feat(g05): make policy runtime native

docs/source/g05.mdx

@@ -9,15 +9,16 @@ conditioned on the same post-reasoning KV state.
 Transformers includes the native multimodal Qwen3.5 backbone, vision tower, and
 processor. G0.5 is not a stock `Qwen3_5ForConditionalGeneration` checkpoint,
 however: it adds the proprioception/action path, action expert, flow-matching
-head, ActionCodec, and unified CoT/action decode. The current integration
-therefore keeps the pinned G0.5 author package as the model backend.
+head, ActionCodec, and unified CoT/action decode. LeRobot implements those G0.5
+components natively and loads converted checkpoints without the OpenGalaxea
+Python package, Hydra, or OmegaConf.
 
 > [!WARNING]
 > G0.5 code and checkpoints use the
 > [G0.5 Community License](https://huggingface.co/OpenGalaxea/G05/blob/main/licenses/LICENSE-G0.5),
-> including non-commercial restrictions. LeRobot does not vendor the author model,
-> download gated files, or imply that Apache-2.0 applies to those materials. Accept
-> the license yourself and use a private or local checkpoint.
+> including non-commercial restrictions. LeRobot does not redistribute checkpoint
+> weights, download gated files, or imply that Apache-2.0 applies to those materials.
+> Accept the license yourself and use a private or local checkpoint.
 
 ## Supported checkpoint contracts
 
@@ -29,8 +30,8 @@ therefore keeps the pinned G0.5 author package as the model backend.
 | `g05-so101`      | Flow or AR ActionCodec + native CoT        | right arm joints 6 → 20D grouped layout      | exterior, optional left + right wrist |        32 |       16 | stepwise q01/q99                |
 
 Each packaged checkpoint stores the resolved model and processor configuration,
-ActionCodec metadata, statistics, exact prompt template, source revision, and
-license. Loading rejects a different head, horizon, processor mode, or
+ActionCodec metadata, statistics, exact prompt template, and license. Loading
+rejects a different head, horizon, processor mode, or
 normalization contract.
 
 The converted checkpoints are private under the LeRobot organization:
@@ -51,23 +52,12 @@ Atomic-4 dataset; reusing the R1 Lite statistics would be incorrect.
 
 ## Install
 
-Install LeRobot's small config dependency:
+Install LeRobot with the G0.5 Transformers dependency:
 
 ```bash
 uv sync --extra g05 --extra test
 ```
 
-Then clone the audited author source and install it only after reviewing and
-accepting its license. The author package currently declares Python 3.10 while
-LeRobot uses Python 3.12, so a compatible deployment environment or an upstream
-Python-support update is required for real-model execution.
-
-```bash
-git clone https://github.com/OpenGalaxea/GalaxeaVLA.git
-git -C GalaxeaVLA checkout b34966f387dd2ae0f003143b81494afd9213e613
-export PYTHONPATH="/path/to/GalaxeaVLA/src:${PYTHONPATH}"
-```
-
 The LeRobot organization hosts the prepared base, LIBERO, RoboTwin, and SO-101
 checkpoints privately. Authenticate with `hf auth login` before loading them.
 SO-100 and SO-101 share the released `so100` embodiment token and six-joint
@@ -124,9 +114,10 @@ the checkpoint's native System 2 CoT telemetry.
 
 ## Fine-tune with `lerobot-train`
 
-G0.5 implements LeRobot's training surface: `forward` runs the author training
-backend, the policy exposes the author VLM/vision/action optimizer groups, and
-the checkpoint can be saved, resumed, and loaded by the normal LeRobot scripts.
+G0.5 implements LeRobot's training surface natively: `forward` computes
+assistant-token cross entropy and flow-matching loss, the policy exposes
+VLM/vision/action optimizer groups, and the checkpoint can be saved, resumed,
+and loaded by the normal LeRobot scripts.
 For example, fine-tune the private SO-101 checkpoint on a LeRobot dataset:
 
 ```bash
@@ -157,7 +148,7 @@ Grounded VQA boxes are converted from pixel-space `xyxy` JSON using the source
 camera dimensions captured before image resizing, then serialized as G0.5
 `<locXXXX>` tokens. Joint samples preserve the released checkpoint's
 `BBox → Subtask → Action` order. The user/task conditioning tokens remain
-masked; the author backend applies its language/action objective to the
+masked; the native backend applies its language/action objective to the
 assistant sequence.
 
 Generate the required `subtask` and grounded `vqa` language columns with
@@ -197,30 +188,26 @@ lerobot-train \
 
 CPU unit tests cover factory loading, config incompatibilities, prompt pass-through,
 LIBERO and `atomic_4` mappings, padding masks, inverse action projection, a finite
-forward/backward/update, author optimizer-group wiring, and save/reload parity:
+forward/backward/update, optimizer-group wiring, and save/reload parity:
 
 ```bash
 uv run pytest tests/policies/g05 tests/runtime/test_g05_adapter.py -q
 uv run ruff check src/lerobot/policies/g05 tests/policies/g05
 ```
 
-An RTX 5090 smoke test loaded the real private `g05_libero` checkpoint and
-completed a batch-size-one BF16 forward, backward, gradient clip, and AdamW
-step. It produced finite loss `2.77356`, finite pre-clip gradient norm `54.38`,
-all six author optimizer groups, and 23.59 GiB peak allocated CUDA memory.
+The converted private `g05_base` checkpoint strict-loaded all 945 native model
+tensors, and its ActionCodec sidecar strict-loaded all 208 tensors, with no
+missing, unexpected, or shape-mismatched keys. Prompt token IDs and masks match
+the released runtime exactly. ActionCodec code IDs match exactly; decoded values
+differ only by normal floating-point noise. A batch-size-one System 1 flow smoke
+produced a finite `[1, 32, 27]` action chunk on an RTX 5090.
 
-The same RTX 5090 also loaded the private `g05_so101` checkpoint and completed
-a real joint `BBox → Subtask → Action` forward and backward through the
-recipe-driven path. It produced finite total loss `4.38332`, including non-zero
-`ce_loss=4.04244` and `fm_loss=0.340881`, with 15.58 GiB peak allocated CUDA
-memory.
-
-The converted private `g05_base` checkpoint strict-loaded all 946 mapped tensors
-with no missing, duplicate, unexpected, or shape-mismatched keys. Author/LeRobot
-parity was exact for images, tokens, and masks; normalized state/action inputs
-matched within `1.2e-7`, and postprocessing within `1.8e-6`. A System 2 smoke
-generated a native `Subtask:` trace and a finite `[1, 32, 27]` action chunk in
-the same pass, using 11.02 GiB peak allocated memory.
+The same native base checkpoint completed a real joint language/action forward
+and backward on the RTX 5090. It produced finite `ce_loss=13.8141` and
+`fm_loss=1.32647`, finite gradients for all 945 model tensors, all six optimizer
+groups, and 19.32 GiB peak allocated CUDA memory. A System 2 smoke generated
+`Subtask: grasp and lift the red cup with the right gripper` and a finite
+same-pass `[1, 32, 27]` action in 1.07 seconds at 11.0 GiB peak.
 
 A 50-episode LIBERO/RoboTwin success-rate comparison additionally requires the
 matching simulator, task assets, reset seeds, and author evaluator; no task-level

pyproject.toml

@@ -238,10 +238,9 @@ evo1 = ["lerobot[transformers-dep]"]
 hilserl = ["lerobot[transformers-dep]", "lerobot[dataset]", "gym-hil>=0.1.14,<0.2.0", "lerobot[grpcio-dep]", "lerobot[placo-dep]"]
 vla_jepa = ["lerobot[transformers-dep]", "lerobot[diffusers-dep]", "lerobot[qwen-vl-utils-dep]"]
 lingbot_va = ["lerobot[transformers-dep]", "lerobot[diffusers-dep]", "lerobot[accelerate-dep]"]
-# The G0.5 model implementation and weights carry Galaxea's separate community
-# license and are intentionally not redistributed as an Apache LeRobot dependency.
-# This extra supplies only the config runtime used by converted local checkpoints.
-g05 = ["omegaconf>=2.3.0,<3.0.0"]
+# Checkpoint weights retain their upstream licenses. The runtime itself is native
+# LeRobot code built on Transformers' Qwen3.5 implementation.
+g05 = ["transformers>=5.4.0,<5.6.0"]
 
 # Features
 async = ["lerobot[grpcio-dep]", "lerobot[matplotlib-dep]"]

src/lerobot/policies/g05/action_codec_g05.py

@@ -0,0 +1,671 @@
+# 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.
+
+"""Native inference implementation of G0.5's ActionCodec sidecar."""
+
+from __future__ import annotations
+
+import math
+from collections.abc import Mapping
+from pathlib import Path
+from typing import Any
+
+import torch
+import torch.nn.functional as functional
+from torch import Tensor, nn
+
+
+class _BlockDCT(nn.Module):
+    def __init__(self, block_size: int) -> None:
+        super().__init__()
+        self.block_size = block_size
+        frequency = torch.arange(block_size, dtype=torch.float32)
+        time = torch.arange(block_size, dtype=torch.float32)
+        basis = torch.cos(math.pi / block_size * (time + 0.5).unsqueeze(0) * frequency.unsqueeze(1))
+        basis[0] *= math.sqrt(1 / block_size)
+        basis[1:] *= math.sqrt(2 / block_size)
+        self.register_buffer("basis", basis, persistent=False)
+
+    def dct(self, values: Tensor) -> Tensor:
+        batch, horizon, dimension = values.shape
+        pad = (-horizon) % self.block_size
+        if pad:
+            values = functional.pad(values, (0, 0, 0, pad))
+        blocks = values.shape[1] // self.block_size
+        values = values.reshape(batch * blocks, self.block_size, dimension)
+        transformed = torch.einsum("kn,bnd->bkd", self.basis.to(values), values)
+        return transformed.reshape(batch, blocks * self.block_size, dimension)
+
+    def idct(self, values: Tensor, horizon: int) -> Tensor:
+        batch, padded_horizon, dimension = values.shape
+        blocks = padded_horizon // self.block_size
+        values = values.reshape(batch * blocks, self.block_size, dimension)
+        restored = torch.einsum("nk,bkd->bnd", self.basis.to(values), values)
+        return restored.reshape(batch, padded_horizon, dimension)[:, :horizon]
+
+
+def _rotate_half(values: Tensor) -> Tensor:
+    first, second = values.chunk(2, dim=-1)
+    return torch.cat((-second, first), dim=-1)
+
+
+class _CodecAttention(nn.Module):
+    def __init__(self, dimension: int, num_heads: int, head_dim: int, rope_base: int) -> None:
+        super().__init__()
+        self.num_heads = num_heads
+        self.head_dim = head_dim
+        inner_dim = num_heads * head_dim
+        self.to_qkv = nn.Linear(dimension, inner_dim * 3, bias=False)
+        self.to_out = nn.Linear(inner_dim, dimension, bias=False)
+        self.q_norm = nn.LayerNorm(head_dim, eps=1e-6)
+        self.k_norm = nn.LayerNorm(head_dim, eps=1e-6)
+        rope_dim = max(head_dim // 2, 32)
+        inverse = 1 / (rope_base ** (torch.arange(0, rope_dim, 2, dtype=torch.float32) / rope_dim))
+        self.register_buffer("_inverse_frequency", inverse, persistent=False)
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        batch, sequence_length, _ = hidden_states.shape
+        query, key, value = self.to_qkv(hidden_states).chunk(3, dim=-1)
+
+        def heads(values: Tensor) -> Tensor:
+            return values.view(batch, sequence_length, self.num_heads, self.head_dim).transpose(1, 2)
+
+        query, key, value = (heads(values) for values in (query, key, value))
+        query, key = self.q_norm(query), self.k_norm(key)
+        time = torch.arange(sequence_length, device=hidden_states.device, dtype=torch.float32)
+        phase = torch.outer(time, self._inverse_frequency.to(hidden_states.device))
+        phase = torch.cat((phase, phase), dim=-1).to(hidden_states.dtype)[None, None]
+        cosine, sine = phase.cos(), phase.sin()
+        rotary_dim = cosine.shape[-1]
+        query_rotary, query_pass = query[..., :rotary_dim], query[..., rotary_dim:]
+        key_rotary, key_pass = key[..., :rotary_dim], key[..., rotary_dim:]
+        query = torch.cat((query_rotary * cosine + _rotate_half(query_rotary) * sine, query_pass), dim=-1)
+        key = torch.cat((key_rotary * cosine + _rotate_half(key_rotary) * sine, key_pass), dim=-1)
+        attended = functional.scaled_dot_product_attention(query, key, value)
+        attended = attended.transpose(1, 2).reshape(batch, sequence_length, -1)
+        return self.to_out(attended)
+
+
+class _CodecFFN(nn.Module):
+    def __init__(self, dimension: int, multiplier: float) -> None:
+        super().__init__()
+        inner_dim = int(dimension * multiplier)
+        self.w_up = nn.Linear(dimension, inner_dim * 2, bias=False)
+        self.w_down = nn.Linear(inner_dim, dimension, bias=False)
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        value, gate = self.w_up(hidden_states).chunk(2, dim=-1)
+        return self.w_down(value * functional.gelu(gate))
+
+
+class _CodecTransformerLayer(nn.Module):
+    def __init__(self, dimension: int, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        self.ls1 = nn.Parameter(torch.empty(dimension))
+        self.ls2 = nn.Parameter(torch.empty(dimension))
+        self.norm1 = nn.LayerNorm(dimension, eps=1e-6)
+        self.attn = _CodecAttention(
+            dimension,
+            int(config["num_heads"]),
+            int(config["dim_heads"]),
+            int(config["rope_base"]),
+        )
+        self.norm2 = nn.LayerNorm(dimension, eps=1e-6)
+        self.ffn = _CodecFFN(dimension, float(config["ffn_mult"]))
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        hidden_states = hidden_states + self.attn(self.norm1(hidden_states)) * self.ls1
+        return hidden_states + self.ffn(self.norm2(hidden_states)) * self.ls2
+
+
+class _CodecDownBlock(nn.Module):
+    def __init__(
+        self,
+        input_channels: int,
+        output_channels: int,
+        stride: tuple[int, int],
+        depth: int,
+        config: Mapping[str, Any],
+    ) -> None:
+        super().__init__()
+        stride_h, stride_a = stride
+        if stride_h > 1 or input_channels != output_channels:
+            kernel_h = 2 * stride_h if stride_h > 1 else 1
+            self.conv = nn.Conv2d(
+                input_channels,
+                output_channels,
+                kernel_size=(kernel_h, 1),
+                stride=(stride_h, stride_a),
+                padding=(kernel_h // 2 - int(stride_h > 1), 0),
+            )
+        else:
+            self.conv = nn.Identity()
+        self.transformer_layers = nn.ModuleList(
+            [_CodecTransformerLayer(output_channels, config) for _ in range(depth)]
+        )
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        hidden_states = self.conv(hidden_states)
+        batch, channels, height, action_dim = hidden_states.shape
+        sequence = hidden_states.permute(0, 2, 3, 1).reshape(batch, height * action_dim, channels)
+        for layer in self.transformer_layers:
+            sequence = layer(sequence)
+        return sequence.reshape(batch, height, action_dim, channels).permute(0, 3, 1, 2)
+
+
+class _CodecUpBlock(nn.Module):
+    def __init__(
+        self,
+        input_channels: int,
+        output_channels: int,
+        stride: tuple[int, int],
+        depth: int,
+        config: Mapping[str, Any],
+    ) -> None:
+        super().__init__()
+        self.transformer_layers = nn.ModuleList(
+            [_CodecTransformerLayer(input_channels, config) for _ in range(depth)]
+        )
+        stride_h, stride_a = stride
+        if stride_h > 1 or input_channels != output_channels:
+            kernel_h = 2 * stride_h if stride_h > 1 else 1
+            self.conv = nn.ConvTranspose2d(
+                input_channels,
+                output_channels,
+                kernel_size=(kernel_h, 1),
+                stride=(stride_h, stride_a),
+                padding=(kernel_h // 2 - int(stride_h > 1), 0),
+            )
+        else:
+            self.conv = nn.Identity()
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        batch, channels, height, action_dim = hidden_states.shape
+        sequence = hidden_states.permute(0, 2, 3, 1).reshape(batch, height * action_dim, channels)
+        for layer in self.transformer_layers:
+            sequence = layer(sequence)
+        hidden_states = sequence.reshape(batch, height, action_dim, channels).permute(0, 3, 1, 2)
+        return self.conv(hidden_states)
+
+
+class _CodecEncoder(nn.Module):
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        base = int(config["encoder_channels"])
+        channel_dims = [base * int(multiplier) for multiplier in config["c_mults"]]
+        dims = [base] + channel_dims
+        self.blocks = nn.ModuleList(
+            [
+                _CodecDownBlock(
+                    dims[index],
+                    dims[index + 1],
+                    tuple(stride),
+                    int(config["transformer_depths"][index]),
+                    config,
+                )
+                for index, stride in enumerate(config["strides"])
+            ]
+        )
+        self.out_proj = nn.Conv2d(dims[-1], int(config["latent_dim"]), kernel_size=1)
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        for block in self.blocks:
+            hidden_states = block(hidden_states)
+        return self.out_proj(hidden_states)
+
+
+class _CodecDecoder(nn.Module):
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        base = int(config["encoder_channels"])
+        channel_dims = [base * int(multiplier) for multiplier in config["c_mults"]]
+        dims = [base] + channel_dims
+        self.in_proj = nn.Conv2d(int(config["latent_dim"]), dims[-1], kernel_size=1)
+        self.blocks = nn.ModuleList(
+            [
+                _CodecUpBlock(
+                    input_channels,
+                    output_channels,
+                    tuple(stride),
+                    int(depth),
+                    config,
+                )
+                for stride, depth, input_channels, output_channels in zip(
+                    reversed(config["strides"]),
+                    reversed(config["transformer_depths"]),
+                    reversed(dims[1:]),
+                    reversed(dims[:-1]),
+                    strict=True,
+                )
+            ]
+        )
+
+    def forward(self, hidden_states: Tensor) -> Tensor:
+        hidden_states = self.in_proj(hidden_states)
+        for block in self.blocks:
+            hidden_states = block(hidden_states)
+        return hidden_states
+
+
+class _CodecQuantizer(nn.Module):
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        input_dim = int(config["latent_dim"])
+        codebook_dim = int(config["codebook_dim"])
+        codebook_size = int(config["codebook_size"])
+        self.input_dim = input_dim
+        self.in_proj = nn.Linear(input_dim, codebook_dim, bias=False)
+        self.out_proj = nn.Linear(codebook_dim, input_dim, bias=False)
+        self.register_buffer("codebook", torch.zeros(codebook_size, codebook_dim))
+        self.register_buffer("embed_avg", torch.zeros(codebook_size, codebook_dim))
+        self.register_buffer("cluster_size", torch.zeros(codebook_size))
+        self.register_buffer("inited", torch.tensor(False))
+
+    def encode(self, values: Tensor) -> tuple[Tensor, Tensor]:
+        projected = self.in_proj(values.transpose(1, 2))
+        flat = projected.reshape(-1, projected.shape[-1]).float()
+        codebook = self.codebook.float()
+        distances = (
+            flat.square().sum(dim=1, keepdim=True)
+            - 2 * flat @ codebook.t()
+            + codebook.square().sum(dim=1)[None]
+        )
+        codes = distances.argmin(dim=-1).reshape(values.shape[0], values.shape[2])
+        quantized = functional.embedding(codes, self.codebook)
+        quantized = self.out_proj(quantized).transpose(1, 2)
+        return quantized.to(values.dtype), codes
+
+    def decode_codes(self, codes: Tensor) -> Tensor:
+        return self.out_proj(functional.embedding(codes, self.codebook)).transpose(1, 2)
+
+
+class _ResidualCodecQuantizer(nn.Module):
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        self.quantizers = nn.ModuleList([_CodecQuantizer(config) for _ in range(int(config["n_codebooks"]))])
+
+    def encode(self, values: Tensor) -> Tensor:
+        residual = values
+        codes = []
+        for quantizer in self.quantizers:
+            quantized, level_codes = quantizer.encode(residual)
+            residual = residual - quantized
+            codes.append(level_codes)
+        return torch.stack(codes, dim=1)
+
+    def from_codes(self, codes: Tensor) -> Tensor:
+        quantized = torch.zeros(
+            codes.shape[0],
+            self.quantizers[0].input_dim,
+            codes.shape[-1],
+            dtype=self.quantizers[0].codebook.dtype,
+            device=codes.device,
+        )
+        for level, quantizer in enumerate(self.quantizers[: codes.shape[1]]):
+            quantized = quantized + quantizer.decode_codes(codes[:, level])
+        return quantized
+
+
+class _ActionCodecModel(nn.Module):
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        self.config = dict(config)
+        self.block_dct = (
+            _BlockDCT(int(config["block_dct_block_size"]))
+            if bool(config.get("use_block_dct", False))
+            else None
+        )
+        self.conv_in = nn.Conv2d(
+            int(config["horizon_patch_size"]),
+            int(config["encoder_channels"]),
+            kernel_size=(1, int(config["conv_in_action_kernel"])),
+        )
+        self.encoder = _CodecEncoder(config)
+        self.rvq = _ResidualCodecQuantizer(config)
+        self.decoder = _CodecDecoder(config)
+        self.conv_out = nn.ConvTranspose2d(
+            int(config["encoder_channels"]),
+            int(config["horizon_patch_size"]),
+            kernel_size=(1, int(config["conv_in_action_kernel"])),
+        )
+
+    @property
+    def code_h(self) -> int:
+        height = int(self.config["horizon"]) // int(self.config["horizon_patch_size"])
+        for stride_h, _ in self.config["strides"]:
+            height //= int(stride_h)
+        return height
+
+    @property
+    def code_a(self) -> int:
+        return int(self.config["max_component_dim"]) - int(self.config["conv_in_action_kernel"]) + 1
+
+    def _pad(self, values: Tensor) -> Tensor:
+        maximum = int(self.config["max_component_dim"])
+        if values.shape[-1] < maximum:
+            return functional.pad(values, (0, maximum - values.shape[-1]))
+        return values[..., :maximum]
+
+    def encode(self, components: dict[str, Tensor]) -> dict[str, Tensor]:
+        names = list(components)
+        batch_size = next(iter(components.values())).shape[0]
+        values = torch.cat([self._pad(components[name].float()) for name in names], dim=0)
+        if self.block_dct is not None:
+            values = self.block_dct.dct(values)
+        patch = int(self.config["horizon_patch_size"])
+        values = values.reshape(values.shape[0], -1, patch, values.shape[-1]).transpose(1, 2)
+        latent = self.encoder(self.conv_in(values)).flatten(2)
+        codes = self.rvq.encode(latent)
+        return {
+            name: codes[index * batch_size : (index + 1) * batch_size] for index, name in enumerate(names)
+        }
+
+    def decode(self, components: dict[str, Tensor], dimensions: Mapping[str, int]) -> dict[str, Tensor]:
+        names = list(components)
+        batch_size = next(iter(components.values())).shape[0]
+        codes = torch.cat([components[name] for name in names], dim=0)
+        quantized = self.rvq.from_codes(codes)
+        quantized = quantized.reshape(
+            quantized.shape[0],
+            quantized.shape[1],
+            self.code_h,
+            self.code_a,
+        )
+        decoded = self.conv_out(self.decoder(quantized))
+        decoded = decoded.transpose(1, 2).reshape(decoded.shape[0], -1, decoded.shape[-1])
+        if self.block_dct is not None:
+            decoded = self.block_dct.idct(decoded, int(self.config["horizon"]))
+        return {
+            name: decoded[index * batch_size : (index + 1) * batch_size, :, : dimensions[name]]
+            for index, name in enumerate(names)
+        }
+
+
+class _NativeCodecModule(nn.Module):
+    """Module hierarchy matching ``action_tokenizer.pt`` exactly."""
+
+    def __init__(self, config: Mapping[str, Any]) -> None:
+        super().__init__()
+        self.model = _ActionCodecModel(config)
+
+
+class _BinarySequenceCodec:
+    def __init__(self, sequence_length: int, min_block_length: int, vocab_size: int) -> None:
+        self.sequence_length = sequence_length
+        self.min_block_length = min_block_length
+        self.vocab_size = vocab_size
+        self._count_cache: dict[tuple[int, int, int, bool], int] = {}
+        self.num_sequences = self._count(sequence_length, -1, 0, True)
+        self.num_tokens = max(1, math.ceil(math.log(self.num_sequences, vocab_size)))
+
+    def _count(self, remaining: int, last: int, run_length: int, first: bool) -> int:
+        cache_key = (remaining, last, run_length, first)
+        if cache_key in self._count_cache:
+            return self._count_cache[cache_key]
+        if remaining == 0:
+            return 1
+        total = 0
+        for bit in (0, 1):
+            if last == -1 or bit == last:
+                total += self._count(
+                    remaining - 1,
+                    bit,
+                    min(run_length + 1, self.min_block_length + 1),
+                    first,
+                )
+            elif first or run_length > self.min_block_length:
+                total += self._count(remaining - 1, bit, 1, False)
+        self._count_cache[cache_key] = total
+        return total
+
+    def _repair(self, bits: list[int]) -> list[int]:
+        bits = bits.copy()
+        while True:
+            runs = []
+            start = 0
+            for index in range(1, len(bits)):
+                if bits[index] != bits[index - 1]:
+                    runs.append((bits[start], start, index))
+                    start = index
+            runs.append((bits[start], start, len(bits)))
+            invalid = next(
+                (
+                    (start, stop, runs[index - 1][0])
+                    for index, (_, start, stop) in enumerate(runs[1:-1], start=1)
+                    if stop - start <= self.min_block_length
+                ),
+                None,
+            )
+            if invalid is None:
+                return bits
+            start, stop, value = invalid
+            bits[start:stop] = [value] * (stop - start)
+
+    def _zero_completions(self, remaining: int, last: int, run: int, first: bool) -> int:
+        if last in (-1, 0):
+            return self._count(
+                remaining,
+                0,
+                1 if last == -1 else min(run + 1, self.min_block_length + 1),
+                first,
+            )
+        return self._count(remaining, 0, 1, False) if first or run > self.min_block_length else 0
+
+    def encode(self, values: Tensor, threshold: float) -> Tensor:
+        output = []
+        for row in values:
+            bits = self._repair([int(value >= threshold) for value in row.tolist()])
+            rank, last, run, first = 0, -1, 0, True
+            for position, bit in enumerate(bits):
+                remaining = len(bits) - position - 1
+                if bit:
+                    rank += self._zero_completions(remaining, last, run, first)
+                if last == -1:
+                    last, run = bit, 1
+                elif bit == last:
+                    run = min(run + 1, self.min_block_length + 1)
+                else:
+                    last, run, first = bit, 1, False
+            tokens = []
+            for _ in range(self.num_tokens):
+                tokens.append(rank % self.vocab_size)
+                rank //= self.vocab_size
+            output.append(list(reversed(tokens)))
+        return torch.tensor(output, dtype=torch.long, device=values.device)
+
+    def decode(self, tokens: Tensor) -> Tensor:
+        rows = []
+        for row in tokens.tolist():
+            rank = 0
+            for token in row:
+                rank = rank * self.vocab_size + max(0, min(int(token), self.vocab_size - 1))
+            rank = min(rank, self.num_sequences - 1)
+            bits, last, run, first = [], -1, 0, True
+            for position in range(self.sequence_length):
+                remaining = self.sequence_length - position - 1
+                zeros = self._zero_completions(remaining, last, run, first)
+                if rank < zeros:
+                    bit = 0
+                else:
+                    rank -= zeros
+                    bit = 1
+                bits.append(bit)
+                if last == -1:
+                    last, run = bit, 1
+                elif bit == last:
+                    run = min(run + 1, self.min_block_length + 1)
+                else:
+                    last, run, first = bit, 1, False
+            rows.append(bits)
+        return torch.tensor(rows, dtype=torch.float32, device=tokens.device)
+
+
+class G05NativeActionCodec:
+    """Non-registered sidecar wrapper for native ActionCodec encode/decode."""
+
+    def __init__(self, config: Mapping[str, Any], *, action_token_begin: int) -> None:
+        self.config = dict(config)
+        architecture = self.config["model_arch"]
+        self.module = _NativeCodecModule(architecture)
+        self.model = self.module.model
+        self.action_token_begin = action_token_begin
+        self.parts = {
+            key: int(value) for key, value in self.config["parts_meta"].items() if value is not None
+        }
+        patterns = tuple(self.config.get("rule_based_key_patterns") or ())
+        self.rule_parts = [key for key in self.parts if any(pattern in key for pattern in patterns)]
+        self.neural_parts = [key for key in self.parts if key not in self.rule_parts]
+        self.codebook_size = int(architecture["codebook_size"])
+        self.max_residuals = int(architecture["n_codebooks"])
+        self.num_residuals = int(self.config.get("num_residuals") or self.max_residuals)
+        self.code_length = self.model.code_h * self.model.code_a
+        marker_names = [
+            f"<{part}_{level}>" for level in range(self.max_residuals) for part in self.neural_parts
+        ] + [f"<{part}>" for part in self.rule_parts]
+        self.marker_indices = {name: self.codebook_size + index for index, name in enumerate(marker_names)}
+        self.rule_codec = _BinarySequenceCodec(
+            int(architecture["horizon"]),
+            int(self.config.get("rule_based_min_block_len", 1)),
+            self.codebook_size,
+        )
+
+    @property
+    def action_token_length(self) -> int:
+        neural = len(self.neural_parts) * self.num_residuals * (self.code_length + 1)
+        rules = len(self.rule_parts) * (self.rule_codec.num_tokens + 1)
+        return neural + rules
+
+    @classmethod
+    def load(
+        cls,
+        config: Mapping[str, Any],
+        *,
+        action_token_begin: int,
+    ) -> G05NativeActionCodec:
+        codec = cls(config, action_token_begin=action_token_begin)
+        checkpoint = torch.load(
+            Path(str(config["ckpt_dir"])),
+            map_location="cpu",
+            mmap=True,
+            weights_only=True,
+        )
+        state_dict = checkpoint.get("model_state_dict", checkpoint)
+        codec.module.load_state_dict(state_dict, strict=True)
+        codec.module.eval()
+        return codec
+
+    def to(self, device: torch.device | str) -> G05NativeActionCodec:
+        self.module.to(device=device, dtype=torch.float32)
+        return self
+
+    def _split(self, actions: Tensor) -> dict[str, Tensor]:
+        splits = torch.split(actions[..., : sum(self.parts.values())], list(self.parts.values()), dim=-1)
+        return dict(zip(self.parts, splits, strict=True))
+
+    @torch.no_grad()
+    def encode_for_language(self, payload: Mapping[str, Any]) -> list[int]:
+        actions = torch.as_tensor(payload["value"])
+        if actions.ndim == 2:
+            actions = actions.unsqueeze(0)
+        components = self._split(actions)
+        neural = {key: components[key] for key in self.neural_parts}
+        codes = self.model.encode(neural)
+        rule_codes = {
+            key: self.rule_codec.encode(
+                components[key][..., 0],
+                float(self.config.get("rule_based_binarize_threshold", 0)),
+            )
+            for key in self.rule_parts
+        }
+        indices = []
+        for level in range(self.num_residuals):
+            for key in self.neural_parts:
+                indices.append(self.marker_indices[f"<{key}_{level}>"])
+                indices.extend(codes[key][0, level].tolist())
+        for key in self.rule_parts:
+            indices.append(self.marker_indices[f"<{key}>"])
+            indices.extend(rule_codes[key][0].tolist())
+        return [self.action_token_begin + int(index) for index in indices]
+
+    @torch.no_grad()
+    def decode_language_tokens(
+        self,
+        token_ids: Tensor,
+        *,
+        horizon: int,
+        action_dim: int,
+    ) -> tuple[Tensor, set[str]]:
+        indices = (token_ids.long() - self.action_token_begin).tolist()
+        marker_to_name = {value: name for name, value in self.marker_indices.items()}
+        neural: dict[str, list[list[int] | None]] = {
+            key: [None] * self.num_residuals for key in self.neural_parts
+        }
+        rules: dict[str, list[int]] = {}
+        cursor = 0
+        while cursor < len(indices):
+            marker = marker_to_name.get(indices[cursor])
+            if marker is None:
+                cursor += 1
+                continue
+            marker = marker[1:-1]
+            if marker in self.rule_parts:
+                length = self.rule_codec.num_tokens
+                values = indices[cursor + 1 : cursor + 1 + length]
+                if len(values) == length and all(0 <= value < self.codebook_size for value in values):
+                    rules[marker] = values
+                cursor += length + 1
+                continue
+            part, level_text = marker.rsplit("_", 1)
+            level = int(level_text)
+            if part in neural and level < self.num_residuals:
+                values = indices[cursor + 1 : cursor + 1 + self.code_length]
+                if len(values) == self.code_length and all(
+                    0 <= value < self.codebook_size for value in values
+                ):
+                    neural[part][level] = values
+            cursor += self.code_length + 1
+
+        absent = {
+            key
+            for key in self.parts
+            if (key in neural and not any(level is not None for level in neural[key]))
+            or (key in self.rule_parts and key not in rules)
+        }
+        device = next(self.module.parameters()).device
+        code_tensors = {}
+        for key, levels in neural.items():
+            if not any(level is not None for level in levels):
+                continue
+            filled = [level if level is not None else [0] * self.code_length for level in levels]
+            code_tensors[key] = torch.tensor([filled], dtype=torch.long, device=device)
+        decoded = (
+            self.model.decode(code_tensors, {key: self.parts[key] for key in code_tensors})
+            if code_tensors
+            else {}
+        )
+        for key in self.rule_parts:
+            if key in rules:
+                tokens = torch.tensor([rules[key]], dtype=torch.long, device=device)
+                binary = self.rule_codec.decode(tokens)
+                decoded[key] = binary[:, :, None] * 2 - 1
+        # ``absent_key_fill_value`` is an internal partitioner sentinel. The
+        # released marker-aware final decoder converts absent/no-op body parts
+        # to zero motion before returning an action.
+        batch = torch.zeros((1, horizon, action_dim), dtype=torch.float32, device=device)
+        offset = 0
+        for key, dimension in self.parts.items():
+            if key in decoded:
+                batch[..., offset : offset + dimension] = decoded[key][..., :dimension]
+            offset += dimension
+        return batch[0], absent

src/lerobot/policies/g05/configuration_g05.py

@@ -188,9 +188,9 @@ _PROFILE_DEFAULTS = {
 class G05Config(PreTrainedConfig):
     """LeRobot-side, checkpoint-auditable configuration for G0.5.
 
-    ``author_model_config`` comes from the packaged checkpoint's resolved Hydra
-    config. It is intentionally checkpoint state rather than a collection of
-    guessed LeRobot defaults.
+    ``author_model_config`` is the backward-compatible serialized field holding
+    the packaged checkpoint's resolved native architecture. It is checkpoint
+    state rather than a collection of guessed LeRobot defaults.
     """
 
     checkpoint_profile: str = "g05-base"

src/lerobot/policies/g05/modeling_g05.py

@@ -10,7 +10,6 @@
 
 from __future__ import annotations
 
-import importlib
 import json
 import shutil
 from collections import deque
@@ -33,27 +32,25 @@ from .configuration_g05 import (
     make_g05_cot_prompt_template,
     make_g05_prompt_template,
 )
+from .native_g05 import G05NativeBackend
 
 
-def _author_backend(config: G05Config) -> nn.Module:
+def _native_backend(config: G05Config) -> nn.Module:
     if not config.author_model_config:
         raise ValueError(
             "G0.5 author_model_config is empty. Load a packaged checkpoint, or "
             "inject a backend explicitly for testing."
         )
-    try:
-        from omegaconf import OmegaConf
-
-        module = importlib.import_module("g05.models.g05.g05_policy_qwen35")
-    except ImportError as exc:
-        raise ImportError(
-            "The OpenGalaxea G0.5 author package is required for real model execution. "
-            "Clone the pinned GalaxeaVLA source, accept LICENSE-G0.5, and install its "
-            "runtime dependencies in a compatible environment. LeRobot does not vendor "
-            "or silently download that non-commercial code."
-        ) from exc
-    backend_cls = module.G05PolicyQwen35
-    return backend_cls(**OmegaConf.to_container(OmegaConf.create(config.author_model_config)))
+    model_config = dict(config.author_model_config)
+    model_config.update(
+        {
+            "predict_cot": config.predict_cot,
+            "discrete_action": config.discrete_action,
+            "continuous_action": config.continuous_action,
+            "return_continuous_action": config.return_continuous_action,
+        }
+    )
+    return G05NativeBackend.from_config(model_config)
 
 
 class G05Policy(PreTrainedPolicy):
@@ -65,7 +62,7 @@ class G05Policy(PreTrainedPolicy):
     def __init__(self, config: G05Config, backend: nn.Module | None = None):
         super().__init__(config)
         config.validate_features()
-        self.backend = backend if backend is not None else _author_backend(config)
+        self.backend = backend if backend is not None else _native_backend(config)
         if not isinstance(self.backend, nn.Module):
             raise TypeError(f"G0.5 backend must be an nn.Module, got {type(self.backend)}.")
         self._action_queue: deque[Tensor] = deque()
@@ -150,7 +147,7 @@ class G05Policy(PreTrainedPolicy):
                 shutil.copy2(source, save_directory / name)
 
         # Serialized paths are portable sidecar names. Local/Hub loading resolves them
-        # against the downloaded checkpoint directory before constructing the author model.
+        # against the downloaded checkpoint directory before constructing the native model.
         if (processor_path is not None and processor_path.exists()) or (
             tokenizer_path is not None and tokenizer_path.exists()
         ):
@@ -191,7 +188,7 @@ class G05Policy(PreTrainedPolicy):
                 weight.data = weight.data.float()
 
     def to(self, *args, **kwargs) -> G05Policy:
-        """Apply author inference precision and move the ActionCodec sidecar."""
+        """Apply the released inference precision and move the ActionCodec sidecar."""
 
         result = super().to(*args, **kwargs)
         explicit_dtype = "dtype" in kwargs or any(isinstance(arg, torch.dtype | Tensor) for arg in args)

src/lerobot/policies/g05/processing_g05.py

@@ -0,0 +1,353 @@
+# 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.
+
+"""Native G0.5 prompt serialization and tokenizer registration."""
+
+from __future__ import annotations
+
+import re
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Any
+
+import torch
+from torch import Tensor
+
+IGNORE_INDEX = -100
+
+
+class G05TokenType:
+    """Token categories stored in G0.5's attention-mask tensor."""
+
+    PADDING = 0
+    IMAGE = 1
+    PROPRIO = 2
+    ACTION = 3
+    TEXT = 4
+    COT = 5
+    PRED_TEXT = 6
+
+
+@dataclass
+class G05SequenceBatch:
+    input_ids: Tensor
+    labels: Tensor
+    token_types: Tensor
+    split_index: int | None = None
+
+
+@dataclass
+class _Segment:
+    kind: str
+    content: str = ""
+    sample_key: str = ""
+    processor: str = ""
+    masked: bool = False
+    max_tokens: int | None = None
+
+
+class G05Tokenizer:
+    """Checkpoint-compatible G0.5 tokenizer and template serializer.
+
+    G0.5 extends Qwen3.5's tokenizer with ActionCodec codes, per-group
+    residual markers, ``<EOV>``, and ``<state>``. Registration order is model
+    state: changing it changes the rows used by the tied language head.
+    """
+
+    _PLACEHOLDER = re.compile(r"<([^<>|]+)>")
+
+    def __init__(self, processor_path: str | Path, model_config: dict[str, Any]) -> None:
+        from transformers import AutoTokenizer
+
+        self.processor_path = Path(processor_path)
+        self.tokenizer = AutoTokenizer.from_pretrained(
+            self.processor_path,
+            trust_remote_code=False,
+            local_files_only=True,
+        )
+        self.model_config = model_config
+        at_config = model_config["AT_CONFIG"]
+        architecture = at_config["model_arch"]
+
+        self.action_tokens = [f"<action{index:04d}>" for index in range(int(architecture["codebook_size"]))]
+        parts = list(at_config["parts_meta"])
+        rule_patterns = tuple(at_config.get("rule_based_key_patterns") or ())
+        self.rule_parts = [name for name in parts if any(pattern in name for pattern in rule_patterns)]
+        self.neural_parts = [name for name in parts if name not in self.rule_parts]
+        self.group_tokens = [
+            f"<{part}_{residual}>"
+            for residual in range(int(architecture["n_codebooks"]))
+            for part in self.neural_parts
+        ] + [f"<{part}>" for part in self.rule_parts]
+        self.tokenizer.add_tokens(self.action_tokens + self.group_tokens + ["<EOV>", "<state>"])
+
+        self.pad_token_id = int(model_config["pad_token_id"])
+        self.eos_token_id = int(model_config["eos_token_id"])
+        self.image_token_id = int(model_config["image_token_index"])
+        self.vision_start_token_id = int(self.tokenizer.convert_tokens_to_ids("<|vision_start|>"))
+        self.vision_end_token_id = int(self.tokenizer.convert_tokens_to_ids("<|vision_end|>"))
+        self.eov_token_id = int(self.tokenizer.convert_tokens_to_ids("<EOV>"))
+        self.state_token_id = int(self.tokenizer.convert_tokens_to_ids("<state>"))
+        self.action_token_begin = int(self.tokenizer.convert_tokens_to_ids(self.action_tokens[0]))
+        self.action_token_end = self.action_token_begin + len(self.action_tokens)
+        self.action_token_end_with_markers = self.action_token_end + len(self.group_tokens)
+
+    def __len__(self) -> int:
+        return len(self.tokenizer)
+
+    def encode_text(self, text: str) -> list[int]:
+        return self.tokenizer(text, add_special_tokens=False)["input_ids"]
+
+    def decode(self, ids: Tensor | list[int]) -> str:
+        if isinstance(ids, Tensor):
+            ids = ids.detach().cpu().tolist()
+        return self.tokenizer.decode(ids, skip_special_tokens=False)
+
+    @staticmethod
+    def _resolve_template(template: str) -> str:
+        replacements = {
+            "<bos>": "",
+            "<eos>": "<|endoftext|>",
+            "<chat_user_prefix>": "",
+            "<chat_user_suffix>": "",
+            "<chat_assistant_prefix>": "",
+        }
+        for placeholder, value in replacements.items():
+            template = template.replace(placeholder, value)
+        return template
+
+    def _parse(self, template: str) -> list[_Segment]:
+        template = self._resolve_template(template)
+        segments: list[_Segment] = []
+        last = 0
+        for match in self._PLACEHOLDER.finditer(template):
+            if match.start() > last:
+                segments.append(_Segment("static", template[last : match.start()]))
+            raw = match.group(1).strip()
+            if raw in {"EOC", "EOV"}:
+                segments.append(_Segment("control", raw))
+                last = match.end()
+                continue
+
+            max_tokens = None
+            limit = re.match(r"^(.+)_(\d+)$", raw)
+            if limit:
+                raw, max_tokens = limit.group(1), int(limit.group(2))
+            masked = raw.endswith("_!")
+            key = raw[:-2] if masked else raw
+            if "_" not in key:
+                token = f"<{raw}>"
+                token_id = self.tokenizer.convert_tokens_to_ids(token)
+                if token_id is None:
+                    raise ValueError(f"Unknown G0.5 template token {token!r}.")
+                segments.append(_Segment("static", token))
+            else:
+                sample_key, processor = key.rsplit("_", 1)
+                segments.append(
+                    _Segment(
+                        "dynamic",
+                        sample_key=sample_key,
+                        processor=processor,
+                        masked=masked,
+                        max_tokens=max_tokens,
+                    )
+                )
+            last = match.end()
+        if last < len(template):
+            segments.append(_Segment("static", template[last:]))
+        return segments
+
+    @staticmethod
+    def _slice_segments(segments: list[_Segment], mode: str | None, *, pred_eov: bool) -> list[_Segment]:
+        eoc = next(
+            (
+                index
+                for index, segment in enumerate(segments)
+                if segment.kind == "control" and segment.content == "EOC"
+            ),
+            None,
+        )
+        eov = next(
+            (
+                index
+                for index, segment in enumerate(segments)
+                if segment.kind == "control" and segment.content == "EOV"
+            ),
+            None,
+        )
+
+        def strip(values: list[_Segment], keep_eov: bool) -> list[_Segment]:
+            output: list[_Segment] = []
+            after_eoc = False
+            for segment in values:
+                if segment.kind == "control":
+                    if segment.content == "EOC":
+                        after_eoc = True
+                    elif segment.content == "EOV" and keep_eov:
+                        output.append(
+                            _Segment(
+                                "dynamic",
+                                content="<EOV>",
+                                processor="text",
+                                masked=not pred_eov,
+                            )
+                        )
+                    continue
+                if after_eoc and segment.kind == "static":
+                    output.append(
+                        _Segment("dynamic", content=segment.content, processor="text", masked=False)
+                    )
+                else:
+                    output.append(segment)
+            return output
+
+        if mode == "context":
+            return strip(segments if eoc is None else segments[:eoc], keep_eov=True)
+        if mode == "prefix":
+            return strip(segments if eov is None else segments[: eov + 1], keep_eov=True)
+        if mode == "suffix":
+            return [] if eov is None else strip(segments[eov + 1 :], keep_eov=False)
+        return strip(segments, keep_eov=True)
+
+    def _serialize_segment(
+        self,
+        segment: _Segment,
+        sample: dict[str, Any],
+        *,
+        action_codec: Any | None,
+    ) -> tuple[list[int], list[int], list[float]]:
+        if segment.kind == "static":
+            ids = self.encode_text(segment.content)
+            return ids, [IGNORE_INDEX] * len(ids), [float(G05TokenType.TEXT)] * len(ids)
+
+        if segment.sample_key:
+            if segment.sample_key not in sample:
+                raise KeyError(f"G0.5 prompt is missing sample field {segment.sample_key!r}.")
+            value = sample[segment.sample_key]
+        else:
+            value = segment.content
+
+        if segment.processor == "text":
+            ids = self.encode_text(value if isinstance(value, str) else str(value))
+            token_type = G05TokenType.TEXT if segment.masked else G05TokenType.PRED_TEXT
+            labels = [IGNORE_INDEX] * len(ids) if segment.masked else ids.copy()
+        elif segment.processor == "image":
+            if not isinstance(value, (tuple, list)) or len(value) != 2:
+                raise ValueError("G0.5 image placeholders require an (height, width) pair.")
+            height, width = (int(item) for item in value)
+            vision = self.model_config["vision"]
+            count = (height // int(vision["patch_size"]) // int(vision["spatial_merge_size"])) * (
+                width // int(vision["patch_size"]) // int(vision["spatial_merge_size"])
+            )
+            ids = [self.vision_start_token_id] + [self.image_token_id] * count + [self.vision_end_token_id]
+            labels = [IGNORE_INDEX] * len(ids)
+            types = (
+                [float(G05TokenType.TEXT)] + [float(G05TokenType.IMAGE)] * count + [float(G05TokenType.TEXT)]
+            )
+            return ids, labels, types
+        elif segment.processor == "proprio":
+            state = value["value"] if isinstance(value, dict) else value
+            count = 1 if torch.as_tensor(state).ndim <= 1 else int(torch.as_tensor(state).shape[0])
+            ids = [self.state_token_id] * count
+            labels = [IGNORE_INDEX] * count
+            token_type = G05TokenType.PROPRIO
+        elif segment.processor == "action":
+            if action_codec is None:
+                raise RuntimeError(
+                    "This G0.5 training template includes ActionCodec targets, but the "
+                    "checkpoint has no native ActionCodec sidecar loaded."
+                )
+            ids = action_codec.encode_for_language(value)
+            labels = ids.copy()
+            token_type = G05TokenType.ACTION
+        else:
+            ids = self.encode_text(value if isinstance(value, str) else str(value))
+            labels = [IGNORE_INDEX] * len(ids) if segment.masked else ids.copy()
+            token_type = G05TokenType.COT
+
+        if segment.max_tokens is not None:
+            ids = ids[: segment.max_tokens]
+            labels = labels[: segment.max_tokens]
+        return ids, labels, [float(token_type)] * len(ids)
+
+    def _serialize(
+        self,
+        sample: dict[str, Any],
+        *,
+        mode: str | None,
+        action_codec: Any | None,
+    ) -> tuple[list[int], list[int], list[float]]:
+        pred_eov = bool(self.model_config.get("input_preprocessor", {}).get("pred_eov", False))
+        segments = self._slice_segments(self._parse(sample["template"]), mode, pred_eov=pred_eov)
+        ids: list[int] = []
+        labels: list[int] = []
+        types: list[float] = []
+        for segment in segments:
+            segment_ids, segment_labels, segment_types = self._serialize_segment(
+                segment, sample, action_codec=action_codec
+            )
+            ids.extend(segment_ids)
+            labels.extend(segment_labels)
+            types.extend(segment_types)
+        return ids, labels, types
+
+    def _pad(
+        self,
+        rows: list[tuple[list[int], list[int], list[float]]],
+        *,
+        right_align: bool,
+        device: torch.device,
+    ) -> G05SequenceBatch:
+        length = max(len(row[0]) for row in rows)
+        input_ids = torch.full((len(rows), length), self.pad_token_id, dtype=torch.long, device=device)
+        labels = torch.full((len(rows), length), IGNORE_INDEX, dtype=torch.long, device=device)
+        token_types = torch.zeros((len(rows), length), dtype=torch.float32, device=device)
+        for index, (ids, row_labels, types) in enumerate(rows):
+            start = length - len(ids) if right_align else 0
+            stop = start + len(ids)
+            input_ids[index, start:stop] = torch.tensor(ids, dtype=torch.long, device=device)
+            labels[index, start:stop] = torch.tensor(row_labels, dtype=torch.long, device=device)
+            token_types[index, start:stop] = torch.tensor(types, dtype=torch.float32, device=device)
+        return G05SequenceBatch(input_ids, labels, token_types)
+
+    def encode_inference(
+        self,
+        samples: list[dict[str, Any]],
+        *,
+        device: torch.device,
+    ) -> G05SequenceBatch:
+        rows = [self._serialize(sample, mode="context", action_codec=None) for sample in samples]
+        return self._pad(rows, right_align=True, device=device)
+
+    def encode_train(
+        self,
+        samples: list[dict[str, Any]],
+        *,
+        device: torch.device,
+        action_codec: Any | None,
+    ) -> G05SequenceBatch:
+        prefix_rows = [
+            self._serialize(sample, mode="prefix", action_codec=action_codec) for sample in samples
+        ]
+        suffix_rows = [
+            self._serialize(sample, mode="suffix", action_codec=action_codec) for sample in samples
+        ]
+        prefix = self._pad(prefix_rows, right_align=True, device=device)
+        suffix = self._pad(suffix_rows, right_align=False, device=device)
+        return G05SequenceBatch(
+            input_ids=torch.cat((prefix.input_ids, suffix.input_ids), dim=1),
+            labels=torch.cat((prefix.labels, suffix.labels), dim=1),
+            token_types=torch.cat((prefix.token_types, suffix.token_types), dim=1),
+            split_index=prefix.input_ids.shape[1],
+        )

tests/policies/g05/test_action_codec_g05.py

@@ -0,0 +1,83 @@
+# 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.
+
+import torch
+
+from lerobot.policies.g05.action_codec_g05 import G05NativeActionCodec, _BinarySequenceCodec
+
+
+def _tiny_codec_config() -> dict:
+    return {
+        "parts_meta": {
+            "left_control": 3,
+            "left_gripper": 1,
+            "right_control": 3,
+            "right_gripper": 1,
+        },
+        "rule_based_key_patterns": ["gripper"],
+        "rule_based_min_block_len": 1,
+        "rule_based_binarize_threshold": 0.0,
+        "num_residuals": 2,
+        "model_arch": {
+            "horizon": 8,
+            "horizon_patch_size": 2,
+            "max_component_dim": 3,
+            "conv_in_action_kernel": 2,
+            "encoder_channels": 64,
+            "c_mults": [1],
+            "strides": [[1, 1]],
+            "transformer_depths": [1],
+            "latent_dim": 16,
+            "num_heads": 1,
+            "dim_heads": 64,
+            "rope_base": 10_000,
+            "ffn_mult": 2,
+            "n_codebooks": 2,
+            "codebook_size": 16,
+            "codebook_dim": 4,
+            "use_block_dct": False,
+        },
+    }
+
+
+def test_binary_sequence_codec_roundtrip_repairs_short_middle_runs() -> None:
+    codec = _BinarySequenceCodec(sequence_length=8, min_block_length=1, vocab_size=16)
+    values = torch.tensor([[0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, 1.0]])
+
+    tokens = codec.encode(values, threshold=0.5)
+    decoded = codec.decode(tokens)
+
+    assert tokens.shape == (1, codec.num_tokens)
+    assert decoded.tolist() == [[0.0, 0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0]]
+
+
+def test_native_action_codec_language_roundtrip_and_absent_groups() -> None:
+    codec = G05NativeActionCodec(_tiny_codec_config(), action_token_begin=100)
+    actions = torch.linspace(-1, 1, 8 * 8).reshape(8, 8)
+
+    token_ids = codec.encode_for_language({"value": actions})
+    decoded, absent = codec.decode_language_tokens(
+        torch.tensor(token_ids),
+        horizon=8,
+        action_dim=8,
+    )
+
+    assert len(token_ids) == codec.action_token_length
+    assert decoded.shape == (8, 8)
+    assert torch.isfinite(decoded).all()
+    assert absent == set()
+    assert all(key.startswith("model.") for key in codec.module.state_dict())
+
+    empty, absent = codec.decode_language_tokens(torch.empty(0, dtype=torch.long), horizon=8, action_dim=8)
+    assert absent == set(codec.parts)
+    assert torch.equal(empty, torch.zeros_like(empty))

uv.lock

@@ -2879,7 +2879,6 @@ all = [
     { name = "motorbridge-smart-servo" },
     { name = "mypy" },
     { name = "num2words" },
-    { name = "omegaconf" },
     { name = "pandas" },
     { name = "peft" },
     { name = "placo" },
@@ -3022,7 +3021,7 @@ feetech = [
     { name = "pyserial" },
 ]
 g05 = [
-    { name = "omegaconf" },
+    { name = "transformers" },
 ]
 gamepad = [
     { name = "hidapi" },
@@ -3456,7 +3455,6 @@ requires-dist = [
     { name = "mypy", marker = "extra == 'dev'", specifier = ">=1.19.1" },
     { name = "num2words", marker = "extra == 'smolvla'", specifier = ">=0.5.14,<0.6.0" },
     { name = "numpy", specifier = ">=2.0.0,<2.3.0" },
-    { name = "omegaconf", marker = "extra == 'g05'", specifier = ">=2.3.0,<3.0.0" },
     { name = "onnx", marker = "extra == 'unitree-g1'", specifier = ">=1.16.0,<2.0.0" },
     { name = "onnxruntime", marker = "extra == 'unitree-g1'", specifier = ">=1.16.0,<2.0.0" },
     { name = "openai", marker = "extra == 'annotations'", specifier = ">=1.40,<2.0" },
@@ -3505,6 +3503,7 @@ requires-dist = [
     { name = "torchvision", marker = "sys_platform != 'linux'", specifier = ">=0.22.0,<0.27.0" },
     { name = "torchvision", marker = "sys_platform == 'linux'", specifier = ">=0.22.0,<0.27.0", index = "https://download.pytorch.org/whl/cu128" },
     { name = "tqdm", specifier = ">=4.66.0,<5.0.0" },
+    { name = "transformers", marker = "extra == 'g05'", specifier = ">=5.4.0,<5.6.0" },
     { name = "transformers", marker = "extra == 'transformers-dep'", specifier = ">=5.4.0,<5.6.0" },
     { name = "wandb", marker = "extra == 'training'", specifier = ">=0.24.0,<0.28.0" },
 ]