MCP server gates on the obsolete flat storage path → AUTH_REQUIRED on every call (notebooklm-py moved to the profiles/ layout)

[Grisemine]

Thanks for this skill + MCP server. Reporting a root cause (with a one-line fix) for AUTH_REQUIRED errors that now happen on every tool call.

Summary

Every MCP tool call — including read-only nlm_list — returns [AUTH_REQUIRED], even though the Google session is valid (notebooklm doctor passes). The cause is a pre-flight check on a hardcoded flat storage path that current notebooklm-py no longer uses and actively deletes.

Root cause

• mcp_server/tools.py:2 — the server is written against notebooklm-py v0.3.4, but uvx resolves a current notebooklm-py (0.7.0 here) at runtime.
• mcp_server/tools.py:19 — _STORAGE_PATH = ~/.notebooklm/storage_state.json (flat).
• mcp_server/tools.py:48 — _get_client() raises AUTH_REQUIRED if that flat file is missing, before every tool call.
• Since notebooklm-py ≥ 0.4.0, the canonical auth location moved to ~/.notebooklm/profiles/<profile>/storage_state.json. Its migration (notebooklm/migration.py, ensure_profiles_dir() → migrate_to_profiles()) treats a flat file at the root as legacy and removes it on every CLI run. So the flat path the gate checks no longer persists.

Proof the gate is the only blocker

With no flat file present at all, the very call the server makes one line later succeeds:

# ~/.notebooklm/storage_state.json does NOT exist
async with await NotebookLMClient.from_storage() as c:
    ...  # authenticates fine via profiles/default/

from_storage() already resolves the current layout. The pre-flight _STORAGE_PATH.exists() check is therefore both redundant and wrong.

Impact

As soon as any notebooklm CLI command runs (which deletes the flat file), every MCP tool fails with AUTH_REQUIRED, despite valid auth. The MCP server is effectively unusable alongside a current notebooklm-py.

Suggested fix

Drop the redundant pre-flight gate and let from_storage() be the single source of truth (it already resolves profiles/ and honors NOTEBOOKLM_AUTH_JSON). The existing except block at tools.py:53-57 already turns auth failures into the friendly message, so nothing is lost:

async def _get_client():
    try:
        async with await NotebookLMClient.from_storage() as client:
            yield client
    except Exception as exc:
        msg = str(exc).lower()
        if any(k in msg for k in ("auth", "login", "credential", "session", "storage")):
            raise RuntimeError(_AUTH_ERROR_MESSAGE) from exc
        raise

(Alternatively, resolve the path through notebooklm-py's own path API rather than hardcoding the flat path.) Either way, _AUTH_ERROR_MESSAGE should stop pointing at ~/.notebooklm/storage_state.json, since that file no longer exists by design.

Environment

• notebooklm-skill 1.2.1 (MCP server)
• notebooklm-py 0.7.0 (resolved at runtime via uvx)
• Python 3.13, Linux

Happy to open a PR if useful. Thanks!