Database

Database

Mingly uses sql.js (SQLite compiled to WebAssembly) for data persistence. This means no native modules, no compilation — it works identically on macOS and Windows.

Storage Location

Mode	Location
Standalone (Electron)	{userData}/mingly.db (OS-specific app data folder)
Server (Node.js)	{MINGLY_DATA_DIR}/mingly.db (default: ./data/)

Schema

Core Tables (Migration 1)

conversations

Column	Type	Description
id	TEXT PK	UUID
title	TEXT	Conversation title
provider	TEXT	LLM provider (anthropic, openai, etc.)
model	TEXT	Model name
created_at	DATETIME	Creation timestamp
updated_at	DATETIME	Last update timestamp

messages

Column	Type	Description
id	TEXT PK	UUID
conversation_id	TEXT FK	References conversations.id
role	TEXT	user, assistant, system
content	TEXT	Message content
tokens	INTEGER	Token count
created_at	DATETIME	Timestamp

Index: idx_messages_conversation on (conversation_id, created_at)

settings

Column	Type	Description
key	TEXT PK	Setting name
value	TEXT	JSON-encoded value

Analytics Tables (Migration 2)

tracking_events

Column	Type	Description
id	INTEGER PK	Auto-increment
conversation_id	TEXT	References conversations.id
provider	TEXT	LLM provider
model	TEXT	Model name
input_tokens	INTEGER	Tokens sent
output_tokens	INTEGER	Tokens received
cost	REAL	Estimated cost (USD)
latency_ms	INTEGER	Response time
success	INTEGER	1 = success, 0 = failure
error_message	TEXT	Error details (if failed)
rag_sources	TEXT	JSON array of RAG source paths
created_at	DATETIME	Event timestamp

Indexes on: created_at, conversation_id, provider

Migration System

Migrations are tracked via a _meta table:

CREATE TABLE IF NOT EXISTS _meta (
  key TEXT PRIMARY KEY,
  value TEXT
);

The current migration version is stored under key schema_version. New migrations run automatically on startup when the stored version is behind the code version.

Write Strategy

• Debounced saves: Database changes are buffered and written to disk every 100ms (configurable). This prevents excessive I/O during rapid operations like streaming token counts.
• Auto-save on close: closeDatabase() forces a final persist before shutdown.
• Foreign keys enabled: PRAGMA foreign_keys = ON
• Parameter binding: All queries use prepared statements to prevent SQL injection.

Key Functions

Function	Purpose
initializeDatabase(dataDir?)	Load or create database, run migrations
getDatabase()	Get active instance (throws if not initialized)
dbRun(sql, params)	Execute SQL + auto-schedule save
dbAll(sql, params)	Query all matching rows
dbGet(sql, params)	Query first matching row
closeDatabase()	Persist and cleanup
scheduleSave()	Debounce disk write

Data Export

Users can export all their data via Settings > GDPR > Export. This produces a JSON file containing conversations, messages, settings, and tracking events.

Data Deletion

Full data deletion (Settings > GDPR > Delete) removes all records and resets the database to a clean state. This is irreversible.

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