Add server-side model download for remote web UI.

Expose POST /download_model so browser clients fetch models onto the host
instead of the user's laptop. Enabled by default via Comfy.ModelDownloadEnabled.

app/model_manager.py

@@ -3,6 +3,10 @@ import base64
 import json
 import time
 import logging
+import requests
+from tqdm.auto import tqdm
+from urllib.parse import unquote, urlparse
+from typing import Callable
 import folder_paths
 import glob
 import comfy.utils
@@ -13,8 +17,9 @@ from folder_paths import map_legacy, filter_files_extensions, filter_files_conte
 
 
 class ModelFileManager:
-    def __init__(self) -> None:
+    def __init__(self, is_download_model_enabled: Callable[[], bool] = lambda: True) -> None:
         self.cache: dict[str, tuple[list[dict], dict[str, float], float]] = {}
+        self.is_download_model_enabled = is_download_model_enabled
 
     def get_cache(self, key: str, default=None) -> tuple[list[dict], dict[str, float], float] | None:
         return self.cache.get(key, default)
@@ -47,6 +52,70 @@ class ModelFileManager:
             files = self.get_model_file_list(folder)
             return web.json_response(files)
 
+
+        @routes.post("/download_model")
+        async def post_download_model(request):
+            if not self.is_download_model_enabled():
+                logging.error("Download Model endpoint is disabled")
+                return web.Response(status=403)
+
+            json_data = await request.json()
+            url = json_data.get("url")
+            if not url:
+                return web.json_response({"error": "url required"}, status=400)
+
+            save_dir = json_data.get("save_dir")
+            if save_dir not in folder_paths.folder_names_and_paths:
+                return web.json_response({"error": "invalid save_dir"}, status=400)
+
+            default_filename = unquote(urlparse(url).path.split("/")[-1].split("?")[0])
+            filename = json_data.get("filename") or default_filename
+            if not filename or filename in (".", "..") or "/" in filename or "\\" in filename:
+                return web.json_response({"error": "invalid filename"}, status=400)
+
+            allowed_sources = (
+                "https://civitai.com/",
+                "https://civitai.red/",
+                "https://huggingface.co/",
+                "https://github.com/",
+                "http://localhost:",
+            )
+            if not any(url.startswith(src) for src in allowed_sources):
+                return web.json_response({"error": "url not allowed"}, status=400)
+
+            save_root = folder_paths.folder_names_and_paths[save_dir][0][0]
+            save_path = os.path.join(save_root, filename)
+            save_real = os.path.realpath(save_path)
+            root_real = os.path.realpath(save_root)
+            if not save_real.startswith(root_real + os.sep) and save_real != root_real:
+                return web.json_response({"error": "invalid path"}, status=400)
+
+            tmp_path = save_path + ".tmp"
+            token = json_data.get("token")
+            headers = {"Authorization": f"Bearer {token}"} if token else {}
+
+            try:
+                with requests.get(url, headers=headers, stream=True, timeout=60) as r:
+                    r.raise_for_status()
+                    total_size = int(r.headers.get("content-length", 0))
+                    os.makedirs(os.path.dirname(save_path), exist_ok=True)
+                    with open(tmp_path, "wb") as f:
+                        with tqdm(total=total_size, unit="iB", unit_scale=True, desc=filename) as pbar:
+                            for chunk in r.iter_content(chunk_size=1024 * 1024):
+                                if not chunk:
+                                    break
+                                size = f.write(chunk)
+                                pbar.update(size)
+                os.replace(tmp_path, save_path)
+                logging.info("Downloaded model to %s", save_path)
+                return web.json_response({"ok": True, "path": save_path, "save_dir": save_dir, "filename": filename})
+            except Exception as e:
+                logging.error("Failed to download model: %s", e)
+                if os.path.exists(tmp_path):
+                    os.remove(tmp_path)
+                return web.json_response({"error": str(e)}, status=500)
+
+
         @routes.get("/experiment/models/preview/{folder}/{path_index}/{filename:.*}")
         async def get_model_preview(request):
             folder_name = request.match_info.get("folder", None)

server.py

@@ -206,7 +206,21 @@ class PromptServer():
         PromptServer.instance = self
 
         self.user_manager = UserManager()
-        self.model_file_manager = ModelFileManager()
+        def _is_model_download_enabled():
+            settings_path = os.path.join(folder_paths.get_user_directory(), "default", "comfy.settings.json")
+            try:
+                if os.path.isfile(settings_path):
+                    with open(settings_path) as f:
+                        settings = json.load(f)
+                    return settings.get("Comfy.ModelDownloadEnabled", True)
+            except Exception:
+                pass
+            return True
+
+        self.model_file_manager = ModelFileManager(is_download_model_enabled=_is_model_download_enabled)
+            if hasattr(self.user_manager.settings, "get_settings")
+            else True
+        )
         self.custom_node_manager = CustomNodeManager()
         self.subgraph_manager = SubgraphManager()
         self.node_replace_manager = NodeReplaceManager()