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Building a Second Brain with Claude, Obsidian, and Cloudflare

*April 12, 2026 · 8 min read*

What if your AI never forgot a conversation? What if every insight, every connection, every pattern you've ever noticed was available to Claude the moment you needed it?

That's what MindWiki does. And this is the story of how it came to be.

The Problem With AI Memory

I use Claude every day. For coding, for thinking, for writing. But every conversation starts from zero. I explain the same context over and over. My best thinking — the connections I've drawn between physics and product design, the patterns I've noticed across domains — all of it evaporates between sessions.

Meanwhile, I have notes scattered across five different apps. Some in Obsidian, some in Apple Notes, some in email threads I'll never find again. My knowledge doesn't compound. It just... accumulates.

The Obsidian Foundation

Obsidian got the hard part right: local markdown files with wikilinks. No vendor lock-in, no proprietary format, no cloud dependency. Your notes are just text files on your computer.

But Obsidian is a tool for manual knowledge management. You have to decide where things go, what links to what, and how it all connects. That's exactly the kind of work AI should be doing.

Enter MCP

The Model Context Protocol changed everything. MCP lets AI assistants connect to external tools and data — which means Claude can directly search, read, and write to a structured knowledge base.

I built a Brain MCP Server on Cloudflare that indexes an Obsidian vault using D1 (SQL database) and Vectorize (semantic search). Claude can now search my vault with natural language, read specific pages for context, and even write new captures.

The AI Agent Layer

The real magic is in the agents — autonomous AI workflows that run on a schedule:

  • Weekly Classifier: Takes raw captures from my inbox and files them into the right folder with proper frontmatter
  • Auto-Linker: Scans every page for concept mentions that should be wikilinks and adds them
  • Pattern Detector: The most powerful one — reads the entire vault monthly and finds structural isomorphisms across domains

What It Looks Like in Practice

Last month, the pattern detector found something I'd never noticed: the same feedback loop dynamic appeared in my notes about complex systems (physics), habit formation (psychology), and viral growth (business). It created a pattern page called "Feedback Loops" that mapped the abstract structure and linked to every relevant page.

Now when I ask Claude about feedback dynamics in any domain, it pulls from that pattern page and every connected note. My AI doesn't just remember — it sees connections I missed.

The Stack

Everything runs on Cloudflare's free tier:

  • Obsidian — local markdown vault
  • Cloudflare R2 — vault sync to the cloud
  • Brain MCP Server — D1 + Vectorize for indexing and search
  • Cloudflare Workers — AI agents on cron schedules

Total cost: effectively zero, beyond my existing Claude subscription.

What's Next

We're turning this into a product. MindWiki will be a macOS app that wraps the vault management, sync, and agent configuration into a beautiful interface. The waitlist is open at mindwiki.io.

Your AI should remember everything you've ever thought. That's not science fiction — it's just good infrastructure.

*Sign up for early access at mindwiki.io.*