# Decision Index

## Active Decisions

| ID | Decision | Status | Date | Applies To | Detail |
|---|---|---|---|---|---|
| RDS-001 | Production persistence uses explicit direct PostgreSQL through one server-only adapter; local JSON is explicit development/test mode. | Accepted | 2026-08-12 | Server stores and scripts | `ZHINIAN_DATA_BACKEND=postgres` fails closed and never silently falls back. |
| RDS-002 | Database changes use versioned, checksummed, advisory-locked migrations executed by a one-shot deployment Job. | Accepted | 2026-08-12 | Database schema and ACK rollout | Migrations do not run in each Web pod init container. |
| ACK-001 | Worker remains an HTTP poller and does not receive RDS credentials; Web owns database access. | Accepted | 2026-08-12 | ACK workloads | Worker calls the internal Web Service with a shared internal token. |

## Superseded Decisions

| ID | Decision | Superseded By | Date |
|---|---|---|---|

## Decision Criteria

Create or update an ADR when a choice affects:

- project positioning
- architecture boundaries
- public behavior
- data model
- long-term maintenance
- user-facing workflow