feat(policies): Allow users to register 3rd party policies - pip install lerobot_policy_mypolicy (#2308)

* feat: Register external policies

* ruff fix

* move policy util functions to policy factory

* refactor register_third_party_devices -> register_third_party_plugins

* feat: Update docs with bring your own policies

* Improve docs for new policies

* fix: Inconsistent quotation marks

* fix: Remove print statement

* fix: wrong base class name in documentation

* fix: Handle better how the models are parsed

* fix: precommit passing

* Update docs/source/bring_your_own_policies.mdx

Co-authored-by: Steven Palma <imstevenpmwork@ieee.org>
Signed-off-by: Daniel San José Pro <42489409+danielsanjosepro@users.noreply.github.com>

---------

Signed-off-by: Steven Palma <imstevenpmwork@ieee.org>
Signed-off-by: Daniel San José Pro <42489409+danielsanjosepro@users.noreply.github.com>
Co-authored-by: Steven Palma <imstevenpmwork@ieee.org>

src/lerobot/policies/factory.py

@@ -16,6 +16,7 @@
 
 from __future__ import annotations
 
+import importlib
 import logging
 from typing import Any, TypedDict
 
@@ -108,7 +109,10 @@ def get_policy_class(name: str) -> type[PreTrainedPolicy]:
 
         return GrootPolicy
     else:
-        raise NotImplementedError(f"Policy with name {name} is not implemented.")
+        try:
+            return _get_policy_cls_from_policy_name(name=name)
+        except Exception as e:
+            raise ValueError(f"Policy type '{name}' is not available.") from e
 
 
 def make_policy_config(policy_type: str, **kwargs) -> PreTrainedConfig:
@@ -151,7 +155,11 @@ def make_policy_config(policy_type: str, **kwargs) -> PreTrainedConfig:
     elif policy_type == "groot":
         return GrootConfig(**kwargs)
     else:
-        raise ValueError(f"Policy type '{policy_type}' is not available.")
+        try:
+            config_cls = PreTrainedConfig.get_choice_class(policy_type)
+            return config_cls(**kwargs)
+        except Exception as e:
+            raise ValueError(f"Policy type '{policy_type}' is not available.") from e
 
 
 class ProcessorConfigKwargs(TypedDict, total=False):
@@ -331,7 +339,13 @@ def make_pre_post_processors(
         )
 
     else:
-        raise NotImplementedError(f"Processor for policy type '{policy_cfg.type}' is not implemented.")
+        try:
+            processors = _make_processors_from_policy_config(
+                config=policy_cfg,
+                dataset_stats=kwargs.get("dataset_stats"),
+            )
+        except Exception as e:
+            raise ValueError(f"Processor for policy type '{policy_cfg.type}' is not implemented.") from e
 
     return processors
 
@@ -425,3 +439,65 @@ def make_policy(
         # TODO: (jadechoghari) - add a check_state(cfg, features) and check_action(cfg, features)
 
     return policy
+
+
+def _get_policy_cls_from_policy_name(name: str) -> type[PreTrainedConfig]:
+    """Get policy class from its registered name using dynamic imports.
+
+    This is used as a helper function to import policies from 3rd party lerobot plugins.
+
+    Args:
+        name: The name of the policy.
+    Returns:
+        The policy class corresponding to the given name.
+    """
+    if name not in PreTrainedConfig.get_known_choices():
+        raise ValueError(
+            f"Unknown policy name '{name}'. Available policies: {PreTrainedConfig.get_known_choices()}"
+        )
+
+    config_cls = PreTrainedConfig.get_choice_class(name)
+    config_cls_name = config_cls.__name__
+
+    model_name = config_cls_name.removesuffix("Config")  # e.g., DiffusionConfig -> Diffusion
+    if model_name == config_cls_name:
+        raise ValueError(
+            f"The config class name '{config_cls_name}' does not follow the expected naming convention."
+            f"Make sure it ends with 'Config'!"
+        )
+    cls_name = model_name + "Policy"  # e.g., DiffusionConfig -> DiffusionPolicy
+    module_path = config_cls.__module__.replace(
+        "configuration_", "modeling_"
+    )  # e.g., configuration_diffusion -> modeling_diffusion
+
+    module = importlib.import_module(module_path)
+    policy_cls = getattr(module, cls_name)
+    return policy_cls
+
+
+def _make_processors_from_policy_config(
+    config: PreTrainedConfig,
+    dataset_stats: dict[str, dict[str, torch.Tensor]] | None = None,
+) -> tuple[Any, Any]:
+    """Create pre- and post-processors from a policy configuration using dynamic imports.
+
+    This is used as a helper function to import processor factories from 3rd party lerobot plugins.
+
+    Args:
+        config: The policy configuration object.
+        dataset_stats: Dataset statistics for normalization.
+    Returns:
+        A tuple containing the input (pre-processor) and output (post-processor) pipelines.
+    """
+
+    policy_type = config.type
+    function_name = f"make_{policy_type}_pre_post_processors"
+    module_path = config.__class__.__module__.replace(
+        "configuration_", "processor_"
+    )  # e.g., configuration_diffusion -> processor_diffusion
+    logging.debug(
+        f"Instantiating pre/post processors using function '{function_name}' from module '{module_path}'"
+    )
+    module = importlib.import_module(module_path)
+    function = getattr(module, function_name)
+    return function(config, dataset_stats=dataset_stats)

src/lerobot/scripts/lerobot_calibrate.py

@@ -52,7 +52,7 @@ from lerobot.teleoperators import (  # noqa: F401
     so100_leader,
     so101_leader,
 )
-from lerobot.utils.import_utils import register_third_party_devices
+from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.utils import init_logging
 
 
@@ -84,7 +84,7 @@ def calibrate(cfg: CalibrateConfig):
 
 
 def main():
-    register_third_party_devices()
+    register_third_party_plugins()
     calibrate()
 
 

src/lerobot/scripts/lerobot_eval.py

@@ -82,6 +82,7 @@ from lerobot.policies.factory import make_policy, make_pre_post_processors
 from lerobot.policies.pretrained import PreTrainedPolicy
 from lerobot.processor import PolicyAction, PolicyProcessorPipeline
 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.utils import (
@@ -792,6 +793,7 @@ def eval_policy_all(
 
 def main():
     init_logging()
+    register_third_party_plugins()
     eval_main()
 
 

src/lerobot/scripts/lerobot_record.py

@@ -118,7 +118,7 @@ from lerobot.utils.control_utils import (
     sanity_check_dataset_name,
     sanity_check_dataset_robot_compatibility,
 )
-from lerobot.utils.import_utils import register_third_party_devices
+from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.robot_utils import precise_sleep
 from lerobot.utils.utils import (
     get_safe_torch_device,
@@ -512,7 +512,7 @@ def record(cfg: RecordConfig) -> LeRobotDataset:
 
 
 def main():
-    register_third_party_devices()
+    register_third_party_plugins()
     record()
 
 

src/lerobot/scripts/lerobot_replay.py

@@ -61,7 +61,7 @@ from lerobot.robots import (  # noqa: F401
     so101_follower,
 )
 from lerobot.utils.constants import ACTION
-from lerobot.utils.import_utils import register_third_party_devices
+from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.robot_utils import precise_sleep
 from lerobot.utils.utils import (
     init_logging,
@@ -127,7 +127,7 @@ def replay(cfg: ReplayConfig):
 
 
 def main():
-    register_third_party_devices()
+    register_third_party_plugins()
     replay()
 
 

src/lerobot/scripts/lerobot_teleoperate.py

@@ -88,7 +88,7 @@ from lerobot.teleoperators import (  # noqa: F401
     so100_leader,
     so101_leader,
 )
-from lerobot.utils.import_utils import register_third_party_devices
+from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.robot_utils import precise_sleep
 from lerobot.utils.utils import init_logging, move_cursor_up
 from lerobot.utils.visualization_utils import init_rerun, log_rerun_data
@@ -217,7 +217,7 @@ def teleoperate(cfg: TeleoperateConfig):
 
 
 def main():
-    register_third_party_devices()
+    register_third_party_plugins()
     teleoperate()
 
 

src/lerobot/scripts/lerobot_train.py

@@ -36,6 +36,7 @@ from lerobot.policies.factory import make_policy, make_pre_post_processors
 from lerobot.policies.pretrained import PreTrainedPolicy
 from lerobot.rl.wandb_utils import WandBLogger
 from lerobot.scripts.lerobot_eval import eval_policy_all
+from lerobot.utils.import_utils import register_third_party_plugins
 from lerobot.utils.logging_utils import AverageMeter, MetricsTracker
 from lerobot.utils.random_utils import set_seed
 from lerobot.utils.train_utils import (
@@ -446,6 +447,7 @@ def train(cfg: TrainPipelineConfig, accelerator: Accelerator | None = None):
 
 
 def main():
+    register_third_party_plugins()
     train()
 
 

src/lerobot/utils/import_utils.py

@@ -130,14 +130,14 @@ def make_device_from_device_class(config: ChoiceRegistry) -> Any:
     )
 
 
-def register_third_party_devices() -> None:
+def register_third_party_plugins() -> None:
     """
     Discover and import third-party lerobot_* plugins so they can register themselves.
 
     Scans top-level modules on sys.path for packages starting with
-    'lerobot_robot_', 'lerobot_camera_' or 'lerobot_teleoperator_' and imports them.
+    'lerobot_robot_', 'lerobot_camera_', 'lerobot_teleoperator_' or 'lerobot_policy_' and imports them.
     """
-    prefixes = ("lerobot_robot_", "lerobot_camera_", "lerobot_teleoperator_")
+    prefixes = ("lerobot_robot_", "lerobot_camera_", "lerobot_teleoperator_", "lerobot_policy_")
     imported: list[str] = []
     failed: list[str] = []