The Second Brain Concept

Tiago Forte coined “Second Brain” — using external tools to extend human memory and thinking. Obsidian is the note layer; adding AI creates the interaction layer.

Tech Stack

  • Note Layer: Obsidian (local Markdown)
  • Vectorization: Script to convert notes to embeddings
  • Retrieval Layer: Semantic search for relevant notes
  • Generation Layer: LLM generates answers based on retrieval results

Key Challenges

Notes need re-indexing after updates. Privacy-sensitive data shouldn’t be uploaded to cloud LLMs — local deployment is preferred.

This is essentially a personal application of RAG Retrieval-Augmented Generation in Practice, with knowledge management methods from AI Knowledge Management with Obsidian, and interaction patterns inspired by Agent Design Patterns.