How to build a secure WhatsApp AI assistant with Arcade and Claude Code (OpenClaw alternative)

I texted "prep me for my 2pm" on WhatsApp. Thirty seconds later, my phone buzzed back with a structured briefing: who I was meeting, what we last discussed over email, what my team said about them in Slack, and three talking points. No browser tab. No laptop. Just a message on my commute. That's the promise of an always-on AI assistant. And until recently, it was almost impossible to build one that actually worked. Open-source frameworks like OpenClaw made headless, two-way messaging agents popular. Anthropic's Claude Code Channels confirmed the approach had legs. Channels is currently in research preview, but the direction is clear. Anthropic already uses this pattern for hand-offs between their desktop app, mobile app, and Claude Code. Expect this to GA in some form. But getting from a weekend demo to a reliable assistant exposes gaps that no amount of prompt engineering fixes. Authorization. Tool reliability. Session management. The agent needs access to your calendar, email, and Sl