speed up benchmark eval scheduling and docker workflow

docker/Dockerfile.eval-base

@@ -0,0 +1,59 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+ARG CUDA_VERSION=12.4.1
+ARG OS_VERSION=22.04
+FROM nvidia/cuda:${CUDA_VERSION}-base-ubuntu${OS_VERSION}
+
+ARG PYTHON_VERSION=3.12
+
+ENV DEBIAN_FRONTEND=noninteractive \
+    MUJOCO_GL=egl \
+    PATH=/lerobot/.venv/bin:$PATH
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    software-properties-common build-essential git curl \
+    libglib2.0-0 libgl1-mesa-glx libegl1-mesa libosmesa6 \
+    ffmpeg libusb-1.0-0-dev speech-dispatcher libgeos-dev portaudio19-dev \
+    cmake pkg-config ninja-build \
+    && add-apt-repository -y ppa:deadsnakes/ppa \
+    && apt-get update \
+    && apt-get install -y --no-install-recommends \
+       python${PYTHON_VERSION} \
+       python${PYTHON_VERSION}-venv \
+       python${PYTHON_VERSION}-dev \
+    && curl -LsSf https://astral.sh/uv/install.sh | sh \
+    && mv /root/.local/bin/uv /usr/local/bin/uv \
+    && useradd --create-home --shell /bin/bash user_lerobot \
+    && apt-get clean && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /lerobot
+RUN chown -R user_lerobot:user_lerobot /lerobot
+USER user_lerobot
+
+ENV HOME=/home/user_lerobot \
+    HF_HOME=/home/user_lerobot/.cache/huggingface \
+    HF_LEROBOT_HOME=/home/user_lerobot/.cache/huggingface/lerobot \
+    TORCH_HOME=/home/user_lerobot/.cache/torch \
+    TRITON_CACHE_DIR=/home/user_lerobot/.cache/triton
+
+RUN uv venv --seed --python python${PYTHON_VERSION}
+
+COPY --chown=user_lerobot:user_lerobot setup.py pyproject.toml README.md MANIFEST.in ./
+COPY --chown=user_lerobot:user_lerobot src/ src/
+RUN uv pip install --no-cache .
+
+COPY --chown=user_lerobot:user_lerobot . .
+
+CMD ["/bin/bash"]

docker/Dockerfile.eval-libero

@@ -0,0 +1,22 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM lerobot-eval-base:latest
+
+RUN PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -m pip install --no-cache-dir ".[libero]" \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import libero"
+
+CMD ["/bin/bash"]

docker/Dockerfile.eval-libero-plus

@@ -0,0 +1,25 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM lerobot-eval-base:latest
+
+RUN PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -m pip install --no-cache-dir ".[libero_plus]" \
+    && git clone --depth 1 https://github.com/sylvestf/LIBERO-plus.git /tmp/LIBERO-plus \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import pathlib, site; pathlib.Path(site.getsitepackages()[0], 'libero_plus_repo.pth').write_text('/tmp/LIBERO-plus\n')" \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import libero, robosuite, bddl"
+
+CMD ["/bin/bash"]

docker/Dockerfile.eval-metaworld

@@ -0,0 +1,22 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM lerobot-eval-base:latest
+
+RUN PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -m pip install --no-cache-dir ".[metaworld]" \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import metaworld"
+
+CMD ["/bin/bash"]

docker/Dockerfile.eval-robocasa

@@ -0,0 +1,22 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM lerobot-eval-base:latest
+
+RUN PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -m pip install --no-cache-dir ".[robocasa]" \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import robocasa"
+
+CMD ["/bin/bash"]

docker/Dockerfile.eval-robomme

@@ -0,0 +1,22 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM lerobot-eval-base:latest
+
+RUN PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -m pip install --no-cache-dir ".[robomme]" \
+    && PATH=/usr/bin:/bin:/lerobot/.venv/bin:$PATH \
+    /lerobot/.venv/bin/python -c "import robomme"
+
+CMD ["/bin/bash"]

docs/source/benchmark_training.mdx

@@ -47,6 +47,116 @@ For multi-GPU training you also need [Accelerate](https://huggingface.co/docs/ac
 pip install accelerate
 ```
 
+## Docker-isolated evaluation (EnvHub)
+
+LeRobot eval now supports running the full eval worker in a Docker container
+while keeping policy loading compatible with local checkpoints and local code changes.
+
+Use `lerobot-eval` with `--eval.runtime=docker`:
+
+```bash
+lerobot-eval \
+  --policy.path=outputs/train/my_policy/checkpoints/050000/pretrained_model \
+  --env.type=libero_plus \
+  --eval.runtime=docker \
+  --eval.docker.envhub_ref=envhub://lerobot/libero_plus@v1 \
+  --eval.n_episodes=10 \
+  --eval.batch_size=10
+```
+
+`eval.docker.envhub_ref` is optional. If omitted, LeRobot resolves a default
+image from `env.type`. You can also override the image directly:
+
+```bash
+--eval.docker.image=docker://ghcr.io/huggingface/lerobot-eval-libero-plus:latest
+```
+
+By default (`eval.docker.use_local_code=true`), the local repository is mounted
+in the container and added to `PYTHONPATH`, so edited policy/env code and local
+checkpoints continue to work without rebuilding the image for each change.
+
+Common Docker runtime options:
+
+```bash
+--eval.docker.pull=true \
+--eval.docker.gpus=all \
+--eval.docker.shm_size=8g \
+--eval.docker.use_local_code=true
+```
+
+The benchmark runner supports the same Docker eval path (extra args are
+forwarded to each generated `lerobot-eval` call):
+
+```bash
+lerobot-benchmark eval \
+    --benchmarks libero_plus,robocasa \
+    --hub-user $HF_USER \
+    --n-episodes 50 \
+    --eval.runtime=docker \
+    --eval.docker.pull=true
+```
+
+Build benchmark images locally:
+
+```bash
+make build-eval-images
+```
+
+## Fast single-machine eval tuning
+
+`lerobot-eval` now has two orthogonal throughput knobs:
+
+- `eval.batch_size`: number of sub-envs per task (inside one vector env).
+- `env.max_parallel_tasks`: number of tasks scheduled concurrently.
+- `eval.instance_count`: number of full eval instances (process-level sharding).
+
+Use them in this order:
+
+1. Increase `eval.batch_size` first for per-task throughput.
+2. Then increase `env.max_parallel_tasks` to overlap tasks, while monitoring RAM/VRAM.
+3. Optionally increase `eval.instance_count` for process-level parallelism (best with enough CPU/RAM and small models).
+
+The eval logs print the active scheduler mode (`sequential`, `threaded`, or `batched_lazy`) so you can verify the effective concurrency path.
+
+### Suggested starting points
+
+| Benchmark | Conservative | Faster (single GPU) | Notes |
+|---|---|---|---|
+| `libero` / `libero_plus` | `eval.batch_size=1`, `env.max_parallel_tasks=4` | `eval.batch_size=1`, `env.max_parallel_tasks=16` | For large suite sweeps, increase `max_parallel_tasks` before `batch_size` to avoid MuJoCo memory spikes. |
+| `metaworld` | `eval.batch_size=8`, `env.max_parallel_tasks=1` | `eval.batch_size=16`, `env.max_parallel_tasks=2` | Prefer larger per-task vectorization first. |
+| `robocasa` | `eval.batch_size=4`, `env.max_parallel_tasks=1` | `eval.batch_size=8`, `env.max_parallel_tasks=2` | Rendering/memory can dominate at high image resolution. |
+| `robomme` | `eval.batch_size=4`, `env.max_parallel_tasks=1` | `eval.batch_size=8`, `env.max_parallel_tasks=2` | Start small and scale gradually with task count. |
+
+### Local fast eval recipe
+
+```bash
+lerobot-eval \
+  --policy.path=$HF_USER/smolvla_libero_plus \
+  --env.type=libero_plus \
+  --eval.n_episodes=1 \
+  --eval.batch_size=1 \
+  --env.max_parallel_tasks=16 \
+  --eval.instance_count=2 \
+  --rename_map='{"observation.images.image":"observation.images.camera1","observation.images.image2":"observation.images.camera2"}' \
+  --output_dir=outputs/eval/smolvla_libero_plus \
+  --push_to_hub=true
+```
+
+### Docker fast eval recipe
+
+```bash
+lerobot-eval \
+  --policy.path=$HF_USER/smolvla_libero_plus \
+  --env.type=libero_plus \
+  --eval.runtime=docker \
+  --eval.docker.envhub_ref=envhub://lerobot/libero_plus@v1 \
+  --eval.docker.gpus=all \
+  --eval.docker.shm_size=16g \
+  --eval.n_episodes=1 \
+  --eval.batch_size=1 \
+  --env.max_parallel_tasks=16
+```
+
 ## Quick start — single benchmark
 
 Train SmolVLA on LIBERO-plus with 4 GPUs for 50 000 steps:
@@ -95,7 +205,7 @@ lerobot-benchmark all \
 For each benchmark the runner:
 1. Trains a policy on its dataset.
 2. Evaluates on every eval task in the benchmark (e.g. 4 suites for LIBERO).
-3. Uploads eval results + videos to the Hub.
+3. Pushes HF-native `.eval_results` rows (and optional artifacts) to the Hub.
 
 <Tip>
 
@@ -140,7 +250,9 @@ for SUITE in libero_spatial libero_object libero_goal libero_10; do
         --eval.n_episodes=50 \
         --eval.batch_size=10 \
         --output_dir=outputs/eval/smolvla_libero_plus/$SUITE \
-        --policy.device=cuda
+        --policy.device=cuda \
+        --push_to_hub=true \
+        --benchmark_dataset_id=lerobot/sim-benchmarks
 done
 ```
 
@@ -226,28 +338,44 @@ outputs/
 
 Each `eval_info.json` contains per-episode rewards, success rates, and aggregate metrics.
 
-## Uploading eval results to the Hub
+## HF Eval Results + Leaderboard
 
-Add `--push-eval-to-hub` to upload evaluation metrics and videos to the policy's
+LeRobot publishes benchmark scores using Hugging Face's native
-Hub repo after each eval run:
+`/.eval_results/*.yaml` format, which powers model-page eval cards and
+benchmark leaderboards.
+
+Add `--push-eval-to-hub` to push results after each eval run:
 
 ```bash
 lerobot-benchmark eval \
     --benchmarks libero_plus,robocasa \
     --hub-user $HF_USER \
+    --benchmark-dataset-id lerobot/sim-benchmarks \
     --push-eval-to-hub
 ```
 
-For LIBERO-plus, each suite's results are uploaded to `eval/libero_spatial/`,
+This writes one or more files under `.eval_results/` in the model repo, for example:
-`eval/libero_object/`, etc. inside the `$HF_USER/smolvla_libero_plus` model repo.
 
-This also works with the `all` subcommand — pass `--push-eval-to-hub` and results
+```yaml
-are automatically uploaded after each eval run.
+- dataset:
+    id: lerobot/sim-benchmarks
+    task_id: libero_plus/spatial
+  value: 82.4
+  notes: lerobot-eval
+```
+
+Notes:
+- `--benchmark-dataset-id` points to your consolidated benchmark dataset repo.
+- `task_id` values are derived from `env.type` and evaluated suite/task names.
+- Eval artifacts (`eval_info.json`, `eval_config.json`, videos) are still uploaded
+  for provenance, but leaderboard ranking comes from `.eval_results`.
 
 ## Passing extra arguments
 
 Any arguments after the recognized flags are forwarded to `lerobot-train` or
-`lerobot-eval`. For example, to use PEFT/LoRA during training:
+`lerobot-eval`.
+
+Example (training): use PEFT/LoRA during training.
 
 ```bash
 lerobot-benchmark train \
@@ -258,3 +386,13 @@ lerobot-benchmark train \
     --steps 50000 \
     --peft.method_type=LORA --peft.r=16
 ```
+
+Example (evaluation): forward Docker runtime flags to each `lerobot-eval` call.
+
+```bash
+lerobot-benchmark eval \
+    --benchmarks libero_plus \
+    --hub-user $HF_USER \
+    --eval.runtime=docker \
+    --eval.docker.envhub_ref=envhub://lerobot/libero_plus@v1
+```

src/lerobot/configs/default.py

@@ -49,15 +49,51 @@ class WandBConfig:
     mode: str | None = None  # Allowed values: 'online', 'offline' 'disabled'. Defaults to 'online'
 
 
+@dataclass
+class EvalDockerConfig:
+    # Docker image to use for evaluation (e.g., "ghcr.io/org/lerobot-eval-libero:latest").
+    # Takes precedence over eval.envhub_ref.
+    image: str | None = None
+    # Optional EnvHub reference to resolve an image, e.g. "envhub://lerobot/libero_plus@v1".
+    envhub_ref: str | None = None
+    # If true, mount the local repository and prefer local source code in the container.
+    use_local_code: bool = True
+    # Pull the image before running.
+    pull: bool = True
+    # Docker --gpus value. Set to None to disable GPU flags and run CPU-only.
+    gpus: str | None = "all"
+    # Docker --shm-size value (increase when using larger eval.batch_size values).
+    shm_size: str = "8g"
+
+
 @dataclass
 class EvalConfig:
     n_episodes: int = 50
-    # `batch_size` specifies the number of environments to use in a gym.vector.VectorEnv.
+    # Number of sub-envs per task inside one VectorEnv. Increase to improve per-task
+    # inference throughput until GPU or simulator memory saturates.
     batch_size: int = 50
-    # `use_async_envs` specifies whether to use asynchronous environments (multiprocessing).
+    # Use AsyncVectorEnv (multiprocessing). Prefer SyncVectorEnv unless your environment
+    # spends significant time in Python-side stepping and can benefit from process parallelism.
     use_async_envs: bool = False
+    # Runtime where evaluation executes: "local" or "docker".
+    runtime: str = "local"
+    docker: EvalDockerConfig = field(default_factory=EvalDockerConfig)
+    # Number of parallel eval script instances to launch for one run.
+    # instance_count > 1 enables multi-instance task sharding.
+    instance_count: int = 1
+    # 0-indexed shard id for this process. Users usually leave this at 0.
+    # Additional shards are launched automatically by `lerobot-eval` when instance_count > 1.
+    instance_id: int = 0
 
     def __post_init__(self) -> None:
+        if self.runtime not in {"local", "docker"}:
+            raise ValueError(f"Unsupported eval.runtime '{self.runtime}'. Expected one of: local, docker.")
+        if self.instance_count < 1:
+            raise ValueError("eval.instance_count must be >= 1.")
+        if self.instance_id < 0 or self.instance_id >= self.instance_count:
+            raise ValueError(
+                f"eval.instance_id must be in [0, {self.instance_count - 1}] (got {self.instance_id})."
+            )
         if self.batch_size > self.n_episodes:
             raise ValueError(
                 "The eval batch size is greater than the number of eval episodes "

src/lerobot/envs/configs.py

@@ -45,6 +45,10 @@ class EnvConfig(draccus.ChoiceRegistry, abc.ABC):
     fps: int = 30
     features: dict[str, PolicyFeature] = field(default_factory=dict)
     features_map: dict[str, str] = field(default_factory=dict)
+    # Upper bound on concurrent task evaluation in `lerobot-eval`.
+    # - For lazy wrappers (e.g. LIBERO/LIBERO-plus), values >1 can enable chunked
+    #   task batching with one policy forward pass over multiple tasks.
+    # - For other envs, values >1 use a threaded task scheduler fallback.
     max_parallel_tasks: int = 1
     disable_env_checker: bool = True
 
@@ -356,7 +360,7 @@ class LiberoPlusEnv(LiberoEnv):
     in experiment configs (`env.type=libero_plus`).
     """
 
-    task: str = "libero_spatial"
+    task: str = "libero_spatial,libero_object,libero_goal,libero_10"
 
 
 @EnvConfig.register_subclass("robocasa")

src/lerobot/envs/factory.py

@@ -125,7 +125,7 @@ def make_env(
     use_async_envs: bool = False,
     hub_cache_dir: str | None = None,
     trust_remote_code: bool = False,
-) -> dict[str, dict[int, gym.vector.VectorEnv]]:
+) -> dict[str, dict[int, Any]]:
     """Makes a gym vector environment according to the config or Hub reference.
 
     Args:
@@ -143,8 +143,9 @@ def make_env(
         ModuleNotFoundError: If the requested env package is not installed
 
     Returns:
-        dict[str, dict[int, gym.vector.VectorEnv]]:
+        dict[str, dict[int, Any]]:
-            A mapping from suite name to indexed vectorized environments.
+            A mapping from suite name to indexed environments. Values are either
+            materialized vector envs or lazy wrappers that materialize on first use.
             - For multi-task benchmarks (e.g., LIBERO): one entry per suite, and one vec env per task_id.
             - For single-task environments: a single suite entry (cfg.type) with task_id=0.
 

src/lerobot/envs/lazy_vec_env.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+from __future__ import annotations
+
+from collections.abc import Callable, Sequence
+from typing import Any
+
+
+class LazyVectorEnv:
+    """Defer vector-env construction until first usage.
+
+    This is useful for benchmarks with many tasks: we can register one env object
+    per task without eagerly allocating all simulator/rendering resources.
+    """
+
+    def __init__(self, env_cls: Callable[[Sequence[Callable[[], Any]]], Any], factory_fns: list[Callable]):
+        self._env_cls = env_cls
+        self._factory_fns = factory_fns
+        self._env = None
+
+    @property
+    def env_cls(self) -> Callable[[Sequence[Callable[[], Any]]], Any]:
+        return self._env_cls
+
+    @property
+    def factory_fns(self) -> list[Callable]:
+        return self._factory_fns
+
+    @property
+    def num_factory_fns(self) -> int:
+        return len(self._factory_fns)
+
+    def materialize(self):
+        if self._env is None:
+            self._env = self._env_cls(self._factory_fns)
+        return self._env
+
+    def close(self):
+        if self._env is not None:
+            self._env.close()
+            self._env = None
+
+    def __getattr__(self, name):
+        return getattr(self.materialize(), name)
+

src/lerobot/envs/libero.py

@@ -75,6 +75,7 @@ if "wand" not in sys.modules:
 from libero.libero import benchmark, get_libero_path
 from libero.libero.envs import OffScreenRenderEnv
 
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
 from lerobot.processor import RobotObservation
 
 _ASSET_DOWNLOAD_INSTRUCTIONS = """\
@@ -104,6 +105,145 @@ def _check_libero_plus_assets() -> None:
         raise FileNotFoundError(_ASSET_DOWNLOAD_INSTRUCTIONS.format(assets_dir=assets_dir))
 
 
+# ---- Perturbation support for LIBERO-Plus -----------------------------------
+
+PERTURBATION_DIMENSIONS = (
+    "Camera Viewpoints",
+    "Robot Initial States",
+    "Language Instructions",
+    "Light Conditions",
+    "Background Textures",
+    "Sensor Noise",
+    "Objects Layout",
+)
+
+PERTURBATION_SHORT_KEYS = {
+    "Camera Viewpoints": "camera",
+    "Robot Initial States": "robot",
+    "Language Instructions": "language",
+    "Light Conditions": "light",
+    "Background Textures": "background",
+    "Sensor Noise": "noise",
+    "Objects Layout": "layout",
+}
+
+
+def load_task_classification() -> dict:
+    """Load task_classification.json shipped with LIBERO-Plus."""
+    import json
+
+    benchmark_root = Path(get_libero_path("benchmark_root"))
+    candidates = [
+        benchmark_root / "benchmark" / "task_classification.json",
+        benchmark_root / "task_classification.json",
+        benchmark_root.parent / "benchmark" / "task_classification.json",
+    ]
+    for p in candidates:
+        if p.exists():
+            with open(p) as f:
+                return json.load(f)
+    raise FileNotFoundError(
+        f"task_classification.json not found. Tried: {[str(c) for c in candidates]}"
+    )
+
+
+def build_perturbation_index(suite_name: str) -> dict[int, str]:
+    """Return {0-indexed task_id: perturbation_dimension} for *suite_name*."""
+    tc = load_task_classification()
+    suite_data = tc.get(suite_name, {})
+    index: dict[int, str] = {}
+
+    # LIBERO-Plus task_classification.json has appeared in two shapes:
+    # 1) dict[suite][task_id_str] -> meta
+    # 2) dict[suite] -> list[{id, category, ...}]
+    if isinstance(suite_data, list):
+        for item in suite_data:
+            if not isinstance(item, dict):
+                continue
+            raw_id = item.get("id")
+            if raw_id is None:
+                continue
+            try:
+                # list-form ids are 1-indexed in current LIBERO-Plus release.
+                tid = int(raw_id) - 1
+            except (TypeError, ValueError):
+                continue
+            if tid < 0:
+                continue
+            dim = item.get("perturbation_type") or item.get("category", "unknown")
+            index[tid] = dim
+        return index
+
+    if isinstance(suite_data, dict):
+        # Handle both 0-indexed and 1-indexed key conventions.
+        numeric_keys: list[int] = []
+        for k in suite_data:
+            try:
+                numeric_keys.append(int(k))
+            except (TypeError, ValueError):
+                continue
+        one_indexed = bool(numeric_keys) and 0 not in numeric_keys and min(numeric_keys) >= 1
+
+        for task_id_str, meta in suite_data.items():
+            try:
+                tid = int(task_id_str)
+            except (TypeError, ValueError):
+                continue
+            if one_indexed:
+                tid -= 1
+            if tid < 0:
+                continue
+            if isinstance(meta, dict):
+                dim = meta.get("perturbation_type") or meta.get("category", "unknown")
+            else:
+                dim = "unknown"
+            index[tid] = dim
+        return index
+
+    return index
+
+
+def aggregate_by_perturbation(
+    per_task: list[dict], suite_indices: dict[str, dict[int, str]]
+) -> dict[str, dict]:
+    """Aggregate per-task eval results by perturbation dimension.
+
+    Args:
+        per_task: list of {"task_group": str, "task_id": int, "metrics": {...}}
+        suite_indices: {suite_name: {task_id: dimension_name}} from build_perturbation_index
+
+    Returns:
+        {short_key: {"pc_success": float, "n_episodes": int}} for each perturbation dimension
+    """
+    dim_successes: dict[str, list] = defaultdict(list)
+    for entry in per_task:
+        suite = entry["task_group"]
+        tid = entry["task_id"]
+        idx = suite_indices.get(suite, {})
+        dim = idx.get(tid, "unknown")
+        short = PERTURBATION_SHORT_KEYS.get(dim, dim.lower().replace(" ", "_"))
+        successes = entry["metrics"].get("successes", [])
+        dim_successes[short].extend(successes)
+
+    results: dict[str, dict] = {}
+    all_successes: list = []
+    for short_key in list(PERTURBATION_SHORT_KEYS.values()) + ["unknown"]:
+        if short_key not in dim_successes:
+            continue
+        s = dim_successes[short_key]
+        all_successes.extend(s)
+        results[short_key] = {
+            "pc_success": float(np.nanmean(s) * 100) if s else float("nan"),
+            "n_episodes": len(s),
+        }
+    if all_successes:
+        results["total"] = {
+            "pc_success": float(np.nanmean(all_successes) * 100),
+            "n_episodes": len(all_successes),
+        }
+    return results
+
+
 def _parse_camera_names(camera_name: str | Sequence[str]) -> list[str]:
     """Normalize camera_name into a non-empty list of strings."""
     if isinstance(camera_name, str):
@@ -143,26 +283,31 @@ def get_task_init_states(task_suite: Any, i: int) -> np.ndarray:
     init_states_dir = Path(get_libero_path("init_states")) / task_suite.tasks[i].problem_folder
     init_states_file = task_suite.tasks[i].init_states_file
 
-    candidate_names = [init_states_file]
+    # 1. Direct match
-    # Some LIBERO-plus task names include a "_table_<n>" suffix while shipped
+    direct = init_states_dir / init_states_file
-    # init files use the base name without that table suffix.
+    if direct.exists():
-    if "_table_" in init_states_file:
+        return torch.load(direct, weights_only=False)  # nosec B614
-        candidate_names.append(re.sub(r"_table_\d+(?=\.pruned_init$|\.init$)", "", init_states_file))
 
-    for name in candidate_names:
+    # 2. LIBERO-Plus perturbation filenames append suffixes like
-        candidate_path = init_states_dir / name
+    #    _view_0_0_100_0_0_initstate_1, _language_19, _noise_45, _table_1, _tb_9, _add_16
-        if candidate_path.exists():
+    #    to the base task name.  Instead of regex-matching every variant, find the
-            return torch.load(candidate_path, weights_only=False)  # nosec B614
+    #    longest existing base file whose stem is a prefix of the perturbation stem.
+    stem, ext = os.path.splitext(init_states_file)
+    best_match: Path | None = None
+    best_len = 0
+    for candidate in init_states_dir.glob(f"*{ext}"):
+        cstem = candidate.stem
+        if stem == cstem or (stem.startswith(cstem) and stem[len(cstem)] == "_"):
+            if len(cstem) > best_len:
+                best_len = len(cstem)
+                best_match = candidate
 
-    # Last-resort fallback: pick any file matching the base prefix + extension.
+    if best_match is not None:
-    stem, suffix = os.path.splitext(init_states_file)
+        return torch.load(best_match, weights_only=False)  # nosec B614
-    stem = re.sub(r"_table_\d+$", "", stem)
-    fallback_matches = sorted(init_states_dir.glob(f"{stem}*{suffix}"))
-    if fallback_matches:
-        return torch.load(fallback_matches[0], weights_only=False)  # nosec B614
 
     raise FileNotFoundError(
-        f"Could not find init states for task {i}. Tried {candidate_names} in '{init_states_dir}'."
+        f"Could not find init states for task {i}. "
+        f"Tried '{init_states_file}' and prefix matching in '{init_states_dir}'."
     )
 
 
@@ -259,6 +404,7 @@ class LiberoEnv(gym.Env):
         # Load once and keep
         self._init_states = get_task_init_states(task_suite, self.task_id) if self.init_states else None
         self._reset_stride = n_envs  # when performing a reset, append `_reset_stride` to `init_state_id`.
+        self._init_state_error_warned = False
 
         self.init_state_id = self.episode_index  # tie each sub-env to a fixed init state
 
@@ -410,8 +556,21 @@ class LiberoEnv(gym.Env):
         self._env.seed(seed)
         raw_obs = self._env.reset()
         if self.init_states and self._init_states is not None:
+            try:
                 raw_obs = self._env.set_init_state(self._init_states[self.init_state_id % len(self._init_states)])
                 self.init_state_id += self._reset_stride  # Change init_state_id when reset
+            except Exception as exc:
+                # Some LIBERO-Plus perturbation tasks (notably object-layout variants)
+                # can have different simulator state dimensions than their base init files.
+                # Fall back to plain env.reset() instead of aborting the whole evaluation.
+                self.init_states = False
+                if not self._init_state_error_warned:
+                    print(
+                        "WARNING: Failed to apply init state for "
+                        f"task_id={self.task_id} ({self.task}). "
+                        f"Falling back to plain reset. Error: {exc}"
+                    )
+                    self._init_state_error_warned = True
 
         # After reset, objects may be unstable (slightly floating, intersecting, etc.).
         # Step the simulator with a no-op action for a few frames so everything settles.
@@ -500,6 +659,9 @@ def _make_env_fns(
     return fns
 
 
+_LazyVecEnv = LazyVectorEnv
+
+
 # ---- Main API ----------------------------------------------------------------
 
 
@@ -543,12 +705,23 @@ def create_libero_envs(
         print(f"Restricting to task_ids={task_ids_filter}")
 
     out: dict[str, dict[int, Any]] = defaultdict(dict)
+    total_tasks = 0
     for suite_name in suite_names:
         suite = _get_suite(suite_name)
         total = len(suite.tasks)
         selected = _select_task_ids(total, task_ids_filter)
         if not selected:
             raise ValueError(f"No tasks selected for suite '{suite_name}' (available: {total}).")
+        total_tasks += len(selected)
+
+    lazy = total_tasks > 50
+    if lazy:
+        print(f"Using lazy env creation for {total_tasks} tasks (envs created on demand)")
+
+    for suite_name in suite_names:
+        suite = _get_suite(suite_name)
+        total = len(suite.tasks)
+        selected = _select_task_ids(total, task_ids_filter)
 
         for tid in selected:
             fns = _make_env_fns(
@@ -562,6 +735,9 @@ def create_libero_envs(
                 gym_kwargs=gym_kwargs,
                 control_mode=control_mode,
             )
+            if lazy:
+                out[suite_name][tid] = LazyVectorEnv(env_cls, fns)
+            else:
                 out[suite_name][tid] = env_cls(fns)
                 print(f"Built vec env | suite={suite_name} | task_id={tid} | n_envs={n_envs}")
 

src/lerobot/envs/metaworld.py

@@ -25,6 +25,7 @@ import metaworld.policies as policies
 import numpy as np
 from gymnasium import spaces
 
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
 from lerobot.processor import RobotObservation
 
 # ---- Load configuration data from the external JSON file ----
@@ -297,19 +298,24 @@ def create_metaworld_envs(
 
     print(f"Creating Meta-World envs | task_groups={task_groups} | n_envs(per task)={n_envs}")
 
+    group_to_tasks = {group: DIFFICULTY_TO_TASKS.get(group, [group]) for group in task_groups}
+    total_tasks = sum(len(tasks) for tasks in group_to_tasks.values())
+    lazy = total_tasks > 50
+    if lazy:
+        print(f"Using lazy env creation for {total_tasks} tasks (envs created on demand)")
+
     out: dict[str, dict[int, Any]] = defaultdict(dict)
 
     for group in task_groups:
-        # if not in difficulty presets, treat it as a single custom task
+        tasks = group_to_tasks[group]
-        tasks = DIFFICULTY_TO_TASKS.get(group, [group])
 
         for tid, task_name in enumerate(tasks):
+            if not lazy:
                 print(f"Building vec env | group={group} | task_id={tid} | task={task_name}")
 
             # build n_envs factories
             fns = [(lambda tn=task_name: MetaworldEnv(task=tn, **gym_kwargs)) for _ in range(n_envs)]
-
+            out[group][tid] = LazyVectorEnv(env_cls, fns) if lazy else env_cls(fns)
-            out[group][tid] = env_cls(fns)
 
     # return a plain dict for consistency
     return {group: dict(task_map) for group, task_map in out.items()}

src/lerobot/envs/robocasa.py

@@ -24,6 +24,7 @@ import gymnasium as gym
 import numpy as np
 from gymnasium import spaces
 
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
 
 # Action layout (flat 12D, normalized to [-1, 1]):
 #   [0:3]   end_effector_position  (delta x, y, z)
@@ -256,8 +257,12 @@ def create_robocasa_envs(
 
     gym_kwargs = dict(gym_kwargs or {})
     out: dict[str, dict[int, Any]] = defaultdict(dict)
+    total_tasks = len(task_list)
+    lazy = total_tasks > 50
 
     print(f"Creating RoboCasa envs | tasks={task_list} | n_envs(per task)={n_envs} | split={split}")
+    if lazy:
+        print(f"Using lazy env creation for {total_tasks} tasks (envs created on demand)")
     for task in task_list:
         fns = _make_env_fns(
             task=task,
@@ -267,7 +272,8 @@ def create_robocasa_envs(
             episode_length=episode_length,
             gym_kwargs=gym_kwargs,
         )
-        out["robocasa"][len(out["robocasa"])] = env_cls(fns)
+        out["robocasa"][len(out["robocasa"])] = LazyVectorEnv(env_cls, fns) if lazy else env_cls(fns)
+        if not lazy:
             print(f"  Built vec env | task={task} | n_envs={n_envs}")
 
     return {suite: dict(task_map) for suite, task_map in out.items()}

src/lerobot/envs/robomme.py

@@ -14,12 +14,16 @@ Install: pip install robomme  (or from source: https://github.com/RoboMME/robomm
 
 from __future__ import annotations
 
+from collections.abc import Callable, Sequence
+from functools import partial
 from typing import Any
 
 import gymnasium as gym
 import numpy as np
 from gymnasium import spaces
 
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
+
 ROBOMME_TASKS = [
     "BinFill", "PickXtimes", "SwingXtimes", "StopCube",
     "VideoUnmask", "VideoUnmaskSwap", "ButtonUnmask", "ButtonUnmaskSwap",
@@ -113,6 +117,29 @@ class RoboMMEGymEnv(gym.Env):
         }
 
 
+def _make_env_fns(
+    *,
+    task: str,
+    n_envs: int,
+    action_space_type: str,
+    dataset: str,
+    episode_length: int,
+    task_id: int,
+) -> list[Callable[[], RoboMMEGymEnv]]:
+    """Build n_envs factory callables for one RoboMME task id."""
+
+    def _make_one(episode_index: int) -> RoboMMEGymEnv:
+        return RoboMMEGymEnv(
+            task=task,
+            action_space_type=action_space_type,
+            dataset=dataset,
+            episode_idx=episode_index,
+            max_steps=episode_length,
+        )
+
+    return [partial(_make_one, task_id + i) for i in range(n_envs)]
+
+
 def create_robomme_envs(
     task: str,
     n_envs: int = 1,
@@ -120,35 +147,35 @@ def create_robomme_envs(
     dataset: str = "test",
     episode_length: int = 300,
     task_ids: list[int] | None = None,
-    env_cls=None,
+    env_cls: Callable[[Sequence[Callable[[], Any]]], Any] | None = None,
 ) -> dict[str, dict[int, gym.vector.VectorEnv]]:
     """Create vectorized RoboMME environments for evaluation.
 
     Returns {suite_name: {task_id: VectorEnv}} matching lerobot's expected format.
     """
-    if env_cls is None:
+    if env_cls is None or not callable(env_cls):
-        env_cls = gym.vector.SyncVectorEnv
+        raise ValueError("env_cls must be a callable that wraps a list of env factory callables.")
+    if not isinstance(n_envs, int) or n_envs <= 0:
+        raise ValueError(f"n_envs must be a positive int; got {n_envs}.")
 
     if task_ids is None:
         task_ids = [0]
 
     suite_name = "robomme"
     envs_by_task = {}
+    lazy = len(task_ids) > 50
+    if lazy:
+        print(f"Using lazy env creation for {len(task_ids)} tasks (envs created on demand)")
 
     for task_id in task_ids:
-        def _make_one(ep_idx=task_id):
+        fns = _make_env_fns(
-            return RoboMMEGymEnv(
             task=task,
+            n_envs=n_envs,
             action_space_type=action_space_type,
             dataset=dataset,
-                episode_idx=ep_idx,
+            episode_length=episode_length,
-                max_steps=episode_length,
+            task_id=task_id,
         )
-
+        envs_by_task[task_id] = LazyVectorEnv(env_cls, fns) if lazy else env_cls(fns)
-        vec = env_cls(
-            [_make_one for _ in range(n_envs)],
-            autoreset_mode=gym.vector.AutoresetMode.SAME_STEP,
-        )
-        envs_by_task[task_id] = vec
 
     return {suite_name: envs_by_task}

src/lerobot/scripts/lerobot_eval.py

@@ -49,7 +49,9 @@ You can learn about the CLI options for this script in the `EvalPipelineConfig`
 import concurrent.futures as cf
 import json
 import logging
-import re
+import shutil
+import subprocess
+import sys
 import threading
 import time
 from collections import defaultdict
@@ -72,6 +74,8 @@ from tqdm import trange
 
 from lerobot.configs import parser
 from lerobot.configs.eval import EvalPipelineConfig
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
+from lerobot.envs.docker_runtime import run_eval_in_docker
 from lerobot.envs.factory import make_env, make_env_pre_post_processors
 from lerobot.envs.utils import (
     add_envs_task,
@@ -86,6 +90,11 @@ from lerobot.utils.constants import ACTION, DONE, OBS_STR, REWARD
 from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.io_utils import write_video
 from lerobot.utils.random_utils import set_seed
+from lerobot.utils.hf_eval_results import (
+    build_eval_results_rows,
+    default_eval_date,
+    upload_eval_results_yaml,
+)
 from lerobot.utils.utils import (
     get_safe_torch_device,
     init_logging,
@@ -521,16 +530,22 @@ def push_eval_to_hub(
     output_dir: Path,
     info: dict,
     env_type: str,
-    eval_config: dict | None = None,
+    env_task: str | None,
+    benchmark_dataset_id: str,
+    source_url: str | None = None,
+    notes: str | None = None,
 ) -> str:
-    """Upload eval results, videos, config, and an updated model card to the Hub.
+    """Upload eval artifacts and `.eval_results` rows to the Hub.
 
     Args:
         repo_id: HF model repo (e.g. "user/my_policy").
         output_dir: Local directory containing eval_info.json and videos/.
         info: The eval results dict (as returned by eval_policy_all).
         env_type: Environment type string (e.g. "libero_plus", "pusht").
-        eval_config: Serialized EvalPipelineConfig dict (policy + env + eval settings).
+        env_task: The env task string from eval config.
+        benchmark_dataset_id: HF dataset id of the consolidated benchmark dataset.
+        source_url: Optional source URL for `.eval_results` attribution.
+        notes: Optional setup notes to include in `.eval_results`.
 
     Returns:
         URL of the last Hub commit.
@@ -572,96 +587,95 @@ def push_eval_to_hub(
             commit_message=f"Upload eval rollout videos for {env_type}",
         )
 
-    # 4. Update the model card with an eval results table and config summary
+    # 4. Upload HF-native `.eval_results` rows (canonical leaderboard surface).
-    _update_model_card_with_eval(api, repo_id, info, env_type, eval_config=eval_config)
+    rows = build_eval_results_rows(
+        info=info,
+        env_type=env_type,
+        env_task=env_task,
+        benchmark_dataset_id=benchmark_dataset_id,
+        source_url=source_url,
+        notes=notes,
+        eval_date=default_eval_date(),
+    )
+    commit_url = upload_eval_results_yaml(
+        api=api,
+        repo_id=repo_id,
+        rows=rows,
+        env_type=env_type,
+        env_task=env_task,
+        output_dir=output_dir,
+    )
 
     logging.info(f"Eval results pushed to https://huggingface.co/{repo_id}")
     return commit_url
 
 
-def _format_eval_table(info: dict, env_type: str, eval_config: dict | None = None) -> str:
-    """Build a markdown table from eval results, optionally including config."""
-    lines = [
-        f"### Evaluation: `{env_type}`\n",
-        "| Suite | Success Rate (%) | Avg Sum Reward | Episodes |",
-        "|-------|-----------------|----------------|----------|",
-    ]
-
-    per_group = info.get("per_group", {})
-    for group_name, stats in sorted(per_group.items()):
-        sr = stats.get("pc_success", float("nan"))
-        reward = stats.get("avg_sum_reward", float("nan"))
-        n_ep = stats.get("n_episodes", 0)
-        lines.append(f"| {group_name} | {sr:.1f} | {reward:.2f} | {n_ep} |")
-
-    overall = info.get("overall", {})
-    if overall:
-        sr = overall.get("pc_success", float("nan"))
-        reward = overall.get("avg_sum_reward", float("nan"))
-        n_ep = overall.get("n_episodes", 0)
-        lines.append(f"| **Overall** | **{sr:.1f}** | **{reward:.2f}** | **{n_ep}** |")
-
-    if eval_config:
-        lines.append("")
-        lines.append("<details><summary>Eval configuration</summary>\n")
-        lines.append("```json")
-        lines.append(json.dumps(eval_config, indent=2))
-        lines.append("```\n")
-        lines.append("</details>")
-
-    video_paths = overall.get("video_paths", [])
-    if video_paths:
-        lines.append("")
-        lines.append("<details><summary>Rollout videos</summary>\n")
-        for vp in video_paths[:10]:
-            video_name = Path(vp).name
-            parent = Path(vp).parent.name
-            lines.append(f"**{parent}/{video_name}**\n")
-            lines.append(f"![{video_name}](eval/{env_type}/videos/{parent}/{video_name})\n")
-        lines.append("</details>")
-
-    return "\n".join(lines)
-
-
-def _update_model_card_with_eval(
-    api: Any, repo_id: str, info: dict, env_type: str, eval_config: dict | None = None
-) -> None:
-    """Append or replace the eval section in the model card README."""
-    from huggingface_hub import ModelCard
-
-    try:
-        card = ModelCard.load(repo_id)
-    except Exception:
-        card = ModelCard("")
-
-    content = card.content or ""
-
-    eval_table = _format_eval_table(info, env_type, eval_config=eval_config)
-
-    section_marker_start = f"<!-- eval-results-{env_type}-start -->"
-    section_marker_end = f"<!-- eval-results-{env_type}-end -->"
-    new_section = f"{section_marker_start}\n{eval_table}\n{section_marker_end}"
-
-    if section_marker_start in content:
-        content = re.sub(
-            rf"{re.escape(section_marker_start)}.*?{re.escape(section_marker_end)}",
-            new_section,
-            content,
-            flags=re.DOTALL,
-        )
-    else:
-        eval_header = "\n## Evaluation Results\n\n"
-        if "## Evaluation Results" not in content:
-            content += eval_header
-        content += f"\n{new_section}\n"
-
-    card.content = content
-    card.push_to_hub(repo_id, commit_message=f"Update eval results for {env_type}")
-
-
 @parser.wrap()
 def eval_main(cfg: EvalPipelineConfig):
     logging.info(pformat(asdict(cfg)))
+    if cfg.eval.instance_count > 1 and cfg.eval.instance_id == 0:
+        _orchestrate_multi_instance_eval(cfg)
+    else:
+        _run_eval_worker(cfg)
+
+
+def _maybe_add_libero_plus_perturbation(info: dict, cfg: EvalPipelineConfig) -> None:
+    if cfg.env.type != "libero_plus":
+        return
+    try:
+        from lerobot.envs.libero import aggregate_by_perturbation, build_perturbation_index
+
+        suite_names = [s.strip() for s in cfg.env.task.split(",") if s.strip()]
+        suite_indices = {s: build_perturbation_index(s) for s in suite_names}
+        perturbation_results = aggregate_by_perturbation(info["per_task"], suite_indices)
+        info["perturbation_results"] = perturbation_results
+        print("\n=== Perturbation Results ===")
+        for dim, stats in perturbation_results.items():
+            print(f"  {dim}: {stats['pc_success']:.1f}% ({stats['n_episodes']} episodes)")
+    except Exception as exc:
+        # Never fail a finished long-running eval on post-processing.
+        print(f"WARNING: Failed to compute LIBERO-Plus perturbation breakdown: {exc}")
+        print("Continuing with per-suite + overall metrics only.")
+
+
+def _save_eval_outputs(cfg: EvalPipelineConfig, info: dict) -> None:
+    output_dir = Path(cfg.output_dir)
+    output_dir.mkdir(parents=True, exist_ok=True)
+    with open(output_dir / "eval_info.json", "w") as f:
+        json.dump(info, f, indent=2)
+
+    eval_cfg_dict = _serializable_config(asdict(cfg))
+    with open(output_dir / "eval_config.json", "w") as f:
+        json.dump(eval_cfg_dict, f, indent=2)
+
+
+def _maybe_push_eval_outputs(cfg: EvalPipelineConfig, info: dict) -> None:
+    if not cfg.push_to_hub:
+        return
+    repo_id = str(cfg.policy.pretrained_path)
+    try:
+        push_eval_to_hub(
+            repo_id=repo_id,
+            output_dir=Path(cfg.output_dir),
+            info=info,
+            env_type=cfg.env.type,
+            env_task=cfg.env.task,
+            benchmark_dataset_id=cfg.benchmark_dataset_id,
+            source_url=cfg.eval_result_source_url,
+            notes=cfg.eval_result_notes,
+        )
+    except Exception as exc:
+        logging.warning("Failed to push eval artifacts/results to Hub: %s", exc)
+
+
+def _run_eval_worker(cfg: EvalPipelineConfig) -> dict:
+    logging.info(pformat(asdict(cfg)))
+
+    if cfg.eval.runtime == "docker":
+        run_eval_in_docker(cfg)
+        output_dir = Path(cfg.output_dir)
+        with open(output_dir / "eval_info.json") as f:
+            return json.load(f)
 
     # Check device is available
     device = get_safe_torch_device(cfg.policy.device, log=True)
@@ -705,6 +719,7 @@ def eval_main(cfg: EvalPipelineConfig):
     # Create environment-specific preprocessor and postprocessor (e.g., for LIBERO environments)
     env_preprocessor, env_postprocessor = make_env_pre_post_processors(env_cfg=cfg.env, policy_cfg=cfg.policy)
 
+    try:
         with torch.no_grad(), torch.autocast(device_type=device.type) if cfg.policy.use_amp else nullcontext():
             info = eval_policy_all(
                 envs=envs,
@@ -718,37 +733,106 @@ def eval_main(cfg: EvalPipelineConfig):
                 videos_dir=Path(cfg.output_dir) / "videos",
                 start_seed=cfg.seed,
                 max_parallel_tasks=cfg.env.max_parallel_tasks,
+                instance_count=cfg.eval.instance_count,
+                instance_id=cfg.eval.instance_id,
             )
             print("Overall Aggregated Metrics:")
             print(info["overall"])
 
-        # Print per-suite stats
+            for key, val in info.get("per_group", {}).items():
-        for task_group, task_group_info in info.items():
+                print(f"\nAggregated Metrics for {key}:")
-            print(f"\nAggregated Metrics for {task_group}:")
+                print(val)
-            print(task_group_info)
+
-    # Close all vec envs
+            _maybe_add_libero_plus_perturbation(info, cfg)
+    finally:
         close_envs(envs)
 
-    # Save info
+    _save_eval_outputs(cfg, info)
-    output_dir = Path(cfg.output_dir)
+    _maybe_push_eval_outputs(cfg, info)
-    output_dir.mkdir(parents=True, exist_ok=True)
-    with open(output_dir / "eval_info.json", "w") as f:
-        json.dump(info, f, indent=2)
 
-    eval_cfg_dict = _serializable_config(asdict(cfg))
+    logging.info("End of eval")
-    with open(output_dir / "eval_config.json", "w") as f:
+    return info
-        json.dump(eval_cfg_dict, f, indent=2)
 
-    if cfg.push_to_hub:
-        repo_id = str(cfg.policy.pretrained_path)
-        push_eval_to_hub(
-            repo_id=repo_id,
-            output_dir=output_dir,
-            info=info,
-            env_type=cfg.env.type,
-            eval_config=eval_cfg_dict,
-        )
 
+def _orchestrate_multi_instance_eval(cfg: EvalPipelineConfig) -> None:
+    start_t = time.time()
+    root_output_dir = Path(cfg.output_dir)
+    instances_root = root_output_dir / "instances"
+    instances_root.mkdir(parents=True, exist_ok=True)
+
+    n_instances = cfg.eval.instance_count
+    logging.info(f"Launching multi-instance eval with {n_instances} workers.")
+
+    # Spawn workers for shard 1..N-1, run shard 0 in-process.
+    child_procs: list[tuple[int, subprocess.Popen]] = []
+    argv = [
+        arg
+        for arg in sys.argv[1:]
+        if not arg.startswith("--eval.instance_id=")
+        and not arg.startswith("--output_dir=")
+        and not arg.startswith("--push_to_hub=")
+    ]
+    for i in range(1, n_instances):
+        child_output_dir = instances_root / str(i)
+        cmd = [
+            sys.executable,
+            "-m",
+            "lerobot.scripts.lerobot_eval",
+            *argv,
+            f"--eval.instance_id={i}",
+            f"--output_dir={child_output_dir}",
+            "--push_to_hub=false",
+        ]
+        logging.info("Starting eval worker %s/%s", i + 1, n_instances)
+        child_procs.append((i, subprocess.Popen(cmd)))
+
+    cfg0 = deepcopy(cfg)
+    cfg0.eval.instance_id = 0
+    cfg0.push_to_hub = False
+    cfg0.output_dir = instances_root / "0"
+    _run_eval_worker(cfg0)
+
+    failed = []
+    for idx, proc in child_procs:
+        rc = proc.wait()
+        if rc != 0:
+            failed.append((idx, rc))
+    if failed:
+        raise RuntimeError(f"Multi-instance eval failed for workers: {failed}")
+
+    partial_infos: list[dict] = []
+    for i in range(n_instances):
+        info_path = instances_root / str(i) / "eval_info.json"
+        with open(info_path) as f:
+            partial_infos.append(json.load(f))
+
+    merged_per_task = []
+    for info in partial_infos:
+        merged_per_task.extend(info.get("per_task", []))
+    merged_per_task.sort(key=lambda x: (x["task_group"], x["task_id"]))
+
+    # Merge videos from each shard into final output dir.
+    merged_videos_dir = root_output_dir / "videos"
+    for i in range(n_instances):
+        shard_dir = instances_root / str(i)
+        shard_videos = shard_dir / "videos"
+        if shard_videos.is_dir():
+            shutil.copytree(shard_videos, merged_videos_dir, dirs_exist_ok=True)
+            old_prefix = str(shard_videos)
+            new_prefix = str(merged_videos_dir)
+            for entry in merged_per_task:
+                paths = entry.get("metrics", {}).get("video_paths", [])
+                entry["metrics"]["video_paths"] = [
+                    p.replace(old_prefix, new_prefix, 1) if p.startswith(old_prefix) else p for p in paths
+                ]
+
+    merged_info = _aggregate_eval_from_per_task(merged_per_task, total_eval_s=time.time() - start_t)
+    _maybe_add_libero_plus_perturbation(merged_info, cfg)
+    print("Overall Aggregated Metrics:")
+    print(merged_info["overall"])
+
+    _save_eval_outputs(cfg, merged_info)
+    _maybe_push_eval_outputs(cfg, merged_info)
     logging.info("End of eval")
 
 
@@ -763,6 +847,177 @@ class TaskMetrics(TypedDict):
 ACC_KEYS = ("sum_rewards", "max_rewards", "successes", "video_paths")
 
 
+def _aggregate_eval_from_per_task(per_task_infos: list[dict], total_eval_s: float) -> dict:
+    """Aggregate eval metrics from per-task payloads."""
+    group_acc: dict[str, dict[str, list]] = defaultdict(lambda: {k: [] for k in ACC_KEYS})
+    overall: dict[str, list] = {k: [] for k in ACC_KEYS}
+
+    def _append(group: str, key: str, value: Any):
+        if value is None:
+            return
+        if isinstance(value, list):
+            group_acc[group][key].extend(value)
+            overall[key].extend(value)
+        else:
+            group_acc[group][key].append(value)
+            overall[key].append(value)
+
+    for entry in per_task_infos:
+        group = entry["task_group"]
+        metrics = entry["metrics"]
+        _append(group, "sum_rewards", metrics.get("sum_rewards"))
+        _append(group, "max_rewards", metrics.get("max_rewards"))
+        _append(group, "successes", metrics.get("successes"))
+        paths = metrics.get("video_paths", [])
+        if paths:
+            group_acc[group]["video_paths"].extend(paths)
+            overall["video_paths"].extend(paths)
+
+    def _agg_from_list(xs: list[float]) -> float:
+        if not xs:
+            return float("nan")
+        arr = np.array(xs, dtype=float)
+        return float(np.nanmean(arr))
+
+    groups_aggregated = {}
+    for group, acc in group_acc.items():
+        groups_aggregated[group] = {
+            "avg_sum_reward": _agg_from_list(acc["sum_rewards"]),
+            "avg_max_reward": _agg_from_list(acc["max_rewards"]),
+            "pc_success": _agg_from_list(acc["successes"]) * 100 if acc["successes"] else float("nan"),
+            "n_episodes": len(acc["sum_rewards"]),
+            "video_paths": list(acc["video_paths"]),
+        }
+
+    overall_agg = {
+        "avg_sum_reward": _agg_from_list(overall["sum_rewards"]),
+        "avg_max_reward": _agg_from_list(overall["max_rewards"]),
+        "pc_success": _agg_from_list(overall["successes"]) * 100 if overall["successes"] else float("nan"),
+        "n_episodes": len(overall["sum_rewards"]),
+        "eval_s": total_eval_s,
+        "eval_ep_s": total_eval_s / max(1, len(overall["sum_rewards"])),
+        "video_paths": list(overall["video_paths"]),
+    }
+
+    return {"per_task": per_task_infos, "per_group": groups_aggregated, "overall": overall_agg}
+
+
+def _eval_task_batch(
+    batch: list[tuple[str, int, LazyVectorEnv]],
+    policy,
+    env_preprocessor: PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
+    env_postprocessor: PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
+    preprocessor: PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
+    postprocessor: PolicyProcessorPipeline[PolicyAction, PolicyAction],
+    start_seed: int | None,
+    max_episodes_rendered: int = 0,
+    videos_dir: Path | None = None,
+) -> list[tuple[str, int, TaskMetrics]]:
+    """Evaluate N tasks in a single batched rollout for GPU efficiency.
+
+    Each task contributes one sub-env to a combined SyncVectorEnv so the policy
+    processes all N observations in one forward pass per step.
+    """
+    all_fns: list[Callable] = []
+    task_slices: list[tuple[str, int, int, int]] = []
+    offset = 0
+    for task_group, task_id, lazy_env in batch:
+        fns = lazy_env.factory_fns
+        if not fns:
+            continue
+        start = offset
+        offset += len(fns)
+        all_fns.extend(fns)
+        task_slices.append((task_group, task_id, start, offset))
+
+    if not all_fns:
+        return []
+
+    env_cls = batch[0][2].env_cls
+    combined_env = env_cls(all_fns)
+
+    try:
+        seeds = None
+        if start_seed is not None:
+            seeds = list(range(start_seed, start_seed + combined_env.num_envs))
+
+        ep_frames: list[np.ndarray] = []
+
+        def render_frame(env: gym.vector.VectorEnv):
+            if max_episodes_rendered <= 0:
+                return
+            n = min(max_episodes_rendered, env.num_envs)
+            if isinstance(env, gym.vector.SyncVectorEnv):
+                ep_frames.append(np.stack([env.envs[i].render() for i in range(n)]))
+            elif isinstance(env, gym.vector.AsyncVectorEnv):
+                ep_frames.append(np.stack(env.call("render")[:n]))
+
+        rollout_data = rollout(
+            env=combined_env,
+            policy=policy,
+            env_preprocessor=env_preprocessor,
+            env_postprocessor=env_postprocessor,
+            preprocessor=preprocessor,
+            postprocessor=postprocessor,
+            seeds=seeds,
+            render_callback=render_frame if max_episodes_rendered > 0 else None,
+        )
+
+        n_steps = rollout_data["done"].shape[1]
+        done_indices = torch.argmax(rollout_data["done"].to(int), dim=1)
+        mask = (torch.arange(n_steps) <= einops.repeat(done_indices + 1, "b -> b s", s=n_steps)).int()
+        batch_sum_rewards = einops.reduce((rollout_data["reward"] * mask), "b n -> b", "sum")
+        batch_max_rewards = einops.reduce((rollout_data["reward"] * mask), "b n -> b", "max")
+        batch_successes = einops.reduce((rollout_data["success"] * mask), "b n -> b", "any")
+
+        video_paths_per_task: dict[tuple[str, int], list[str]] = defaultdict(list)
+        if max_episodes_rendered > 0 and ep_frames and videos_dir:
+            stacked = np.stack(ep_frames, axis=1)  # (batch, time, h, w, c)
+            rendered = 0
+            threads = []
+            for tg, tid, start_i, end_i in task_slices:
+                if rendered >= max_episodes_rendered:
+                    break
+                task_dir = videos_dir / f"{tg}_{tid}"
+                task_dir.mkdir(parents=True, exist_ok=True)
+                for env_idx in range(start_i, end_i):
+                    if rendered >= max_episodes_rendered:
+                        break
+                    episode_index = env_idx - start_i
+                    video_path = task_dir / f"eval_episode_{episode_index}.mp4"
+                    video_paths_per_task[(tg, tid)].append(str(video_path))
+                    di = done_indices[env_idx].item()
+                    thread = threading.Thread(
+                        target=write_video,
+                        args=(
+                            str(video_path),
+                            stacked[env_idx, : di + 1],
+                            combined_env.unwrapped.metadata["render_fps"],
+                        ),
+                    )
+                    thread.start()
+                    threads.append(thread)
+                    rendered += 1
+            for t in threads:
+                t.join()
+
+        results: list[tuple[str, int, TaskMetrics]] = []
+        for tg, tid, start_i, end_i in task_slices:
+            results.append((
+                tg,
+                tid,
+                TaskMetrics(
+                    sum_rewards=batch_sum_rewards[start_i:end_i].tolist(),
+                    max_rewards=batch_max_rewards[start_i:end_i].tolist(),
+                    successes=batch_successes[start_i:end_i].tolist(),
+                    video_paths=video_paths_per_task.get((tg, tid), []),
+                ),
+            ))
+        return results
+    finally:
+        combined_env.close()
+
+
 def eval_one(
     env: gym.vector.VectorEnv,
     *,
@@ -807,7 +1062,7 @@ def eval_one(
 def run_one(
     task_group: str,
     task_id: int,
-    env,
+    env: Any,
     *,
     policy,
     env_preprocessor,
@@ -851,7 +1106,7 @@ def run_one(
 
 
 def eval_policy_all(
-    envs: dict[str, dict[int, gym.vector.VectorEnv]],
+    envs: dict[str, dict[int, Any]],
     policy,
     env_preprocessor: PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
     env_postprocessor: PolicyProcessorPipeline[dict[str, Any], dict[str, Any]],
@@ -864,6 +1119,8 @@ def eval_policy_all(
     return_episode_data: bool = False,
     start_seed: int | None = None,
     max_parallel_tasks: int = 1,
+    instance_count: int = 1,
+    instance_id: int = 0,
 ) -> dict:
     """
     Evaluate a nested `envs` dict: {task_group: {task_id: vec_env}}.
@@ -876,6 +1133,13 @@ def eval_policy_all(
 
     # Flatten envs into list of (task_group, task_id, env)
     tasks = [(tg, tid, vec) for tg, group in envs.items() for tid, vec in group.items()]
+    if instance_count > 1:
+        total_tasks = len(tasks)
+        tasks = [task for idx, task in enumerate(tasks) if idx % instance_count == instance_id]
+        logging.info(
+            f"Instance shard {instance_id + 1}/{instance_count}: "
+            f"{len(tasks)}/{total_tasks} tasks assigned."
+        )
 
     # accumulators: track metrics at both per-group level and across all groups
     group_acc: dict[str, dict[str, list]] = defaultdict(lambda: {k: [] for k in ACC_KEYS})
@@ -921,59 +1185,81 @@ def eval_policy_all(
         start_seed=start_seed,
     )
 
-    if max_parallel_tasks <= 1:
+    all_lazy = all(isinstance(env, LazyVectorEnv) for _, _, env in tasks)
-        # sequential path (single accumulator path on the main thread)
+    single_factory_per_task = all(
-        # NOTE: keeping a single-threaded accumulator avoids concurrent list appends or locks
+        not isinstance(env, LazyVectorEnv) or env.num_factory_fns == 1 for _, _, env in tasks
+    )
+    can_batch = max_parallel_tasks > 1 and all_lazy and single_factory_per_task and n_episodes == 1
+
+    if can_batch:
+        # Multi-task batched path: combine N tasks into one SyncVectorEnv per chunk
+        # so the policy processes all N observations in a single forward pass per step.
+        chunk_size = max_parallel_tasks
+        logging.info(f"Task scheduler mode: batched_lazy (chunk_size={chunk_size})")
+        n_chunks = (len(tasks) + chunk_size - 1) // chunk_size
+        rendered_so_far = 0
+        for chunk_idx in range(n_chunks):
+            chunk = tasks[chunk_idx * chunk_size : (chunk_idx + 1) * chunk_size]
+            render_budget = max(0, max_episodes_rendered - rendered_so_far)
+            logging.info(
+                f"Batch {chunk_idx + 1}/{n_chunks}: evaluating {len(chunk)} tasks "
+                f"({chunk_idx * chunk_size + 1}–{chunk_idx * chunk_size + len(chunk)}/{len(tasks)})"
+            )
+            batch_results = _eval_task_batch(
+                chunk,
+                policy=policy,
+                env_preprocessor=env_preprocessor,
+                env_postprocessor=env_postprocessor,
+                preprocessor=preprocessor,
+                postprocessor=postprocessor,
+                start_seed=start_seed,
+                max_episodes_rendered=render_budget,
+                videos_dir=videos_dir,
+            )
+            for tg, tid, metrics in batch_results:
+                _accumulate_to(tg, metrics)
+                per_task_infos.append({"task_group": tg, "task_id": tid, "metrics": metrics})
+                rendered_so_far += len(metrics.get("video_paths", []))
+
+            if overall["successes"]:
+                sr = np.nanmean(overall["successes"]) * 100
+                logging.info(f"  running success rate: {sr:.1f}%")
+    elif max_parallel_tasks <= 1:
+        logging.info("Task scheduler mode: sequential")
         for task_group, task_id, env in tasks:
+            try:
                 tg, tid, metrics = task_runner(task_group, task_id, env)
                 _accumulate_to(tg, metrics)
                 per_task_infos.append({"task_group": tg, "task_id": tid, "metrics": metrics})
+            finally:
+                env.close()
     else:
-        # threaded path: submit all tasks, consume completions on main thread and accumulate there
+        # Threaded fallback for cases where batched lazy mode cannot be used.
+        if all_lazy and n_episodes != 1:
+            logging.info(
+                "Task scheduler mode: threaded (lazy batching disabled because n_episodes != 1)"
+            )
+        elif all_lazy and not single_factory_per_task:
+            logging.info(
+                "Task scheduler mode: threaded (lazy batching disabled because eval.batch_size > 1)"
+            )
+        else:
+            logging.info(f"Task scheduler mode: threaded (max_workers={max_parallel_tasks})")
         with cf.ThreadPoolExecutor(max_workers=max_parallel_tasks) as executor:
-            fut2meta = {}
+            fut2meta: dict[cf.Future, tuple[str, int, Any]] = {}
             for task_group, task_id, env in tasks:
                 fut = executor.submit(task_runner, task_group, task_id, env)
-                fut2meta[fut] = (task_group, task_id)
+                fut2meta[fut] = (task_group, task_id, env)
             for fut in cf.as_completed(fut2meta):
-                tg, tid, metrics = fut.result()
+                tg, tid, env = fut2meta[fut]
+                try:
+                    _, _, metrics = fut.result()
                     _accumulate_to(tg, metrics)
                     per_task_infos.append({"task_group": tg, "task_id": tid, "metrics": metrics})
+                finally:
+                    env.close()
 
-    # compute aggregated metrics helper (robust to lists/scalars)
+    return _aggregate_eval_from_per_task(per_task_infos, total_eval_s=time.time() - start_t)
-    def _agg_from_list(xs):
-        if not xs:
-            return float("nan")
-        arr = np.array(xs, dtype=float)
-        return float(np.nanmean(arr))
-
-    # compute per-group aggregates
-    groups_aggregated = {}
-    for group, acc in group_acc.items():
-        groups_aggregated[group] = {
-            "avg_sum_reward": _agg_from_list(acc["sum_rewards"]),
-            "avg_max_reward": _agg_from_list(acc["max_rewards"]),
-            "pc_success": _agg_from_list(acc["successes"]) * 100 if acc["successes"] else float("nan"),
-            "n_episodes": len(acc["sum_rewards"]),
-            "video_paths": list(acc["video_paths"]),
-        }
-
-    # overall aggregates
-    overall_agg = {
-        "avg_sum_reward": _agg_from_list(overall["sum_rewards"]),
-        "avg_max_reward": _agg_from_list(overall["max_rewards"]),
-        "pc_success": _agg_from_list(overall["successes"]) * 100 if overall["successes"] else float("nan"),
-        "n_episodes": len(overall["sum_rewards"]),
-        "eval_s": time.time() - start_t,
-        "eval_ep_s": (time.time() - start_t) / max(1, len(overall["sum_rewards"])),
-        "video_paths": list(overall["video_paths"]),
-    }
-
-    return {
-        "per_task": per_task_infos,
-        "per_group": groups_aggregated,
-        "overall": overall_agg,
-    }
 
 
 def main():

tests/envs/test_lazy_vec_env.py

@@ -0,0 +1,62 @@
+#!/usr/bin/env python
+
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
+
+
+class _DummyVectorEnv:
+    def __init__(self):
+        self.marker = "ok"
+        self.closed = False
+
+    def close(self):
+        self.closed = True
+
+
+def test_lazy_vec_env_materializes_only_on_access():
+    created = []
+
+    def _make_env(fns):
+        created.append(len(fns))
+        return _DummyVectorEnv()
+
+    lazy = LazyVectorEnv(_make_env, [lambda: None, lambda: None])
+    assert created == []
+    assert lazy.num_factory_fns == 2
+
+    assert lazy.marker == "ok"
+    assert created == [2]
+
+    # Second access should re-use the same materialized env.
+    assert lazy.marker == "ok"
+    assert created == [2]
+
+
+def test_lazy_vec_env_can_rematerialize_after_close():
+    created = []
+
+    def _make_env(fns):
+        created.append(len(fns))
+        return _DummyVectorEnv()
+
+    lazy = LazyVectorEnv(_make_env, [lambda: None])
+    lazy.materialize()
+    assert created == [1]
+
+    lazy.close()
+    lazy.materialize()
+    assert created == [1, 1]
+

tests/scripts/test_eval_scheduler.py

@@ -0,0 +1,244 @@
+#!/usr/bin/env python
+
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from lerobot.envs.lazy_vec_env import LazyVectorEnv
+from lerobot.scripts import lerobot_eval
+
+
+class _DummyTaskEnv:
+    def __init__(self):
+        self.close_calls = 0
+
+    def close(self):
+        self.close_calls += 1
+
+
+class _TrackedLazyEnv(LazyVectorEnv):
+    def __init__(self, n_factory_fns: int = 1):
+        super().__init__(lambda fns: None, [lambda: None for _ in range(n_factory_fns)])
+        self.close_calls = 0
+
+    def close(self):
+        self.close_calls += 1
+        super().close()
+
+
+def _fake_metrics():
+    return {
+        "sum_rewards": [1.0],
+        "max_rewards": [1.0],
+        "successes": [True],
+        "video_paths": [],
+    }
+
+
+def test_eval_policy_all_sequential_closes_envs(monkeypatch):
+    def _fake_run_one(task_group, task_id, env, **kwargs):  # noqa: ARG001
+        return task_group, task_id, _fake_metrics()
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _fake_run_one)
+    env_a = _DummyTaskEnv()
+    env_b = _DummyTaskEnv()
+    envs = {"suite": {0: env_a, 1: env_b}}
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=1,
+        max_parallel_tasks=1,
+    )
+
+    assert env_a.close_calls == 1
+    assert env_b.close_calls == 1
+    assert result["overall"]["n_episodes"] == 2
+
+
+def test_eval_policy_all_threaded_fallback_closes_envs(monkeypatch):
+    def _fake_run_one(task_group, task_id, env, **kwargs):  # noqa: ARG001
+        return task_group, task_id, _fake_metrics()
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _fake_run_one)
+    env_a = _DummyTaskEnv()
+    env_b = _DummyTaskEnv()
+    env_c = _DummyTaskEnv()
+    envs = {"suite": {0: env_a, 1: env_b, 2: env_c}}
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=1,
+        max_parallel_tasks=2,
+    )
+
+    assert env_a.close_calls == 1
+    assert env_b.close_calls == 1
+    assert env_c.close_calls == 1
+    assert result["overall"]["n_episodes"] == 3
+
+
+def test_eval_policy_all_uses_batched_lazy_mode(monkeypatch):
+    def _run_one_should_not_be_called(*args, **kwargs):
+        raise AssertionError("run_one should not run in batched lazy mode")
+
+    chunk_sizes = []
+
+    def _fake_eval_task_batch(chunk, **kwargs):  # noqa: ARG001
+        chunk_sizes.append(len(chunk))
+        return [(tg, tid, _fake_metrics()) for tg, tid, _ in chunk]
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _run_one_should_not_be_called)
+    monkeypatch.setattr(lerobot_eval, "_eval_task_batch", _fake_eval_task_batch)
+
+    envs = {
+        "suite": {
+            0: LazyVectorEnv(lambda fns: None, [lambda: None]),
+            1: LazyVectorEnv(lambda fns: None, [lambda: None]),
+            2: LazyVectorEnv(lambda fns: None, [lambda: None]),
+        }
+    }
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=1,
+        max_parallel_tasks=2,
+    )
+
+    assert chunk_sizes == [2, 1]
+    assert result["overall"]["n_episodes"] == 3
+
+
+def test_eval_policy_all_disables_batched_lazy_when_n_episodes_not_one(monkeypatch):
+    def _fake_run_one(task_group, task_id, env, **kwargs):  # noqa: ARG001
+        return task_group, task_id, _fake_metrics()
+
+    def _batch_should_not_run(*args, **kwargs):
+        raise AssertionError("_eval_task_batch should not run when n_episodes != 1")
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _fake_run_one)
+    monkeypatch.setattr(lerobot_eval, "_eval_task_batch", _batch_should_not_run)
+
+    env_a = _TrackedLazyEnv()
+    env_b = _TrackedLazyEnv()
+    envs = {"suite": {0: env_a, 1: env_b}}
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=2,
+        max_parallel_tasks=2,
+    )
+
+    assert env_a.close_calls == 1
+    assert env_b.close_calls == 1
+    assert result["overall"]["n_episodes"] == 2
+
+
+def test_eval_policy_all_disables_batched_lazy_when_batch_size_above_one(monkeypatch):
+    def _fake_run_one(task_group, task_id, env, **kwargs):  # noqa: ARG001
+        return task_group, task_id, _fake_metrics()
+
+    def _batch_should_not_run(*args, **kwargs):
+        raise AssertionError("_eval_task_batch should not run when eval.batch_size > 1")
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _fake_run_one)
+    monkeypatch.setattr(lerobot_eval, "_eval_task_batch", _batch_should_not_run)
+
+    env_a = _TrackedLazyEnv(n_factory_fns=2)
+    env_b = _TrackedLazyEnv(n_factory_fns=2)
+    envs = {"suite": {0: env_a, 1: env_b}}
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=1,
+        max_parallel_tasks=2,
+    )
+
+    assert env_a.close_calls == 1
+    assert env_b.close_calls == 1
+    assert result["overall"]["n_episodes"] == 2
+
+
+def test_eval_policy_all_applies_instance_sharding(monkeypatch):
+    called = []
+
+    def _fake_run_one(task_group, task_id, env, **kwargs):  # noqa: ARG001
+        called.append(task_id)
+        return task_group, task_id, _fake_metrics()
+
+    monkeypatch.setattr(lerobot_eval, "run_one", _fake_run_one)
+    envs = {"suite": {0: _DummyTaskEnv(), 1: _DummyTaskEnv(), 2: _DummyTaskEnv(), 3: _DummyTaskEnv()}}
+
+    result = lerobot_eval.eval_policy_all(
+        envs=envs,
+        policy=None,
+        env_preprocessor=None,
+        env_postprocessor=None,
+        preprocessor=None,
+        postprocessor=None,
+        n_episodes=1,
+        max_parallel_tasks=1,
+        instance_count=2,
+        instance_id=1,
+    )
+
+    assert called == [1, 3]
+    assert result["overall"]["n_episodes"] == 2
+
+
+def test_aggregate_eval_from_per_task_merges_groups_and_overall():
+    per_task = [
+        {
+            "task_group": "a",
+            "task_id": 0,
+            "metrics": {"sum_rewards": [1.0], "max_rewards": [2.0], "successes": [True], "video_paths": ["v0"]},
+        },
+        {
+            "task_group": "b",
+            "task_id": 1,
+            "metrics": {"sum_rewards": [3.0], "max_rewards": [4.0], "successes": [False], "video_paths": []},
+        },
+    ]
+
+    merged = lerobot_eval._aggregate_eval_from_per_task(per_task, total_eval_s=10.0)
+
+    assert merged["overall"]["n_episodes"] == 2
+    assert merged["overall"]["avg_sum_reward"] == 2.0
+    assert merged["overall"]["pc_success"] == 50.0
+    assert merged["overall"]["eval_s"] == 10.0
+    assert set(merged["per_group"]) == {"a", "b"}
+