Delx Memory MCP server

delx-memory

Local-first persistent memory MCP server. One shared SQLite store any MCP-speaking agent (Claude Desktop, Cursor, Hermes, OpenClaw, Codex) can read and write — so context survives across sessions AND across tools.

Why

Every chat client has its own ephemeral context. Quit the tab → preferences gone. Switch from Claude Desktop to Cursor → starting from scratch. Pin a side project in Hermes → invisible to the next agent.

delx-memory is a tiny MCP server that exposes a single shared SQLite file as a key/value memory layer. Any client that speaks MCP can read and write the same memory file → real continuity, real cross-tool context.

• 15 tools — discovery + handoff + batch ops + FTS5 search + mutations gated by intent.
• SQLite at ~/.delx-memory/db.sqlite (0700 dir, 0600 file).
• Secret-blocking: refuses to store credential-shaped keys or values.
• TTL support (lazy expiry on read).
• Tags + prefix filters + FTS5 full-text search (bm25 ranking, stemming, diacritic folding; LIKE fallback if FTS5 is unavailable).
• Mutations require explicituserintent: true so over-eager agents can't silently rewrite your context.
• Zero telemetry. Zero phone-home. The file is yours.

Multi-agent namespaces

# Agent A
DELX_MEMORY_NAMESPACE=claude npx -y delx-memory

# Agent B (same machine, isolated keys)
DELX_MEMORY_NAMESPACE=cursor npx -y delx-memory

Keys are stored as namespace::key. Omit the env var for a single global store (default).

Footprint / lightweight mode

• Default transport is lite: tools-only MCP over stdio without loading the MCP SDK (biggest RSS win for always-on agents).
• Full SDK surface (prompts + resources): delx-memory --sdk or DELXMEMORYTRANSPORT=sdk.
• Optional HTTP: delx-memory --http (Express + SDK; still loopback by default).
• DELXMEMORYLEAN=1 applies to the SDK path only (skip prompts/resources).
• doctor --json reports rss_kb. Dominant remaining cost is Node + native better-sqlite3 (no embeddings).

Community measurements (custom transport vs SDK) pointed at the SDK tree as the main overhead — see issue #7.

Install + run

# Run once (npx will download + boot)
npx -y delx-memory doctor

# Or install globally
npm install -g delx-memory
delx-memory doctor

The doctor command checks Node version, DB writability, and file permissions, then prints next steps.

HTTP (v2 stateless)

Default is stdio. Optional Streamable HTTP — no session id, JSON responses, loopback only:

npx -y delx-memory --http
# GET  http://127.0.0.1:3030/health
# POST http://127.0.0.1:3030/mcp   (sessionless)

Env: DELXMEMORYHOST, DELXMEMORYPORT, DELXMEMORYTRANSPORT=http.

Wire it into your MCP client

Claude Desktop

Add to ~/Library/Application Support/Claude/claudedesktopconfig.json (macOS):

{
  "mcpServers": {
    "delx-memory": {
      "command": "npx",
      "args": ["-y", "delx-memory"]
    }
  }
}

Then restart Claude Desktop. See examples/claude-desktop.json.

Cursor

Add to ~/.cursor/mcp.json. See examples/cursor.json.

Shortened. The full README is on GitHub.