My Mastra Agent Found a Production Bug in Five Minutes

I saw a tweet about Sentry shipping an AI agent that watches your error logs and auto-suggests fixes. I thought: I can build that. So I did — from my phone, on a Friday afternoon, while walking around the house. I stood up a Mastra workflow via Telegram, pointed it at my three Cloudflare Workers sites, and ran it. Within five minutes it flagged scriptThrewException errors on all three sites. Bots were hitting my media proxy endpoint, the Worker was crashing on every request, and my uptime monitor had been saying everything was fine for days. The whole thing — Mastra for the workflow engine, Cloudflare's GraphQL Analytics API for the data, a Telegram bot for alerts — runs locally on my Mac, costs nothing, and took about two hours to build. The same afternoon I pushed a blog post from a mountain via Telegram. Here's how it works and what it found. Why "Is It Up?" Isn't Enough I already had an uptime monitor running as a GitHub Action every 30 minutes. It hits each site, checks for a 200