Lake of Vectors

Local semantic search over your personal knowledge bases. Index Obsidian notes, SQLite databases, plaintext, and Notion/Confluence (not supported yet) files into ChromaDB, exposed to Claude via an MCP server.

Features

• Multiple Publishers: Crawl Markdown directories, SQLite tables, and plaintext files
• Semantic Search: Find relevant content by meaning, not just keywords
• Local Vectors: Runs entirely on your machine with sentence-transformers
• OpenAI Support: Optional OpenAI embeddings if preferred
• MCP Server: Integrates directly with Claude Code for seamless querying

Installation

uv pip install -e .

Configuration

Copy the example config and adjust paths for your sources:

mkdir -p ~/.config/lake-of-vectors
cp config.example.yaml ~/.config/lake-of-vectors/config.yaml

Edit ~/.config/lake-of-vectors/config.yaml:

sources:
  - type: markdown
    name: my-notes
    path: ~/obsidian-vault/Notes/

  - type: sqlite
    name: knowledge-db
    path: ~/knowledge.db
    table: notes
    content_column: body
    metadata_columns: [title, tags]

  - type: plaintext
    name: misc-notes
    path: ~/notes/

embedding:
  backend: local
  model: all-MiniLM-L6-v2

Source Types

Type	Description
markdown	Recursive crawl of .md files in a directory
sqlite	Query a SQLite table with content and metadata columns
plaintext	Recursive crawl of .txt files in a directory

Embedding Backends

• Local (default): Uses all-MiniLM-L6-v2 via sentence-transformers. No API key needed.
• OpenAI: Uses text-embedding-3-small or another OpenAI model. Requires api_key in config.

embedding:
  backend: openai
  model: text-embedding-3-small
  api_key: sk-...

Usage

Sync your sources

lake sync                 # Sync all sources
lake sync --source my-notes    # Sync only one source
lake sync --rebuild      # Delete and re-embed everything

Check status

lake status

Start the MCP server

lake serve

Claude Code Integration

Register as a global MCP server using the Claude Code CLI:

claude mcp add -s user lake-of-vectors $(pwd)/.venv/bin/lake serve

The -s user scope makes it available in all sessions. Restart Claude Code after running.

Qwen Code Integration

Register as a global MCP server using the Qwen Code CLI:

qwen mcp add -s user lake-of-vectors $(pwd)/.venv/bin/lake serve

The -s user scope makes it available in all sessions. Restart Qwen Code after running.

To scope it to a single project instead, add a .mcp.json file in the project root:

{
  "mcpServers": {
    "lake-of-vectors": {
      "command": "lake",
      "args": ["serve"]
    }
  }
}

Add to your CLAUDE.md:

When answering security questions or searching your personal knowledge, always use lake-of-vectors semantic_search first.

CLI Commands

Command	Description
lake sync	Sync all configured sources into ChromaDB
lake sync --source <name>	Sync a specific source
lake sync --rebuild	Delete all vectors and re-sync everything
lake prune	Remove stale collections not in current config
lake prune --dry-run	Preview what would be pruned without deleting
lake serve	Start the MCP server (stdio mode)
lake status	Show sync status for all sources

Data

ChromaDB vectors are stored at:

~/.local/share/lake-of-vectors/chromadb

Architecture

  ┌──────────────────────────────────────────────────────────────────┐
  │                      lake-of-vectors                             │                                                                   
  │                                                                  │
  │  ┌─────────────┐   ┌──────────────────┐   ┌──────────────────┐   │                                                                    
  │  │  Publishers │──▶│   Sync Engine    │──▶│    ChromaDB      │   │                                                                    
  │  │             │   │                  │   │    (on-disk)     │   │                                                                    
  │  │ • Markdown  │   │ • Chunking       │   │                  │   │                                                                    
  │  │ • SQLite    │   │ • Content hash   │   │ one collection   │   │                                                                    
  │  │ • Plaintext │   │   diffing        │   │ per source       │   │                                                                    
  │  └─────────────┘   │ • Embedding      │   └────────┬─────────┘   │                                                                    
  │                    │ • ChromaDB upsert│            │             │                                                                    
  │                    └──────────────────┘            │             │                                                                    
  │                                                    │             │                                                                  
  │  ┌─────────────────────┐   ┌──────────────────┐    │             │                                                                     
  │  │  Embedding Backends │   │   MCP Server     │◀───┘             │                                                                     
  │  │                     │   │   (stdio)        │                  │                                                                     
  │  │ • Local             │   │                  │                  │                                                                     
  │  │   (sentence-        │   │ • semantic_search│                  │                                                                     
  │  │    transformers)    │   │ • list_sources   │                  │                                                                   
  │  │ • OpenAI API        │   └──────────────────┘                  │                                                                     
  │  └─────────────────────┘                                         │                                                                  
  │                                                                  │                                                                   
  │  CLI: lake sync | lake serve | lake prune | lake status          │                                                                 
  └──────────────────────────────────────────────────────────────────┘  

License

MIT