Second Brain — iMessage Agent

An iMessage agent that captures your raw thoughts throughout the day, connects the dots you missed, and pushes you to think deeper.

"I text my half-baked thoughts and my agent connects the dots I missed."

Built with Photon iMessage Kit + Claude or Gemini API.

Why

• You're watching a video fullscreen and have a thought — grab your phone, text it. No app switching.
• AI is making us lazy thinkers. This agent fights back — it asks you hard questions instead of giving you easy answers.
• Over time it builds a map of YOUR thinking patterns, contradictions, and blind spots.

How It Works

1. Text any thought to the agent
2. It saves the thought, finds connections to your previous ideas, and asks a provocative follow-up
3. Text digest to get a weekly summary of your thinking patterns
4. Text search <topic> to find related past thoughts
5. Text stats to see your thought count and top themes

Setup

Requirements: macOS, Bun, Gemini or Anthropic API key

# Install Bun (if not installed)
curl -fsSL https://bun.sh/install | bash

# Clone and install
git clone https://github.com/ngjupeng/second-brain-agent
cd second-brain-agent
bun install

# Configure
cp .env.example .env
# Edit .env with your API key and phone number

# Grant Full Disk Access
# System Settings → Privacy & Security → Full Disk Access → Add your terminal app

# Run
bun run start

Then text yourself from another device (or ask a friend to text you) and the agent replies.

Commands

Text	Action
Any text	Captures thought, finds connections, asks follow-up
digest	Weekly summary of your thinking patterns
search payments	Find past thoughts about payments
stats	Total thoughts, this week count, top themes

Architecture

Phone (iMessage) → macOS iMessage DB → Watcher (polls every 2s)
    → LLM (Claude or Gemini — processes thought, finds connections)
    → brain.json (persistent storage)
    → iMessage reply back to you