Self-Hosted Memory Layer for Claude Runs Free on Cloudflare

A Reddit user built second-brain-cloudflare, an open-source MCP server that adds persistent memory to Claude. It runs entirely on Cloudflare's free tier using Workers, D1 (SQLite), Vectorize, and Workers AI.

Key Features

• Four MCP tools: remember, recall, list_recent, forget.
• Semantic search via recall: notes are vector-embedded using bge-small-en-v1.5 model via Workers AI and stored in Cloudflare Vectorize. Searches match by meaning, not keywords.
• Works with Claude Desktop, Claude Code, and claude.ai (via custom connectors).

How It Works

You add instructions to Claude's system prompt. The server is deployed via one-click deploy button on the repo. Context: remember stores a note, recall searches semantic embeddings, list_recent shows recent notes, forget deletes a note. The stack: TypeScript, Cloudflare Workers + D1 + Vectorize + Workers AI.

Tradeoffs and Implementation Details

The author notes that semantic search has tradeoffs — embedding quality, latency, and cost are discussed in the Reddit thread. The free tier handles personal use without issue.