Enable inference serving && fix train stability (#59)

* enable serving

* lint

* update

* update

wall_x/model/action_head.py

@@ -307,7 +307,7 @@ class ActionProcessor(nn.Module):
             torch.Tensor: Sampled timesteps of shape [batch_size]
         """
         sample = self.beta_dist.sample([batch_size]).to(device=device, dtype=dtype)
-        time = (self.s - sample) / self.s
+        time = (1 - sample) / self.s
         return time
 
     def proprioception_proj(

wall_x/serving/README.md

@@ -0,0 +1,263 @@
+# Wall-X Model Serving
+
+This directory contains scripts for serving Wall-X models via a websocket server, allowing remote clients to connect and get action predictions from observations.
+
+## Overview
+
+The serving infrastructure consists of three main components:
+
+1. **WebsocketPolicyServer** (`wall_x/serving/websocket_policy_server.py`): Generic websocket server that can serve any policy implementing the `BasePolicy` interface
+2. **WallXPolicy** (`wall_x/serving/policy/wall_x_policy.py`): Policy wrapper that adapts the Wall-X model to the `BasePolicy` interface
+3. **launch_serving.py**: Main script for starting the server with various configurations
+
+## Quick Start
+
+### Basic Usage
+
+Serve a model with default LIBERO configuration:
+
+```bash
+cd /x2robot_v2/vincent/workspace/opensource
+python -m wall_x.serving.launch_serving \
+  --env libero \
+  --model-config.model-path /path/to/libero_model_stuff \
+  --model-config.action-tokenizer-path /path/to/fast/ \
+  --model-config.train-config-path /path/to/config.yml
+```
+
+### Specify Environment
+
+Serve with a specific environment preset:
+
+```bash
+# LIBERO (single arm, 7 DOF)
+python -m wall_x.serving.launch_serving --env libero
+
+# ALOHA (dual arm, 14 DOF)
+python -m wall_x.serving.launch_serving --env aloha
+```
+
+### Custom Configuration
+
+Serve with custom model paths and settings:
+
+```bash
+python -m wall_x.serving.launch_serving \
+  --model-config.model-path /path/to/model \
+  --model-config.action-tokenizer-path /path/to/tokenizer \
+  --model-config.train-config-path /path/to/train_config.yml \
+  --model-config.action-dim 7 \
+  --model-config.state-dim 8 \
+  --model-config.pred-horizon 32 \
+  --model-config.camera-key front_view left_wrist_view \
+  --port 8000
+```
+
+## Command Line Arguments
+
+### Basic Arguments
+
+- `--env {libero,aloha}`: Environment mode (default: libero)
+- `--port PORT`: Port to serve on (default: 8000)
+- `--host HOST`: Host to bind to (default: 0.0.0.0)
+- `--default-prompt TEXT`: Default text prompt if not provided in observation
+- `--debug`: Enable debug logging
+
+### Model Configuration
+
+All model configuration arguments use the `--model-config.` prefix:
+
+- `--model-config.model-path PATH`: Path to pretrained model checkpoint (required)
+- `--model-config.action-tokenizer-path PATH`: Path to action tokenizer (required)
+- `--model-config.train-config-path PATH`: Path to train config YAML file (required)
+- `--model-config.action-dim INT`: Action space dimension (default: 7)
+- `--model-config.state-dim INT`: Robot state dimension (default: 8)
+- `--model-config.pred-horizon INT`: Prediction horizon (default: 32)
+- `--model-config.device {cuda,cpu}`: Device to run on (default: cuda)
+- `--model-config.dtype {bfloat16,float16,float32}`: Model dtype (default: bfloat16)
+- `--model-config.predict-mode {fast,diffusion}`: Prediction mode (default: fast)
+- `--model-config.camera-key KEY1 KEY2 ...`: Camera keys for observation images
+
+### Camera Keys
+
+The `camera-key` parameter specifies which camera views are expected in the observation dictionary. This is **critical** for proper operation:
+
+- Keys must match between server configuration and client observations
+- Order matters: keys are processed in the order specified
+- Common keys: `front_view`, `left_wrist_view`, `right_wrist_view`, `face_view`
+
+Example:
+```bash
+--model-config.camera-key front_view left_wrist_view
+```
+
+Client must send observations with matching keys:
+```python
+obs = {
+    "front_view": image1,        # Must match camera-key[0]
+    "left_wrist_view": image2,   # Must match camera-key[1]
+    "prompt": "task description",
+    "state": robot_state,
+}
+```
+
+## Default Configurations
+
+### LIBERO (Single Arm)
+
+```python
+ModelConfig(
+    model_path="/path/to/model",
+    action_tokenizer_path="/path/to/action_tokenizer",
+    train_config_path="/path/to/train_config",
+    state_dim=8,
+    action_dim=7,
+    pred_horizon=32,
+    device="cuda",
+    dtype="bfloat16",
+    predict_mode="fast",
+    camera_key=["front_view", "left_wrist_view"],
+)
+```
+
+### ALOHA (Dual Arm)
+
+```python
+ModelConfig(
+    model_path="/path/to/model",
+    action_tokenizer_path="/path/to/action_tokenizer",
+    train_config_path="/path/to/train_config",
+    state_dim=14,
+    action_dim=14,
+    pred_horizon=32,
+    device="cuda",
+    dtype="bfloat16",
+    predict_mode="fast",
+    camera_key=["face_view", "left_wrist_view", "right_wrist_view"],
+)
+```
+
+## Server Protocol
+
+### Connection Flow
+
+1. Client connects to `ws://host:port`
+2. Server sends metadata JSON with policy information
+3. Client sends observation (msgpack-encoded)
+4. Server responds with action prediction (msgpack-encoded)
+5. Repeat steps 3-4 for each inference
+
+### Observation Format
+
+Observations must be a dictionary with camera keys matching server configuration:
+
+```python
+obs = {
+    # Image observations - keys must match server's camera_key configuration
+    "front_view": np.ndarray,      # (H, W, 3) uint8 or float
+    "left_wrist_view": np.ndarray, # (H, W, 3) uint8 or float
+
+    # Required fields
+    "prompt": str,                 # Task description
+    "dataset_names": List[str],    # Dataset/robot name, e.g., ["physical-intelligence/libero"]
+    "state": np.ndarray,           # Robot proprioception state (state_dim,)
+}
+```
+
+**Important**: The image keys (`front_view`, `left_wrist_view`, etc.) must exactly match the `camera_key` parameter configured on the server.
+
+### Action Response Format
+
+Actions are returned as a dictionary:
+
+```python
+{
+    "action": np.ndarray,       # Predicted action [pred_horizon, action_dim]
+    "server_timing": {
+        "infer_ms": float,      # Inference time in milliseconds
+        "prev_total_ms": float, # Total time for previous request
+    }
+}
+```
+
+### Server Metadata
+
+When connecting, the server sends metadata:
+
+```python
+{
+    "action_dim": int,          # Action space dimension
+    "pred_horizon": int,        # Number of future actions predicted
+    "device": str,              # Device model runs on
+    "predict_mode": str,        # Prediction mode (fast/diffusion)
+    "env": str,                 # Environment name
+}
+```
+
+### Health Check
+
+HTTP health check endpoint available at:
+```
+http://host:port/healthz
+```
+
+Returns `200 OK` if the server is running.
+
+## Client Example
+
+### Synchronous Python Client
+
+For synchronous usage, see `wall_x/serving/client.py`:
+
+```python
+from wall_x.serving.client import WallXClient
+
+# Create and connect
+client = WallXClient(uri="ws://localhost:8000")
+client.connect_sync()
+
+# Prepare observation
+obs = {
+    "front_view": image1,
+    "left_wrist_view": image2,
+    "prompt": "task description",
+    "state": robot_state,
+    "dataset_names": ["physical-intelligence/libero"],
+}
+
+# Get prediction
+response = client.predict_sync(obs)
+action = response["action"]
+
+# Close connection
+client.close_sync()
+```
+
+## Architecture
+
+### WebsocketPolicyServer
+
+Generic websocket server that:
+- Handles websocket connections with msgpack serialization
+- Tracks inference timing and performance metrics
+- Provides health check endpoint
+- Handles errors gracefully with proper logging
+- Supports concurrent client connections
+
+### WallXPolicy
+
+Policy wrapper that:
+- Loads and manages the Wall-X model from pretrained checkpoint
+- Processes multi-camera observations
+- Handles image preprocessing (smart resize, normalization)
+- Manages device placement and dtype conversion
+- Provides policy metadata to clients
+- Supports both fast tokenizer and diffusion prediction modes
+
+### Image Processing Pipeline
+
+1. **Camera Key Matching**: Extracts images from observation dict using configured camera keys
+2. **Format Conversion**: Converts numpy arrays to PIL Images
+3. **Smart Resize**: Applies Qwen's smart resize algorithm based on min/max pixels
+4. **Vision Token Formatting**: Inserts vision tokens in text prompt
+5. **Batch Preparation**: Creates model-ready BatchFeature input

wall_x/serving/__init__.py

@@ -0,0 +1,3 @@
+from .websocket_policy_server import WebsocketPolicyServer, BasePolicy
+
+__all__ = ["WebsocketPolicyServer", "BasePolicy"]

wall_x/serving/client.py

@@ -0,0 +1,380 @@
+#!/usr/bin/env python3
+"""
+Example client for Wall-X model server with sync support.
+
+This script demonstrates how to connect to a Wall-X server and request
+action predictions from observations in both sync and async contexts.
+"""
+
+import asyncio
+import logging
+from typing import Dict, List
+import numpy as np
+import threading
+import yaml
+import torch
+import matplotlib.pyplot as plt
+import os
+
+from wall_x.model.action_head import Normalizer
+from wall_x.model.qwen2_5_based.modeling_qwen2_5_vl_act import (
+    Qwen2_5_VLMoEForAction,
+)
+from lerobot.datasets.lerobot_dataset import LeRobotDataset, LeRobotDatasetMetadata
+from wall_x.utils.constant import action_statistic_dof
+
+try:
+    import msgpack
+    import msgpack_numpy as m
+
+    m.patch()
+except ImportError:
+    print("Please install msgpack-numpy: pip install msgpack-numpy")
+    exit(1)
+
+try:
+    import websockets
+except ImportError:
+    print("Please install websockets: pip install websockets")
+    exit(1)
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
+
+
+class WallXClient:
+    """Client for connecting to Wall-X model server."""
+
+    def __init__(self, config_path: str, uri: str = "ws://localhost:8000"):
+        """Initialize client.
+
+        Args:
+            uri: WebSocket URI of the server (e.g., ws://localhost:8000)
+        """
+        self.uri = uri
+        self.websocket = None
+        self.metadata = None
+        self._loop = None
+        self._thread = None
+
+        with open(config_path, "r") as f:
+            self.train_config = yaml.load(f, Loader=yaml.FullLoader)
+
+        self.init_normalizer(self.train_config)
+
+    async def connect(self):
+        """Connect to the server and receive metadata."""
+        logger.info(f"Connecting to {self.uri}...")
+        self.websocket = await websockets.connect(
+            self.uri,
+            ping_interval=None,
+            ping_timeout=None,
+            max_size=None,
+        )
+
+        self.metadata = msgpack.unpackb(await self.websocket.recv())
+        logger.info(f"Connected! Server metadata: {self.metadata}")
+
+    async def predict(self, obs: Dict) -> Dict:
+        """Get action prediction from observation.
+
+        Args:
+            obs: Observation dictionary containing:
+                - 'image': Image array (H, W, C)
+                - 'prompt': Optional text prompt
+                - 'state': Optional robot state
+
+        Returns:
+            Dictionary with:
+                - 'action': Predicted action array
+                - 'server_timing': Timing information
+        """
+        if self.websocket is None:
+            raise RuntimeError("Not connected. Call connect() first.")
+
+        await self.websocket.send(msgpack.packb(obs))
+        response = msgpack.unpackb(await self.websocket.recv())
+        return response
+
+    async def close(self):
+        """Close the connection."""
+        if self.websocket:
+            await self.websocket.close()
+            logger.info("Connection closed")
+
+    async def reset(self):
+        """Reset the policy (if supported)."""
+        pass
+
+    # ============ Synchronous methods (using independent thread event loop) ============
+
+    def _start_background_loop(self):
+        """Start event loop in background thread."""
+        self._loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(self._loop)
+        self._loop.run_forever()
+
+    def _ensure_loop(self):
+        """Ensure background event loop is running."""
+        if self._loop is None or not self._loop.is_running():
+            self._thread = threading.Thread(
+                target=self._start_background_loop, daemon=True
+            )
+            self._thread.start()
+            # Wait for loop to start
+            import time
+
+            while self._loop is None:
+                time.sleep(0.01)
+
+    def _run_async(self, coro):
+        """Run coroutine in background event loop."""
+        self._ensure_loop()
+        future = asyncio.run_coroutine_threadsafe(coro, self._loop)
+        return future.result()
+
+    def connect_sync(self):
+        """Synchronously connect to server."""
+        return self._run_async(self.connect())
+
+    def norm_state(
+        self,
+        state: np.ndarray,
+        dataset_names: List[str],
+        state_mask: torch.Tensor = None,
+    ) -> np.ndarray:
+        """Normalize state."""
+        return self.normalizer_propri.normalize_data(state, dataset_names, state_mask)
+
+    def predict_sync(self, obs: Dict) -> Dict:
+        """Synchronous prediction method.
+
+        Args:
+            obs: Observation dictionary
+
+        Returns:
+            Prediction result dictionary
+        """
+        return self._run_async(self.predict(obs))
+
+    def close_sync(self):
+        """Synchronously close connection."""
+        result = self._run_async(self.close())
+        # Stop event loop
+        if self._loop:
+            self._loop.call_soon_threadsafe(self._loop.stop)
+        return result
+
+    def init_normalizer(self, train_config):
+        customized_dof_config = train_config["customized_robot_config"][
+            "customized_dof_config"
+        ]
+        customized_agent_pos_config = train_config["customized_robot_config"][
+            "customized_agent_pos_config"
+        ]
+        Qwen2_5_VLMoEForAction._set_customized_config(train_config)
+
+        self.normalizer_action = Normalizer(
+            action_statistic_dof, customized_dof_config
+        ).to("cuda")
+        self.normalizer_propri = Normalizer(
+            action_statistic_dof, customized_agent_pos_config
+        ).to("cuda")
+
+        print("Normalizer initialized")
+
+
+def prepare_batch_sync(data, normalizer_action, normalizer_propri, dataset_names):
+    """Synchronous version of prepare_batch."""
+    image = (data["image"].permute(1, 2, 0) * 255).to(torch.uint8).cpu().numpy()
+    wrist_image = (
+        (data["wrist_image"].permute(1, 2, 0) * 255).to(torch.uint8).cpu().numpy()
+    )
+    prompt = data["task"]
+
+    state = data["state"].to("cuda")
+    if state.dim() == 1:
+        state = state.unsqueeze(0)
+
+    state_mask = torch.ones([1, 32, 20]).to("cuda")
+    state_mask[:, :, 8:] = 0
+
+    state = normalizer_propri.normalize_data(state, dataset_names, state_mask)
+    state = state.cpu().numpy().astype(np.float32)
+
+    obs = {
+        "front_view": image,
+        "left_wrist_view": wrist_image,
+        "prompt": prompt,
+        "state": state,
+        "dataset_names": dataset_names,
+    }
+    return obs
+
+
+def init_serving_sample_dataset(train_config):
+    repo_id = train_config["data"]["lerobot_config"]["repo_id"]
+
+    meta_info = LeRobotDatasetMetadata(repo_id)
+    dataset_fps = meta_info.fps
+    delta_timestamps = {
+        "actions": [t / dataset_fps for t in range(32)],
+    }
+    dataset = LeRobotDataset(
+        repo_id,
+        episodes=[0],
+        delta_timestamps=delta_timestamps,
+        video_backend="pyav",
+    )
+
+    return dataset, repo_id
+
+
+# ============ Synchronous version of main function ============
+
+
+def main_sync(args):
+    """Synchronous version of main function."""
+
+    # Create client and connect
+    client = WallXClient(args.config_path, uri=args.uri)
+    client.connect_sync()
+
+    dataset, repo_id = init_serving_sample_dataset(client.train_config)
+
+    total_frames = len(dataset)
+    gt_traj = np.zeros((total_frames, args.action_dim))
+    pred_traj = np.zeros((total_frames, args.action_dim))
+    import torch
+
+    dof_mask = torch.ones([1, 32, 20]).to("cuda")
+    dof_mask[:, :, args.action_dim :] = 0
+
+    # Synchronous processing
+    for idx, data in enumerate(dataset):
+        if idx % args.pred_horizon == 0 and idx + args.pred_horizon < total_frames:
+            print(f"Processing frame {idx}")
+            obs = prepare_batch_sync(
+                data,
+                client.normalizer_action,
+                client.normalizer_propri,
+                dataset_names=[repo_id],
+            )
+            response = client.predict_sync(obs)
+            pred_action = response["action"]
+            pred_traj[idx : idx + args.pred_horizon] = pred_action
+            gt_traj[idx : idx + args.pred_horizon] = data["actions"]
+
+    # Draw plot
+    timesteps = gt_traj.shape[0]
+    fig, axs = plt.subplots(
+        args.action_dim, 1, figsize=(15, 5 * args.action_dim), sharex=True
+    )
+    fig.suptitle("Action Comparison for lerobot", fontsize=16)
+
+    for i in range(args.action_dim):
+        axs[i].plot(range(timesteps), gt_traj[:, i], label="Ground Truth")
+        axs[i].plot(range(timesteps), pred_traj[:, i], label="Prediction")
+        axs[i].set_ylabel(f"Action Dim {i+1}")
+        axs[i].legend()
+        axs[i].grid(True)
+
+    axs[-1].set_xlabel("Timestep")
+    plt.tight_layout(rect=[0, 0.03, 1, 0.95])
+    os.makedirs(args.save_dir, exist_ok=True)
+    save_path = os.path.join(args.save_dir, "lerobot_comparison_serving.png")
+    plt.savefig(save_path)
+    print(f"Saved plot to {save_path}")
+    plt.close()
+
+    # Close connection
+    client.close_sync()
+
+
+# ============ Asynchronous version of main function (keep original functionality) ============
+
+
+async def main(args):
+    client = WallXClient(args.config_path, uri=args.uri)
+    await client.connect()
+    dataset, repo_id = init_serving_sample_dataset(client.train_config)
+
+    total_frames = len(dataset)
+    gt_traj = np.zeros((total_frames, args.action_dim))
+    pred_traj = np.zeros((total_frames, args.action_dim))
+
+    for idx, data in enumerate(dataset):
+        if idx % args.pred_horizon == 0 and idx + args.pred_horizon < total_frames:
+            print(f"Processing frame {idx}")
+            obs = prepare_batch_sync(
+                data,
+                client.normalizer_action,
+                client.normalizer_propri,
+                dataset_names=[repo_id],
+            )
+            response = await client.predict(obs)
+            pred_action = response["action"]
+            print(pred_action.shape)
+            pred_traj[idx : idx + args.pred_horizon] = pred_action
+            gt_traj[idx : idx + args.pred_horizon] = data["actions"]
+
+    timesteps = gt_traj.shape[0]
+
+    fig, axs = plt.subplots(
+        args.action_dim, 1, figsize=(15, 5 * args.action_dim), sharex=True
+    )
+    fig.suptitle("Action Comparison for lerobot", fontsize=16)
+
+    for i in range(args.action_dim):
+        axs[i].plot(range(timesteps), gt_traj[:, i], label="Ground Truth")
+        axs[i].plot(range(timesteps), pred_traj[:, i], label="Prediction")
+        axs[i].set_ylabel(f"Action Dim {i+1}")
+        axs[i].legend()
+        axs[i].grid(True)
+
+    axs[-1].set_xlabel("Timestep")
+    plt.tight_layout(rect=[0, 0.03, 1, 0.95])
+    os.makedirs(args.save_dir, exist_ok=True)
+    save_path = os.path.join(args.save_dir, "lerobot_comparison_serving.png")
+    plt.savefig(save_path)
+    print(f"Saved plot to {save_path}")
+    plt.close()
+
+
+if __name__ == "__main__":
+    """Asynchronous version of main function."""
+    import argparse
+
+    parser = argparse.ArgumentParser(description="Wall-X client examples")
+    parser.add_argument(
+        "--example",
+        choices=["single", "multiple", "benchmark"],
+        default="single",
+        help="Example to run",
+    )
+    parser.add_argument(
+        "--uri",
+        default="ws://localhost:8000",
+        help="Server URI",
+    )
+    parser.add_argument(
+        "--pred_horizon", type=int, default=32, help="Prediction horizon"
+    )
+    parser.add_argument("--action_dim", type=int, default=7, help="Action dimension")
+    parser.add_argument(
+        "--config_path",
+        default="/x2robot_v2/vincent/workspace/opensource/cfg/config_from_qwen_libero.yml",
+        help="Train config path",
+    )
+    parser.add_argument(
+        "--save_dir",
+        default="/x2robot_v2/vincent/workspace/opensource/plots/libero",
+        help="Save directory",
+    )
+    args = parser.parse_args()
+
+    # Synchronous mode
+    main_sync(args)
+
+    # Asynchronous mode
+    # asyncio.run(main(args))

wall_x/serving/launch_serving.py

@@ -0,0 +1,220 @@
+#!/usr/bin/env python3
+"""
+Server script for Wall-X model.
+
+This script serves a Wall-X model using a websocket server, allowing
+clients to connect and get action predictions from observations.
+
+Based on the OpenPI serve_policy.py script structure.
+"""
+
+import dataclasses
+from dataclasses import field
+import enum
+import logging
+import socket
+import sys
+import yaml
+from pathlib import Path
+from typing import List
+
+import tyro
+
+from wall_x.serving.policy.wall_x_policy import WallXPolicy
+from wall_x.serving.websocket_policy_server import WebsocketPolicyServer
+
+logger = logging.getLogger(__name__)
+
+
+class EnvMode(enum.Enum):
+    """Supported environments/datasets."""
+
+    LIBERO = "libero"
+    ALOHA = "aloha"
+
+
+@dataclasses.dataclass
+class ModelConfig:
+    """Configuration for loading a Wall-X model."""
+
+    # Path to the pretrained model checkpoint
+    model_path: str
+    # Path to the action tokenizer
+    action_tokenizer_path: str
+    # Path to train config yaml
+    train_config_path: str
+    # Action dimension for the environment
+    action_dim: int = 7
+    # State dimension for the environment
+    state_dim: int = 8
+    # Prediction horizon (number of future actions to predict)
+    pred_horizon: int = 32
+    # Device to run model on
+    device: str = "cuda"
+    # Model dtype (bfloat16, float16, float32)
+    dtype: str = "bfloat16"
+    # Prediction mode (fast or slow)
+    predict_mode: str = "fast"
+    # Camera key for the environment
+    camera_key: List[str] = field(
+        default_factory=lambda: ["front_view", "left_wrist_view", "right_wrist_view"]
+    )
+
+
+@dataclasses.dataclass
+class Args:
+    """Arguments for the serve_wall_x script."""
+
+    # Environment mode (used for default configurations)
+    env: EnvMode = EnvMode.LIBERO
+
+    # Model configuration. If not provided, uses default config for the environment
+    model_config: ModelConfig | None = None
+
+    # Default text prompt to use if not provided in observation
+    default_prompt: str | None = None
+
+    # Port to serve the policy on
+    port: int = 8000
+
+    # Host to bind the server to
+    host: str = "0.0.0.0"
+
+    # Enable debug logging
+    debug: bool = False
+
+
+# Default model configurations for each environment
+DEFAULT_CONFIGS: dict[EnvMode, ModelConfig] = {
+    EnvMode.LIBERO: ModelConfig(
+        model_path="/path/to/model",
+        action_tokenizer_path="/path/to/action_tokenizer",
+        train_config_path="/path/to/train_config",
+        state_dim=8,
+        action_dim=7,
+        pred_horizon=32,
+        device="cuda",
+        dtype="bfloat16",
+        predict_mode="fast",
+        camera_key=["front_view", "left_wrist_view"],
+    ),
+    EnvMode.ALOHA: ModelConfig(
+        model_path="/path/to/model",
+        action_tokenizer_path="/path/to/action_tokenizer",
+        train_config_path="/path/to/train_config",
+        state_dim=14,
+        action_dim=14,
+        pred_horizon=32,
+        device="cuda",
+        dtype="bfloat16",
+        predict_mode="fast",
+        camera_key=["face_view", "left_wrist_view", "right_wrist_view"],
+    ),
+}
+
+
+def get_model_config(args: Args) -> ModelConfig:
+    """Get model configuration from args or defaults."""
+    if args.model_config is not None:
+        return args.model_config
+
+    if config := DEFAULT_CONFIGS.get(args.env):
+        logger.info(f"Using default configuration for {args.env.value}")
+        return config
+
+    raise ValueError(
+        f"No default configuration for {args.env.value}. "
+        f"Please provide --model-config with model_path and action_tokenizer_path."
+    )
+
+
+def create_policy(args: Args) -> WallXPolicy:
+    """Create a Wall-X policy from the given arguments."""
+    config = get_model_config(args)
+    logger.info(f"Creating Wall-X policy with config: {config}")
+
+    # Validate paths
+    if not Path(config.model_path).exists():
+        logger.warning(f"Model path does not exist: {config.model_path}")
+
+    if not Path(config.action_tokenizer_path).exists():
+        logger.warning(
+            f"Action tokenizer path does not exist: {config.action_tokenizer_path}"
+        )
+
+    with open(config.train_config_path, "r") as f:
+        train_config = yaml.load(f, Loader=yaml.FullLoader)
+
+    policy = WallXPolicy(
+        model_path=config.model_path,
+        train_config=train_config,
+        action_tokenizer_path=config.action_tokenizer_path,
+        action_dim=config.action_dim,
+        agent_pos_dim=config.state_dim,
+        pred_horizon=config.pred_horizon,
+        device=config.device,
+        dtype=config.dtype,
+        predict_mode=config.predict_mode,
+        default_prompt=args.default_prompt,
+        camera_key=config.camera_key,
+    )
+
+    return policy
+
+
+def main(args: Args) -> None:
+    """Main function to start the Wall-X model server."""
+    log_level = logging.DEBUG if args.debug else logging.INFO
+    logging.basicConfig(
+        level=log_level,
+        format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
+    )
+
+    logger.info("Starting Wall-X model server")
+    logger.info(f"Environment: {args.env.value}")
+    logger.info(f"Port: {args.port}")
+    logger.info(f"Host: {args.host}")
+
+    # Create policy
+    try:
+        policy = create_policy(args)
+    except Exception as e:
+        logger.error(f"Failed to create policy: {e}")
+        sys.exit(1)
+
+    # Get policy metadata
+    policy_metadata = policy.metadata
+    policy_metadata["env"] = args.env.value
+
+    # Get network info
+    hostname = socket.gethostname()
+    try:
+        local_ip = socket.gethostbyname(hostname)
+    except Exception:
+        local_ip = "unknown"
+
+    logger.info(f"Server hostname: {hostname}")
+    logger.info(f"Server IP: {local_ip}")
+    logger.info(f"Server will be available at: ws://{args.host}:{args.port}")
+    logger.info(f"Health check endpoint: http://{args.host}:{args.port}/healthz")
+
+    # Create and start server
+    server = WebsocketPolicyServer(
+        policy=policy,
+        host=args.host,
+        port=args.port,
+        metadata=policy_metadata,
+    )
+
+    logger.info("Starting server...")
+    try:
+        server.serve_forever()
+    except KeyboardInterrupt:
+        logger.info("Server stopped by user")
+    except Exception as e:
+        logger.error(f"Server error: {e}")
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main(tyro.cli(Args))

wall_x/serving/policy/__init__.py

@@ -0,0 +1,3 @@
+from .wall_x_policy import WallXPolicy
+
+__all__ = ["WallXPolicy"]

wall_x/serving/policy/utils.py

@@ -0,0 +1,246 @@
+from typing import Dict, List
+import logging
+import numpy as np
+from wall_x.data.utils import preprocesser_call
+from qwen_vl_utils.vision_process import smart_resize
+import torch
+from PIL import Image
+from transformers import BatchFeature
+
+logger = logging.getLogger(__name__)
+
+
+def prepare_batch(
+    obs: Dict,
+    processor,
+    camera_key: List[str],
+    agent_pos_dim,
+    action_dim,
+    pred_horizon,
+    fixed_action_dim,
+    max_length,
+    image_factor: int,
+    min_pixels: int,
+    max_pixels: int,
+    predict_mode: str = "fast",
+    device: str = "cuda",
+) -> BatchFeature:
+    """Prepare observation into model input format.
+
+    Args:
+        obs: Dictionary containing:
+            - 'camera_key_0' : image 0
+            - 'camera_key_1' : image 1
+            ...
+            - 'prompt': Text prompt
+            - 'state': Robot state/proprioception
+            - 'dataset_names': Dataset names
+
+    Returns:
+        BatchFeature object ready for model input
+    """
+    # Handle images - can be single image, list of images, or dict of images
+    images = []
+    images = [obs[key] for key in camera_key]
+    # Convert numpy arrays to PIL Images
+    processed_images = []
+    for img in images:
+        if isinstance(img, np.ndarray):
+            # Debug: Log the shape and dtype
+            logger.debug(f"Image shape: {img.shape}, dtype: {img.dtype}")
+
+            # Handle unexpected dimensions - squeeze if needed
+            if img.ndim > 3:
+                logger.warning(
+                    f"Image has {img.ndim} dimensions, squeezing extra dimensions"
+                )
+                img = np.squeeze(img)
+
+            # Verify shape is valid for PIL
+            if img.ndim == 2:
+                # Grayscale image
+                pass
+            elif img.ndim == 3:
+                # Check if channel dimension is first or last
+                if img.shape[0] == 3 or img.shape[0] == 1:
+                    # Channels first, transpose to channels last
+                    img = np.transpose(img, (1, 2, 0))
+                elif img.shape[2] == 3 or img.shape[2] == 1:
+                    # Already channels last
+                    pass
+                else:
+                    raise ValueError(
+                        f"Unexpected image shape: {img.shape}. Expected (H, W, C) or (C, H, W)"
+                    )
+            else:
+                raise ValueError(
+                    f"Invalid image dimensions: {img.ndim}. Expected 2 or 3 dimensions, got shape {img.shape}"
+                )
+
+            # Convert to PIL Image
+            if img.dtype == np.uint8:
+                img = Image.fromarray(img)
+            else:
+                img = Image.fromarray((img * 255).astype(np.uint8))
+        processed_images.append(img)
+
+    # Apply smart resize to images
+    resized_images = process_images(
+        processed_images, image_factor, min_pixels, max_pixels
+    )
+
+    # Handle text prompt - format with vision tokens
+    instruction = obs["prompt"]
+    formatted_text = format_text_with_vision_tokens(
+        instruction, camera_key, predict_mode, pred_horizon
+    )
+
+    # Use processor to prepare inputs
+    inputs = preprocesser_call(
+        processor=processor,
+        text=[formatted_text],
+        images=[resized_images],
+        videos=None,
+        padding=True,
+        truncation=True,
+        return_tensors="pt",
+        max_length=max_length,
+    )
+
+    action_token_id = processor.tokenizer.convert_tokens_to_ids("<|action|>")
+    moe_token_types = inputs.input_ids == action_token_id
+    inputs["moe_token_types"] = moe_token_types
+
+    # Handle robot state/proprioception if available
+    if "state" in obs:
+        state = obs["state"]
+        if isinstance(state, np.ndarray):
+            state = torch.from_numpy(state).float()
+        elif not isinstance(state, torch.Tensor):
+            state = torch.tensor(state, dtype=torch.float32)
+
+        # Add batch dimension if needed
+        if state.dim() == 1:
+            state = state.unsqueeze(0)
+        if state.dim() == 2:
+            state = state.unsqueeze(1)  # [batch, 1, state_dim]
+
+        # Pad to 20 dimensions if needed (same as training)
+        if state.shape[-1] < 20:
+            padding = torch.zeros(state.shape[0], state.shape[1], 20 - state.shape[-1])
+            state = torch.cat([state, padding], dim=-1)
+
+        # Create mask for valid dimensions
+        agent_pos_mask = torch.ones_like(state)
+        if state.shape[-1] > agent_pos_dim:
+            agent_pos_mask[:, :, agent_pos_dim:] = 0
+
+        inputs["proprioception"] = state
+        inputs["agent_pos_mask"] = agent_pos_mask
+
+    # Add dataset name (required by model)
+    inputs["dataset_names"] = obs["dataset_names"]
+
+    # Move all tensors to device
+    for key in inputs:
+        if isinstance(inputs[key], torch.Tensor):
+            inputs[key] = inputs[key].to(device)
+
+    dof_mask = torch.ones([state.shape[0], pred_horizon, fixed_action_dim])
+    dof_mask[:, :, action_dim:] = 0
+
+    inputs["dof_mask"] = dof_mask
+
+    # Convert to BatchFeature to maintain consistency with training pipeline
+    return BatchFeature(data=dict(inputs)).to(device)
+
+
+def process_images(
+    images: List[Image.Image], image_factor: int, min_pixels: int, max_pixels: int
+) -> List[Image.Image]:
+    """Process images with smart resize following the data loading pattern.
+
+    Args:
+        images: List of PIL Images
+
+    Returns:
+        List of resized PIL Images
+    """
+    resized_images = []
+    for img_pil in images:
+        current_width, current_height = img_pil.size
+
+        # Apply smart scaling (Qwen logic)
+        resized_height, resized_width = smart_resize(
+            current_height,
+            current_width,
+            factor=image_factor,
+            min_pixels=min_pixels,
+            max_pixels=max_pixels,
+        )
+
+        resized_img = img_pil.resize((resized_width, resized_height))
+        resized_images.append(resized_img)
+
+    return resized_images
+
+
+def format_text_with_vision_tokens(
+    instruction: str,
+    camera_key: List[str],
+    predict_mode: str = "fast",
+    pred_horizon: int = 32,
+) -> str:
+    """Format text prompt with vision tokens for the model.
+
+    Args:
+        instruction: Task instruction text
+        camera_key: List of camera names
+
+    Returns:
+        Formatted text with special tokens
+    """
+    # Special tokens for formatting
+    role_start_symbol = "<|im_start|>"
+    role_end_symbol = "<|im_end|>"
+    vision_start_symbol = "<|vision_start|>"
+    vision_end_symbol = "<|vision_end|>"
+    image_pad_symbol = "<|image_pad|>"
+    propri_symbol = "<|propri|>"
+    action_symbol = "<|action|>"
+    # action_fast_symbol = "<|action_fast|>"
+
+    # Camera name mapping
+    camera_name_mapping = {
+        "front_view": "front view",
+        "face_view": "front view",
+        "left_wrist_view": "left wrist view",
+        "right_wrist_view": "right wrist view",
+        "top_view": "top view",
+        "wall_view": "wall view",
+    }
+    pred_horizon = 32
+
+    # System prologue
+    prologue = (
+        f"{role_start_symbol}system\nYou are a helpful assistant.{role_end_symbol}\n"
+    )
+
+    # User request with observation
+    user_request = f"{role_start_symbol}user\nObservation:"
+    if camera_key:
+        for cam_name in camera_key:
+            view_name = camera_name_mapping.get(cam_name, cam_name)
+            user_request += f" {view_name}: {vision_start_symbol}{image_pad_symbol}{vision_end_symbol}"
+    user_request += "\nInstruction:"
+
+    text_prompt = (
+        f"\nPredict the next action in robot action.\nProprioception: {propri_symbol}\n"
+    )
+    user_message = f"{user_request} {instruction}{text_prompt}{role_end_symbol}\n"
+    assistant_output = f"{role_start_symbol}assistant\n"
+    if predict_mode == "diffusion":
+        assistant_output += f"{action_symbol * pred_horizon}"
+    complete_text = prologue + user_message + assistant_output
+
+    return complete_text

wall_x/serving/policy/wall_x_policy.py

@@ -0,0 +1,173 @@
+import logging
+from typing import Dict, Any, List
+import torch
+import numpy as np
+from transformers import AutoProcessor
+
+from wall_x.serving.websocket_policy_server import BasePolicy
+from wall_x.model.qwen2_5_based.modeling_qwen2_5_vl_act import Qwen2_5_VLMoEForAction
+from wall_x.serving.policy.utils import prepare_batch
+
+logger = logging.getLogger(__name__)
+
+
+class WallXPolicy(BasePolicy):
+    """Policy wrapper for Wall-X model that implements the BasePolicy interface."""
+
+    def __init__(
+        self,
+        model_path: str,
+        train_config: dict,
+        action_tokenizer_path: str,
+        action_dim: int,
+        agent_pos_dim: int,
+        pred_horizon: int,
+        camera_key: List[str],
+        device: str = "cuda",
+        dtype: str = "bfloat16",
+        predict_mode: str = "fast",
+        default_prompt: str | None = None,
+        min_pixels: int = 4 * 28 * 28,
+        max_pixels: int = 16384 * 28 * 28,
+        image_factor: int = 28,
+        max_length: int = 768,
+    ):
+        """Initialize the Wall-X policy.
+
+        Args:
+            model_path: Path to the pretrained model checkpoint
+            action_tokenizer_path: Path to the action tokenizer
+            action_dim: Dimension of action space
+            pred_horizon: Prediction horizon for actions
+            device: Device to run model on ('cuda' or 'cpu')
+            dtype: Data type for model ('bfloat16', 'float16', or 'float32')
+            predict_mode: Prediction mode ('fast' or 'slow')
+            default_prompt: Default text prompt for the model
+            min_pixels: Minimum pixels for image resizing
+            max_pixels: Maximum pixels for image resizing
+            image_factor: Factor for smart resize
+            max_length: Maximum sequence length for text
+        """
+        logger.info(f"Loading Wall-X model from {model_path}")
+
+        self.model = Qwen2_5_VLMoEForAction.from_pretrained(
+            model_path,
+            train_config=train_config,
+            action_tokenizer_path=action_tokenizer_path,
+        )
+        self.model.eval()
+        self.model = self.model.to(device)
+
+        self.model = self.model.bfloat16()
+
+        # hard code the action dim to 20 for align to wall-x configuration
+        self.fixed_action_dim = 20
+
+        self.action_dim = action_dim
+        self.agent_pos_dim = agent_pos_dim
+        self.pred_horizon = pred_horizon
+        self.device = device
+        self.predict_mode = predict_mode
+        self.default_prompt = default_prompt
+        self.camera_key = camera_key
+
+        # Image preprocessing config
+        self.min_pixels = min_pixels
+        self.max_pixels = max_pixels
+        self.image_factor = image_factor
+        self.max_length = max_length
+
+        # Load processor
+        logger.info("Loading processor and tokenizer...")
+        self.processor = AutoProcessor.from_pretrained(model_path, use_fast=True)
+        self.processor.tokenizer.padding_side = "left"
+
+        # Action buffer for multi-step predictions
+        self.action_buffer = []
+        self.buffer_index = 0
+
+        logger.info(
+            f"Model loaded successfully. Device: {device}, Action dim: {action_dim}, Horizon: {pred_horizon}"
+        )
+
+    @property
+    def metadata(self) -> Dict[str, Any]:
+        """Return metadata about the policy."""
+        return {
+            "action_dim": self.action_dim,
+            "pred_horizon": self.pred_horizon,
+            "device": self.device,
+            "predict_mode": self.predict_mode,
+        }
+
+    def reset(self) -> None:
+        """Reset the policy state."""
+        self.action_buffer = []
+        self.buffer_index = 0
+        logger.debug("Policy reset")
+
+    def infer(self, obs: Dict) -> Dict:
+        """Infer action from observation.
+
+        Args:
+            obs: Dictionary containing:
+                - 'image': Image observation (numpy array or PIL Image)
+                - 'prompt': Optional text prompt
+                - 'state': Optional robot state
+                - Other modality-specific observations
+
+        Returns:
+            Dictionary containing:
+                - 'action': Predicted action (numpy array)
+                - Additional metadata
+        """
+        try:
+            # Need to predict new actions
+            input_batch = prepare_batch(
+                obs,
+                self.processor,
+                self.camera_key,
+                self.agent_pos_dim,
+                self.action_dim,
+                self.pred_horizon,
+                self.fixed_action_dim,
+                self.max_length,
+                self.image_factor,
+                self.min_pixels,
+                self.max_pixels,
+                self.predict_mode,
+                self.device,
+            )
+
+            with torch.no_grad():
+                outputs = self.model(
+                    **input_batch,
+                    action_dim=(
+                        self.action_dim
+                        if self.predict_mode == "fast"
+                        else self.fixed_action_dim
+                    ),
+                    pred_horizon=self.pred_horizon,
+                    mode="predict",
+                    predict_mode=self.predict_mode,
+                )
+
+            if outputs["predict_action"] is None:
+                predicted_actions = np.zeros(
+                    [1, self.pred_horizon, self.action_dim]
+                ).astype(np.float32)
+
+            predicted_actions = (
+                outputs["predict_action"][:, :, : self.action_dim]
+                .detach()
+                .cpu()
+                .to(torch.float32)
+                .numpy()
+            )
+
+            print(predicted_actions.shape)
+            return {"action": predicted_actions}
+
+        except Exception as e:
+            logger.error(f"Error during inference: {e}")
+            raise

wall_x/serving/websocket_policy_server.py

@@ -0,0 +1,132 @@
+import asyncio
+import http
+import logging
+import time
+import traceback
+from typing import Dict, Any
+
+try:
+    import msgpack
+    import msgpack_numpy as m
+
+    m.patch()
+except ImportError:
+    logging.warning(
+        "msgpack-numpy not installed. Install with: pip install msgpack-numpy"
+    )
+    msgpack = None
+
+import websockets.asyncio.server as _server
+import websockets.frames
+
+logger = logging.getLogger(__name__)
+
+
+class BasePolicy:
+    """Base class for policies that can be served."""
+
+    def infer(self, obs: Dict) -> Dict:
+        """Infer actions from observations."""
+        raise NotImplementedError
+
+    def reset(self) -> None:
+        """Reset the policy to its initial state."""
+        pass
+
+    @property
+    def metadata(self) -> Dict[str, Any]:
+        """Return metadata about the policy."""
+        return {}
+
+
+class WebsocketPolicyServer:
+    """Serves a policy using the websocket protocol.
+
+    Implements a websocket server that:
+    1. Sends policy metadata on connection
+    2. Receives observations
+    3. Returns predicted actions
+    4. Tracks timing information
+    """
+
+    def __init__(
+        self,
+        policy: BasePolicy,
+        host: str = "0.0.0.0",
+        port: int = 8000,
+        metadata: Dict | None = None,
+    ) -> None:
+        self._policy = policy
+        self._host = host
+        self._port = port
+        self._metadata = metadata or {}
+        logging.getLogger("websockets.server").setLevel(logging.INFO)
+
+    def serve_forever(self) -> None:
+        asyncio.run(self.run())
+
+    async def run(self):
+        async with _server.serve(
+            self._handler,
+            self._host,
+            self._port,
+            compression=None,
+            max_size=None,
+            ping_interval=None,  # Disable automatic ping for long-running inference
+            ping_timeout=None,  # Disable ping timeout
+            process_request=_health_check,
+        ) as server:
+            logger.info(f"Server started on {self._host}:{self._port}")
+            await server.serve_forever()
+
+    async def _handler(self, websocket: _server.ServerConnection):
+        logger.info(f"Connection from {websocket.remote_address} opened")
+
+        if msgpack is None:
+            await websocket.close(
+                code=websockets.frames.CloseCode.INTERNAL_ERROR,
+                reason="msgpack-numpy not installed on server",
+            )
+            return
+
+        # Send metadata to client
+        await websocket.send(msgpack.packb(self._metadata))
+
+        prev_total_time = None
+        while True:
+            try:
+                start_time = time.monotonic()
+                obs = msgpack.unpackb(await websocket.recv())
+
+                infer_time = time.monotonic()
+                action = self._policy.infer(obs)
+                infer_time = time.monotonic() - infer_time
+
+                action["server_timing"] = {
+                    "infer_ms": infer_time * 1000,
+                }
+                if prev_total_time is not None:
+                    action["server_timing"]["prev_total_ms"] = prev_total_time * 1000
+
+                await websocket.send(msgpack.packb(action))
+                prev_total_time = time.monotonic() - start_time
+
+            except websockets.ConnectionClosed:
+                logger.info(f"Connection from {websocket.remote_address} closed")
+                break
+            except Exception as e:
+                logger.error(f"Error handling request: {e}")
+                await websocket.send(traceback.format_exc())
+                await websocket.close(
+                    code=websockets.frames.CloseCode.INTERNAL_ERROR,
+                    reason="Internal server error. Traceback included in previous frame.",
+                )
+                raise
+
+
+def _health_check(
+    connection: _server.ServerConnection, request: _server.Request
+) -> _server.Response | None:
+    if request.path == "/healthz":
+        return connection.respond(http.HTTPStatus.OK, "OK\n")
+    return None