The symlink deletion part looks good. Using unlink() instead of rmtree() for symlinks is the right call.

The resolve() → absolute() change has a security issue though. absolute() doesn't normalize .., so path traversal passes through:

Path("/models/../../etc").absolute().is_relative_to(Path("/models").absolute())
# True (bad)

Path("/models/../../etc").resolve().is_relative_to(Path("/models").resolve())
# False (safe)

Instead of replacing resolve(), handle symlinks separately in the validation:

if model_path.is_symlink():
    link_parent = model_path.parent.resolve()
    if not link_parent.is_relative_to(parent_model_dir.resolve()):
        raise HTTPException(status_code=400, detail="Invalid model name")
else:
    if not model_path.resolve().is_relative_to(parent_model_dir.resolve()):
        raise HTTPException(status_code=400, detail="Invalid model name")

This validates the link's location without following it, while keeping .. protection.

The is_dir()/is_symlink() check and the unlink() deletion branch are fine as-is. Could you update just the path validation? A test for symlink deletion would also be nice.

Hey, thanks for working on this. The symlink deletion logic (unlink() vs rmtree() branching) looks correct.

The main issue is that the path traversal validation on line 3051 still uses resolve():

if not model_path.resolve().is_relative_to(parent_model_dir.resolve()):
    raise HTTPException(status_code=400, detail="Invalid model name")

Since resolve() follows symlinks, this check rejects symlinked models before the code ever reaches the is_symlink() check or the unlink() deletion path. The bug from #646 is still reproducible as-is.

The fix I suggested in the previous review (handling symlinks separately in validation) would solve this:

if model_path.is_symlink():
    link_parent = model_path.parent.resolve()
    if not link_parent.is_relative_to(parent_model_dir.resolve()):
        raise HTTPException(status_code=400, detail="Invalid model name")
else:
    if not model_path.resolve().is_relative_to(parent_model_dir.resolve()):
        raise HTTPException(status_code=400, detail="Invalid model name")

Also the PR description mentions using absolute() instead of resolve() but the diff doesn't include that change. Might want to update the description to match.

A test for symlink deletion would be great too.