Architecture - Linksee Memory

Overview

Linksee Memory is a single-process Node.js MCP server using SQLite (via better-sqlite3) with WAL mode for concurrent read access.

Database tables

Core tables

Table	Purpose
`entities`	People, companies, projects, concepts, files with normalized dedup and momentum cache
`memories`	6-layer structured memories with importance, protected flag, thread_id, and 3 virtual generated columns
`memories_fts`	FTS5 virtual table with trigram tokenizer for full-text search (supports CJK)

Relationship tables

Table	Purpose
`memory_edges`	Directed relationships between memories (supersedes, resolves, implements, contradicts, extends)
`edges`	Entity-to-entity graph relationships

File tracking

Table	Purpose
`file_snapshots`	Diff cache for `read_smart` — per-file content snapshots with chunk hashes
`file_facts`	Extracted facts per file chunk
`sessions`	Agent/conversation tracking
`session_file_edits`	Conversation-to-file linkage with `context_snippet`

Lifecycle

Table	Purpose
`events`	Time-series log driving momentum calculation
`consolidations`	Audit trail of what got compressed into what
`meta`	Schema version tracking (currently v7)

Virtual generated columns

The memories table has 3 virtual columns auto-extracted from structured JSON content:

altitude  TEXT GENERATED ALWAYS AS (json_extract(content, '$.altitude'))
mem_type  TEXT GENERATED ALWAYS AS (json_extract(content, '$.type'))
mem_state TEXT GENERATED ALWAYS AS (json_extract(content, '$.state'))

These enable SQL-level filtering without parsing JSON at query time.

FTS5 configuration

CREATE VIRTUAL TABLE memories_fts USING fts5(
  content,
  content=memories,
  content_rowid=id,
  tokenize='trigram'
);

The trigram tokenizer handles both English and Japanese text without language-specific stemming.

SQLite pragmas

PRAGMA journal_mode = WAL;
PRAGMA foreign_keys = ON;

WAL mode allows concurrent reads from multiple MCP clients while maintaining write safety.

​Overview

​Database tables

​Core tables

​Relationship tables

​File tracking

​Lifecycle

​Virtual generated columns

​FTS5 configuration

​SQLite pragmas