notebooklm-py-cookies-rejected-by-upstream-client-fingerprint

Migrating cookies from notebooklm-py’s storage_state.json to upstream notebooklm-mcp-cli profile format succeeds at the file level, but Google rejects the session when the upstream client attempts CSRF token refresh. The upstream uses different HTTP headers and user-agent fingerprint than notebooklm-py, causing Google to invalidate the session. Fresh auth via nlm login (interactive browser CDP) or save_auth_tokens MCP tool is required — cookie migration alone is insufficient.