Fix compute utilization bug and add subscriber saturation cap

Three intertwined fixes:

1. Zero-capacity utilization: when inference allocation was 0%, the
   guard clause returned 0% utilization instead of 100%, so the market
   system never penalized satisfaction and subscribers never churned.

2. Stale compute in market: restructured tick order so capacity is
   computed before market runs, giving satisfaction calculations
   current-tick demand/capacity ratio instead of previous tick's.

3. Subscriber growth: replaced pure compound growth (reached billions
   in minutes) with logistic saturation curve. Era-based market caps:
   startup 10K, scaleup 1M, bigtech 20M, agi 100M. Quality and
   reputation expand the effective cap.

Also tuned FLOPS-to-tokens multiplier (10 → 26) for balanced
demand/capacity feel across all eras, and added market saturation
indicator to the Market page.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web/src/pages/MarketPage.tsx

@@ -1,5 +1,8 @@
 import { useGameStore } from '@/store';
-import { formatNumber, formatMoney, formatPercent } from '@ai-tycoon/shared';
+import {
+  formatNumber, formatMoney, formatPercent,
+  MARKET_SIZE_CAP, MARKET_CAP_QUALITY_BONUS, MARKET_CAP_REPUTATION_BONUS,
+} from '@ai-tycoon/shared';
 import { Users, Zap, Shield, TrendingUp, Settings2 } from 'lucide-react';
 
 export function MarketPage() {
@@ -10,9 +13,21 @@ export function MarketPage() {
   const inferenceUtil = useGameStore((s) => s.compute.inferenceUtilization);
   const tokensCapacity = useGameStore((s) => s.compute.tokensPerSecondCapacity);
   const tokensDemand = useGameStore((s) => s.compute.tokensPerSecondDemand);
+  const currentEra = useGameStore((s) => s.meta.currentEra);
+  const reputationScore = useGameStore((s) => s.reputation.score);
+  const deployedModels = useGameStore((s) => s.models.trainedModels.filter(m => m.isDeployed));
   const setProductPricing = useGameStore((s) => s.setProductPricing);
   const setOverloadPolicy = useGameStore((s) => s.setOverloadPolicy);
 
+  const bestQuality = deployedModels.length > 0
+    ? Math.max(...deployedModels.map(m => m.benchmarkScore)) / 100
+    : 0;
+  const eraCapBase = MARKET_SIZE_CAP[currentEra] ?? 100_000_000;
+  const effectiveCap = eraCapBase
+    * (1 + bestQuality * MARKET_CAP_QUALITY_BONUS)
+    * (1 + (reputationScore / 100) * MARKET_CAP_REPUTATION_BONUS);
+  const saturation = effectiveCap > 0 ? consumers.totalSubscribers / effectiveCap : 0;
+
   const chatProduct = productLines.find(p => p.type === 'chat-product');
   const textApi = productLines.find(p => p.type === 'text-api');
 
@@ -20,7 +35,7 @@ export function MarketPage() {
     <div className="space-y-6">
       <h2 className="text-2xl font-bold">Market</h2>
 
-      <div className="grid grid-cols-3 gap-4">
+      <div className="grid grid-cols-4 gap-4">
         <div className="bg-surface-900 border border-surface-700 rounded-xl p-4">
           <div className="flex items-center gap-2 mb-2">
             <Users size={16} className="text-orange-400" />
@@ -55,6 +70,22 @@ export function MarketPage() {
             {formatNumber(tokensDemand)} / {formatNumber(tokensCapacity)} tok/s
           </div>
         </div>
+        <div className="bg-surface-900 border border-surface-700 rounded-xl p-4">
+          <div className="flex items-center gap-2 mb-2">
+            <TrendingUp size={16} className="text-purple-400" />
+            <span className="text-xs text-surface-400 uppercase">Market Saturation</span>
+          </div>
+          <div className="text-2xl font-bold font-mono">{formatPercent(saturation)}</div>
+          <div className="text-xs text-surface-400 mt-1">
+            Cap: {formatNumber(effectiveCap)} ({currentEra})
+          </div>
+          <div className="h-1.5 bg-surface-800 rounded-full mt-2 overflow-hidden">
+            <div
+              className={`h-full rounded-full ${saturation > 0.9 ? 'bg-danger' : saturation > 0.7 ? 'bg-warning' : 'bg-accent'}`}
+              style={{ width: `${Math.min(100, saturation * 100)}%` }}
+            />
+          </div>
+        </div>
       </div>
 
       <div className="grid grid-cols-2 gap-4">

packages/game-engine/src/systems/computeSystem.ts

@@ -1,24 +1,36 @@
 import type { GameState, ComputeState, InfrastructureState } from '@ai-tycoon/shared';
+import { FLOPS_TO_TOKENS_MULTIPLIER } from '@ai-tycoon/shared';
 
-export function processCompute(state: GameState, infrastructure: InfrastructureState): ComputeState {
+export interface CapacityResult {
+  totalFlops: number;
+  trainingAllocation: number;
+  inferenceAllocation: number;
+  tokensPerSecondCapacity: number;
+}
+
+export function computeCapacity(state: GameState, infrastructure: InfrastructureState): CapacityResult {
   const totalFlops = infrastructure.totalFlops;
   const trainingAllocation = state.compute.trainingAllocation;
   const inferenceAllocation = 1 - trainingAllocation;
-
   const inferenceFlops = totalFlops * inferenceAllocation;
-  const tokensPerSecondCapacity = inferenceFlops * 10;
+  const tokensPerSecondCapacity = inferenceFlops * FLOPS_TO_TOKENS_MULTIPLIER;
 
-  const tokensPerSecondDemand = state.compute.tokensPerSecondDemand;
-  const inferenceUtilization = tokensPerSecondCapacity > 0
-    ? Math.min(1, tokensPerSecondDemand / tokensPerSecondCapacity)
-    : 0;
+  return { totalFlops, trainingAllocation, inferenceAllocation, tokensPerSecondCapacity };
+}
+
+export function finalizeCompute(capacity: CapacityResult, totalTokenDemand: number): ComputeState {
+  const inferenceUtilization = capacity.tokensPerSecondCapacity > 0
+    ? Math.min(1, totalTokenDemand / capacity.tokensPerSecondCapacity)
+    : (totalTokenDemand > 0 ? 1 : 0);
 
   return {
-    totalFlops,
-    trainingAllocation,
-    inferenceAllocation,
+    ...capacity,
+    tokensPerSecondDemand: totalTokenDemand,
     inferenceUtilization,
-    tokensPerSecondCapacity,
-    tokensPerSecondDemand,
   };
 }
+
+export function processCompute(state: GameState, infrastructure: InfrastructureState): ComputeState {
+  const cap = computeCapacity(state, infrastructure);
+  return finalizeCompute(cap, state.compute.tokensPerSecondDemand);
+}

packages/game-engine/src/systems/marketSystem.ts

@@ -1,11 +1,16 @@
-import type { GameState, MarketState, ComputeState } from '@ai-tycoon/shared';
+import type { GameState, MarketState } from '@ai-tycoon/shared';
 import {
   CONSUMER_BASE_GROWTH,
   CONSUMER_QUALITY_GROWTH_MULTIPLIER,
   CONSUMER_BASE_CHURN,
+  CONSUMER_TOKENS_PER_SUBSCRIBER,
   API_TOKENS_PER_REQUEST,
   OPEN_SOURCE_REVENUE_PENALTY,
   OPEN_SOURCE_TALENT_ATTRACTION,
+  MARKET_SIZE_CAP,
+  MARKET_CAP_QUALITY_BONUS,
+  MARKET_CAP_REPUTATION_BONUS,
+  OVERLOAD_PENALTY_EXPONENT,
 } from '@ai-tycoon/shared';
 
 export interface MarketTickResult {
@@ -15,7 +20,7 @@ export interface MarketTickResult {
   totalTokenDemand: number;
 }
 
-export function processMarket(state: GameState, compute: ComputeState): MarketTickResult {
+export function processMarket(state: GameState, currentTickCapacity: number): MarketTickResult {
   const bestModel = state.models.trainedModels
     .filter(m => m.isDeployed)
     .sort((a, b) => b.benchmarkScore - a.benchmarkScore)[0];
@@ -33,7 +38,17 @@ export function processMarket(state: GameState, compute: ComputeState): MarketTi
     const fairPrice = 20 + modelQuality * 80;
     const priceRatio = price / Math.max(1, fairPrice);
     const priceAttractiveness = Math.max(0, Math.min(1, 1 - (priceRatio - 1) * 0.8));
-    const growthRate = (CONSUMER_BASE_GROWTH + modelQuality * CONSUMER_QUALITY_GROWTH_MULTIPLIER) * priceAttractiveness;
+
+    // --- Logistic growth with era-based market cap ---
+    const eraCapBase = MARKET_SIZE_CAP[state.meta.currentEra] ?? 100_000_000;
+    const effectiveCap = eraCapBase
+      * (1 + modelQuality * MARKET_CAP_QUALITY_BONUS)
+      * (1 + (state.reputation.score / 100) * MARKET_CAP_REPUTATION_BONUS);
+
+    const saturationFactor = Math.max(0, 1 - consumers.totalSubscribers / effectiveCap);
+
+    const growthRate = (CONSUMER_BASE_GROWTH + modelQuality * CONSUMER_QUALITY_GROWTH_MULTIPLIER)
+      * priceAttractiveness * saturationFactor;
     const priceChurnMultiplier = priceRatio > 1 ? 1 + (priceRatio - 1) * 3 : 1;
     const churnRate = CONSUMER_BASE_CHURN * (1 + (1 - consumers.satisfaction) * 2) * priceChurnMultiplier;
 
@@ -42,25 +57,51 @@ export function processMarket(state: GameState, compute: ComputeState): MarketTi
 
     const newSubs = consumers.totalSubscribers * growthRate;
     const lostSubs = consumers.totalSubscribers * churnRate;
-    consumers.totalSubscribers = Math.max(0, consumers.totalSubscribers + newSubs - lostSubs);
+    consumers.totalSubscribers = Math.max(0, Math.min(
+      effectiveCap,
+      consumers.totalSubscribers + newSubs - lostSubs,
+    ));
 
     if (consumers.totalSubscribers < 100 && modelQuality > 0.1 && priceRatio < 3) {
       consumers.totalSubscribers += 5 + modelQuality * 20;
     }
 
-    const loadPenalty = compute.inferenceUtilization > 0.9
-      ? (compute.inferenceUtilization - 0.9) * 5
-      : 0;
+    // --- Satisfaction from demand/capacity ratio (current tick) ---
+    const consumerDemand = consumers.totalSubscribers * CONSUMER_TOKENS_PER_SUBSCRIBER;
+    let demandCapacityRatio: number;
+    if (currentTickCapacity > 0) {
+      demandCapacityRatio = consumerDemand / currentTickCapacity;
+    } else {
+      demandCapacityRatio = consumerDemand > 0 ? 10 : 0;
+    }
+
+    let headroomBonus = 0;
+    let overloadPenalty = 0;
+    if (demandCapacityRatio <= 1) {
+      headroomBonus = (1 - demandCapacityRatio) * 0.2;
+    } else {
+      overloadPenalty = Math.min(1, Math.pow(demandCapacityRatio - 1, OVERLOAD_PENALTY_EXPONENT));
+    }
+
     consumers.satisfaction = Math.min(1, Math.max(0,
-      0.3 + modelQuality * 0.5 + (1 - Math.min(1, compute.inferenceUtilization)) * 0.2 - loadPenalty,
+      0.3 + modelQuality * 0.5 + headroomBonus - overloadPenalty,
     ));
 
     consumers.viralCoefficient = modelQuality > 0.5 ? 1 + (modelQuality - 0.5) * 2 : 0;
 
     subscriptionRevenue = consumers.totalSubscribers * (chatProduct.pricing.subscriptionPrice / 86400);
+
+    // --- Overload policy ---
+    const policy = state.market.overloadPolicy;
+    if (policy.degradeQualityUnderLoad && demandCapacityRatio > 0.85) {
+      consumers.satisfaction = Math.max(0, consumers.satisfaction - 0.02);
+    }
+    if (policy.prioritizeEnterprise && demandCapacityRatio > 0.9) {
+      consumers.satisfaction = Math.max(0, consumers.satisfaction - 0.01);
+    }
   }
 
-  // --- B2B API market (organic demand based on model quality + reputation) ---
+  // --- B2B API market ---
   const enterprise = { ...state.market.enterprise };
   let apiRevenue = 0;
   let organicApiTokens = 0;
@@ -80,29 +121,26 @@ export function processMarket(state: GameState, compute: ComputeState): MarketTi
       apiRevenue += (contract.tokensPerTick / 1_000_000) * contract.pricePerMToken;
     }
 
-    const totalApiTokens = organicApiTokens + contractTokens;
     apiRevenue += (organicApiTokens / 1_000_000) * textApi.pricing.outputTokenPrice;
-
-    enterprise.totalApiCallsPerTick = totalApiTokens / API_TOKENS_PER_REQUEST;
+    enterprise.totalApiCallsPerTick = (organicApiTokens + contractTokens) / API_TOKENS_PER_REQUEST;
   }
 
   const totalTokenDemand = organicApiTokens +
-    consumers.totalSubscribers * 0.5 +
+    consumers.totalSubscribers * CONSUMER_TOKENS_PER_SUBSCRIBER +
     enterprise.activeContracts.reduce((s, c) => s + c.tokensPerTick, 0);
 
+  // --- Open source effects ---
   const openSourceCount = state.market.openSourcedModels.length;
   if (openSourceCount > 0) {
     const growthBoost = 1 + openSourceCount * OPEN_SOURCE_TALENT_ATTRACTION;
     consumers.totalSubscribers *= growthBoost > 1 ? 1 + (growthBoost - 1) * 0.01 : 1;
     apiRevenue *= 1 - openSourceCount * OPEN_SOURCE_REVENUE_PENALTY * 0.3;
-  }
 
-  const policy = state.market.overloadPolicy;
-  if (policy.degradeQualityUnderLoad && compute.inferenceUtilization > 0.85) {
-    consumers.satisfaction = Math.max(0, consumers.satisfaction - 0.02);
-  }
-  if (policy.prioritizeEnterprise && compute.inferenceUtilization > 0.9) {
-    consumers.satisfaction = Math.max(0, consumers.satisfaction - 0.01);
+    const eraCapBase = MARKET_SIZE_CAP[state.meta.currentEra] ?? 100_000_000;
+    const effectiveCap = eraCapBase
+      * (1 + modelQuality * MARKET_CAP_QUALITY_BONUS)
+      * (1 + (state.reputation.score / 100) * MARKET_CAP_REPUTATION_BONUS);
+    consumers.totalSubscribers = Math.min(effectiveCap, consumers.totalSubscribers);
   }
 
   const subscriberHistory = [...(state.market.subscriberHistory || [])];

packages/game-engine/src/tick.ts

@@ -1,7 +1,7 @@
 import type { GameState, AchievementDefinition } from '@ai-tycoon/shared';
 import { processEconomy } from './systems/economySystem';
 import { processInfrastructure } from './systems/infrastructureSystem';
-import { processCompute } from './systems/computeSystem';
+import { computeCapacity, finalizeCompute } from './systems/computeSystem';
 import { processResearch } from './systems/researchSystem';
 import { processModels } from './systems/modelSystem';
 import { processMarket } from './systems/marketSystem';
@@ -49,13 +49,10 @@ export function processTick(state: GameState): Partial<GameState> {
   }
 
   const stateWithModels = { ...stateWithInfra, models: modelResult.modelsState };
-  const market = processMarket(stateWithModels, state.compute);
 
-  const compute = processCompute(state, infrastructure);
-  compute.tokensPerSecondDemand = market.totalTokenDemand;
-  compute.inferenceUtilization = compute.tokensPerSecondCapacity > 0
-    ? Math.min(1, market.totalTokenDemand / compute.tokensPerSecondCapacity)
-    : 0;
+  const capacity = computeCapacity(state, infrastructure);
+  const market = processMarket(stateWithModels, capacity.tokensPerSecondCapacity);
+  const compute = finalizeCompute(capacity, market.totalTokenDemand);
 
   const talent = processTalent(stateWithModels);
   const stateWithTalent = { ...stateWithModels, talent };

packages/shared/src/constants/gameBalance.ts

@@ -28,9 +28,24 @@ export const CONSUMER_QUALITY_GROWTH_MULTIPLIER = 0.01;
 export const CONSUMER_PRICE_ELASTICITY = -0.5;
 export const CONSUMER_BASE_CHURN = 0.001;
 
+export const CONSUMER_TOKENS_PER_SUBSCRIBER = 0.5;
+
 export const API_TOKENS_PER_REQUEST = 500;
 export const API_REVENUE_PER_MTOK = 1.0;
 
+export const MARKET_SIZE_CAP: Record<string, number> = {
+  startup: 10_000,
+  scaleup: 1_000_000,
+  bigtech: 20_000_000,
+  agi: 100_000_000,
+};
+export const MARKET_CAP_QUALITY_BONUS = 0.3;
+export const MARKET_CAP_REPUTATION_BONUS = 0.2;
+
+export const FLOPS_TO_TOKENS_MULTIPLIER = 26;
+
+export const OVERLOAD_PENALTY_EXPONENT = 1.5;
+
 export const ERA_THRESHOLDS = {
   scaleup: { revenue: 10_000, capability: 15, reputation: 30 },
   bigtech: { revenue: 1_000_000, capability: 50, reputation: 60 },