Initial Commit

openspec/archive/2026-05-24-game-server-enhanced-anti-cheat-lag/proposal.md

@@ -0,0 +1,75 @@
+# Wave C-2 — game-server enhanced: anti-cheat + interest management + lag compensation
+
+## Why
+
+The `@suaveplan/game-server` package's Wave A–B foundation (core / engine /
+state / network / matchmaking / performance) is in place. The next layer —
+the `enhanced/` family — adds server-authoritative safeguards and
+broadcast-scope optimisations needed for any open-world multiplayer game.
+
+Wave C-2 ships the three foundational `enhanced/` modules that are entirely
+self-contained from a dependency standpoint and underpin the rest of the
+`enhanced/` tree (anti-cheat consumed by leaderboard/persistence; interest
+management by state-sync; lag compensation by replay/state-sync):
+
+- `enhanced/anti-cheat/anti-cheat-validator/` — server-authoritative move /
+  action validator with movement, rate-limit, and custom-action rules;
+  player-violation history; punishment escalation FSM.
+- `enhanced/interest-management/interest-manager/` — area-of-interest
+  manager: circular/rectangular/custom zones, per-player view-distance
+  culling, priority-weighted entity visibility, visibility-change deltas.
+- `enhanced/lag-compensation/lag-compensator/` — server-side state-rewind +
+  RTT-aware hit validation: per-entity bounded snapshot ring buffer,
+  per-player RTT statistics (avg/min/max/jitter), interpolated state
+  lookups, clamped compensation.
+
+## What Changes
+
+Add three feature modules under `packages/gaming/games/game-server/src/enhanced/`,
+each as a self-contained `5-files-per-feature` directory:
+
+- `anti-cheat/anti-cheat-validator/{anti-cheat-validator.ts,.test.ts,.types.ts,.md,index.ts}`
+- `interest-management/interest-manager/{interest-manager.ts,.test.ts,.types.ts,.md,index.ts}`
+- `lag-compensation/lag-compensator/{lag-compensator.ts,.test.ts,.types.ts,.md,index.ts}`
+
+Behaviour shift versus the upstream `main` implementation:
+
+- Inject `Clock` (and where ids are minted, `IdGenerator`) from
+  `@suaveplan/types` rather than reading `Date.now`/`Math.random` directly.
+- Replace ad-hoc `Logger` dependency + `EventEmitter` inheritance with a
+  pluggable listener registry (no `@suaveplan/events` runtime dep) and OTel
+  metrics for observability.
+- Throw `GameServerError` via the package-wide `GAME_SERVER_CODES` registry
+  on invalid input or out-of-bounds operations instead of silently
+  returning sentinel values.
+- Validate all caller-supplied configuration with Zod at the boundary.
+
+Extend `GAME_SERVER_CODES` with the following new codes (appended, no
+re-order):
+
+- `CHEAT_DETECTED`
+- `INVALID_VALIDATION_RULE`
+- `INVALID_ANTI_CHEAT_CONFIG`
+- `INTEREST_REGION_INVALID`
+- `INVALID_INTEREST_CONFIG`
+- `INTEREST_PLAYER_NOT_REGISTERED`
+- `LAG_COMPENSATION_HISTORY_EXCEEDED`
+- `INVALID_LAG_COMPENSATION_CONFIG`
+- `LAG_COMPENSATION_ENTITY_NOT_TRACKED`
+
+Extend `package.json` `exports` map additively with subpath exports for the
+three new feature modules.
+
+## Impact
+
+- Affected specs: `game-server` (new requirements for enhanced anti-cheat,
+  interest management, lag compensation).
+- Affected code: `packages/gaming/games/game-server/src/enhanced/**` (new),
+  `packages/gaming/games/game-server/src/errors/game-server-error.ts`
+  (new codes appended), `packages/gaming/games/game-server/package.json`
+  (additive subpath exports), `packages/gaming/games/game-server/src/index.ts`
+  (re-exports for the three new modules).
+- Out of scope: all other `enhanced/*` subtrees (leaderboard, persistence,
+  replay, tournament, service-discovery, state-sync, timing) — owned by
+  Wave C-3/C-4. The orchestrator `src/index.ts` is updated only to add the
+  three Wave C-2 re-exports.