current_value != default_value:
+                    logger.warning(
+                        "EVO1 %s=%s is overridden by training_stage=%s default %s. "
+                        "Set apply_training_stage_defaults=false to keep explicit finetuning flags.",
+                        flag_name,
+                        current_value,
+                        self.training_stage,
+                        default_value,
+                    )
+                setattr(self, flag_name, default_value)
         elif self.training_stage == "stage1":
             if self.finetune_vlm is None:
                 self.finetune_vlm = False
@@ -171,6 +196,11 @@ class Evo1Config(PreTrainedConfig):
             raise ValueError(
                 f"n_action_steps ({self.n_action_steps}) must be <= chunk_size ({self.chunk_size})"
             )
+        if len(self.image_resolution) != 2 or self.image_resolution[0] != self.image_resolution[1]:
+            raise ValueError(
+                "EVO1 currently expects a square image_resolution because InternVL3 preprocessing "
+                f"uses a scalar image_size, got {self.image_resolution}."
+            )
 
     def validate_features(self) -> None:
         if self.input_features is None:

src/lerobot/policies/evo1/evo1_model.py

@@ -21,8 +21,8 @@ import torch
 import torch.nn as nn
 from PIL import Image
 
-from lerobot.policies.evo1.flow_matching import FlowmatchingActionHead
-from lerobot.policies.evo1.internvl3_embedder import InternVL3Embedder
+from .flow_matching import FlowmatchingActionHead
+from .internvl3_embedder import InternVL3Embedder
 
 
 def _cfgget(config: Any, key: str, default=None):
@@ -163,37 +163,6 @@ class EVO1(nn.Module):
             embodiment_id=embodiment_ids,
         )
 
-    @torch.no_grad()
-    def run_inference(
-        self,
-        images: list[Image.Image | torch.Tensor],
-        image_mask: torch.Tensor,
-        prompt: str,
-        state_input: list | torch.Tensor,
-        return_cls_only: bool | None = None,
-        action_mask: torch.Tensor | None = None,
-        embodiment_ids: torch.Tensor | None = None,
-    ) -> torch.Tensor:
-        if image_mask.dim() == 1:
-            image_mask = image_mask.unsqueeze(0)
-
-        fused_tokens = self.get_vl_embeddings(
-            images=[images],
-            image_mask=image_mask,
-            prompt=[prompt],
-            return_cls_only=return_cls_only,
-        )
-        state_tensor = self.prepare_state(state_input)
-        action = self.predict_action(
-            fused_tokens,
-            state_tensor,
-            action_mask=action_mask,
-            embodiment_ids=embodiment_ids,
-        )
-        if isinstance(action, torch.Tensor) and action.dtype == torch.bfloat16:
-            action = action.to(torch.float32)
-        return action
-
     def forward(
         self,
         fused_tokens: torch.Tensor,

src/lerobot/policies/evo1/flow_matching.py

@@ -129,7 +129,10 @@ class MultiEmbodimentActionEncoder(nn.Module):
 
     def forward(self, action_seq: torch.Tensor, category_id: torch.LongTensor):
         batch_size, horizon, action_dim = action_seq.shape
-        assert self.horizon == horizon, "Action sequence length must match horizon"
+        if self.horizon != horizon:
+            raise ValueError(
+                f"Action sequence length must match horizon: got {horizon}, expected {self.horizon}."
+            )
 
         x = action_seq.reshape(batch_size * horizon, action_dim)
         if category_id.dim() == 0:

src/lerobot/policies/evo1/internvl3_embedder.py

@@ -24,7 +24,7 @@ from typing import TYPE_CHECKING
 import torch
 import torch.nn as nn
 import torch.utils.checkpoint
-import torchvision.transforms.functional as TF
+import torchvision.transforms.functional as tvf
 from PIL import Image
 from torchvision.transforms.functional import to_pil_image
 
@@ -46,6 +46,26 @@ logger = logging.getLogger(__name__)
 
 
 def _patch_vision_encoder_checkpointing(encoder: nn.Module, use_reentrant: bool) -> None:
+    for attr_name in ("_gradient_checkpointing_func", "gradient_checkpointing_func"):
+        original_func = getattr(encoder, attr_name, None)
+        if not callable(original_func):
+            continue
+        patch_attr = f"_evo1_{attr_name}_patch_applied"
+        if getattr(encoder, patch_attr, False):
+            encoder.gradient_checkpointing_use_reentrant = use_reentrant
+            return
+
+        def checkpoint_with_kwargs(
+            function, *checkpoint_args, _original_func=original_func, **checkpoint_kwargs
+        ):
+            checkpoint_kwargs.setdefault("use_reentrant", encoder.gradient_checkpointing_use_reentrant)
+            return _original_func(function, *checkpoint_args, **checkpoint_kwargs)
+
+        encoder.gradient_checkpointing_use_reentrant = use_reentrant
+        setattr(encoder, attr_name, checkpoint_with_kwargs)
+        setattr(encoder, patch_attr, True)
+        return
+
     if getattr(encoder, "_evo1_checkpoint_patch_applied", False):
         encoder.gradient_checkpointing_use_reentrant = use_reentrant
         return
@@ -59,6 +79,9 @@ def _patch_vision_encoder_checkpointing(encoder: nn.Module, use_reentrant: bool)
             checkpoint_kwargs.setdefault("use_reentrant", self.gradient_checkpointing_use_reentrant)
             return original_checkpoint(function, *checkpoint_args, **checkpoint_kwargs)
 
+        # Some InternVL3 remote-code versions call torch.utils.checkpoint.checkpoint
+        # directly and do not expose a per-encoder checkpoint function to patch.
+        # Keep this compatibility fallback scoped to encoder.forward and restore it.
         torch.utils.checkpoint.checkpoint = checkpoint
         try:
             return original_forward(*args, **kwargs)
@@ -280,11 +303,13 @@ class InternVL3Embedder(nn.Module):
 
     def _preprocess_single_image(self, image: Image.Image | torch.Tensor) -> torch.Tensor:
         if isinstance(image, torch.Tensor):
+            # Match upstream EVO1/InternVL preprocessing, which converts tensors
+            # through PIL before tiling and ImageNet normalization.
             pil_image = to_pil_image(image.detach().cpu())
         else:
             pil_image = image.convert("RGB")
         tiles = dynamic_preprocess(pil_image, image_size=self.image_size)
-        tile_tensors = torch.stack([TF.to_tensor(tile) for tile in tiles]).to(
+        tile_tensors = torch.stack([tvf.to_tensor(tile) for tile in tiles]).to(
             device=self.device, dtype=torch.bfloat16
         )
         mean = torch.tensor(IMAGENET_MEAN, device=self.device, dtype=torch.bfloat16).view(1, 3, 1, 1)

src/lerobot/policies/evo1/modeling_evo1.py

@@ -45,6 +45,7 @@ class EVO1Policy(PreTrainedPolicy):
         self.config = config
         self.model = EVO1(self._build_model_config(config))
         self.model.set_finetune_flags()
+        self._keep_frozen_embedder_eval()
         self.reset()
 
     @classmethod
@@ -64,7 +65,7 @@ class EVO1Policy(PreTrainedPolicy):
         **kwargs,
     ) -> T:
         if strict is None:
-            strict = not (config is not None and getattr(config, "training_stage", None) == "stage2")
+            strict = True
         return super().from_pretrained(
             pretrained_name_or_path=pretrained_name_or_path,
             config=config,
@@ -85,6 +86,7 @@ class EVO1Policy(PreTrainedPolicy):
             "device": config.device,
             "return_cls_only": config.return_cls_only,
             "vlm_name": config.vlm_model_name,
+            "image_size": int(config.image_resolution[0]),
             "vlm_num_layers": config.vlm_num_layers,
             "vlm_dtype": config.vlm_dtype,
             "use_flash_attn": config.use_flash_attn,
@@ -100,7 +102,8 @@ class EVO1Policy(PreTrainedPolicy):
             "dropout": config.dropout,
             "num_inference_timesteps": config.num_inference_timesteps,
             "num_categories": config.num_categories,
-            "enable_gradient_checkpointing": config.enable_gradient_checkpointing,
+            "enable_gradient_checkpointing": config.enable_gradient_checkpointing
+            and bool(config.finetune_vlm or config.finetune_language_model or config.finetune_vision_model),
             "gradient_checkpointing_use_reentrant": config.gradient_checkpointing_use_reentrant,
             "finetune_vlm": config.finetune_vlm,
             "finetune_language_model": config.finetune_language_model,
@@ -303,6 +306,18 @@ class EVO1Policy(PreTrainedPolicy):
             or self.config.finetune_vision_model
         )
 
+    def _keep_frozen_embedder_eval(self) -> None:
+        if self._tracks_vlm_gradients:
+            return
+        embedder = getattr(self.model, "embedder", None)
+        if embedder is not None:
+            embedder.eval()
+
+    def train(self, mode: bool = True):
+        super().train(mode)
+        self._keep_frozen_embedder_eval()
+        return self
+
     def _collect_image_batches(self, batch: dict[str, Tensor]) -> tuple[list[list[Tensor]], Tensor]:
         camera_keys = self._camera_keys or sorted(key for key in batch if key.startswith(f"{OBS_IMAGES}."))
         if not camera_keys:
@@ -348,23 +363,13 @@ class EVO1Policy(PreTrainedPolicy):
     ) -> Tensor:
         track_vlm_gradients = self._tracks_vlm_gradients
         grad_context = nullcontext() if track_vlm_gradients else torch.no_grad()
-        embedder = getattr(self.model, "embedder", None)
-        embedder_was_training = embedder.training if embedder is not None else None
-
-        if not track_vlm_gradients and embedder is not None:
-            embedder.eval()
-
-        try:
-            with grad_context:
-                fused_tokens = self.model.get_vl_embeddings(
-                    images=image_batches,
-                    image_mask=image_masks,
-                    prompt=prompts,
-                    return_cls_only=self.config.return_cls_only,
-                )
-        finally:
-            if not track_vlm_gradients and embedder is not None and embedder_was_training is not None:
-                embedder.train(embedder_was_training)
+        with grad_context:
+            fused_tokens = self.model.get_vl_embeddings(
+                images=image_batches,
+                image_mask=image_masks,
+                prompt=prompts,
+                return_cls_only=self.config.return_cls_only,
+            )
 
         if not track_vlm_gradients:
             fused_tokens = fused_tokens.detach()
@@ -439,7 +444,7 @@ class EVO1Policy(PreTrainedPolicy):
                 embodiment_ids=embodiment_ids,
             )
         actions = actions.view(states.shape[0], self.config.chunk_size, self.config.max_action_dim)
-        return actions[:, :, : self._env_action_dim]
+        return actions
 
     @torch.no_grad()
     def select_action(self, batch: dict[str, Tensor], **kwargs) -> Tensor:

src/lerobot/policies/evo1/processor_evo1.py

@@ -14,17 +14,24 @@
 
 from __future__ import annotations
 
+from copy import deepcopy
+from dataclasses import dataclass
 from typing import Any
 
 import torch
 
+from lerobot.configs import FeatureType, PipelineFeatureType, PolicyFeature
 from lerobot.policies.evo1.configuration_evo1 import Evo1Config
 from lerobot.processor import (
     AddBatchDimensionProcessorStep,
     DeviceProcessorStep,
     NormalizerProcessorStep,
+    ObservationProcessorStep,
     PolicyAction,
+    PolicyActionProcessorStep,
     PolicyProcessorPipeline,
+    ProcessorStep,
+    ProcessorStepRegistry,
     RenameObservationsProcessorStep,
     UnnormalizerProcessorStep,
 )
@@ -34,11 +41,13 @@ from lerobot.processor.converters import (
     policy_action_to_transition,
     transition_to_policy_action,
 )
+from lerobot.types import EnvTransition, TransitionKey
 from lerobot.utils.constants import (
     ACTION,
     DONE,
     INFO,
     OBS_PREFIX,
+    OBS_STATE,
     POLICY_POSTPROCESSOR_DEFAULT_NAME,
     POLICY_PREPROCESSOR_DEFAULT_NAME,
     REWARD,
@@ -65,6 +74,305 @@ def evo1_batch_to_transition(batch: dict[str, Any]):
     )
 
 
+@dataclass
+@ProcessorStepRegistry.register(name="evo1_pad_state_processor")
+class Evo1PadStateProcessorStep(ObservationProcessorStep):
+    """Pad policy observations to EVO1's fixed state width before normalization."""
+
+    max_state_dim: int = 24
+
+    def observation(self, observation: dict[str, Any]) -> dict[str, Any]:
+        if OBS_STATE not in observation:
+            return observation
+
+        state = observation[OBS_STATE]
+        state_dim = state.shape[-1]
+        if state_dim > self.max_state_dim:
+            raise ValueError(
+                f"EVO1 state has {state_dim} dims, which exceeds max_state_dim={self.max_state_dim}."
+            )
+        if state_dim < self.max_state_dim:
+            observation = observation.copy()
+            observation[OBS_STATE] = torch.nn.functional.pad(state, (0, self.max_state_dim - state_dim))
+        return observation
+
+    def transform_features(
+        self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
+    ) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
+        new_features = {ft: feats.copy() for ft, feats in features.items()}
+        state_feats = new_features.setdefault(FeatureType.STATE, {})
+        if OBS_STATE in state_feats:
+            state_feats[OBS_STATE] = PolicyFeature(type=FeatureType.STATE, shape=(self.max_state_dim,))
+        return new_features
+
+    def get_config(self) -> dict[str, Any]:
+        return {"max_state_dim": self.max_state_dim}
+
+
+@dataclass
+@ProcessorStepRegistry.register(name="evo1_pad_action_processor")
+class Evo1PadActionProcessorStep(ProcessorStep):
+    """Pad training actions and preserve the active action dimensions with action_mask."""
+
+    max_action_dim: int = 24
+
+    def __call__(self, transition: EnvTransition) -> EnvTransition:
+        action = transition.get(TransitionKey.ACTION)
+        if action is None:
+            return transition
+        if not isinstance(action, PolicyAction):
+            raise ValueError(f"EVO1 action should be a PolicyAction tensor, but got {type(action)}.")
+
+        action_dim = action.shape[-1]
+        if action_dim > self.max_action_dim:
+            raise ValueError(
+                f"EVO1 action has {action_dim} dims, which exceeds max_action_dim={self.max_action_dim}."
+            )
+
+        new_transition = transition.copy()
+        new_action = action
+        if action_dim < self.max_action_dim:
+            new_action = torch.nn.functional.pad(action, (0, self.max_action_dim - action_dim))
+
+        complementary_data = dict(new_transition.get(TransitionKey.COMPLEMENTARY_DATA) or {})
+        action_mask = complementary_data.get("action_mask")
+        if action_mask is None:
+            action_mask = torch.ones(action.shape, dtype=torch.bool, device=action.device)
+        else:
+            action_mask = torch.as_tensor(action_mask, dtype=torch.bool, device=action.device)
+            if action_mask.shape != action.shape:
+                raise ValueError(
+                    f"action_mask shape {tuple(action_mask.shape)} does not match action shape {tuple(action.shape)}."
+                )
+        if action_dim < self.max_action_dim:
+            action_mask = torch.nn.functional.pad(action_mask, (0, self.max_action_dim - action_dim))
+
+        complementary_data["action_mask"] = action_mask
+        new_transition[TransitionKey.ACTION] = new_action
+        new_transition[TransitionKey.COMPLEMENTARY_DATA] = complementary_data
+        return new_transition
+
+    def transform_features(
+        self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
+    ) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
+        new_features = {ft: feats.copy() for ft, feats in features.items()}
+        action_feats = new_features.setdefault(FeatureType.ACTION, {})
+        action_feats[ACTION] = PolicyFeature(type=FeatureType.ACTION, shape=(self.max_action_dim,))
+        return new_features
+
+    def get_config(self) -> dict[str, Any]:
+        return {"max_action_dim": self.max_action_dim}
+
+
+@dataclass
+@ProcessorStepRegistry.register(name="evo1_action_processor")
+class Evo1ActionProcessorStep(PolicyActionProcessorStep):
+    """Crop padded EVO1 actions and optionally binarize the LIBERO gripper channel."""
+
+    action_dim: int
+    binarize_gripper: bool = False
+    gripper_index: int = 6
+    gripper_threshold: float = 0.5
+    gripper_below_threshold_value: float = 1.0
+    gripper_above_threshold_value: float = -1.0
+
+    def action(self, action: PolicyAction) -> PolicyAction:
+        if action.shape[-1] < self.action_dim:
+            raise ValueError(
+                f"EVO1 action has {action.shape[-1]} dims, which is smaller than action_dim={self.action_dim}."
+            )
+
+        action = action[..., : self.action_dim]
+        if not self.binarize_gripper:
+            return action
+
+        if not 0 <= self.gripper_index < self.action_dim:
+            raise ValueError(
+                f"gripper_index={self.gripper_index} must be within action_dim={self.action_dim}."
+            )
+
+        action = action.clone()
+        below = torch.as_tensor(
+            self.gripper_below_threshold_value,
+            dtype=action.dtype,
+            device=action.device,
+        )
+        above = torch.as_tensor(
+            self.gripper_above_threshold_value,
+            dtype=action.dtype,
+            device=action.device,
+        )
+        action[..., self.gripper_index] = torch.where(
+            action[..., self.gripper_index] > self.gripper_threshold,
+            above,
+            below,
+        )
+        return action
+
+    def transform_features(
+        self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
+    ) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
+        new_features = {ft: feats.copy() for ft, feats in features.items()}
+        action_feats = new_features.setdefault(FeatureType.ACTION, {})
+        action_feats[ACTION] = PolicyFeature(type=FeatureType.ACTION, shape=(self.action_dim,))
+        return new_features
+
+    def get_config(self) -> dict[str, Any]:
+        return {
+            "action_dim": self.action_dim,
+            "binarize_gripper": self.binarize_gripper,
+            "gripper_index": self.gripper_index,
+            "gripper_threshold": self.gripper_threshold,
+            "gripper_below_threshold_value": self.gripper_below_threshold_value,
+            "gripper_above_threshold_value": self.gripper_above_threshold_value,
+        }
+
+
+def _evo1_action_dim(config: Evo1Config) -> int:
+    if config.postprocess_action_dim is not None:
+        return config.postprocess_action_dim
+    action_feature = config.action_feature
+    if action_feature is None:
+        return config.max_action_dim
+    return int(action_feature.shape[0])
+
+
+def _evo1_normalization_features(config: Evo1Config) -> dict[str, PolicyFeature]:
+    features = {**config.input_features, **config.output_features}
+    features[OBS_STATE] = PolicyFeature(type=FeatureType.STATE, shape=(config.max_state_dim,))
+    features[ACTION] = PolicyFeature(type=FeatureType.ACTION, shape=(config.max_action_dim,))
+    return features
+
+
+def _evo1_action_features(config: Evo1Config) -> dict[str, PolicyFeature]:
+    return {ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(config.max_action_dim,))}
+
+
+_STAT_PAD_VALUES = {
+    "mean": 0.0,
+    "std": 1.0,
+    "min": -1.0,
+    "max": 1.0,
+    "q01": -1.0,
+    "q99": 1.0,
+    "q10": -1.0,
+    "q90": 1.0,
+}
+
+
+def _pad_stat_value(value: Any, target_dim: int, stat_name: str) -> torch.Tensor:
+    tensor = torch.as_tensor(value)
+    if not tensor.is_floating_point():
+        tensor = tensor.to(dtype=torch.float32)
+    if tensor.ndim == 0 or tensor.shape[-1] >= target_dim:
+        return tensor
+
+    pad_shape = (*tensor.shape[:-1], target_dim - tensor.shape[-1])
+    pad_value = _STAT_PAD_VALUES.get(stat_name, 0.0)
+    padding = torch.full(pad_shape, pad_value, dtype=tensor.dtype, device=tensor.device)
+    return torch.cat([tensor, padding], dim=-1)
+
+
+def _pad_feature_stats(
+    stats: dict[str, dict[str, Any]],
+    feature_key: str,
+    target_dim: int,
+) -> None:
+    if feature_key not in stats:
+        return
+    stats[feature_key] = {
+        stat_name: _pad_stat_value(stat_value, target_dim, stat_name)
+        for stat_name, stat_value in stats[feature_key].items()
+    }
+
+
+def _pad_evo1_stats(
+    config: Evo1Config,
+    stats: dict[str, dict[str, Any]] | None,
+) -> dict[str, dict[str, Any]] | None:
+    if stats is None:
+        return None
+
+    padded_stats = deepcopy(stats)
+    # Added dimensions represent zero-padding inside EVO1. These neutral stats keep
+    # padded observations at normalized zero and only provide shape compatibility.
+    _pad_feature_stats(padded_stats, OBS_STATE, config.max_state_dim)
+    _pad_feature_stats(padded_stats, ACTION, config.max_action_dim)
+    return padded_stats
+
+
+def _refresh_evo1_normalization_steps(
+    config: Evo1Config,
+    preprocessor: PolicyProcessorPipeline,
+    postprocessor: PolicyProcessorPipeline,
+) -> None:
+    normalization_features = _evo1_normalization_features(config)
+    action_features = _evo1_action_features(config)
+
+    for step in preprocessor.steps:
+        if isinstance(step, NormalizerProcessorStep):
+            step.features = normalization_features
+            step.stats = _pad_evo1_stats(config, step.stats)
+            step.to(device=step.device, dtype=step.dtype)
+
+    for step in postprocessor.steps:
+        if isinstance(step, UnnormalizerProcessorStep):
+            step.features = action_features
+            step.stats = _pad_evo1_stats(config, step.stats)
+            step.to(device=step.device, dtype=step.dtype)
+
+
+def ensure_evo1_processor_steps(
+    config: Evo1Config,
+    preprocessor: PolicyProcessorPipeline,
+    postprocessor: PolicyProcessorPipeline,
+) -> tuple[PolicyProcessorPipeline, PolicyProcessorPipeline]:
+    """Add EVO1 processor steps when loading older checkpoints that do not serialize them."""
+
+    has_state_padding = any(isinstance(step, Evo1PadStateProcessorStep) for step in preprocessor.steps)
+    if not has_state_padding:
+        steps = list(preprocessor.steps)
+        insert_idx = next(
+            (idx for idx, step in enumerate(steps) if isinstance(step, NormalizerProcessorStep)),
+            len(steps),
+        )
+        steps.insert(insert_idx, Evo1PadStateProcessorStep(max_state_dim=config.max_state_dim))
+        preprocessor.steps = steps
+
+    has_action_padding = any(isinstance(step, Evo1PadActionProcessorStep) for step in preprocessor.steps)
+    if not has_action_padding:
+        steps = list(preprocessor.steps)
+        insert_idx = next(
+            (idx for idx, step in enumerate(steps) if isinstance(step, NormalizerProcessorStep)),
+            len(steps),
+        )
+        steps.insert(insert_idx, Evo1PadActionProcessorStep(max_action_dim=config.max_action_dim))
+        preprocessor.steps = steps
+
+    has_action_processor = any(isinstance(step, Evo1ActionProcessorStep) for step in postprocessor.steps)
+    if not has_action_processor:
+        steps = list(postprocessor.steps)
+        insert_idx = next(
+            (idx + 1 for idx, step in enumerate(steps) if isinstance(step, UnnormalizerProcessorStep)),
+            0,
+        )
+        steps.insert(
+            insert_idx,
+            Evo1ActionProcessorStep(
+                action_dim=_evo1_action_dim(config),
+                binarize_gripper=config.binarize_gripper,
+                gripper_index=config.gripper_index,
+                gripper_threshold=config.gripper_threshold,
+                gripper_below_threshold_value=config.gripper_below_threshold_value,
+                gripper_above_threshold_value=config.gripper_above_threshold_value,
+            ),
+        )
+        postprocessor.steps = steps
+
+    _refresh_evo1_normalization_steps(config, preprocessor, postprocessor)
+    return preprocessor, postprocessor
+
+
 def make_evo1_pre_post_processors(
     config: Evo1Config,
     dataset_stats: dict[str, dict[str, torch.Tensor]] | None = None,
@@ -72,21 +380,35 @@ def make_evo1_pre_post_processors(
     PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
     PolicyProcessorPipeline[PolicyAction, PolicyAction],
 ]:
+    normalization_features = _evo1_normalization_features(config)
+    action_features = _evo1_action_features(config)
+    normalization_stats = _pad_evo1_stats(config, dataset_stats)
+
     input_steps = [
         RenameObservationsProcessorStep(rename_map={}),
         AddBatchDimensionProcessorStep(),
+        Evo1PadStateProcessorStep(max_state_dim=config.max_state_dim),
+        Evo1PadActionProcessorStep(max_action_dim=config.max_action_dim),
         NormalizerProcessorStep(
-            features={**config.input_features, **config.output_features},
+            features=normalization_features,
             norm_map=config.normalization_mapping,
-            stats=dataset_stats,
+            stats=normalization_stats,
         ),
         DeviceProcessorStep(device=config.device),
     ]
     output_steps = [
         UnnormalizerProcessorStep(
-            features=config.output_features,
+            features=action_features,
             norm_map=config.normalization_mapping,
-            stats=dataset_stats,
+            stats=normalization_stats,
+        ),
+        Evo1ActionProcessorStep(
+            action_dim=_evo1_action_dim(config),
+            binarize_gripper=config.binarize_gripper,
+            gripper_index=config.gripper_index,
+            gripper_threshold=config.gripper_threshold,
+            gripper_below_threshold_value=config.gripper_below_threshold_value,
+            gripper_above_threshold_value=config.gripper_above_threshold_value,
         ),
         DeviceProcessorStep(device="cpu"),
     ]

src/lerobot/policies/factory.py

@@ -311,6 +311,14 @@ def make_pre_post_processors(
             to_output=transition_to_policy_action,
         )
         _reconnect_relative_absolute_steps(preprocessor, postprocessor)
+        if isinstance(policy_cfg, Evo1Config):
+            from .evo1.processor_evo1 import ensure_evo1_processor_steps
+
+            preprocessor, postprocessor = ensure_evo1_processor_steps(
+                policy_cfg,
+                preprocessor,
+                postprocessor,
+            )
         return preprocessor, postprocessor
 
     # Create a new processor based on policy type

src/lerobot/processor/__init__.py

@@ -40,7 +40,7 @@ from .converters import (
 )
 from .delta_action_processor import MapDeltaActionToRobotActionStep, MapTensorToDeltaActionDictStep
 from .device_processor import DeviceProcessorStep
-from .env_processor import IsaaclabArenaProcessorStep, LiberoActionProcessorStep, LiberoProcessorStep
+from .env_processor import IsaaclabArenaProcessorStep, LiberoProcessorStep
 from .factory import (
     make_default_processors,
     make_default_robot_action_processor,
@@ -149,7 +149,6 @@ __all__ = [
     "RewardProcessorStep",
     "DataProcessorPipeline",
     "IsaaclabArenaProcessorStep",
-    "LiberoActionProcessorStep",
     "LiberoProcessorStep",
     "TimeLimitProcessorStep",
     "AddBatchDimensionProcessorStep",

src/lerobot/processor/env_processor.py

@@ -18,9 +18,9 @@ from dataclasses import dataclass
 import torch
 
 from lerobot.configs import FeatureType, PipelineFeatureType, PolicyFeature
-from lerobot.utils.constants import ACTION, OBS_IMAGES, OBS_PREFIX, OBS_STATE, OBS_STR
+from lerobot.utils.constants import OBS_IMAGES, OBS_PREFIX, OBS_STATE, OBS_STR
 
-from .pipeline import ActionProcessorStep, ObservationProcessorStep, ProcessorStepRegistry
+from .pipeline import ObservationProcessorStep, ProcessorStepRegistry
 
 
 @dataclass
@@ -46,8 +46,6 @@ class LiberoProcessorStep(ObservationProcessorStep):
     -   This accounts for the HuggingFaceVLA/libero camera orientation convention.
     """
 
-    max_state_dim: int | None = None
-
     def _process_observation(self, observation):
         """
         Processes both image and robot_state observations from LIBERO.
@@ -80,16 +78,6 @@ class LiberoProcessorStep(ObservationProcessorStep):
             state = state.float()
             if state.dim() == 1:
                 state = state.unsqueeze(0)
-            if self.max_state_dim is not None:
-                if state.shape[-1] > self.max_state_dim:
-                    raise ValueError(
-                        f"LIBERO state has {state.shape[-1]} dims, which is larger than "
-                        f"configured max_state_dim={self.max_state_dim}."
-                    )
-                if state.shape[-1] < self.max_state_dim:
-                    pad_width = self.max_state_dim - state.shape[-1]
-                    state = torch.nn.functional.pad(state, (0, pad_width))
-
             processed_obs[OBS_STATE] = state
         return processed_obs
 
@@ -112,7 +100,7 @@ class LiberoProcessorStep(ObservationProcessorStep):
         # add our new flattened state
         state_feats[OBS_STATE] = PolicyFeature(
             type=FeatureType.STATE,
-            shape=(self.max_state_dim or 8,),  # [eef_pos(3), axis_angle(3), gripper(2)] plus padding
+            shape=(8,),  # [eef_pos(3), axis_angle(3), gripper(2)]
         )
 
         new_features[FeatureType.STATE] = state_feats
@@ -122,9 +110,6 @@ class LiberoProcessorStep(ObservationProcessorStep):
     def observation(self, observation):
         return self._process_observation(observation)
 
-    def get_config(self) -> dict:
-        return {"max_state_dim": self.max_state_dim}
-
     def _quat2axisangle(self, quat: torch.Tensor) -> torch.Tensor:
         """
         Convert batched quaternions to axis-angle format.
@@ -167,68 +152,6 @@ class LiberoProcessorStep(ObservationProcessorStep):
         return result
 
 
-@dataclass
-@ProcessorStepRegistry.register(name="libero_action_processor")
-class LiberoActionProcessorStep(ActionProcessorStep):
-    """Slices padded policy actions back to the executable LIBERO action space."""
-
-    action_dim: int = 7
-    binarize_gripper: bool = False
-    gripper_index: int = 6
-    gripper_threshold: float = 0.5
-    gripper_below_threshold_value: float = 1.0
-    gripper_above_threshold_value: float = -1.0
-
-    def action(self, action):
-        if action.shape[-1] < self.action_dim:
-            raise ValueError(
-                f"LIBERO action has {action.shape[-1]} dims, which is smaller than action_dim={self.action_dim}."
-            )
-        action = action[..., : self.action_dim]
-        if not self.binarize_gripper:
-            return action
-
-        if not 0 <= self.gripper_index < self.action_dim:
-            raise ValueError(
-                f"gripper_index={self.gripper_index} must be within sliced action_dim={self.action_dim}."
-            )
-        action = action.clone()
-        below = torch.as_tensor(
-            self.gripper_below_threshold_value,
-            dtype=action.dtype,
-            device=action.device,
-        )
-        above = torch.as_tensor(
-            self.gripper_above_threshold_value,
-            dtype=action.dtype,
-            device=action.device,
-        )
-        action[..., self.gripper_index] = torch.where(
-            action[..., self.gripper_index] > self.gripper_threshold,
-            above,
-            below,
-        )
-        return action
-
-    def transform_features(
-        self, features: dict[PipelineFeatureType, dict[str, PolicyFeature]]
-    ) -> dict[PipelineFeatureType, dict[str, PolicyFeature]]:
-        new_features = {ft: feats.copy() for ft, feats in features.items()}
-        action_feats = new_features.setdefault(FeatureType.ACTION, {})
-        action_feats[ACTION] = PolicyFeature(type=FeatureType.ACTION, shape=(self.action_dim,))
-        return new_features
-
-    def get_config(self) -> dict:
-        return {
-            "action_dim": self.action_dim,
-            "binarize_gripper": self.binarize_gripper,
-            "gripper_index": self.gripper_index,
-            "gripper_threshold": self.gripper_threshold,
-            "gripper_below_threshold_value": self.gripper_below_threshold_value,
-            "gripper_above_threshold_value": self.gripper_above_threshold_value,
-        }
-
-
 @dataclass
 @ProcessorStepRegistry.register(name="isaaclab_arena_processor")
 class IsaaclabArenaProcessorStep(ObservationProcessorStep):

tests/envs/test_dispatch.py

@@ -13,7 +13,7 @@ from gymnasium.envs.registration import register, registry as gym_registry
 from lerobot.configs.types import PolicyFeature
 from lerobot.envs.configs import EnvConfig, LiberoEnv
 from lerobot.envs.factory import make_env, make_env_config, make_env_pre_post_processors
-from lerobot.processor import LiberoActionProcessorStep, LiberoProcessorStep
+from lerobot.processor import LiberoProcessorStep
 from lerobot.utils.constants import OBS_PREFIX, OBS_STATE
 
 logger = logging.getLogger(__name__)
@@ -86,38 +86,18 @@ def test_processors_delegation_supports_legacy_override_signature():
     assert isinstance(post, DataProcessorPipeline)
 
 
-def test_libero_evo1_processors_use_padded_state_and_env_action_dim():
-    """EVO1 uses padded LIBERO state features while env actions stay executable."""
-
-    class _Evo1Config:
-        type = "evo1"
-        max_state_dim = 24
-
+def test_libero_processors_are_policy_agnostic():
     cfg = LiberoEnv()
-    pre, post = make_env_pre_post_processors(cfg, policy_cfg=_Evo1Config())
+    pre, post = make_env_pre_post_processors(cfg, policy_cfg=object())
+
     assert isinstance(pre.steps[0], LiberoProcessorStep)
-    assert pre.steps[0].max_state_dim == 24
-    assert isinstance(post.steps[0], LiberoActionProcessorStep)
-    assert post.steps[0].action_dim == cfg.features["action"].shape[0] == 7
-    assert post.steps[0].binarize_gripper is True
-
-    class _OtherConfig:
-        type = "other"
-
-    pre_other, post_other = make_env_pre_post_processors(cfg, policy_cfg=_OtherConfig())
-    assert pre_other.steps[0].max_state_dim is None
-    assert post_other.steps[0].binarize_gripper is False
-
-    cfg.binarize_gripper = False
-    _, post_disabled = make_env_pre_post_processors(cfg, policy_cfg=_Evo1Config())
-    assert post_disabled.steps[0].binarize_gripper is False
+    assert len(post.steps) == 0
 
 
-def test_libero_processor_pads_state_to_max_dim():
-    step = LiberoProcessorStep(max_state_dim=24)
+def test_libero_processor_flattens_state_to_raw_8_dim():
+    step = LiberoProcessorStep()
     observation = {
-        OBS_PREFIX
-        + "robot_state": {
+        OBS_PREFIX + "robot_state": {
             "eef": {
                 "pos": torch.tensor([[1.0, 2.0, 3.0]]),
                 "quat": torch.tensor([[0.0, 0.0, 0.0, 1.0]]),
@@ -127,39 +107,8 @@ def test_libero_processor_pads_state_to_max_dim():
     }
 
     state = step.observation(observation)[OBS_STATE]
-    assert state.shape == (1, 24)
-    assert torch.allclose(state[:, :8], torch.tensor([[1.0, 2.0, 3.0, 0.0, 0.0, 0.0, 4.0, 5.0]]))
-    assert torch.count_nonzero(state[:, 8:]).item() == 0
-
-
-def test_libero_action_processor_slices_padded_action():
-    step = LiberoActionProcessorStep(action_dim=7)
-    action = torch.arange(2 * 3 * 24, dtype=torch.float32).reshape(2, 3, 24)
-
-    sliced = step.action(action)
-    assert sliced.shape == (2, 3, 7)
-    assert torch.equal(sliced, action[..., :7])
-
-    with pytest.raises(ValueError, match="smaller than action_dim=7"):
-        step.action(torch.zeros(2, 6))
-
-
-def test_libero_action_processor_can_binarize_gripper():
-    step = LiberoActionProcessorStep(action_dim=7, binarize_gripper=True)
-    action = torch.tensor(
-        [
-            [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 0.5, 7.0],
-            [0.0, 1.0, 2.0, 3.0, 4.0, 5.0, 0.6, 7.0],
-        ],
-        dtype=torch.float32,
-    )
-
-    processed = step.action(action)
-
-    assert processed.shape == (2, 7)
-    assert torch.equal(processed[:, :6], action[:, :6])
-    assert torch.equal(processed[:, 6], torch.tensor([1.0, -1.0]))
-    assert torch.equal(action[:, 6], torch.tensor([0.5, 0.6]))
+    assert state.shape == (1, 8)
+    assert torch.allclose(state, torch.tensor([[1.0, 2.0, 3.0, 0.0, 0.0, 0.0, 4.0, 5.0]]))
 
 
 def test_base_create_envs():

tests/policies/evo1/test_evo1.py

@@ -16,6 +16,7 @@
 
 from __future__ import annotations
 
+import pytest
 import torch
 from torch import nn
 
@@ -23,7 +24,15 @@ import lerobot.policies.evo1.modeling_evo1 as modeling_evo1
 from lerobot.configs.types import FeatureType, PolicyFeature
 from lerobot.policies.evo1.configuration_evo1 import Evo1Config
 from lerobot.policies.evo1.flow_matching import FlowmatchingActionHead
+from lerobot.policies.evo1.processor_evo1 import (
+    Evo1ActionProcessorStep,
+    Evo1PadActionProcessorStep,
+    Evo1PadStateProcessorStep,
+    ensure_evo1_processor_steps,
+    make_evo1_pre_post_processors,
+)
 from lerobot.policies.factory import get_policy_class, make_policy_config
+from lerobot.processor import NormalizerProcessorStep, PolicyProcessorPipeline, UnnormalizerProcessorStep
 from lerobot.utils.constants import ACTION, OBS_IMAGES, OBS_STATE
 
 STATE_DIM = 4
@@ -108,6 +117,19 @@ def make_batch(include_action=True):
     return batch
 
 
+def make_stats(state_dim=STATE_DIM, action_dim=ACTION_DIM):
+    return {
+        OBS_STATE: {
+            "min": torch.full((state_dim,), -2.0),
+            "max": torch.full((state_dim,), 2.0),
+        },
+        ACTION: {
+            "min": torch.full((action_dim,), -1.0),
+            "max": torch.full((action_dim,), 1.0),
+        },
+    }
+
+
 def test_evo1_factory_registration():
     cfg = make_policy_config(
         "evo1",
@@ -191,22 +213,151 @@ def test_evo1_stage_defaults_and_consistency():
         raise AssertionError("Expected inconsistent finetune config to raise ValueError")
 
 
+def test_evo1_rejects_non_square_image_resolution():
+    with pytest.raises(ValueError, match="square image_resolution"):
+        make_config(image_resolution=(448, 320))
+
+
+def test_evo1_build_model_config_uses_image_resolution_and_trainable_checkpointing():
+    stage1 = make_config(training_stage="stage1", image_resolution=(224, 224))
+    stage1_model_config = modeling_evo1.EVO1Policy._build_model_config(stage1)
+
+    assert stage1_model_config["image_size"] == 224
+    assert stage1_model_config["enable_gradient_checkpointing"] is False
+
+    stage2 = make_config(training_stage="stage2", image_resolution=(224, 224))
+    stage2_model_config = modeling_evo1.EVO1Policy._build_model_config(stage2)
+
+    assert stage2_model_config["enable_gradient_checkpointing"] is True
+
+
+def test_evo1_policy_processors_pad_state_crop_action_and_binarize_gripper():
+    libero_action_dim = 7
+    config = make_config(
+        max_state_dim=MAX_STATE_DIM,
+        max_action_dim=8,
+        postprocess_action_dim=libero_action_dim,
+        binarize_gripper=True,
+        output_features={ACTION: PolicyFeature(type=FeatureType.ACTION, shape=(libero_action_dim,))},
+    )
+    stats = make_stats(action_dim=libero_action_dim)
+
+    preprocessor, postprocessor = make_evo1_pre_post_processors(config, dataset_stats=stats)
+
+    assert isinstance(preprocessor.steps[2], Evo1PadStateProcessorStep)
+    assert isinstance(preprocessor.steps[3], Evo1PadActionProcessorStep)
+    assert isinstance(preprocessor.steps[4], NormalizerProcessorStep)
+    assert isinstance(postprocessor.steps[0], UnnormalizerProcessorStep)
+    assert isinstance(postprocessor.steps[1], Evo1ActionProcessorStep)
+
+    normalizer = preprocessor.steps[4]
+    assert normalizer.features[OBS_STATE].shape == (MAX_STATE_DIM,)
+    assert normalizer.features[ACTION].shape == (8,)
+    assert normalizer._tensor_stats[OBS_STATE]["min"].shape == (MAX_STATE_DIM,)
+    assert normalizer._tensor_stats[ACTION]["min"].shape == (8,)
+
+    processed_batch = preprocessor(
+        {
+            "task": "pick the block",
+            OBS_STATE: torch.zeros(STATE_DIM),
+            ACTION: torch.zeros(libero_action_dim),
+            f"{OBS_IMAGES}.front": torch.rand(3, 16, 16),
+        }
+    )
+    processed_state = processed_batch[OBS_STATE]
+    assert processed_state.shape == (1, MAX_STATE_DIM)
+    assert torch.allclose(processed_state, torch.zeros_like(processed_state))
+    assert processed_batch[ACTION].shape == (1, 8)
+    assert torch.allclose(processed_batch[ACTION], torch.zeros_like(processed_batch[ACTION]))
+    assert processed_batch["action_mask"].shape == (1, 8)
+    assert processed_batch["action_mask"][:, :libero_action_dim].all()
+    assert not processed_batch["action_mask"][:, libero_action_dim:].any()
+
+    action = torch.tensor(
+        [
+            [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.5, 0.7],
+            [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7],
+        ],
+        dtype=torch.float32,
+    )
+    processed = postprocessor(action)
+
+    assert processed.shape == (2, 7)
+    assert torch.allclose(processed[:, :6], action[:, :6])
+    assert torch.equal(processed[:, 6], torch.tensor([1.0, -1.0]))
+
+
+def test_evo1_legacy_processors_are_completed_before_normalization():
+    config = make_config(
+        max_state_dim=MAX_STATE_DIM,
+        max_action_dim=8,
+        postprocess_action_dim=7,
+        binarize_gripper=True,
+    )
+    stats = make_stats(action_dim=7)
+    legacy_pre = PolicyProcessorPipeline(
+        steps=[
+            NormalizerProcessorStep(
+                features={**config.input_features, **config.output_features},
+                norm_map=config.normalization_mapping,
+                stats=stats,
+            )
+        ]
+    )
+    legacy_post = PolicyProcessorPipeline(
+        steps=[
+            UnnormalizerProcessorStep(
+                features=config.output_features,
+                norm_map=config.normalization_mapping,
+                stats=stats,
+            )
+        ]
+    )
+
+    preprocessor, postprocessor = ensure_evo1_processor_steps(config, legacy_pre, legacy_post)
+
+    assert isinstance(preprocessor.steps[0], Evo1PadStateProcessorStep)
+    assert isinstance(preprocessor.steps[1], Evo1PadActionProcessorStep)
+    assert isinstance(preprocessor.steps[2], NormalizerProcessorStep)
+    assert isinstance(postprocessor.steps[0], UnnormalizerProcessorStep)
+    assert isinstance(postprocessor.steps[1], Evo1ActionProcessorStep)
+    assert postprocessor.steps[1].action_dim == 7
+    assert postprocessor.steps[1].binarize_gripper is True
+    assert preprocessor.steps[2].features[OBS_STATE].shape == (MAX_STATE_DIM,)
+    assert preprocessor.steps[2]._tensor_stats[OBS_STATE]["min"].shape == (MAX_STATE_DIM,)
+    assert preprocessor.steps[2]._tensor_stats[ACTION]["min"].shape == (8,)
+    assert postprocessor.steps[0].features[ACTION].shape == (8,)
+    assert postprocessor.steps[0]._tensor_stats[ACTION]["min"].shape == (8,)
+
+    preprocessor, postprocessor = ensure_evo1_processor_steps(config, preprocessor, postprocessor)
+    assert sum(isinstance(step, Evo1PadStateProcessorStep) for step in preprocessor.steps) == 1
+    assert sum(isinstance(step, Evo1PadActionProcessorStep) for step in preprocessor.steps) == 1
+    assert sum(isinstance(step, Evo1ActionProcessorStep) for step in postprocessor.steps) == 1
+
+
 def test_evo1_policy_forward_and_inference_use_batched_embedding(monkeypatch):
     monkeypatch.setattr(modeling_evo1, "EVO1", DummyEVO1)
     policy = modeling_evo1.EVO1Policy(make_config())
+    preprocessor, _postprocessor = make_evo1_pre_post_processors(policy.config, dataset_stats=make_stats())
+    training_batch = preprocessor(make_batch(include_action=True))
 
-    loss, metrics = policy.forward(make_batch(include_action=True))
+    assert training_batch[ACTION].shape == (2, CHUNK_SIZE, MAX_ACTION_DIM)
+    assert training_batch["action_mask"].shape == (2, CHUNK_SIZE, MAX_ACTION_DIM)
+    assert training_batch["action_mask"][:, :, :ACTION_DIM].all()
+    assert not training_batch["action_mask"][:, :, ACTION_DIM:].any()
+
+    loss, metrics = policy.forward(training_batch)
     assert loss.ndim == 0
     assert torch.isfinite(loss)
     assert metrics["active_action_dims"] == ACTION_DIM * CHUNK_SIZE
     assert policy.model.get_vl_embeddings_calls == 1
 
     action_chunk = policy.predict_action_chunk(make_batch(include_action=False))
-    assert action_chunk.shape == (2, CHUNK_SIZE, ACTION_DIM)
+    assert action_chunk.shape == (2, CHUNK_SIZE, MAX_ACTION_DIM)
 
     policy.reset()
     selected = policy.select_action(make_batch(include_action=False))
-    assert selected.shape == (2, ACTION_DIM)
+    assert selected.shape == (2, MAX_ACTION_DIM)
 
 
 def test_stage1_frozen_vlm_embeddings_do_not_track_gradients(monkeypatch):
@@ -220,7 +371,7 @@ def test_stage1_frozen_vlm_embeddings_do_not_track_gradients(monkeypatch):
     assert policy.model.grad_enabled_calls == [False]
     assert policy.model.embedder_training_calls == [False]
     assert not fused_tokens.requires_grad
-    assert policy.model.embedder.training is True
+    assert policy.model.embedder.training is False
 
 
 def test_stage2_vlm_embeddings_track_gradients(monkeypatch):