gridpilot.gg/docs/architecture/core/CORE_DATA_FLOW.md

Core Data Flow (Strict)

This document defines the Core data flow rules and boundaries.

Core scope:

• core/**

Core does not know:

• HTTP
• Next.js
• databases
• DTOs
• UI models

1) Layers inside Core

Core contains two inner layers:

• Domain
• Application

1.1 Domain

Domain is business truth.

Allowed:

• Entities
• Value Objects
• Domain Services

Forbidden:

• DTOs
• frameworks
• IO

See docs/architecture/core/DOMAIN_OBJECTS.md.

1.2 Application

Application coordinates business intents.

Allowed:

• Use Cases (commands and queries)
• Application-level ports (repository ports, gateways)

Forbidden:

• HTTP
• persistence implementations
• frontend models

2) Core I/O boundary

All communication across the Core boundary occurs through ports.

Rules:

• Port interfaces live in Core.
• Implementations live outside Core.

3) Core data types (strict)

• Use Case inputs are plain data and/or domain types.
• Use Case outputs are plain data and/or domain types.

Core MUST NOT define HTTP DTOs.

4) Canonical flow

Delivery App (HTTP or Website)
  ↓
Core Application (Use Case)
  ↓
Core Domain (Entities, Value Objects)
  ↓
Ports (repository, gateway)
  ↓
Adapter implementation (outside Core)

5) Non-negotiable rules

1. Core is framework-agnostic.
2. DTOs do not enter Core.
3. Core defines ports; outer layers implement them.