Connector Googlemail

If you're building a Caffeine canister that sends email through a user's own Gmail account, this is the mandatory recipe. It enforces the googlemail-client and google-oauth mops packages (Gmail REST API plus OAuth 2.0 with PKCE) and forbids hand-rolled http_request calls to Google endpoints. The skill walks through per-user bearer tokens, on-chain token exchange and refresh, the required non-replicated outcall config, and a four-file backend layout that keeps Client ID/Secret admin-gated while storing access tokens keyed by caller Principal. One sharp edge: Google doesn't rotate refresh tokens, which simplifies persistence but means you hold long-lived credentials. Load this before you write any Gmail integration code.

Install to Claude Code

npx -y skills add caffeinelabs/skills --skill connector-googlemail --agent claude-code