utils/startup_models.py

# utils/startup_models.py
from huggingface_hub import snapshot_download
from pathlib import Path
import os

# Where to put runtime files (works in Spaces; persists if you enable Persistent Storage)
RUNTIME_DIR = Path(os.environ.get("RUNTIME_DIR", "/home/user/app/runtime"))
MODELS_DIR = RUNTIME_DIR / "models"
MODELS_DIR.mkdir(parents=True, exist_ok=True)

def ensure_model(repo_id: str, pattern: str | None = None, local_name: str | None = None) -> str:
    dest = MODELS_DIR / (local_name or repo_id.replace("/", "_"))
    if dest.exists():
        return str(dest)
    snapshot_download(
        repo_id=repo_id,
        local_dir=str(dest),
        local_dir_use_symlinks=False,   # real copies; safer with persistent storage
        allow_patterns=pattern          # e.g. "*.gguf" or "*.onnx"
    )
    return str(dest)