google-auth-core

Single source of truth for the ~/.google credential store, shared by the Google CLIs (gmail-cli, google-calendar-cli) and the Google Workspace MCP servers (gmail-mcp, gcal-mcp, gsheets-mcp, gdocs-mcp, gdrive-mcp).

What it provides

• A unified per-account token store under ~/.google/tokens/google_<account>.json holding all scopes (Gmail + Calendar + Sheets + Docs + Drive), so one consent covers every service for both CLIs and MCP servers.
• Account management: default account, aliases (work, personal), env and directory overrides.
• get_service(api, version, account): an authorized googleapiclient service, cached per (account, api, version) for persistent, multi-account-safe use.
• A consistent error taxonomy (AuthError, NotFoundError, RateLimitError, InvalidArgumentError, UpstreamError) and map_http_error.

CLI

google-auth login [account]        # one-time OAuth, writes a unified token
google-auth list                   # accounts, default, aliases
google-auth alias work you@work.com
google-auth status                 # token health per account
google-auth default you@work.com
google-auth logout you@work.com

Place your OAuth client (Desktop app) at ~/.google/credentials.json first.