Main Data Layer

This directory contains the main process data management implementation.

Documentation

• Overview: docs/references/data/README.md
• DataApi in Main: data-api-in-main.md
• Database Patterns: database-patterns.md

Directory Structure

src/main/data/
├── api/                       # Data API framework
│   ├── core/                  # ApiServer, MiddlewareEngine, adapters
│   └── handlers/              # API endpoint implementations
├── services/                  # Business logic layer (see services/README.md)
│   └── utils/                 # Row → Entity mapping utilities (see utils/README.md)
├── db/                        # Database layer
│   ├── schemas/               # Drizzle table definitions
│   ├── seeding/               # Database initialization
│   └── DbService.ts           # Database connection management
├── migration/                 # Data migration system
├── CacheService.ts            # Cache management
├── DataApiService.ts          # API coordination
├── PreferenceService.ts       # User preferences
└── dataApiDataChange.ts       # DataApi data change notification (post-commit broadcast)

Data Change Notification

notifyDataApiDataChange(effects) is the single publish point for cross-window data convergence: after a business write successfully commits, the owning data service states which read models changed (DataApiDataChangeEffect[]), and the signal is broadcast to all windows. This is a strictly fenced exception to the "no side effects in data services" rule — see Fenced Exception: Data Change Notification for the fences, and the notifier's own doc comment for publish invariants (post-commit timing, *Tx() never notifies, no-op writes may skip) and the delivery contract.

It deliberately lives at the data/ top level, NOT in api/ — api/ is the portable transport framework (HttpAdapter reserved), while this capability is an Electron/IPC special case depending on WindowManager.

Quick Reference

Adding New API Endpoints

1. Define schema in @shared/data/api/schemas/
2. Implement handler in api/handlers/
3. Create business service in services/
4. Create repository in repositories/ (if complex domain)

Database Commands

# Generate migrations
yarn db:migrations:generate