Meridian MCP

Meridian MCP Server Skill

What It Is

A TypeScript MCP server (packages/meridian-mcp/) that exposes Meridian's structured session database to any MCP-compatible AI tool (Claude Code, Claude Desktop, Cursor, etc.).

It opens ~/.meridian/meridian.db read-only using sql.js (pure WebAssembly SQLite — no native Node.js modules, works with any Node.js version) and provides tools for querying app sessions, focus time, and activity history.

Build & Run

cd packages/meridian-mcp

# Install dependencies
npm install

# Build TypeScript → dist/
npm run build

# Start server (stdio transport)
node dist/index.js

Prerequisite: The Meridian daemon must be running and have produced at least one session. The MCP server returns an error message on tool calls (does not crash) if the DB is missing.

Available Tools

Configuration

# Override DB path (default: ~/.meridian/meridian.db)
MERIDIAN_DB=/path/to/custom.db node dist/index.js

Add to Claude Desktop / Claude Code

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "meridian": {
      "command": "node",
      "args": ["/path/to/meridian/packages/meridian-mcp/dist/index.js"]
    }
  }
}

Replace /path/to/meridian with the actual repo path.

Debugging

MCP server errors on startup

# Check if DB exists
ls -lh ~/.meridian/meridian.db

# Check if daemon is running
pgrep meridian

# Run daemon first, then start MCP server
./target/release/meridian &
node packages/meridian-mcp/dist/index.js

TypeScript build errors

cd packages/meridian-mcp
npx tsc --noEmit    # type-check without emitting
npm run build       # full build

Test a tool call manually

npx @modelcontextprotocol/inspector node dist/index.js

Development

# Watch mode (ts-node)
npm run dev

# Type check only
npx tsc --noEmit

# Add a new tool: edit src/index.ts
# 1. Add to the TOOLS array (name, description, inputSchema)
# 2. Add a case in the CallToolRequest handler
# 3. Rebuild: npm run build

File Structure

packages/meridian-mcp/
├── src/
│   └── index.ts          # All MCP logic (single file)
├── dist/                 # Compiled JS (committed)
├── package.json
└── tsconfig.json

Implementation Notes

• Uses sql.js (pure WASM) instead of better-sqlite3 (native) to avoid Node.js version mismatch errors across different environments (Claude Code, Claude Desktop, shell).
• The DB file is loaded into memory on each tool call so data is always fresh (daemon writes every 60s).
• The sql.js engine itself (_SQL) is cached across calls to avoid re-initialising the WASM runtime.
• audio_snippets is intentionally excluded from all MCP tool responses. Audio transcriptions from screenpipe are noisy and prone to hallucinations. They are still stored in app_sessions.audio_snippets and remain searchable via search-sessions (LIKE match on the column).