# Phase Pay-Arch — Payment Architecture Prerequisites

| Field | Value |
| --- | --- |
| Phase ID | `payment-arch` |
| Title | Payment Architecture Prerequisites |
| Status | Complete (documentation-only) |
| Service | `payment` |
| ADR | [ADR-021](architecture/adr/ADR-021.md) (extends [ADR-020](architecture/adr/ADR-020.md)) |

## Purpose

Finalize all architectural prerequisites before `payment-14.0` implementation so future phases never require breaking contract or licensing changes.

## Deliverables

- [ADR-021](architecture/adr/ADR-021.md) — three-layer licensing, provider assignment, contract versioning
- [payment-contracts.md](reference/payment-contracts.md) — all v1 integration contracts + future reserved schemas
- Updated [payment-roadmap.md](payment-roadmap.md) — architecture verification section
- Updated [module-boundaries.md](architecture/module-boundaries.md) — Payment platform section
- Updated [event-catalog.md](reference/event-catalog.md), [services-contracts.md](reference/services-contracts.md), [authorization-architecture.md](architecture/authorization-architecture.md)
- Service snapshot regenerated

## Definition of Done

- [x] All listed contracts documented with v1 JSON shapes
- [x] Service compatibility matrix verified (no existing service code changes)
- [x] Tenant enable/disable, PSP choice, mode switch documented as config-only
- [x] No implementation of payment-14.0

## Related Documents

- [Phase Handover Pay-Arch](phase-handover/phase-pay-arch.md)
- [Payment Roadmap](payment-roadmap.md)
