Smart Connections MCP Server

Smart Connections MCP Server

Exposes your Obsidian Smart Connections vector database to Claude Code via Model Context Protocol (MCP).

What This Does

Instead of using text-based Grep, Claude Code can now perform semantic search across your vault:

• semantic_search: Find notes by meaning, not keywords
• find_related: Get related notes (like Smart Connections sidebar)
• get_context_blocks: Get best context for RAG queries

Architecture

Smart Connections Plugin
    ↓ (creates)
.smart-env/multi/*.ajson
    ↓ (reads)
This MCP Server
    ↓ (exposes via)
MCP Protocol
    ↓ (consumed by)
Claude Code

Installation

Quick Install (Recommended)

cd ~/smart-connections-mcp
./install.sh

The script will:

• ✅ Install UV package manager (if needed)
• ✅ Create virtual environment
• ✅ Install all dependencies
• ✅ Auto-detect your Obsidian vault
• ✅ Configure ~/.mcp.json
• ✅ Verify installation

Manual Installation

1. Install UV

curl -LsSf https://astral.sh/uv/install.sh | sh

2. Create Virtual Environment and Install Dependencies

cd ~/smart-connections-mcp
uv venv
uv pip install -r requirements.txt

Important dependencies:

• mcp>=1.0.0 - Official Model Context Protocol SDK
• sentence-transformers>=2.2.0 - For semantic search
• numpy<2.0.0 - Version 1.x required (2.x breaks compatibility)
• torch>=2.0.0 and transformers>=4.30.0 - ML dependencies

3. Configure Claude Code

Add to ~/.mcp.json:

{
  "mcpServers": {
    "smart-connections": {
      "command": "/Users/YOUR_USERNAME/smart-connections-mcp/.venv/bin/python",
      "args": ["/Users/YOUR_USERNAME/smart-connections-mcp/server.py"],
      "env": {
        "OBSIDIAN_VAULT_PATH": "/path/to/your/obsidian/vault"
      }
    }
  }
}

Note: Use the virtual environment Python, not system Python!

4. Verify Installation

claude mcp list

Expected output:

smart-connections: .venv/bin/python server.py - ✓ Connected

Migration to New Machine

See DEPLOYMENT.md for detailed migration guide.

Quick migration:

# On new machine
git clone https://github.com/dan6684/smart-connections-mcp.git ~/smart-connections-mcp
cd ~/smart-connections-mcp
./install.sh

Important: Keep this MCP server in a separate repository from your Obsidian vault. See DEPLOYMENT.md for rationale and best practices.

Troubleshooting

If you see timeout issues, see TROUBLESHOOTING.md.

Usage Examples

Semantic Search

Old way (Grep):

Grep pattern: "self-compassion"
→ Only finds notes with exact word "self-compassion"

New way (Semantic Search):

semantic_search(query: "recognizing self-worth and releasing shame")
→ Finds: Ann Shulgin note ("I am a treasure")
        BM playa note ("I am beautiful, playa saved me")
        Therapy notes (related concepts)

Find Related Notes

Like Smart Connections sidebar:

find_related(file_path: "DailyNotes/2025-10-25.md")
→ Returns top 10 semantically similar notes

Get Context for RAG

Build context for complex queries:

get_context_blocks(query: "transformation through embodiment")
→ Returns actual text blocks most relevant to query
→ Claude can use these for grounded answers

How It Works

1. Reads existing embeddings from .smart-env/multi/*.ajson
2. No re-indexing needed - uses Smart Connections' work
3. Same model (BGE-micro-v2) for query encoding
4. Cosine similarity to rank results
5. Returns JSON with file paths, similarity scores, metadata

Tools Provided

semantic_search

semantic_search(
    query: str,           # Natural language query
    limit: int = 10,      # Max results
    min_similarity: float = 0.3  # Threshold
)

Returns:

{
  "query": "self-compassion",
  "results_count": 5,
  "results": [
    {
      "path": "DailyNotes/2025-08-29.md",
      "similarity": 0.87,
      "key": "smart_sources:DailyNotes/2025-08-29.md",
      "metadata": {"tags": ["#Dream", "#grateful"]}
    }
  ]
}

find_related

find_related(
    file_path: str,      # e.g., "DailyNotes/2025-10-25.md"
    limit: int = 10
)

get_context_blocks

get_context_blocks(
    query: str,
    max_blocks: int = 5
)

Returns actual text content (not just paths) for RAG.

Performance

• Initial load: ~2-3 seconds (loads 3,249 embeddings)
• Query time: ~100-200ms (cosine similarity across all embeddings)
• Memory: ~50MB (cached embeddings)

Troubleshooting

See TROUBLESHOOTING.md for detailed debugging guide.

Common Issues

Server Timeout on claude mcp list

Symptoms: Connection hangs, no response after 30+ seconds

Fixes:

1. Ensure using virtual environment Python (not system Python)
2. Verify NumPy version is <2.0.0: uv pip list | grep numpy
3. Check server starts manually:

   OBSIDIAN_VAULT_PATH="/path/to/vault" .venv/bin/python server.py
   

Import Errors

Error: ImportError: numpy.core.multiarray failed to import

Fix: Reinstall with NumPy 1.x:

uv pip install "numpy<2.0.0" --force-reinstall

No Results Returned

• Check .smart-env/multi/ has .ajson files
• Verify Smart Connections is enabled in Obsidian
• Lower min_similarity threshold (try 0.2 instead of 0.3)

Wrong Results

• Smart Connections may need to re-index
• Check embedding model matches (BGE-micro-v2)
• Restart server to reload embeddings

Development

Update embeddings:

• Smart Connections auto-updates .smart-env/
• MCP server reads on startup (restart to refresh)
• Future: Add file watcher for auto-reload

Add new tools:Edit handle_request() in server.py

License

MIT - Use freely for personal PKM workflows