memory-mcp

Persistent knowledge graph MCP server with SQLite backend. Drop-in replacement for the off-the-shelf mcp-server-memory (npm) — same tool signatures, but with graph traversal, fuzzy search, temporal queries, and timestamps.

Part of the Palimpsest intelligence fusion toolkit.

Why

The npm mcp-server-memory stores everything in a flat JSONL file. Every operation reads the entire file into memory. No timestamps, no graph queries, keyword-only search.

This replaces it with SQLite (WAL mode) while maintaining JSONL export compatibility. Adds:

• Graph traversal — traverse("shen-meta", depth=2) finds 46 connected nodes across 112 relations
• Fuzzy search — trigram similarity for entity names (no more exact-case matching)
• Temporal queries — recent(hours=24) shows everything added or modified
• Timestamps — every entity, observation, and relation has created_at/updated_at
• Case-insensitive search — search_nodes("project") matches ProjectX

Tools

CRUD (backward compatible)

• create_entities, create_relations, add_observations
• delete_entities, delete_observations, delete_relations
• search_nodes, open_nodes, read_graph

New

• traverse(start_node, depth) — graph walk from a node, returns all entities within N hops
• recent(hours) — entities/relations created or updated in the last N hours
• search_similar(name, threshold) — trigram fuzzy matching for entity names

Usage

pip install -e .

Reads from MEMORY_FILE_PATH (default: ~/.vibe/memory.jsonl). Stores in SQLite at MEMORY_DB_PATH (default: ~/.vibe/memory.db). On first run, auto-migrates existing JSONL into SQLite. All writes go to both stores.