# V2 — Architecture (Page Index)

This directory holds the V2 (competitive fighting game) architecture reference,
decomposed from the single [`../V2_ARCHITECTURE.md`](../V2_ARCHITECTURE.md) hub
into focused, in-depth, code-grounded pages. The hub remains the canonical entry
point and preserves every section heading (so existing `arch§"…"`
cross-references keep resolving); each page below expands one part of the system
with far richer, code-grounded detail and an honest implemented / spec-only
status. The companion feature map lives in
[`../features/`](../features/README.md) (or the
[`../V2_features.md`](../V2_features.md) hub).

> **Cross-reference convention.** Page-to-page links are relative
> (`./<slug>.md`); a bare `§N` points at a section of the V2 backlog, and
> `arch§"<anchor>"` points at a named section of the
> [`../V2_ARCHITECTURE.md`](../V2_ARCHITECTURE.md) hub. Platform-foundation
> links point at the shared [`platform/`](../../platform/overview.html) space.

## Architecture landscape

```mermaid
flowchart TB
  Surfaces[Game HUD XR companion creator and operator surfaces] --> Host[V2 game and service boundaries]
  Host --> Core[Integer-frame combat input GAS and animation]
  Core --> Rollback[Rollback replay tag and deterministic authority]
  Host --> Modes[Mode plugins training events racing and world modes]
  Host --> Presentation[Audio VFX cinematic UI stages and accessibility]
  Host --> Online[Identity matchmaking ranked tournaments and integrity]
  Online --> Services[Progression store community support companion and AI broadcast]
  Core --> Data[(Roster moves balance mode content and save versions)]
  Modes --> Data
  Services --> Evidence[(Results replays telemetry receipts and audits)]
  Data --> Build[Cook patch performance security certification and release]
  Evidence --> Build
```

The diagram shows authority and effect flow at altitude. It does not imply that
every mode shares the same netcode, that racing uses combat physics, or that a
shared provider owns domain truth. Focused pages name the applicable ruleset,
mode, platform, content version, and implementation status.

Use this index to trace a feature end to end: choose the runtime owner, follow
authored data and versions into deterministic or server authority, inspect
presentation and client prediction, then cross the online/persistence/provider
boundary and locate the resulting replay, receipt, telemetry, audit, build, and
recovery evidence. Pair the trace with the
[feature index](../features/README.md) so a technically valid component is never
mistaken for the complete player journey.

Every focused architecture page appears exactly once below. The
[V2 documentation guide](../docs/README.md) supplies role-based reading paths
and the shared truth model; the [diagram atlas](../docs/diagram-atlas.md)
supplies match, data, state, module, production, and release models. Backlog,
dependencies, current code/tests/builds, and platform evidence remain the
completion authority.

## Orientation

- [V2 Product Promise & Cross-Reference Conventions](./v2-product-promise.md) —
  what V2 commits to as a competitive fighter, and how to read this set.
- [Subsystem Glossary, Module Map & Runtime Topology](./glossary-and-module-topology.md)
  — every V2 module and `@v2/*` service mapped to the code that backs it.

## Deterministic Combat Core

- [Combat System: GAS, Frame Data, Game Feel & Determinism](./combat-system-gas-frame-data-and-determinism.md)
  — the authored GAS model, the runtime hit geometry, and the integer-frame sim.
- [Animation Pipeline & Input / Motion Parser](./animation-and-input-pipeline.md)
  — animation authority and the deterministic input/motion-parser path.
- [Rollback Netcode, Client-Server & Tag-Team Sim](./rollback-netcode-and-tag-team.md)
  — `FV2SimWorld`, rollback/re-simulation, and the tag-team architecture.

## Modes, Presentation & Interface

- [Game Modes, Mode Plugins, Training & Replay](./game-modes-training-and-replay.md)
  — the mode-plugin architecture, training tools, and the replay pipeline.
- [Audio, VFX, Cinematic & Signature Content Pipelines](./presentation-av-and-signature-content.md)
  — the presentation pipelines and signature-content systems.
- [UI / HUD, VR / AR & Accessibility](./ui-hud-vr-ar-and-accessibility.md) — the
  HUD/menu architecture, XR surfaces, and the cert-critical accessibility layer.

## Racing, Vehicles & World Modes

- [Racing Component, Vehicles & Peripherals](./racing-and-vehicle-architecture.md)
  — the racing sub-game, vehicle systems, and peripheral support.
- [Open-World, Co-op, Mini-Games & Persistent World](./open-world-coop-and-special-modes.md)
  — the open-world, co-op, and persistent-world special modes.

## Online Services & Live Operations

- [Online Backbone & Competitive Integrity](./online-backbone-and-competitive-integrity.md)
  — `V2OnlineServices`, matchmaking/ranked, anti-cheat, replay-hash validation,
  and cross-play / cross-progression.
- [Live-Ops, Store, Progression & Community](./live-ops-store-progression-and-community.md)
  — content delivery, the store/economy, progression, and community surfaces.
- [Esports, Companion & AI Services](./esports-companion-and-ai-services.md) —
  tournaments, the read-only mobile companion, and the AI-commentary stack.

## Platform Engineering, Compliance & Integration

- [Build, Cook, Assets, Data & Production](./build-cook-assets-data-and-production.md)
  — asset budgets, the BuildGraph/cook/patch pipeline, and the
  spreadsheet-of-truth data architecture.
- [Telemetry, Performance, Testing & Release Gates](./telemetry-performance-testing-and-release-gates.md)
  — telemetry, the per-platform performance budgets, the 441-file test surface,
  and the release gate.
- [Security, Compliance & Sister-Monorepo Integration](./security-compliance-and-sister-monorepo-integration.md)
  — identity, PII/residency/DSR, consent/age-gating, and how V2 composes the
  shared Oshun / Aphrodite / Themis packages.