[Core] Add realtime AR-Diffusion tick sessions for LingBot World 2.0 (#5491)

Signed-off-by: zhangbin.327 <zhangbin.327@bytedance.com> Signed-off-by: Jack47 <scsvip@gmail.com> Co-authored-by: zhangbin.327 <zhangbin.327@bytedance.com> Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>
2026-08-16 09:11:20 +08:00
1 parent 9798bc3a8d
commit 3875f8ded4
@@ -6,7 +6,10 @@ from types import SimpleNamespace

 import pytest

-from vllm_omni.diffusion.models.dreamzero.pipeline_dreamzero import DreamZeroPipeline
+from vllm_omni.diffusion.models.dreamzero.pipeline_dreamzero import (
+    DREAMZERO_MODEL_OWNED_STATE_BYTES_PER_SESSION,
+    DreamZeroPipeline,
+)
 from vllm_omni.diffusion.models.dreamzero.state_dreamzero import DreamZeroState

 pytestmark = [pytest.mark.core_model, pytest.mark.cpu]
@@ -32,6 +35,37 @@ def test_dreamzero_pipeline_state_is_session_keyed() -> None:
    assert session_b.call_count == 3


+def test_dreamzero_kv_spec_accounts_for_model_owned_cuda_state(monkeypatch) -> None:
+    pipeline = DreamZeroPipeline.__new__(DreamZeroPipeline)
+    pipeline.transformer = SimpleNamespace(
+        frame_seqlen=16,
+        blocks=[
+            SimpleNamespace(
+                self_attn=SimpleNamespace(
+                    max_attention_size=96,
+                    tp_num_heads=4,
+                )
+            )
+        ],
+        text_len=8,
+        model_type="t2v",
+        num_layers=2,
+        num_heads=4,
+        dim=256,
+        num_frame_per_block=4,
+        num_action_per_block=2,
+        num_state_per_block=1,
+    )
+    monkeypatch.setattr(
+        "vllm_omni.diffusion.models.dreamzero.pipeline_dreamzero.get_classifier_free_guidance_world_size",
+        lambda: 1,
+    )
+
+    spec = pipeline.ar_diffusion_kv_cache_spec()
+
+    assert spec.model_owned_state_bytes_per_session == DREAMZERO_MODEL_OWNED_STATE_BYTES_PER_SESSION
+
+
 def test_dreamzero_pipeline_state_follows_runner_lifecycle_notifications() -> None:
    pipeline = _empty_pipeline()

@@ -0,0 +1 @@
+# SPDX-License-Identifier: Apache-2.0
@@ -0,0 +1,13 @@
+{
+  "_class_name": "LingBotWorldCausalDMDPipeline",
+  "_diffusers_version": "0.35.0.dev0",
+  "boundary_ratio": 0.9,
+  "image_encoder": [null, null],
+  "image_processor": [null, null],
+  "scheduler": ["diffusers", "UniPCMultistepScheduler"],
+  "text_encoder": ["transformers", "UMT5EncoderModel"],
+  "tokenizer": ["transformers", "T5TokenizerFast"],
+  "transformer": ["diffusers", "CausalLingBotWorldTransformer3DModel"],
+  "transformer_2": [null, null],
+  "vae": ["diffusers", "AutoencoderKLWan"]
+}
@@ -0,0 +1,42 @@
+{
+  "sources": {
+    "config": "https://huggingface.co/robbyant/lingbot-world-v2-14b-causal-fast-diffusers/resolve/main/transformer/config.json",
+    "shard_1_header": "https://huggingface.co/robbyant/lingbot-world-v2-14b-causal-fast-diffusers/resolve/main/transformer/diffusion_pytorch_model-00001-of-00008.safetensors",
+    "shard_8_header": "https://huggingface.co/robbyant/lingbot-world-v2-14b-causal-fast-diffusers/resolve/main/transformer/diffusion_pytorch_model-00008-of-00008.safetensors"
+  },
+  "dtype": "F32",
+  "shard_representatives": {
+    "diffusion_pytorch_model-00001-of-00008.safetensors": "blocks.0.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00002-of-00008.safetensors": "blocks.4.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00003-of-00008.safetensors": "blocks.10.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00004-of-00008.safetensors": "blocks.14.cam_scale_layer.bias",
+    "diffusion_pytorch_model-00005-of-00008.safetensors": "blocks.20.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00006-of-00008.safetensors": "blocks.25.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00007-of-00008.safetensors": "blocks.30.cam_injector_layer1.bias",
+    "diffusion_pytorch_model-00008-of-00008.safetensors": "blocks.35.cam_injector_layer1.bias"
+  },
+  "parameter_shapes": {
+    "blocks.0.cam_injector_layer1.bias": [5120],
+    "blocks.4.cam_injector_layer1.bias": [5120],
+    "blocks.10.cam_injector_layer1.bias": [5120],
+    "blocks.14.cam_scale_layer.bias": [5120],
+    "blocks.20.cam_injector_layer1.bias": [5120],
+    "blocks.25.cam_injector_layer1.bias": [5120],
+    "blocks.30.cam_injector_layer1.bias": [5120],
+    "blocks.35.cam_injector_layer1.bias": [5120],
+    "patch_embedding.weight": [5120, 36, 1, 2, 2],
+    "patch_embedding_wancamctrl.weight": [5120, 1536],
+    "c2ws_hidden_states_layer1.weight": [5120, 5120],
+    "c2ws_hidden_states_layer2.weight": [5120, 5120],
+    "blocks.0.modulation": [1, 6, 5120],
+    "blocks.0.self_attn.q.weight": [5120, 5120],
+    "blocks.0.ffn.0.weight": [13824, 5120],
+    "blocks.0.ffn.2.weight": [5120, 13824],
+    "blocks.0.cam_injector_layer1.weight": [5120, 5120],
+    "blocks.0.cam_injector_layer2.weight": [5120, 5120],
+    "blocks.0.cam_scale_layer.weight": [5120, 5120],
+    "blocks.0.cam_shift_layer.weight": [5120, 5120],
+    "head.modulation": [1, 2, 5120],
+    "head.head.weight": [64, 5120]
+  }
+}
@@ -0,0 +1,30 @@
+{
+  "_class_name": "UniPCMultistepScheduler",
+  "_diffusers_version": "0.35.0.dev0",
+  "beta_end": 0.02,
+  "beta_schedule": "linear",
+  "beta_start": 0.0001,
+  "disable_corrector": [],
+  "dynamic_thresholding_ratio": 0.995,
+  "final_sigmas_type": "zero",
+  "flow_shift": 5.0,
+  "lower_order_final": true,
+  "num_train_timesteps": 1000,
+  "predict_x0": true,
+  "prediction_type": "flow_prediction",
+  "rescale_betas_zero_snr": false,
+  "sample_max_value": 1.0,
+  "solver_order": 2,
+  "solver_p": null,
+  "solver_type": "bh2",
+  "steps_offset": 0,
+  "thresholding": false,
+  "time_shift_type": "exponential",
+  "timestep_spacing": "linspace",
+  "trained_betas": null,
+  "use_beta_sigmas": false,
+  "use_dynamic_shifting": false,
+  "use_exponential_sigmas": false,
+  "use_flow_sigmas": true,
+  "use_karras_sigmas": false
+}
@@ -0,0 +1,112 @@
+{
+  "source": "https://huggingface.co/robbyant/lingbot-world-v2-14b-causal-fast-diffusers/resolve/main/transformer/diffusion_pytorch_model.safetensors.index.json",
+  "index_parameter_count": 1421,
+  "canonical_name_set_sha256": "5d31b7f64fd5e5e271b789b2dbe50fb7bbf146bd8b750646bdc9abb4e5b8139d",
+  "canonical_name_to_shard_sha256": "e1addc27d2b1fad6f10226a23a265ee3e3c61e74dce4d5859727bdf180a67992",
+  "canonical_serialization": "sorted lines formatted as parameter_name=shard_filename with LF separators and no trailing LF",
+  "shards": {
+    "diffusion_pytorch_model-00001-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "81a3d4778de604e75609aae7dac3d8dcbc081811e7748267fe953bbeb375e79d"
+    },
+    "diffusion_pytorch_model-00002-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "4e36e2596a6468f29179fa5795396f2e9a7f7d8debc912b34a6f6c2c7c7c610d"
+    },
+    "diffusion_pytorch_model-00003-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "6f74a7b2cf7444c2daa2b3fc32bd3787589b35543c230c5c13b89f0f0f2a0998"
+    },
+    "diffusion_pytorch_model-00004-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "ec5c967ed5271ba7834337c4ee93a73f8ed0eead4492d4920624251c65c058ac"
+    },
+    "diffusion_pytorch_model-00005-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "ad1fdab5830dd9ce43ea007f112b4be223327b7c8197c766d9cf9219e74d619b"
+    },
+    "diffusion_pytorch_model-00006-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "fd58f0d86be42d8afcf55d3e07d8a22f7f6ef5064da931a600c890b71b6dfbae"
+    },
+    "diffusion_pytorch_model-00007-of-00008.safetensors": {
+      "parameter_count": 180,
+      "parameter_names_sha256": "305a1714b5f4fb54d5877c593b451273ab1490d90fd0896a299d96e140295047"
+    },
+    "diffusion_pytorch_model-00008-of-00008.safetensors": {
+      "parameter_count": 161,
+      "parameter_names_sha256": "4c18d94d96168682eb212f93e3cdf7313928776d8d9e6e4de0255fe899decb25"
+    }
+  },
+  "top_level_modules": [
+    "blocks",
+    "c2ws_hidden_states_layer1",
+    "c2ws_hidden_states_layer2",
+    "head",
+    "patch_embedding",
+    "patch_embedding_wancamctrl",
+    "text_embedding",
+    "time_embedding",
+    "time_projection"
+  ],
+  "non_block_parameters": [
+    "c2ws_hidden_states_layer1.bias",
+    "c2ws_hidden_states_layer1.weight",
+    "c2ws_hidden_states_layer2.bias",
+    "c2ws_hidden_states_layer2.weight",
+    "head.head.bias",
+    "head.head.weight",
+    "head.modulation",
+    "patch_embedding.bias",
+    "patch_embedding.weight",
+    "patch_embedding_wancamctrl.bias",
+    "patch_embedding_wancamctrl.weight",
+    "text_embedding.0.bias",
+    "text_embedding.0.weight",
+    "text_embedding.2.bias",
+    "text_embedding.2.weight",
+    "time_embedding.0.bias",
+    "time_embedding.0.weight",
+    "time_embedding.2.bias",
+    "time_embedding.2.weight",
+    "time_projection.1.bias",
+    "time_projection.1.weight"
+  ],
+  "block_parameter_suffixes": [
+    "cam_injector_layer1.bias",
+    "cam_injector_layer1.weight",
+    "cam_injector_layer2.bias",
+    "cam_injector_layer2.weight",
+    "cam_scale_layer.bias",
+    "cam_scale_layer.weight",
+    "cam_shift_layer.bias",
+    "cam_shift_layer.weight",
+    "cross_attn.k.bias",
+    "cross_attn.k.weight",
+    "cross_attn.norm_k.weight",
+    "cross_attn.norm_q.weight",
+    "cross_attn.o.bias",
+    "cross_attn.o.weight",
+    "cross_attn.q.bias",
+    "cross_attn.q.weight",
+    "cross_attn.v.bias",
+    "cross_attn.v.weight",
+    "ffn.0.bias",
+    "ffn.0.weight",
+    "ffn.2.bias",
+    "ffn.2.weight",
+    "modulation",
+    "norm3.bias",
+    "norm3.weight",
+    "self_attn.k.bias",
+    "self_attn.k.weight",
+    "self_attn.norm_k.weight",
+    "self_attn.norm_q.weight",
+    "self_attn.o.bias",
+    "self_attn.o.weight",
+    "self_attn.q.bias",
+    "self_attn.q.weight",
+    "self_attn.v.bias",
+    "self_attn.v.weight"
+  ]
+}
@@ -0,0 +1,294 @@
+# SPDX-License-Identifier: Apache-2.0
+
+from __future__ import annotations
+
+import asyncio
+
+import pytest
+import torch
+
+from vllm_omni.diffusion.models.lingbot_world.actions import (
+    LINGBOT_CAMERA_ACTION_SCHEMA,
+    LINGBOT_CAMERA_TRAJECTORY_SCHEMA,
+    LingBotCameraControlReducer,
+    integrate_lingbot_camera_actions,
+    parse_lingbot_camera_action_frames,
+)
+from vllm_omni.experimental.ar_diffusion.session import (
+    ARDiffusionSession,
+    ARDiffusionSessionEvent,
+)
+from vllm_omni.experimental.ar_diffusion.tick_protocol import (
+    ARDiffusionChunkMetadata,
+    ARDiffusionControlInput,
+    ARDiffusionTickRequest,
+)
+
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
+
+def _action_control(mode: str, **data) -> ARDiffusionControlInput:
+    return ARDiffusionControlInput(
+        track="camera",
+        schema=LINGBOT_CAMERA_ACTION_SCHEMA,
+        data={"mode": mode, **data},
+    )
+
+
+def _prepared_frames(prepared) -> tuple[tuple[str, ...], ...]:
+    assert len(prepared.controls) == 1
+    return prepared.controls[0].data["frames"]
+
+
+def test_state_controls_hold_release_and_preserve_short_pulse() -> None:
+    reducer = LingBotCameraControlReducer()
+    pressed = reducer.prepare(
+        current_controls={},
+        events=(
+            ARDiffusionSessionEvent(
+                event_id=1,
+                controls=(
+                    _action_control(
+                        "state",
+                        transitions=[{"actions": ["W"], "client_ts_ms": 10}],
+                    ),
+                ),
+            ),
+        ),
+        chunk_index=0,
+    )
+    assert _prepared_frames(pressed) == (("w",), ("w",), ("w",))
+    assert pressed.controls[0].to_dict()["data"]["frames"] == [["w"], ["w"], ["w"]]
+    reducer.commit(pressed)
+
+    held = reducer.prepare(
+        current_controls={"camera": pressed.controls[0]},
+        events=(),
+        chunk_index=1,
+    )
+    assert _prepared_frames(held) == (("w",), ("w",), ("w",))
+    reducer.commit(held)
+
+    pulse = reducer.prepare(
+        current_controls={"camera": held.controls[0]},
+        events=(
+            ARDiffusionSessionEvent(
+                event_id=2,
+                controls=(
+                    _action_control(
+                        "state",
+                        transitions=[
+                            {"actions": ["j"], "client_ts_ms": 20},
+                            {"actions": [], "client_ts_ms": 21},
+                        ],
+                    ),
+                ),
+            ),
+        ),
+        chunk_index=2,
+    )
+    assert _prepared_frames(pulse) == (("j",), (), ())
+    reducer.commit(pulse)
+
+    released = reducer.prepare(
+        current_controls={"camera": pulse.controls[0]},
+        events=(),
+        chunk_index=3,
+    )
+    assert _prepared_frames(released) == ((), (), ())
+
+
+def test_script_is_transactional_consumed_once_and_neutral_padded() -> None:
+    reducer = LingBotCameraControlReducer()
+    event = ARDiffusionSessionEvent(
+        event_id=1,
+        controls=(
+            _action_control(
+                "script",
+                frames=[["w"], ["d"], ["l"], ["i"]],
+            ),
+        ),
+    )
+    first_attempt = reducer.prepare(
+        current_controls={},
+        events=(event,),
+        chunk_index=0,
+    )
+    assert _prepared_frames(first_attempt) == (("w",), ("d",), ("l",))
+
+    # An uncommitted failed attempt must not consume the reducer's script.
+    second_attempt = reducer.prepare(
+        current_controls={},
+        events=(event,),
+        chunk_index=0,
+    )
+    assert _prepared_frames(second_attempt) == (("w",), ("d",), ("l",))
+    reducer.commit(second_attempt)
+
+    tail = reducer.prepare(
+        current_controls={"camera": second_attempt.controls[0]},
+        events=(),
+        chunk_index=1,
+    )
+    assert _prepared_frames(tail) == (("i",), (), ())
+    reducer.commit(tail)
+    exhausted = reducer.prepare(
+        current_controls={"camera": tail.controls[0]},
+        events=(),
+        chunk_index=2,
+    )
+    assert _prepared_frames(exhausted) == ((), (), ())
+
+
+def test_trajectory_control_remains_an_expert_override() -> None:
+    reducer = LingBotCameraControlReducer()
+    trajectory = ARDiffusionControlInput(
+        track="camera",
+        schema=LINGBOT_CAMERA_TRAJECTORY_SCHEMA,
+        data={"poses": [[[1.0]]], "intrinsics": [[1.0]]},
+    )
+    prepared = reducer.prepare(
+        current_controls={},
+        events=(
+            ARDiffusionSessionEvent(
+                event_id=1,
+                controls=(trajectory,),
+            ),
+        ),
+        chunk_index=0,
+    )
+    assert prepared.controls == (trajectory,)
+
+
+def test_action_integrator_matches_lingbot_motion_and_calibration() -> None:
+    trajectory, pitch = integrate_lingbot_camera_actions(
+        [["w"], ["d"], ["l"]],
+        width=832,
+        height=480,
+    )
+
+    assert pitch == 0.0
+    torch.testing.assert_close(
+        trajectory.poses[0, :3, 3],
+        torch.tensor([0.0, 0.0, 0.05], dtype=torch.float64),
+        atol=1e-6,
+        rtol=0,
+    )
+    torch.testing.assert_close(
+        trajectory.poses[1, :3, 3],
+        torch.tensor([0.05, 0.0, 0.05], dtype=torch.float64),
+        atol=1e-6,
+        rtol=0,
+    )
+    expected_yaw = torch.tensor(
+        [
+            [0.9945219, 0.0, 0.10452846],
+            [0.0, 1.0, 0.0],
+            [-0.10452846, 0.0, 0.9945219],
+        ],
+        dtype=torch.float64,
+    )
+    torch.testing.assert_close(
+        trajectory.poses[2, :3, :3],
+        expected_yaw,
+        atol=1e-6,
+        rtol=0,
+    )
+    torch.testing.assert_close(
+        trajectory.intrinsics[0],
+        torch.tensor([500.0, 500.0, 416.0, 240.0]),
+    )
+
+    resized, _ = integrate_lingbot_camera_actions(
+        [[]],
+        width=416,
+        height=240,
+    )
+    scaled = resized.intrinsics[0] * torch.tensor([416 / 832, 240 / 480, 416 / 832, 240 / 480])
+    torch.testing.assert_close(
+        scaled,
+        torch.tensor([500.0, 500.0, 208.0, 120.0]),
+    )
+
+
+@pytest.mark.parametrize(
+    ("data", "message"),
+    [
+        ({"mode": "frames", "frames": [["x"], [], []]}, "W/A/S/D/I/J/K/L"),
+        ({"mode": "frames", "frames": [["w"]]}, "exactly one action list"),
+        ({"mode": "state", "frames": [[], [], []]}, "mode='frames'"),
+    ],
+)
+def test_model_tick_action_payload_validation(data, message: str) -> None:
+    with pytest.raises(ValueError, match=message):
+        parse_lingbot_camera_action_frames(data, expected_frames=3)
+
+
+class _TickConsumer:
+    def __init__(self) -> None:
+        self.ticks: list[ARDiffusionTickRequest] = []
+
+    async def execute_tick(self, tick: ARDiffusionTickRequest) -> ARDiffusionChunkMetadata:
+        self.ticks.append(tick)
+        return ARDiffusionChunkMetadata.from_tick(tick)
+
+    def chunk_metadata(self, output: ARDiffusionChunkMetadata) -> ARDiffusionChunkMetadata:
+        return output
+
+
+class _Lifecycle:
+    async def reset_session(self, session_id: str) -> None:
+        del session_id
+
+    async def close_session(self, session_id: str) -> None:
+        del session_id
+
+
+def test_session_reducer_keeps_prompt_and_actions_atomic_and_resets() -> None:
+    async def exercise() -> None:
+        consumer = _TickConsumer()
+        reducer = LingBotCameraControlReducer()
+        session = ARDiffusionSession(
+            "world-actions",
+            tick_consumer=consumer,
+            lifecycle=_Lifecycle(),
+            max_pending_events=8,
+            request_id_factory=lambda session_id, chunk_index: f"{session_id}-{chunk_index}",
+            control_reducer=reducer,
+        )
+        await session.accept_event(
+            ARDiffusionSessionEvent(
+                event_id=1,
+                prompt="turn toward the window",
+                controls=(
+                    _action_control(
+                        "state",
+                        transitions=[{"actions": ["d"]}],
+                    ),
+                ),
+            )
+        )
+        await session.next_chunk()
+
+        tick = consumer.ticks[0]
+        assert tick.prompt == "turn toward the window"
+        assert tick.applied_event_ids == (1,)
+        assert tick.controls[0].data["frames"] == (("d",), ("d",), ("d",))
+
+        await session.reset()
+        await session.accept_event(
+            ARDiffusionSessionEvent(
+                event_id=2,
+                controls=(
+                    _action_control(
+                        "state",
+                        transitions=[{"actions": []}],
+                    ),
+                ),
+            )
+        )
+        await session.next_chunk()
+        assert consumer.ticks[1].chunk_index == 0
+        assert consumer.ticks[1].controls[0].data["frames"] == ((), (), ())
+
+    asyncio.run(exercise())
@@ -0,0 +1,543 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from __future__ import annotations
+
+import importlib.util
+import math
+import sys
+from pathlib import Path
+from types import ModuleType
+
+import pytest
+import torch
+import torch.nn.functional as F
+from torch import nn
+
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
+_MODULE_PATH = Path(__file__).parents[4] / "vllm_omni/diffusion/models/lingbot_world/transformer.py"
+_MODULE_NAME = "_lingbot_world_attention_under_test"
+_MISSING_MODULE = object()
+_STUBBED_MODULE_NAMES = (
+    "vllm",
+    "vllm.distributed",
+    "vllm.model_executor",
+    "vllm.model_executor.layers",
+    "vllm.model_executor.layers.conv",
+    "vllm.model_executor.layers.linear",
+    "vllm.model_executor.model_loader",
+    "vllm.model_executor.model_loader.weight_utils",
+    "vllm.model_executor.utils",
+    "vllm_omni",
+    "vllm_omni.diffusion",
+    "vllm_omni.diffusion.attention",
+    "vllm_omni.diffusion.attention.layer",
+    "vllm_omni.diffusion.layers",
+    "vllm_omni.diffusion.layers.norm",
+    "vllm_omni.diffusion.layers.rope",
+    "vllm_omni.experimental",
+    "vllm_omni.experimental.ar_diffusion",
+    "vllm_omni.experimental.ar_diffusion.kv_cache",
+    "vllm_omni.experimental.ar_diffusion.kv_cache.paged_attention",
+)
+
+
+@pytest.fixture(autouse=True)
+def _inference_context():
+    with torch.inference_mode():
+        yield
+
+
+def _install_vllm_stubs() -> None:
+    for name in _STUBBED_MODULE_NAMES:
+        sys.modules[name] = ModuleType(name)
+
+    distributed = sys.modules["vllm.distributed"]
+    distributed.get_tensor_model_parallel_rank = lambda: 0
+    distributed.get_tensor_model_parallel_world_size = lambda: 1
+    distributed.tensor_model_parallel_all_reduce = lambda value: value
+
+    def set_weight_attrs(weight: torch.Tensor, attrs: dict) -> None:
+        for name, value in attrs.items():
+            setattr(weight, name, value)
+
+    sys.modules["vllm.model_executor.utils"].set_weight_attrs = set_weight_attrs
+    sys.modules["vllm.model_executor.model_loader.weight_utils"].default_weight_loader = lambda param, loaded_weight: (
+        param.data.copy_(loaded_weight)
+    )
+
+    class _Linear(nn.Module):
+        def __init__(
+            self,
+            input_size: int,
+            output_size: int,
+            *,
+            bias: bool = True,
+            return_bias: bool = False,
+            **kwargs,
+        ) -> None:
+            super().__init__()
+            del kwargs
+            self.return_bias = return_bias
+            self.weight = nn.Parameter(torch.empty(output_size, input_size))
+            self.bias = nn.Parameter(torch.empty(output_size)) if bias else None
+            nn.init.kaiming_uniform_(self.weight, a=math.sqrt(5))
+            if self.bias is not None:
+                nn.init.zeros_(self.bias)
+            self.calls = 0
+
+        def forward(self, value: torch.Tensor):
+            self.calls += 1
+            output = F.linear(value, self.weight, self.bias)
+            return (output, self.bias) if self.return_bias else output
+
+    linear = sys.modules["vllm.model_executor.layers.linear"]
+    linear.ColumnParallelLinear = _Linear
+    linear.RowParallelLinear = _Linear
+
+    class _QKVLinear(nn.Module):
+        def __init__(
+            self,
+            hidden_size: int,
+            head_size: int,
+            total_num_heads: int,
+            total_num_kv_heads: int | None = None,
+            *,
+            bias: bool = True,
+            **kwargs,
+        ) -> None:
+            super().__init__()
+            del kwargs
+            self.num_heads = total_num_heads
+            self.num_kv_heads = total_num_kv_heads or total_num_heads
+            output_size = (self.num_heads + 2 * self.num_kv_heads) * head_size
+            self.weight = nn.Parameter(torch.empty(output_size, hidden_size))
+            self.bias = nn.Parameter(torch.empty(output_size)) if bias else None
+            nn.init.kaiming_uniform_(self.weight, a=math.sqrt(5))
+            if self.bias is not None:
+                nn.init.zeros_(self.bias)
+            self.calls = 0
+
+            def load_shard(param: torch.Tensor, loaded_weight: torch.Tensor, shard_id: str) -> None:
+                shard_index = {"q": 0, "k": 1, "v": 2}[shard_id]
+                shard_size = param.shape[0] // 3
+                param.data.narrow(0, shard_index * shard_size, shard_size).copy_(loaded_weight)
+
+            self.weight.weight_loader = load_shard
+            if self.bias is not None:
+                self.bias.weight_loader = load_shard
+
+        def forward(self, value: torch.Tensor):
+            self.calls += 1
+            return F.linear(value, self.weight, self.bias), None
+
+    linear.QKVParallelLinear = _QKVLinear
+
+    class _Conv3dLayer(nn.Conv3d):
+        def __init__(self, in_channels: int, out_channels: int, kernel_size, stride, **kwargs) -> None:
+            super().__init__(in_channels, out_channels, kernel_size=kernel_size, stride=stride, **kwargs)
+
+    sys.modules["vllm.model_executor.layers.conv"].Conv3dLayer = _Conv3dLayer
+
+    class _LayerNorm(nn.LayerNorm):
+        def __init__(self, dim: int, eps: float = 1e-6, elementwise_affine: bool = True) -> None:
+            super().__init__(dim, eps=eps, elementwise_affine=elementwise_affine)
+
+    sys.modules["vllm_omni.diffusion.layers.norm"].LayerNorm = _LayerNorm
+
+    class _Attention(nn.Module):
+        def __init__(self, *args, softmax_scale: float, **kwargs) -> None:
+            super().__init__()
+            del args
+            self.softmax_scale = softmax_scale
+            self.causal = kwargs["causal"]
+            self.calls: list[tuple[torch.Tensor, torch.Tensor, torch.Tensor]] = []
+
+        def forward(
+            self,
+            query: torch.Tensor,
+            key: torch.Tensor,
+            value: torch.Tensor,
+            attn_metadata=None,
+        ) -> torch.Tensor:
+            del attn_metadata
+            self.calls.append((query.detach().clone(), key.detach().clone(), value.detach().clone()))
+            scores = torch.einsum("bqhd,bkhd->bhqk", query, key) * self.softmax_scale
+            weights = scores.softmax(dim=-1)
+            return torch.einsum("bhqk,bkhd->bqhd", weights, value)
+
+    sys.modules["vllm_omni.diffusion.attention.layer"].Attention = _Attention
+
+    class _RotaryEmbeddingWan(nn.Module):
+        def __init__(self, *args, **kwargs) -> None:
+            super().__init__()
+            del args, kwargs
+            self.calls: list[tuple[torch.Tensor, torch.Tensor]] = []
+
+        def forward(self, value: torch.Tensor, cos: torch.Tensor, sin: torch.Tensor) -> torch.Tensor:
+            self.calls.append((cos.detach().clone(), sin.detach().clone()))
+            return value
+
+    sys.modules["vllm_omni.diffusion.layers.rope"].RotaryEmbeddingWan = _RotaryEmbeddingWan
+
+    paged_attention = sys.modules["vllm_omni.experimental.ar_diffusion.kv_cache.paged_attention"]
+
+    class _PagedLayerContext:
+        pass
+
+    class _PagedLayerInputs:
+        pass
+
+    paged_attention.ARDiffusionPagedLayerContext = _PagedLayerContext
+    paged_attention.ARDiffusionPagedLayerInputs = _PagedLayerInputs
+    paged_attention.ar_diffusion_paged_attention = lambda *args, **kwargs: (_ for _ in ()).throw(
+        AssertionError("CUDA paged attention was not expected in this CPU test")
+    )
+    paged_attention.paged_write_attn = lambda *args, **kwargs: (_ for _ in ()).throw(
+        AssertionError("paged path was not expected in this direct-cache test")
+    )
+
+
+def _load_module():
+    assert _MODULE_PATH.exists(), "LingBot attention module has not been implemented"
+    module_names = (*_STUBBED_MODULE_NAMES, _MODULE_NAME)
+    previous = {name: sys.modules.get(name, _MISSING_MODULE) for name in module_names}
+    try:
+        _install_vllm_stubs()
+        spec = importlib.util.spec_from_file_location(_MODULE_NAME, _MODULE_PATH)
+        assert spec is not None and spec.loader is not None
+        module = importlib.util.module_from_spec(spec)
+        sys.modules[spec.name] = module
+        spec.loader.exec_module(module)
+        return module
+    finally:
+        for name, original in previous.items():
+            if original is _MISSING_MODULE:
+                sys.modules.pop(name, None)
+            else:
+                sys.modules[name] = original
+
+
+def test_load_module_restores_process_module_state() -> None:
+    module_names = (*_STUBBED_MODULE_NAMES, _MODULE_NAME)
+    previous = {name: sys.modules.get(name, _MISSING_MODULE) for name in module_names}
+
+    _load_module()
+
+    for name, original in previous.items():
+        assert sys.modules.get(name, _MISSING_MODULE) is original
+
+
+def test_allocate_lingbot_cache_creates_request_local_layer_storage() -> None:
+    module = _load_module()
+
+    cache = module.allocate_lingbot_cache(
+        batch_size=2,
+        num_layers=3,
+        max_tokens=7,
+        num_local_heads=2,
+        head_dim=4,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    assert len(cache.self_attention) == 3
+    assert len(cache.cross_attention) == 3
+    assert cache.cross_attention == [None, None, None]
+    assert cache.self_attention[0].key.shape == (2, 7, 2, 4)
+    assert cache.self_attention[0].value.shape == (2, 7, 2, 4)
+    assert cache.self_attention[0].key.dtype == torch.float32
+    assert cache.self_attention[0].end == 0
+    assert cache.self_attention[0].key.data_ptr() != cache.self_attention[1].key.data_ptr()
+
+
+def _allocate_single_layer(module, *, max_tokens: int):
+    return module.allocate_lingbot_cache(
+        batch_size=1,
+        num_layers=1,
+        max_tokens=max_tokens,
+        num_local_heads=1,
+        head_dim=2,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+
+def _set_identity_attention(attention: nn.Module) -> None:
+    qkv = getattr(attention, "qkv", None)
+    if qkv is not None:
+        projections = (qkv, attention.o)
+    else:
+        projections = (attention.q, attention.k, attention.v, attention.o)
+    for projection in projections:
+        with torch.no_grad():
+            identity = torch.eye(2)
+            projection.weight.copy_(torch.cat((identity, identity, identity)) if projection is qkv else identity)
+            if projection.bias is not None:
+                projection.bias.zero_()
+    attention.norm_q = nn.Identity()
+    attention.norm_k = nn.Identity()
+
+
+def _tokens(*values: float) -> torch.Tensor:
+    return torch.tensor([[[value, 0.0] for value in values]])
+
+
+def _record_inputs(module: nn.Module) -> list[tuple]:
+    records: list[tuple] = []
+    module.register_forward_pre_hook(lambda _module, args: records.append(args))
+    return records
+
+
+def _record_outputs(module: nn.Module) -> list[torch.Tensor]:
+    records: list[torch.Tensor] = []
+
+    def record(_module, _args, output) -> None:
+        records.append(output[0] if isinstance(output, tuple) else output)
+
+    module.register_forward_hook(record)
+    return records
+
+
+def _cache_snapshot(cache) -> tuple[torch.Tensor, torch.Tensor, tuple[int, int, int | None, int]]:
+    return (
+        cache.key.detach().view(torch.uint8).clone(),
+        cache.value.detach().view(torch.uint8).clone(),
+        (cache.end, cache.absolute_end, cache.last_start, cache.sink_end),
+    )
+
+
+def _assert_cache_unchanged(cache, snapshot) -> None:
+    key, value, metadata = snapshot
+    assert torch.equal(cache.key.detach().view(torch.uint8), key)
+    assert torch.equal(cache.value.detach().view(torch.uint8), value)
+    assert (cache.end, cache.absolute_end, cache.last_start, cache.sink_end) == metadata
+
+
+def test_self_attention_repeated_offset_overwrites_then_later_offset_appends() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    cache = _allocate_single_layer(module, max_tokens=6).self_attention[0]
+
+    attention(_tokens(1, 2), cache=cache, current_start=0, sink_tokens=0)
+    attention(_tokens(10, 20), cache=cache, current_start=0, sink_tokens=0)
+
+    assert cache.end == 2
+    assert cache.absolute_end == 2
+    torch.testing.assert_close(cache.key[0, : cache.end, 0, 0], torch.tensor([10.0, 20.0]))
+
+    attention(_tokens(3, 4), cache=cache, current_start=2, sink_tokens=0)
+
+    assert cache.end == 4
+    assert cache.absolute_end == 4
+    torch.testing.assert_close(cache.key[0, : cache.end, 0, 0], torch.tensor([10.0, 20.0, 3.0, 4.0]))
+
+
+def test_self_attention_uses_one_fused_qkv_projection() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    cache = _allocate_single_layer(module, max_tokens=2).self_attention[0]
+
+    attention(_tokens(1, 2), cache=cache, current_start=0, sink_tokens=0)
+
+    assert attention.qkv.calls == 1
+
+
+def test_self_attention_routes_paged_inputs_through_engine_owned_cache() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    paged_inputs = module.ARDiffusionPagedLayerInputs()
+    calls = []
+
+    def paged_write(inputs, query, key, value, k_act, v_act, scale):
+        calls.append((inputs, query.clone(), key.clone(), value.clone(), k_act, v_act, scale))
+        return query
+
+    module.paged_write_attn = paged_write
+    output = attention(
+        _tokens(1, 2),
+        cache=paged_inputs,
+        current_start=0,
+        sink_tokens=0,
+        update_cache=False,
+    )
+
+    assert output.shape == (1, 2, 2)
+    assert len(calls) == 1
+    assert calls[0][0] is paged_inputs
+    assert calls[0][4:6] == (None, None)
+    assert attention.attn.calls == []
+    assert not any(hasattr(attention, name) for name in ("q", "k", "v"))
+
+
+def test_self_attention_is_chunk_causal_without_masking_inside_current_chunk() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    cache = _allocate_single_layer(module, max_tokens=8).self_attention[0]
+    attention_inputs = _record_inputs(attention.attn)
+
+    attention(_tokens(1, 2), cache=cache, current_start=0, sink_tokens=0)
+    first_keys = attention_inputs[-1][1].detach().clone()
+    attention(_tokens(3, 4), cache=cache, current_start=2, sink_tokens=0)
+    second_keys = attention_inputs[-1][1].detach().clone()
+
+    assert attention.attn.causal is False
+    torch.testing.assert_close(first_keys[0, :, 0, 0], torch.tensor([1.0, 2.0]))
+    torch.testing.assert_close(second_keys[0, :, 0, 0], torch.tensor([1.0, 2.0, 3.0, 4.0]))
+
+
+def test_self_attention_retains_sink_and_latest_local_history_after_eviction() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    cache = _allocate_single_layer(module, max_tokens=4).self_attention[0]
+    attention_inputs = _record_inputs(attention.attn)
+
+    attention(_tokens(1, 2), cache=cache, current_start=0, sink_tokens=1)
+    attention(_tokens(3, 4), cache=cache, current_start=2, sink_tokens=1)
+    attention(_tokens(5, 6), cache=cache, current_start=4, sink_tokens=1)
+
+    visible_keys = attention_inputs[-1][1].detach().clone()
+    assert cache.end == 4
+    assert cache.absolute_end == 6
+    torch.testing.assert_close(visible_keys[0, :, 0, 0], torch.tensor([1.0, 4.0, 5.0, 6.0]))
+    torch.testing.assert_close(cache.key[0, : cache.end, 0, 0], torch.tensor([1.0, 4.0, 5.0, 6.0]))
+
+
+def test_cross_attention_projects_encoder_kv_once_per_request() -> None:
+    module = _load_module()
+    attention = module.LingBotCrossAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    key_outputs = _record_outputs(attention.k)
+    value_outputs = _record_outputs(attention.v)
+    attention_inputs = _record_inputs(attention.attn)
+
+    output, cache = attention(_tokens(1), _tokens(2, 3), cache=None)
+    second_output, reused_cache = attention(_tokens(4), _tokens(20, 30), cache=cache)
+
+    assert output.shape == second_output.shape == (1, 1, 2)
+    assert reused_cache is cache
+    assert len(key_outputs) == 1
+    assert len(value_outputs) == 1
+    assert cache.end == 2
+    torch.testing.assert_close(cache.key[0, :, 0, 0], torch.tensor([2.0, 3.0]))
+    torch.testing.assert_close(attention_inputs[-1][1], cache.key)
+
+
+def test_self_attention_cache_is_isolated_between_requests() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    _set_identity_attention(attention)
+    first = _allocate_single_layer(module, max_tokens=4).self_attention[0]
+    second = _allocate_single_layer(module, max_tokens=4).self_attention[0]
+
+    attention(_tokens(1, 2), cache=first, current_start=0, sink_tokens=0)
+
+    assert first.end == 2
+    assert second.end == 0
+    assert torch.count_nonzero(second.key) == 0
+    attention(_tokens(8), cache=second, current_start=0, sink_tokens=0)
+    torch.testing.assert_close(first.key[0, : first.end, 0, 0], torch.tensor([1.0, 2.0]))
+    torch.testing.assert_close(second.key[0, : second.end, 0, 0], torch.tensor([8.0]))
+
+
+def test_cross_attention_keeps_checkpoint_qkvo_and_norm_parameter_names() -> None:
+    module = _load_module()
+    attention = module.LingBotCrossAttention(dim=4, num_heads=2)
+
+    names = set(attention.state_dict())
+
+    assert {
+        "q.weight",
+        "k.weight",
+        "v.weight",
+        "o.weight",
+        "norm_q.weight",
+        "norm_k.weight",
+    } <= names
+    assert callable(attention.norm_q.weight.weight_loader)
+
+
+def test_tp_world_size_one_attention_output_shapes() -> None:
+    module = _load_module()
+    self_attention = module.LingBotSelfAttention(dim=4, num_heads=2)
+    cross_attention = module.LingBotCrossAttention(dim=4, num_heads=2)
+    cache = module.allocate_lingbot_cache(
+        batch_size=2,
+        num_layers=1,
+        max_tokens=5,
+        num_local_heads=2,
+        head_dim=2,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+    hidden_states = torch.randn(2, 3, 4)
+    encoder_hidden_states = torch.randn(2, 5, 4)
+
+    self_output = self_attention(hidden_states, cache=cache.self_attention[0], current_start=0, sink_tokens=0)
+    cross_output, cache.cross_attention[0] = cross_attention(
+        hidden_states,
+        encoder_hidden_states,
+        cache=cache.cross_attention[0],
+    )
+
+    assert self_output.shape == hidden_states.shape
+    assert cross_output.shape == hidden_states.shape
+    assert cache.cross_attention[0] is not None
+
+
+def test_self_attention_applies_rotary_embedding_to_current_query_and_key() -> None:
+    module = _load_module()
+    attention = module.LingBotSelfAttention(dim=2, num_heads=1)
+    cache = _allocate_single_layer(module, max_tokens=2).self_attention[0]
+    cos = torch.ones(2, 1)
+    sin = torch.zeros(2, 1)
+    rotary_inputs = _record_inputs(attention.rotary_embedding)
+
+    attention(_tokens(1, 2), cache=cache, current_start=0, rotary_emb=(cos, sin), sink_tokens=0)
+
+    assert len(rotary_inputs) == 2
+    torch.testing.assert_close(rotary_inputs[0][1], cos)
+    torch.testing.assert_close(rotary_inputs[1][2], sin)
+
+
+def test_attention_block_owns_checkpoint_parent_namespaces() -> None:
+    module = _load_module()
+    block = module.LingBotAttentionBlock(dim=4, num_heads=2, prefix="blocks.0")
+
+    names = set(block.state_dict())
+    expected = {
+        *(f"self_attn.{child}.weight" for child in ("qkv", "o", "norm_q", "norm_k")),
+        *(f"cross_attn.{child}.weight" for child in ("q", "k", "v", "o", "norm_q", "norm_k")),
+    }
+
+    assert expected <= names
+
+
+def test_cross_attention_caches_are_isolated_between_requests() -> None:
+    module = _load_module()
+    attention = module.LingBotCrossAttention(dim=2, num_heads=1)
+
+    _, first = attention(_tokens(1), _tokens(2, 3), cache=None)
+    _, second = attention(_tokens(1), _tokens(8, 9), cache=None)
+
+    assert first.key.untyped_storage().data_ptr() != second.key.untyped_storage().data_ptr()
+    assert first.value.untyped_storage().data_ptr() != second.value.untyped_storage().data_ptr()
+    second_key = second.key.clone()
+    first.key.zero_()
+    torch.testing.assert_close(second.key, second_key)
+
+
+def test_tp_rmsnorm_weight_loader_selects_rank_shard(monkeypatch: pytest.MonkeyPatch) -> None:
+    module = _load_module()
+    monkeypatch.setattr(module, "get_tensor_model_parallel_world_size", lambda: 2)
+    monkeypatch.setattr(module, "get_tensor_model_parallel_rank", lambda: 1)
+    norm = module._LingBotRMSNorm(2, eps=1e-6)
+
+    norm.weight.weight_loader(norm.weight, torch.tensor([10.0, 20.0, 30.0, 40.0]))
+
+    torch.testing.assert_close(norm.weight, torch.tensor([30.0, 40.0]))
@@ -0,0 +1,525 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from __future__ import annotations
+
+import importlib.util
+import math
+import subprocess
+import sys
+from pathlib import Path
+
+import numpy as np
+import pytest
+import torch
+
+_MODULE_PATH = Path(__file__).parents[4] / "vllm_omni/diffusion/models/lingbot_world/camera.py"
+_SPEC = importlib.util.spec_from_file_location("_lingbot_world_camera_under_test", _MODULE_PATH)
+assert _SPEC is not None and _SPEC.loader is not None
+_CAMERA_MODULE = importlib.util.module_from_spec(_SPEC)
+sys.modules[_SPEC.name] = _CAMERA_MODULE
+_SPEC.loader.exec_module(_CAMERA_MODULE)
+
+CameraTrajectory = _CAMERA_MODULE.CameraTrajectory
+build_plucker_embedding = _CAMERA_MODULE.build_plucker_embedding
+interpolate_camera_trajectory = _CAMERA_MODULE.interpolate_camera_trajectory
+load_camera_trajectory = _CAMERA_MODULE.load_camera_trajectory
+resolve_trusted_action_directory = _CAMERA_MODULE.resolve_trusted_action_directory
+
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
+
+def _identity_poses(num_frames: int) -> np.ndarray:
+    return np.repeat(np.eye(4, dtype=np.float64)[None], num_frames, axis=0)
+
+
+def _write_trajectory(
+    directory: Path,
+    poses: np.ndarray,
+    intrinsics: np.ndarray,
+) -> None:
+    np.save(directory / "poses.npy", poses)
+    np.save(directory / "intrinsics.npy", intrinsics)
+
+
+def _trusted(directory: Path):
+    return resolve_trusted_action_directory(".", directory)
+
+
+def _trajectory(
+    poses: torch.Tensor,
+    intrinsics: torch.Tensor | None = None,
+) -> CameraTrajectory:
+    if intrinsics is None:
+        intrinsics = torch.tensor([[832.0 / 3.0, 160.0, 416.0, 240.0]]).repeat(poses.shape[0], 1)
+    return CameraTrajectory(poses=poses, intrinsics=intrinsics)
+
+
+@pytest.mark.parametrize("present_file", [None, "poses.npy"])
+def test_load_camera_trajectory_rejects_missing_files(tmp_path: Path, present_file: str | None) -> None:
+    if present_file == "poses.npy":
+        np.save(tmp_path / present_file, _identity_poses(1))
+
+    missing_file = "poses.npy" if present_file is None else "intrinsics.npy"
+    with pytest.raises(FileNotFoundError, match=missing_file):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+@pytest.mark.parametrize(
+    ("poses", "intrinsics", "message"),
+    [
+        (np.zeros((2, 3, 4)), np.zeros((2, 4)), "poses.npy"),
+        (_identity_poses(2), np.zeros((2, 3)), "intrinsics.npy"),
+        (_identity_poses(0), np.zeros((0, 4)), "1 and 4096 source frames"),
+        (_identity_poses(2), np.zeros((1, 4)), "same number of frames"),
+    ],
+)
+def test_load_camera_trajectory_rejects_invalid_shapes(
+    tmp_path: Path,
+    poses: np.ndarray,
+    intrinsics: np.ndarray,
+    message: str,
+) -> None:
+    _write_trajectory(tmp_path, poses, intrinsics)
+
+    with pytest.raises(ValueError, match=message):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+@pytest.mark.parametrize("array_name", ["poses", "intrinsics"])
+def test_load_camera_trajectory_rejects_non_finite_values(tmp_path: Path, array_name: str) -> None:
+    poses = _identity_poses(1)
+    intrinsics = np.ones((1, 4), dtype=np.float64)
+    if array_name == "poses":
+        poses[0, 0, 0] = np.nan
+    else:
+        intrinsics[0, 0] = np.inf
+    _write_trajectory(tmp_path, poses, intrinsics)
+
+    with pytest.raises(ValueError, match="finite"):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+def test_load_camera_trajectory_preserves_raw_c2w_poses(tmp_path: Path) -> None:
+    first_c2w = np.array(
+        [
+            [0.0, -1.0, 0.0, 2.0],
+            [1.0, 0.0, 0.0, 3.0],
+            [0.0, 0.0, 1.0, 4.0],
+            [0.0, 0.0, 0.0, 1.0],
+        ]
+    )
+    second_c2w = np.array(
+        [
+            [0.0, 0.0, 1.0, 5.0],
+            [0.0, 1.0, 0.0, 4.0],
+            [-1.0, 0.0, 0.0, 6.0],
+            [0.0, 0.0, 0.0, 1.0],
+        ]
+    )
+    poses = np.stack((first_c2w, second_c2w))
+    intrinsics = np.array([[100.0, 110.0, 120.0, 130.0]] * 2)
+    _write_trajectory(tmp_path, poses, intrinsics)
+
+    trajectory = load_camera_trajectory(_trusted(tmp_path))
+
+    assert trajectory.poses.dtype == torch.float32
+    assert trajectory.intrinsics.dtype == torch.float32
+    torch.testing.assert_close(trajectory.poses, torch.from_numpy(poses).float())
+    torch.testing.assert_close(trajectory.intrinsics, torch.from_numpy(intrinsics).float())
+
+
+def test_load_camera_trajectory_rejects_object_dtype_before_materializing(tmp_path: Path) -> None:
+    poses = _identity_poses(1).astype(object)
+    intrinsics = np.ones((1, 4), dtype=np.float32)
+    _write_trajectory(tmp_path, poses, intrinsics)
+
+    with pytest.raises(ValueError, match="poses.npy.*real numeric"):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+def test_load_camera_trajectory_accepts_official_length_and_materializes_request_prefix(tmp_path: Path) -> None:
+    _write_trajectory(
+        tmp_path,
+        _identity_poses(269),
+        np.arange(269 * 4, dtype=np.float32).reshape(269, 4),
+    )
+
+    trajectory = load_camera_trajectory(_trusted(tmp_path))
+
+    assert trajectory.poses.shape == (117, 4, 4)
+    assert trajectory.intrinsics.shape == (117, 4)
+    np.testing.assert_array_equal(
+        trajectory.intrinsics.numpy(),
+        np.arange(269 * 4, dtype=np.float32).reshape(269, 4)[:117],
+    )
+
+
+def test_load_camera_trajectory_rejects_unbounded_source_frame_count(tmp_path: Path) -> None:
+    _write_trajectory(
+        tmp_path,
+        _identity_poses(4097),
+        np.ones((4097, 4), dtype=np.float32),
+    )
+
+    with pytest.raises(ValueError, match="poses.npy.*bounded camera-array limit|4096 source frames"):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+def test_load_camera_trajectory_rejects_truncated_payload_before_loading(tmp_path: Path) -> None:
+    _write_trajectory(tmp_path, _identity_poses(1), np.ones((1, 4), dtype=np.float32))
+    poses_path = tmp_path / "poses.npy"
+    poses_path.write_bytes(poses_path.read_bytes()[:-1])
+
+    with pytest.raises(ValueError, match="poses.npy byte size"):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+def test_load_camera_trajectory_rejects_oversized_npy_header(tmp_path: Path) -> None:
+    header_size = 20_000
+    (tmp_path / "poses.npy").write_bytes(
+        np.lib.format.magic(2, 0) + header_size.to_bytes(4, "little") + b" " * (header_size - 1) + b"\n"
+    )
+    np.save(tmp_path / "intrinsics.npy", np.ones((1, 4), dtype=np.float32))
+
+    with pytest.raises(ValueError, match="poses.npy.*oversized NPY header"):
+        load_camera_trajectory(_trusted(tmp_path))
+
+
+def test_load_camera_trajectory_rejects_symlink_swap_after_resolution(tmp_path: Path) -> None:
+    trusted_root = tmp_path / "trusted"
+    action_directory = trusted_root / "action"
+    outside = tmp_path / "outside"
+    action_directory.mkdir(parents=True)
+    outside.mkdir()
+    _write_trajectory(action_directory, _identity_poses(1), np.ones((1, 4), dtype=np.float32))
+    _write_trajectory(outside, _identity_poses(1), np.ones((1, 4), dtype=np.float32))
+    resolved = resolve_trusted_action_directory("action", trusted_root)
+    action_directory.rename(trusted_root / "original-action")
+    action_directory.symlink_to(outside, target_is_directory=True)
+
+    with pytest.raises(ValueError, match="securely open.*action directory"):
+        load_camera_trajectory(resolved)
+
+
+def test_load_camera_trajectory_rejects_symlinked_camera_file(tmp_path: Path) -> None:
+    trusted_root = tmp_path / "trusted"
+    action_directory = trusted_root / "action"
+    outside = tmp_path / "outside"
+    action_directory.mkdir(parents=True)
+    outside.mkdir()
+    _write_trajectory(action_directory, _identity_poses(1), np.ones((1, 4), dtype=np.float32))
+    np.save(outside / "poses.npy", _identity_poses(1))
+    resolved = resolve_trusted_action_directory("action", trusted_root)
+    (action_directory / "poses.npy").unlink()
+    (action_directory / "poses.npy").symlink_to(outside / "poses.npy")
+
+    with pytest.raises(ValueError, match="poses.npy.*opened securely"):
+        load_camera_trajectory(resolved)
+
+
+@pytest.mark.skipif(not hasattr(__import__("os"), "mkfifo"), reason="requires POSIX FIFO support")
+def test_load_camera_trajectory_rejects_fifo_without_blocking(tmp_path: Path) -> None:
+    import os
+
+    os.mkfifo(tmp_path / "poses.npy")
+    np.save(tmp_path / "intrinsics.npy", np.ones((1, 4), dtype=np.float32))
+    script = """
+import importlib.util
+import sys
+
+spec = importlib.util.spec_from_file_location("_lingbot_camera_fifo_test", sys.argv[1])
+module = importlib.util.module_from_spec(spec)
+sys.modules[spec.name] = module
+spec.loader.exec_module(module)
+action = module.resolve_trusted_action_directory(".", sys.argv[2])
+try:
+    module.load_camera_trajectory(action)
+except ValueError as error:
+    print(error)
+else:
+    raise AssertionError("FIFO camera input was accepted")
+"""
+
+    completed = subprocess.run(
+        [sys.executable, "-c", script, str(_MODULE_PATH), str(tmp_path)],
+        capture_output=True,
+        text=True,
+        timeout=3,
+        check=False,
+    )
+
+    assert completed.returncode == 0, completed.stderr
+    assert "poses.npy must be a regular NPY file" in completed.stdout
+
+
+def test_load_camera_trajectory_decodes_the_validated_file_snapshot(tmp_path: Path, monkeypatch) -> None:
+    original_poses = _identity_poses(1)
+    replacement_poses = original_poses.copy()
+    replacement_poses[0, 0, 3] = 123.0
+    _write_trajectory(tmp_path, original_poses, np.ones((1, 4), dtype=np.float32))
+    poses_path = tmp_path / "poses.npy"
+    original_load = _CAMERA_MODULE.np.load
+    mutation_count = 0
+
+    def mutate_source_then_decode(source, *args, **kwargs):
+        nonlocal mutation_count
+        if mutation_count == 0:
+            mutation_count += 1
+            np.save(poses_path, replacement_poses)
+        return original_load(source, *args, **kwargs)
+
+    monkeypatch.setattr(_CAMERA_MODULE.np, "load", mutate_source_then_decode)
+
+    trajectory = load_camera_trajectory(_trusted(tmp_path))
+
+    assert mutation_count == 1
+    torch.testing.assert_close(trajectory.poses, torch.from_numpy(original_poses).float())
+
+
+def test_load_camera_trajectory_ignores_non_camera_event_files(tmp_path: Path) -> None:
+    poses = _identity_poses(1)
+    intrinsics = np.ones((1, 4), dtype=np.float32)
+    _write_trajectory(tmp_path, poses, intrinsics)
+    np.save(tmp_path / "wasd_events.npy", np.array([{"key": "w"}], dtype=object))
+
+    trajectory = load_camera_trajectory(_trusted(tmp_path))
+
+    torch.testing.assert_close(trajectory.poses, torch.from_numpy(poses).float())
+
+
+def test_interpolate_camera_trajectory_uses_linear_and_spherical_interpolation() -> None:
+    poses = torch.eye(4).repeat(2, 1, 1)
+    poses[1, :3, :3] = torch.tensor(
+        [
+            [0.0, -1.0, 0.0],
+            [1.0, 0.0, 0.0],
+            [0.0, 0.0, 1.0],
+        ]
+    )
+    poses[1, :3, 3] = torch.tensor([2.0, 4.0, 6.0])
+    intrinsics = torch.tensor([[10.0, 20.0, 30.0, 40.0], [20.0, 40.0, 60.0, 80.0]])
+    trajectory = CameraTrajectory(poses=poses, intrinsics=intrinsics)
+
+    result = interpolate_camera_trajectory(trajectory, 3)
+
+    torch.testing.assert_close(result.poses[0], poses[0])
+    torch.testing.assert_close(result.poses[-1], poses[-1])
+    torch.testing.assert_close(result.poses[1, :3, 3], torch.tensor([1.0, 2.0, 3.0]))
+    expected_mid_rotation = torch.tensor(
+        [
+            [math.sqrt(0.5), -math.sqrt(0.5), 0.0],
+            [math.sqrt(0.5), math.sqrt(0.5), 0.0],
+            [0.0, 0.0, 1.0],
+        ]
+    )
+    torch.testing.assert_close(result.poses[1, :3, :3], expected_mid_rotation)
+    torch.testing.assert_close(result.intrinsics[1], torch.tensor([15.0, 30.0, 45.0, 60.0]))
+
+
+def test_build_plucker_embedding_has_forward_center_ray() -> None:
+    trajectory = _trajectory(torch.eye(4).unsqueeze(0))
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=3,
+        width=3,
+        target_height=3,
+        target_width=3,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    torch.testing.assert_close(result[0, :3, 1, 1], torch.zeros(3))
+    torch.testing.assert_close(result[0, 3:, 1, 1], torch.tensor([0.0, 0.0, 1.0]))
+
+
+def test_build_plucker_embedding_scales_reference_intrinsics() -> None:
+    trajectory = _trajectory(
+        torch.eye(4).unsqueeze(0),
+        torch.tensor([[416.0, 240.0, 416.0, 240.0]]),
+    )
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=4,
+        width=8,
+        target_height=4,
+        target_width=8,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    expected_corner_direction = torch.tensor([-0.875, -0.75, 1.0])
+    expected_corner_direction /= torch.linalg.vector_norm(expected_corner_direction)
+    torch.testing.assert_close(result[0, 3:, 0, 0], expected_corner_direction)
+
+
+def test_build_plucker_embedding_samples_target_pixel_centers() -> None:
+    trajectory = _trajectory(
+        torch.eye(4).unsqueeze(0),
+        torch.tensor([[416.0, 240.0, 416.0, 240.0]]),
+    )
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=6,
+        width=10,
+        target_height=2,
+        target_width=5,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    # Target centers map through the source scale: (0.5 * 2, 0.5 * 3).
+    expected_direction = torch.tensor([-0.8, -0.5, 1.0])
+    expected_direction /= torch.linalg.vector_norm(expected_direction)
+    torch.testing.assert_close(result[0, 3:, 0, 0], expected_direction)
+
+
+def test_build_plucker_embedding_uses_framewise_deltas_for_rotations_and_translations() -> None:
+    poses = torch.eye(4).repeat(3, 1, 1)
+    poses[0, :3, 3] = torch.tensor([5.0, 7.0, 11.0])
+    poses[1, :3, :3] = torch.tensor(
+        [
+            [0.0, -1.0, 0.0],
+            [1.0, 0.0, 0.0],
+            [0.0, 0.0, 1.0],
+        ]
+    )
+    poses[1, :3, 3] = torch.tensor([5.0, 9.0, 11.0])
+    poses[2, :3, :3] = torch.tensor(
+        [
+            [-1.0, 0.0, 0.0],
+            [0.0, -1.0, 0.0],
+            [0.0, 0.0, 1.0],
+        ]
+    )
+    poses[2, :3, 3] = torch.tensor([3.0, 9.0, 11.0])
+    trajectory = _trajectory(
+        poses,
+        torch.tensor([[416.0, 480.0, 208.0, 240.0]]).repeat(3, 1),
+    )
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=1,
+        width=2,
+        target_height=1,
+        target_width=2,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    expected_direction = torch.tensor([0.0, 1.0, 1.0]) / math.sqrt(2.0)
+    torch.testing.assert_close(result[0, :3, 0, 1], torch.zeros(3))
+    torch.testing.assert_close(result[1, :3, 0, 1], torch.tensor([0.0, 1.0, 0.0]))
+    torch.testing.assert_close(result[2, :3, 0, 1], torch.tensor([0.0, 1.0, 0.0]))
+    torch.testing.assert_close(result[1, 3:, 0, 1], expected_direction)
+    torch.testing.assert_close(result[2, 3:, 0, 1], expected_direction)
+
+
+def test_build_plucker_embedding_normalizes_framewise_translation_by_max_norm() -> None:
+    poses = torch.eye(4).repeat(3, 1, 1)
+    poses[:, :3, 3] = torch.tensor(
+        [
+            [10.0, -2.0, 5.0],
+            [13.0, 2.0, 5.0],
+            [19.0, 10.0, 5.0],
+        ]
+    )
+
+    result = build_plucker_embedding(
+        _trajectory(poses),
+        height=1,
+        width=1,
+        target_height=1,
+        target_width=1,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    expected_origins = torch.tensor([[0.0, 0.0, 0.0], [0.3, 0.4, 0.0], [0.6, 0.8, 0.0]])
+    torch.testing.assert_close(result[:, :3, 0, 0], expected_origins)
+
+
+def test_build_plucker_embedding_interpolates_raw_poses_before_framewise_conversion() -> None:
+    poses = torch.eye(4).repeat(2, 1, 1)
+    poses[0, :3, 3] = torch.tensor([20.0, 4.0, -2.0])
+    poses[1, :3, 3] = torch.tensor([26.0, 12.0, -2.0])
+    raw = _trajectory(poses)
+
+    interpolated = interpolate_camera_trajectory(raw, 3)
+    result = build_plucker_embedding(
+        interpolated,
+        height=1,
+        width=1,
+        target_height=1,
+        target_width=1,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    expected_delta = torch.tensor([0.6, 0.8, 0.0])
+    torch.testing.assert_close(result[0, :3, 0, 0], torch.zeros(3))
+    torch.testing.assert_close(result[1, :3, 0, 0], expected_delta)
+    torch.testing.assert_close(result[2, :3, 0, 0], expected_delta)
+
+
+def test_build_plucker_embedding_uses_half_pixel_centers_and_origin_direction_channel_order() -> None:
+    poses = torch.eye(4).repeat(2, 1, 1)
+    poses[1, :3, 3] = torch.tensor([2.0, 0.0, 0.0])
+    trajectory = _trajectory(
+        poses,
+        torch.tensor([[832.0, 480.0, 0.0, 0.0]]).repeat(2, 1),
+    )
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=1,
+        width=2,
+        target_height=1,
+        target_width=2,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    expected_direction = torch.tensor([0.25, 0.5, 1.0])
+    expected_direction /= torch.linalg.vector_norm(expected_direction)
+    torch.testing.assert_close(result[1, :3, 0, 0], torch.tensor([1.0, 0.0, 0.0]))
+    torch.testing.assert_close(result[1, 3:, 0, 0], expected_direction)
+
+
+def test_build_plucker_embedding_honors_shape_dtype_and_device() -> None:
+    trajectory = _trajectory(torch.eye(4).repeat(2, 1, 1))
+
+    result = build_plucker_embedding(
+        trajectory,
+        height=12,
+        width=20,
+        target_height=3,
+        target_width=5,
+        device=torch.device("cpu"),
+        dtype=torch.float64,
+    )
+
+    assert result.shape == (2, 6, 3, 5)
+    assert result.dtype == torch.float64
+    assert result.device == torch.device("cpu")
+
+
+def test_build_plucker_embedding_is_deterministic() -> None:
+    trajectory = _trajectory(torch.eye(4).repeat(2, 1, 1))
+    kwargs = {
+        "height": 12,
+        "width": 20,
+        "target_height": 3,
+        "target_width": 5,
+        "device": torch.device("cpu"),
+        "dtype": torch.float32,
+    }
+
+    first = build_plucker_embedding(trajectory, **kwargs)
+    second = build_plucker_embedding(trajectory, **kwargs)
+
+    torch.testing.assert_close(first, second, rtol=0.0, atol=0.0)
@@ -0,0 +1,685 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from __future__ import annotations
+
+import hashlib
+import inspect
+import json
+import math
+from pathlib import Path
+
+import pytest
+import torch
+
+from tests.diffusion.models.lingbot_world import test_lingbot_world_attention as attention_tests
+
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
+_FIXTURE_PATH = Path(__file__).with_name("fixtures") / "lingbot_world_weight_index_names.json.fixture"
+_SHAPE_FIXTURE_PATH = Path(__file__).with_name("fixtures") / "lingbot_world_official_shapes.json.fixture"
+
+
+@pytest.fixture(autouse=True)
+def _inference_context():
+    with torch.inference_mode():
+        yield
+
+
+def _tiny_model(
+    module,
+    *,
+    num_layers: int = 2,
+    num_frames_per_block: int = 1,
+    sliding_window_num_frames: int = 3,
+):
+    return module.CausalLingBotWorldTransformer3DModel(
+        patch_size=(1, 2, 2),
+        num_attention_heads=2,
+        attention_head_dim=2,
+        in_channels=36,
+        out_channels=2,
+        text_dim=6,
+        freq_dim=4,
+        ffn_dim=8,
+        num_layers=num_layers,
+        cross_attn_norm=True,
+        eps=1e-6,
+        rope_max_seq_len=16,
+        sink_size=1,
+        num_frames_per_block=num_frames_per_block,
+        sliding_window_num_frames=sliding_window_num_frames,
+        local_attn_size=-1,
+    )
+
+
+def _cache(module, model, *, max_tokens: int | None = None):
+    if max_tokens is None:
+        window_frames = (
+            model.config.local_attn_size
+            if model.config.local_attn_size != -1
+            else model.config.sliding_window_num_frames
+        )
+        max_tokens = window_frames * 2 * 2
+    return module.allocate_lingbot_cache(
+        batch_size=1,
+        num_layers=len(model.blocks),
+        max_tokens=max_tokens,
+        num_local_heads=2,
+        head_dim=2,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+
+def _checkpoint_parameter_specs(model) -> dict[str, tuple[torch.Size, torch.dtype]]:
+    specs: dict[str, tuple[torch.Size, torch.dtype]] = {}
+    for name, parameter in model.named_parameters():
+        marker = ".self_attn.qkv."
+        if marker not in name:
+            specs[name] = (parameter.shape, parameter.dtype)
+            continue
+        shard_shape = torch.Size((parameter.shape[0] // 3, *parameter.shape[1:]))
+        for projection in ("q", "k", "v"):
+            specs[name.replace(marker, f".self_attn.{projection}.")] = (shard_shape, parameter.dtype)
+    return specs
+
+
+def _checkpoint_weights_for_model(model) -> tuple[dict[str, torch.Tensor], dict[str, torch.Tensor]]:
+    checkpoint_weights: dict[str, torch.Tensor] = {}
+    expected_parameters: dict[str, torch.Tensor] = {}
+    next_value = 1
+    for name, parameter in model.named_parameters():
+        marker = ".self_attn.qkv."
+        if marker not in name:
+            value = torch.full_like(parameter, next_value)
+            checkpoint_weights[name] = value
+            expected_parameters[name] = value
+            next_value += 1
+            continue
+        shards = []
+        shard_shape = (parameter.shape[0] // 3, *parameter.shape[1:])
+        for projection in ("q", "k", "v"):
+            value = torch.full(shard_shape, next_value, dtype=parameter.dtype, device=parameter.device)
+            checkpoint_weights[name.replace(marker, f".self_attn.{projection}.")] = value
+            shards.append(value)
+            next_value += 1
+        expected_parameters[name] = torch.cat(shards)
+    return checkpoint_weights, expected_parameters
+
+
+def _self_cache_snapshot(cache) -> list[tuple[torch.Tensor, torch.Tensor, tuple[int, int, int | None, int]]]:
+    return [attention_tests._cache_snapshot(layer_cache) for layer_cache in cache.self_attention]
+
+
+def _assert_self_cache_unchanged(cache, snapshot) -> None:
+    for layer_cache, layer_snapshot in zip(cache.self_attention, snapshot, strict=True):
+        attention_tests._assert_cache_unchanged(layer_cache, layer_snapshot)
+
+
+def test_tiny_transformer_runs_four_chunks_with_explicit_cache_commit_and_camera_path() -> None:
+    torch.manual_seed(7)
+    module = attention_tests._load_module()
+    model = _tiny_model(module).eval()
+    cache = _cache(module, model)
+    encoder_hidden_states = torch.randn(1, 3, 6)
+    camera_hidden_states = torch.randn(1, 6 * 8 * 8, 1, 4, 4)
+    cross_key_outputs = [attention_tests._record_outputs(block.cross_attn.k) for block in model.blocks]
+    text_projection_outputs = attention_tests._record_outputs(model.text_embedding)
+    outputs = []
+
+    assert model.patch_embedding.in_channels == 36
+    assert model.patch_embedding_wancamctrl.in_features == 6 * 8 * 8 * 1 * 2 * 2
+
+    for start_frame in range(4):
+        hidden_states = torch.randn(1, 36, 1, 4, 4)
+        timestep = torch.tensor([float(start_frame + 1)])
+        snapshot = _self_cache_snapshot(cache)
+
+        transient_output = model(
+            hidden_states,
+            timestep,
+            encoder_hidden_states,
+            camera_hidden_states,
+            cache=cache,
+            start_frame=start_frame,
+            update_cache=False,
+        )
+
+        assert transient_output.shape == (1, 2, 1, 4, 4)
+        _assert_self_cache_unchanged(cache, snapshot)
+        assert all(layer_cache is not None for layer_cache in cache.cross_attention)
+
+        committed_output = model(
+            hidden_states,
+            timestep,
+            encoder_hidden_states,
+            camera_hidden_states,
+            cache=cache,
+            start_frame=start_frame,
+            update_cache=True,
+        )
+        torch.testing.assert_close(committed_output, transient_output)
+        outputs.append(committed_output)
+
+        expected_token_end = (start_frame + 1) * 2 * 2
+        assert all(layer_cache.absolute_end == expected_token_end for layer_cache in cache.self_attention)
+
+    assert len(outputs) == 4
+    assert all(len(outputs) == 1 for outputs in cross_key_outputs)
+    assert len(text_projection_outputs) == 1
+
+    alternate_cache = _cache(module, model)
+    alternate_output = model(
+        torch.zeros(1, 36, 1, 4, 4),
+        torch.tensor([1.0]),
+        encoder_hidden_states,
+        torch.zeros_like(camera_hidden_states),
+        cache=alternate_cache,
+        start_frame=0,
+        update_cache=False,
+    )
+    camera_output = model(
+        torch.zeros(1, 36, 1, 4, 4),
+        torch.tensor([1.0]),
+        encoder_hidden_states,
+        torch.ones_like(camera_hidden_states),
+        cache=_cache(module, model),
+        start_frame=0,
+        update_cache=False,
+    )
+    assert not torch.equal(camera_output, alternate_output)
+
+
+def test_partial_cross_attention_cache_projects_text_only_for_missing_layers() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=2).eval()
+    cache = _cache(module, model)
+    hidden_states = torch.randn(1, 36, 1, 4, 4)
+    timestep = torch.tensor([1.0])
+    encoder_hidden_states = torch.randn(1, 3, 6)
+    camera_hidden_states = torch.randn(1, 6 * 8 * 8, 1, 4, 4)
+
+    model(
+        hidden_states,
+        timestep,
+        encoder_hidden_states,
+        camera_hidden_states,
+        cache=cache,
+        start_frame=0,
+        update_cache=False,
+    )
+    cache.cross_attention[1] = None
+    text_projection_outputs = attention_tests._record_outputs(model.text_embedding)
+    cross_key_outputs = [attention_tests._record_outputs(block.cross_attn.k) for block in model.blocks]
+
+    model(
+        hidden_states,
+        timestep,
+        encoder_hidden_states,
+        camera_hidden_states,
+        cache=cache,
+        start_frame=0,
+        update_cache=False,
+    )
+
+    assert len(text_projection_outputs) == 1
+    assert [len(outputs) for outputs in cross_key_outputs] == [0, 1]
+    assert all(layer_cache is not None for layer_cache in cache.cross_attention)
+
+
+@pytest.mark.parametrize("frames", [1, 6], ids=("partial", "multiple_blocks"))
+def test_forward_rejects_chunks_that_do_not_equal_configured_block_size(frames: int) -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(
+        module,
+        num_layers=1,
+        num_frames_per_block=3,
+        sliding_window_num_frames=6,
+    )
+    cache = _cache(module, model)
+    snapshot = _self_cache_snapshot(cache)
+    patch_inputs = attention_tests._record_inputs(model.patch_embedding)
+
+    with pytest.raises(ValueError, match="exactly 3 post-patch frames"):
+        model(
+            torch.randn(1, 36, frames, 4, 4),
+            torch.tensor([1.0]),
+            torch.randn(1, 3, 6),
+            torch.randn(1, 6 * 8 * 8, frames, 4, 4),
+            cache=cache,
+            start_frame=0,
+            update_cache=True,
+        )
+
+    assert patch_inputs == []
+    _assert_self_cache_unchanged(cache, snapshot)
+    assert cache.cross_attention == [None]
+
+
+def test_forward_accepts_exactly_one_configured_frame_block() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(
+        module,
+        num_layers=1,
+        num_frames_per_block=3,
+        sliding_window_num_frames=6,
+    )
+
+    output = model(
+        torch.randn(1, 36, 3, 4, 4),
+        torch.tensor([1.0]),
+        torch.randn(1, 3, 6),
+        torch.randn(1, 6 * 8 * 8, 3, 4, 4),
+        cache=_cache(module, model),
+        start_frame=0,
+        update_cache=False,
+    )
+
+    assert output.shape == (1, 2, 3, 4, 4)
+
+
+def test_transformer_allocates_request_cache_from_its_configured_geometry() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(
+        module,
+        num_layers=2,
+        num_frames_per_block=3,
+        sliding_window_num_frames=6,
+    )
+
+    cache = model.allocate_cache(
+        batch_size=2,
+        latent_height=8,
+        latent_width=12,
+        device=torch.device("cpu"),
+        dtype=torch.float32,
+    )
+
+    assert len(cache.self_attention) == 2
+    assert len(cache.cross_attention) == 2
+    assert cache.cross_attention == [None, None]
+    assert all(layer.key.shape == (2, 6 * 4 * 6, 2, 2) for layer in cache.self_attention)
+    assert all(layer.value.shape == (2, 6 * 4 * 6, 2, 2) for layer in cache.self_attention)
+
+
+def test_video_patch_embedding_uses_temporal_height_width_token_order() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=1, num_frames_per_block=2)
+    hidden_states = torch.zeros(1, 36, 2, 2, 4)
+    hidden_states[0, 0] = torch.tensor(
+        [
+            [[1.0, 2.0, 3.0, 4.0], [5.0, 6.0, 7.0, 8.0]],
+            [[9.0, 10.0, 11.0, 12.0], [13.0, 14.0, 15.0, 16.0]],
+        ]
+    )
+    with torch.no_grad():
+        model.patch_embedding.weight.zero_()
+        model.patch_embedding.bias.zero_()
+        model.patch_embedding.weight[0, 0, 0, 0, 0] = 1
+
+    tokens = model.patch_embedding(hidden_states).flatten(2).transpose(1, 2)
+
+    torch.testing.assert_close(tokens[0, :, 0], torch.tensor([1.0, 3.0, 9.0, 11.0]))
+
+
+def test_unpatchify_restores_two_frame_channel_and_spatial_order() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=1, num_frames_per_block=2)
+    hidden_states = (
+        torch.stack(
+            (
+                torch.arange(0, 8),
+                torch.arange(10, 18),
+                torch.arange(20, 28),
+                torch.arange(30, 38),
+            )
+        )
+        .unsqueeze(0)
+        .float()
+    )
+    expected = torch.tensor(
+        [
+            [
+                [[0, 2, 10, 12], [4, 6, 14, 16]],
+                [[20, 22, 30, 32], [24, 26, 34, 36]],
+            ],
+            [
+                [[1, 3, 11, 13], [5, 7, 15, 17]],
+                [[21, 23, 31, 33], [25, 27, 35, 37]],
+            ],
+        ],
+        dtype=torch.float32,
+    ).unsqueeze(0)
+
+    output = model._unpatchify(
+        hidden_states,
+        batch_size=1,
+        frames=2,
+        height=1,
+        width=2,
+    )
+
+    torch.testing.assert_close(output, expected)
+
+
+def test_head_modulation_broadcasts_distinct_condition_per_frame() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=1, num_frames_per_block=2)
+    model.head.norm = torch.nn.Identity()
+    with torch.no_grad():
+        model.head.modulation.zero_()
+        model.head.head.weight.zero_()
+        model.head.head.bias.zero_()
+        model.head.head.weight[:, 0] = 1
+    hidden_states = torch.ones(1, 4, model.dim)
+    timestep_embedding = torch.tensor([[[10.0, 0.0, 0.0, 0.0], [20.0, 0.0, 0.0, 0.0]]])
+    expected = torch.tensor([21.0, 21.0, 41.0, 41.0]).view(1, 4, 1).expand(1, 4, 8)
+
+    output = model.head(hidden_states, timestep_embedding)
+
+    torch.testing.assert_close(output, expected)
+
+
+def test_constructor_defaults_match_official_checkpoint_config() -> None:
+    module = attention_tests._load_module()
+    parameters = inspect.signature(module.CausalLingBotWorldTransformer3DModel.__init__).parameters
+    expected = {
+        "in_channels": 36,
+        "out_channels": 16,
+        "num_layers": 40,
+        "num_attention_heads": 40,
+        "attention_head_dim": 128,
+        "patch_size": (1, 2, 2),
+        "text_dim": 4096,
+        "ffn_dim": 13824,
+        "freq_dim": 256,
+        "rope_max_seq_len": 1024,
+        "eps": 1e-6,
+        "cross_attn_norm": True,
+        "sink_size": 9,
+        "num_frames_per_block": 3,
+        "sliding_window_num_frames": 18,
+        "local_attn_size": -1,
+    }
+
+    assert {name: parameters[name].default for name in expected} == expected
+
+
+def test_transformer_exposes_parameter_dtype_for_pipeline_runtime() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module)
+
+    assert model.dtype == next(model.parameters()).dtype
+
+
+def test_transformer_declares_regional_compile_block() -> None:
+    module = attention_tests._load_module()
+
+    assert module.CausalLingBotWorldTransformer3DModel._repeated_blocks == ["LingBotAttentionBlock"]
+
+
+def test_lingbot_rms_norm_uses_global_tp_square_mean(monkeypatch) -> None:
+    module = attention_tests._load_module()
+    reduced_values: list[torch.Tensor] = []
+
+    monkeypatch.setattr(module, "get_tensor_model_parallel_world_size", lambda: 2)
+
+    def all_reduce(value: torch.Tensor) -> torch.Tensor:
+        reduced_values.append(value.detach().clone())
+        return value * 2
+
+    monkeypatch.setattr(module, "tensor_model_parallel_all_reduce", all_reduce)
+    norm = module._LingBotRMSNorm(hidden_size=2, eps=0.0)
+    value = torch.tensor([[3.0, 4.0]])
+
+    output = norm(value)
+
+    torch.testing.assert_close(output, value / math.sqrt(12.5))
+    assert len(reduced_values) == 1
+    torch.testing.assert_close(reduced_values[0], torch.tensor([[25.0]]))
+
+
+def test_attention_rejects_heads_not_divisible_by_tp_size(monkeypatch) -> None:
+    module = attention_tests._load_module()
+    monkeypatch.setattr(module, "get_tensor_model_parallel_world_size", lambda: 3)
+
+    with pytest.raises(ValueError, match="num_heads=2.*tp_size=3"):
+        module.LingBotSelfAttention(dim=4, num_heads=2)
+
+
+def test_constructor_rejects_unsupported_qk_norm_with_config_error() -> None:
+    module = attention_tests._load_module()
+
+    with pytest.raises(ValueError, match="qk_norm.*rms_norm_across_heads"):
+        module.CausalLingBotWorldTransformer3DModel(qk_norm="layer_norm")
+
+
+@pytest.mark.parametrize("field", ["image_dim", "added_kv_proj_dim", "pos_embed_seq_len"])
+def test_constructor_rejects_non_null_image_embedding_fields(field: str) -> None:
+    module = attention_tests._load_module()
+
+    with pytest.raises(ValueError, match=field):
+        module.CausalLingBotWorldTransformer3DModel(**{field: 4})
+
+
+def test_constructor_rejects_unsupported_quantization_with_runtime_error() -> None:
+    module = attention_tests._load_module()
+
+    with pytest.raises(RuntimeError, match="quant_config.*not supported"):
+        module.CausalLingBotWorldTransformer3DModel(quant_config=object())
+
+
+def test_from_config_accepts_diffusers_metadata_and_normalizes_patch_size() -> None:
+    module = attention_tests._load_module()
+
+    class ConfigProbe(module.CausalLingBotWorldTransformer3DModel):
+        def __init__(self, **kwargs) -> None:
+            self.received_kwargs = kwargs
+
+    config = {
+        "_class_name": "CausalLingBotWorldTransformer3DModel",
+        "_diffusers_version": "0.35.0.dev0",
+        "patch_size": [1, 2, 2],
+        "num_attention_heads": 40,
+        "attention_head_dim": 128,
+        "in_channels": 36,
+        "out_channels": 16,
+        "text_dim": 4096,
+        "freq_dim": 256,
+        "ffn_dim": 13824,
+        "num_layers": 40,
+        "cross_attn_norm": True,
+        "eps": 1e-6,
+        "image_dim": None,
+        "added_kv_proj_dim": None,
+        "rope_max_seq_len": 1024,
+        "pos_embed_seq_len": None,
+        "qk_norm": "rms_norm_across_heads",
+        "sink_size": 9,
+        "num_frames_per_block": 3,
+        "sliding_window_num_frames": 18,
+        "local_attn_size": -1,
+    }
+
+    model = ConfigProbe.from_config(config, prefix="transformer")
+
+    assert model.received_kwargs["patch_size"] == (1, 2, 2)
+    assert model.received_kwargs["num_layers"] == 40
+    assert model.received_kwargs["prefix"] == "transformer"
+
+
+@pytest.mark.parametrize(
+    ("field", "value"),
+    [
+        ("in_channels", 35),
+        ("num_layers", 39),
+        ("num_attention_heads", 32),
+        ("attention_head_dim", 64),
+        ("ffn_dim", 10240),
+        ("num_frames_per_block", 4),
+        ("sliding_window_num_frames", 24),
+        ("sink_size", 0),
+    ],
+)
+def test_from_config_rejects_checkpoint_topology_drift(field: str, value: object) -> None:
+    module = attention_tests._load_module()
+    config = {
+        "_class_name": "CausalLingBotWorldTransformer3DModel",
+        "_diffusers_version": "0.35.0.dev0",
+        "patch_size": [1, 2, 2],
+        "num_attention_heads": 40,
+        "attention_head_dim": 128,
+        "in_channels": 36,
+        "out_channels": 16,
+        "text_dim": 4096,
+        "freq_dim": 256,
+        "ffn_dim": 13824,
+        "num_layers": 40,
+        "cross_attn_norm": True,
+        "eps": 1e-6,
+        "image_dim": None,
+        "added_kv_proj_dim": None,
+        "rope_max_seq_len": 1024,
+        "pos_embed_seq_len": None,
+        "qk_norm": "rms_norm_across_heads",
+        "sink_size": 9,
+        "num_frames_per_block": 3,
+        "sliding_window_num_frames": 18,
+        "local_attn_size": -1,
+    }
+    config[field] = value
+
+    with pytest.raises(ValueError, match=field):
+        module.CausalLingBotWorldTransformer3DModel.from_config(config)
+
+
+def test_from_config_ignores_non_semantic_checkpoint_metadata() -> None:
+    module = attention_tests._load_module()
+    config = {
+        "_class_name": "CausalLingBotWorldTransformer3DModel",
+        "architectures": ["CausalLingBotWorldTransformer3DModel"],
+        "future_diffusers_metadata": {"version": 1},
+    }
+
+    with torch.device("meta"):
+        model = module.CausalLingBotWorldTransformer3DModel.from_config(config)
+
+    assert model.config.in_channels == 36
+    assert model.config.num_layers == 40
+
+
+def test_load_weights_uses_parameter_loaders_and_rejects_unknown_model_keys() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=1)
+    checkpoint_weights, expected_parameters = _checkpoint_weights_for_model(model)
+    loader_calls: list[str] = []
+    qkv_weight = model.blocks[0].self_attn.qkv.weight
+
+    def record_loader(param: torch.Tensor, loaded_weight: torch.Tensor, shard_id: str) -> None:
+        loader_calls.append(shard_id)
+        shard_index = {"q": 0, "k": 1, "v": 2}[shard_id]
+        shard_size = param.shape[0] // 3
+        param.data.narrow(0, shard_index * shard_size, shard_size).copy_(loaded_weight)
+
+    qkv_weight.weight_loader = record_loader
+    loaded = model.load_weights(iter(checkpoint_weights.items()))
+
+    assert set(checkpoint_weights) <= loaded
+    assert set(dict(model.named_parameters())) <= loaded
+    assert loader_calls == ["q", "k", "v"]
+    for name, param in model.named_parameters():
+        torch.testing.assert_close(param, expected_parameters[name])
+
+    first_name = next(iter(checkpoint_weights))
+    partial = _tiny_model(module, num_layers=1)
+    partial_loaded = partial.load_weights([(first_name, checkpoint_weights[first_name])])
+    expected_partial = {first_name}
+    for projection in ("q", "k", "v"):
+        marker = f".self_attn.{projection}."
+        if marker in first_name:
+            expected_partial.add(first_name.replace(marker, ".self_attn.qkv."))
+            break
+    assert partial_loaded == expected_partial
+
+    with pytest.raises(KeyError, match="unexpected_model.weight"):
+        model.load_weights([("unexpected_model.weight", torch.ones(1))])
+
+
+def test_load_weights_consumes_checkpoint_iterator_incrementally() -> None:
+    module = attention_tests._load_module()
+    model = _tiny_model(module, num_layers=1)
+    first_name, first_param = next(iter(model.named_parameters()))
+    loaded_weight = torch.full_like(first_param, 17)
+
+    def weights():
+        yield first_name, loaded_weight
+        torch.testing.assert_close(first_param, loaded_weight)
+
+    assert model.load_weights(weights()) == {first_name}
+
+
+def test_real_auto_weights_loader_covers_fused_model_parameter_namespace() -> None:
+    utils = pytest.importorskip("vllm.model_executor.models.utils")
+    module = attention_tests._load_module()
+    transformer = _tiny_model(module, num_layers=1)
+    checkpoint_weights, _ = _checkpoint_weights_for_model(transformer)
+
+    class Pipeline(torch.nn.Module):
+        def __init__(self) -> None:
+            super().__init__()
+            self.transformer = transformer
+
+    pipeline = Pipeline()
+    loaded = utils.AutoWeightsLoader(pipeline).load_weights(
+        (f"transformer.{name}", value) for name, value in checkpoint_weights.items()
+    )
+
+    assert set(dict(pipeline.named_parameters())) <= loaded
+
+
+def test_checkpoint_weight_index_fixture_matches_model_namespaces() -> None:
+    module = attention_tests._load_module()
+    fixture = json.loads(_FIXTURE_PATH.read_text())
+    model = _tiny_model(module, num_layers=1)
+    parameter_names = set(_checkpoint_parameter_specs(model))
+
+    assert {name.split(".", 1)[0] for name in parameter_names} == set(fixture["top_level_modules"])
+    assert {name for name in parameter_names if not name.startswith("blocks.")} == set(fixture["non_block_parameters"])
+    assert {name.removeprefix("blocks.0.") for name in parameter_names if name.startswith("blocks.0.")} == set(
+        fixture["block_parameter_suffixes"]
+    )
+    expanded_names = set(fixture["non_block_parameters"])
+    expanded_names.update(
+        f"blocks.{layer}.{suffix}" for layer in range(40) for suffix in fixture["block_parameter_suffixes"]
+    )
+    canonical_names = "\n".join(sorted(expanded_names))
+
+    assert len(expanded_names) == fixture["index_parameter_count"] == 1421
+    assert hashlib.sha256(canonical_names.encode()).hexdigest() == fixture["canonical_name_set_sha256"]
+    assert fixture["canonical_name_to_shard_sha256"] == (
+        "e1addc27d2b1fad6f10226a23a265ee3e3c61e74dce4d5859727bdf180a67992"
+    )
+    assert list(fixture["shards"]) == [
+        f"diffusion_pytorch_model-{index:05}-of-00008.safetensors" for index in range(1, 9)
+    ]
+    assert sum(shard["parameter_count"] for shard in fixture["shards"].values()) == 1421
+    assert all(len(shard["parameter_names_sha256"]) == 64 for shard in fixture["shards"].values())
+
+
+def test_official_default_shapes_match_public_safetensors_header_fixture() -> None:
+    module = attention_tests._load_module()
+    fixture = json.loads(_SHAPE_FIXTURE_PATH.read_text())
+
+    with torch.device("meta"):
+        model = module.CausalLingBotWorldTransformer3DModel()
+    parameter_specs = _checkpoint_parameter_specs(model)
+    expected_dtype = {"F32": torch.float32}[fixture["dtype"]]
+
+    assert len(fixture["shard_representatives"]) == 8
+    assert set(fixture["shard_representatives"].values()) <= set(fixture["parameter_shapes"])
+
+    for name, expected_shape in fixture["parameter_shapes"].items():
+        shape, dtype = parameter_specs[name]
+        assert tuple(shape) == tuple(expected_shape), name
+        assert dtype == expected_dtype
@@ -0,0 +1,39 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from __future__ import annotations
+
+import ast
+from pathlib import Path
+
+import pytest
+
+pytestmark = [pytest.mark.core_model, pytest.mark.diffusion, pytest.mark.cpu]
+
+_ROOT = Path(__file__).parents[4]
+_PRODUCTION_FILES = (
+    _ROOT / "vllm_omni/diffusion/models/lingbot_world/camera.py",
+    _ROOT / "vllm_omni/diffusion/models/lingbot_world/transformer.py",
+    _ROOT / "vllm_omni/diffusion/models/lingbot_world/pipeline.py",
+)
+
+
+def test_all_lingbot_production_functions_have_complete_annotations() -> None:
+    missing: list[str] = []
+    for path in _PRODUCTION_FILES:
+        tree = ast.parse(path.read_text())
+        for node in ast.walk(tree):
+            if not isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef)):
+                continue
+            arguments = (*node.args.posonlyargs, *node.args.args, *node.args.kwonlyargs)
+            for argument in arguments:
+                if argument.arg not in {"self", "cls"} and argument.annotation is None:
+                    missing.append(f"{path.name}:{node.lineno}:{node.name}:{argument.arg}")
+            if node.args.vararg is not None and node.args.vararg.annotation is None:
+                missing.append(f"{path.name}:{node.lineno}:{node.name}:*{node.args.vararg.arg}")
+            if node.args.kwarg is not None and node.args.kwarg.annotation is None:
+                missing.append(f"{path.name}:{node.lineno}:{node.name}:**{node.args.kwarg.arg}")
+            if node.returns is None:
+                missing.append(f"{path.name}:{node.lineno}:{node.name}:return")
+
+    assert missing == []