docs(pretrained): add usage guide for dp pretrained

- document dp pretrained download command and alias usage\n- include model/pretrained.md in docs index\n- keep CLI path output and add log message for visibility\n- clarify pretrained backend is an internal virtual alias backend\n\nAuthored by OpenClaw (model: custom-chat-jinzhezeng-group/gpt-5.3-codex)

Author: OpenClaw

deepmd/backend/pretrained.py

@@ -26,7 +26,12 @@
 
 @Backend.register("pretrained")
 class PretrainedBackend(Backend):
-    """Backend for ``*.pretrained`` model aliases."""
+    """Internal virtual backend for ``*.pretrained`` alias dispatch.
+
+    This backend is not intended to be selected explicitly by users as a real
+    compute backend (such as TensorFlow/PyTorch/Paddle/JAX). It only bridges
+    ``*.pretrained`` aliases into the regular deep-eval loading path.
+    """
 
     name = "Pretrained"
     features: ClassVar[Backend.Feature] = Backend.Feature.DEEP_EVAL

deepmd/pretrained/entrypoints.py

@@ -5,6 +5,7 @@
     annotations,
 )
 
+import logging
 from pathlib import (
     Path,
 )
@@ -25,6 +26,7 @@ def pretrained_entrypoint(args: argparse.Namespace) -> None:
     if args.pretrained_command == "download":
         cache_dir = Path(args.cache_dir) if args.cache_dir else None
         path = download_model(args.MODEL, cache_dir=cache_dir)
+        logging.getLogger(__name__).info("Pretrained model path: %s", path)
         print(path)  # noqa: T201
         return
 

doc/model/index.rst

@@ -29,3 +29,4 @@ Model
    change-bias
    precision
    show-model-info
+   pretrained

doc/model/pretrained.md

@@ -0,0 +1,48 @@
+# Use `dp pretrained` to download built-in models
+
+The `dp pretrained` command provides a simple way to download built-in pre-trained models and store them in a local cache.
+
+## Command syntax
+
+```bash
+dp pretrained download <MODEL> [--cache-dir <PATH>]
+```
+
+- `<MODEL>`: the built-in model name.
+- `--cache-dir <PATH>`: optional cache directory. If omitted, DeePMD-kit uses the default cache path.
+
+## Available built-in models
+
+You can run `dp pretrained download -h` to see the currently supported model list in your installed version.
+
+Examples in this release include:
+
+- `DPA-3.2-5M`
+- `DPA-3.1-3M`
+
+## Examples
+
+```bash
+# Download to default cache directory
+dp pretrained download DPA-3.2-5M
+
+# Download to a custom cache directory
+dp pretrained download DPA-3.2-5M --cache-dir ./models
+```
+
+The command prints the local path of the downloaded model file on success.
+
+## Use downloaded models via alias
+
+After downloading, you can use the `.pretrained` alias directly in DeepEval/DeepPot workflows.
+
+For example:
+
+```python
+from deepmd.infer import DeepPot
+
+# DeePMD-kit resolves this alias to the corresponding local model file
+pot = DeepPot("DPA-3.2-5M.pretrained")
+```
+
+The `.pretrained` alias is designed for user-facing model selection, while backend details are handled internally.