mnemo-secondbrain 0.2.0

Personal knowledge graph system for Obsidian vaults with hybrid search

Mnemo — Personal Knowledge Graph for Obsidian

Turn your Obsidian vault into a queryable knowledge graph with hybrid search (vector + graph traversal).

Features

• Automatic Graph Building — Parses [[wikilinks]], YAML frontmatter, and tags from your Obsidian vault into a NetworkX knowledge graph
• Hybrid Search — Combines vector similarity search with graph-based multi-hop traversal
• Ontology Classification — Auto-classifies entities (Person, Concept, Project, Tool, Insight, etc.)
• Knowledge Collectors — Web clipping, trust evaluation, and automated knowledge pipeline
• REST API — FastAPI server for programmatic access
• Obsidian Plugin — Companion plugin for in-vault queries (see obsidian-plugin/)
• CLI Interface — Full-featured command-line tool for graph operations

Quick Start

Installation

# Core (graph + CLI)
pip install mnemo-secondbrain

# With API server
pip install mnemo-secondbrain[api]

# With sentence-transformers embeddings
pip install mnemo-secondbrain[sbert]

# Everything
pip install mnemo-secondbrain[all]

Configuration

Create a config.yaml (see config.example.yaml):

vault_path: ~/Documents/MyVault
embedding:
  provider: sbert          # or "openai", "ollama"
  model: all-MiniLM-L6-v2

Or use environment variables:

Variable	Description	Example
MNEMO_VAULT_PATH	Path to your Obsidian vault	~/Documents/MyVault
OPENAI_API_KEY	OpenAI API key (if using OpenAI embeddings)	sk-...

CLI Usage

# Build the knowledge graph from your vault
mnemo build

# Search your knowledge graph
mnemo search "machine learning fundamentals"

# Show graph statistics
mnemo stats

# Export graph
mnemo export --format graphml

API Server

# Start the API server (requires mnemo-secondbrain[api])
mnemo serve --host 0.0.0.0 --port 8000

Endpoints:

Method	Path	Description
GET	/api/search	Hybrid search
GET	/api/graph/stats	Graph statistics
GET	/api/graph/node/{id}	Get node details
GET	/api/graph/neighbors/{id}	Get node neighbors

Obsidian Plugin

The companion Obsidian plugin lives in obsidian-plugin/. See its README for installation instructions. It connects to the Mnemo API server for in-vault search and graph visualization.

Architecture

Obsidian Vault (Markdown + YAML + [[links]])
        ↓  parse
   NetworkX Graph (in-memory)
        ↓  embed
   Vector Index + Graph Index
        ↓  query
   Hybrid Search (vector + graph traversal)
        ↓  rerank
   Results with context

Development

git clone https://github.com/jini92/MAISECONDBRAIN.git
cd MAISECONDBRAIN
pip install -e ".[dev,all]"
pytest

License

MIT — see LICENSE.