2 posts tagged with "Gmail"

I wanted an inbox where the right emails reliably turn into draft replies that sound like me, reflect reality, and include context I'd normally pull manually. Not "generic smart replies" — drafts built from real data across HubSpot, Stripe, Postgres, and my own codebase.

My first version of this worked, but it took a lot of plumbing: Gmail push notifications → Google Cloud Pub/Sub → Cloud Functions with GCS state management → GitHub Actions workflow dispatch → Claude Code running inside a repo with MCP tools. Three failed attempts before the event pipeline was stable. Custom cursor tracking, lease coalescing, retry handling. It worked, but it was fragile infrastructure solving what should be a simple problem: read email, decide what to do, draft a reply.

So I rebuilt it on the MCPBundles agent system. The entire pipeline collapsed into two markdown files and a scheduled runner.

I’ve been really interested in making AI actually useful in email — not “generic smart replies,” but an inbox where the right messages reliably turn into drafts that sound like me, reflect reality, and include the context I’d pull manually if I had time.

The catch: the context I need rarely lives inside Gmail.

It lives in:

• HubSpot (who is this person, what’s the account history, are they VIP, what did we promise?)
• Stripe (are they a customer, what plan, what happened with billing?)
• Postgres (internal source of truth: flags, entitlements, state)
• This repo (docs, runbooks, decisions, roadmaps, patterns)

So I built an AI-active Gmail inbox: Gmail stays the event source, but the agent runs inside a GitHub repo with MCP tools that can pull real context and draft replies that are personalized, accurate, and safe.

I did this without relying on Google’s AI. Gmail is plumbing (labels + push notifications). The intelligence and guardrails are mine.

Three non-negotiable constraints guided the build:

• No polling: I want push-driven events, not a cron job hammering APIs.
• No auto-send: drafts only; I approve every message.
• No inbox-only context: the agent must be able to query the systems that actually matter.

What I wanted was a workflow where Claude Code runs inside a GitHub repo (so it can read everything I’ve written and shipped), connects to MCP tools (so it can pull live customer context), drafts a reply in Gmail, and then pings me for approval. No surprises. No polling. No hallucinated promises.

We actually looked at building this with our Fastmail MCP first. I love Fastmail, but their API didn't give us a clean event trigger we could hook into without polling constantly. I hate polling. It feels messy and wasteful.

Gmail, however, has a push notification system that talks to Google Cloud Pub/Sub. That’s the hook.

Here's the war story of how I built a real-time, event-driven pipeline that turns "new important email" into "draft reply ready," with real context + personalization — and the mistakes I had to fix along the way.