# FastAPI Async SQLAlchemy References Index

Purpose: concept registry for modernization guidance used by this skill.

---

## Concepts

| Concept | File | Status | Decision Level | Owner | Last Reviewed |
|---|---|---|---|---|---|
| Engine lifecycle and ownership | [engine.md](engine.md) | adopted | mandatory | platform/backend | 2026-06-17 |
| Session factory and scope | [session.md](session.md) | adopted | mandatory | platform/backend | 2026-06-17 |
| Transaction boundaries | [transactions.md](transactions.md) | adopted | mandatory | platform/backend | 2026-06-17 |
| Implicit ORM I/O under asyncio | [implicit_io.md](implicit_io.md) | adopted | advisory | platform/backend | 2026-06-17 |
| Observability and resilience | [observability.md](observability.md) | adopted | mandatory | platform/backend | 2026-06-17 |

---

## How to Use This Folder

- `SKILL.md` defines the planning workflow and migration procedure.
- Each concept doc defines policy-level guidance for one concern.
- Use the template in [template.md](template.md) for new concept docs.
- Keep references source-linked and implementation snippets minimal.

---

## Update Rules

- If a PR changes database lifecycle/session/ORM loading behavior, update the relevant concept file.
- Keep `Status`, `Decision Level`, and `Last Reviewed` current.
- Use `advisory` only when incremental rollout is intended; use `mandatory` for required runtime policy.