fix(usage): harden models.dev analytics integration

src/web-server/models-dev/registry-cache.ts

@@ -9,6 +9,8 @@ const CACHE_FILE_NAME = 'models-dev-registry-cache.json';
 const CACHE_TTL_MS = 24 * 60 * 60 * 1000;
 const LIVE_FETCH_TIMEOUT_MS = 3000;
 
+let pendingBackgroundRefresh: Promise<ModelsDevRegistry | null> | null = null;
+
 export interface RegistryCacheReadOptions {
   allowStale?: boolean;
   now?: number;
@@ -131,3 +133,17 @@ export async function refreshModelsDevRegistry(
     clearTimeout(timeoutId);
   }
 }
+
+export function startModelsDevRegistryRefresh(
+  options: RegistryRefreshOptions = {}
+): Promise<ModelsDevRegistry | null> {
+  if (!pendingBackgroundRefresh) {
+    pendingBackgroundRefresh = refreshModelsDevRegistry(options)
+      .catch(() => null)
+      .finally(() => {
+        pendingBackgroundRefresh = null;
+      });
+  }
+
+  return pendingBackgroundRefresh;
+}

src/web-server/usage/aggregator.ts

@@ -34,7 +34,8 @@ import {
 } from './cliproxy-usage-syncer';
 import { scanCodexNativeUsageEntries } from './codex-native-usage-collector';
 import { scanDroidNativeUsageEntries } from './droid-native-usage-collector';
-import { refreshModelsDevRegistry } from '../models-dev/registry-cache';
+import { startModelsDevRegistryRefresh } from '../models-dev/registry-cache';
+import { getModelsUsed, getProviderModelKey } from './model-identity';
 
 // ============================================================================
 // Multi-Instance Support - Aggregate usage from CCS profiles
@@ -112,10 +113,6 @@ function getHourlyRequestCount(hour: HourlyUsage): number {
   return hour.requestCount ?? hour.modelBreakdowns.length;
 }
 
-function getModelBreakdownKey(breakdown: { modelName: string; provider?: string }): string {
-  return `${breakdown.provider ?? ''}\u0000${breakdown.modelName}`;
-}
-
 /**
  * Merge daily usage data from multiple sources
  * Combines entries with same date by aggregating tokens
@@ -133,14 +130,11 @@ export function mergeDailyData(sources: DailyUsage[][]): DailyUsage[] {
         existing.cacheCreationTokens += day.cacheCreationTokens;
         existing.cacheReadTokens += day.cacheReadTokens;
         existing.totalCost += day.totalCost;
-        // Merge unique models
-        const modelSet = new Set([...existing.modelsUsed, ...day.modelsUsed]);
-        existing.modelsUsed = Array.from(modelSet);
         // Merge model breakdowns by aggregating same modelName
         for (const breakdown of day.modelBreakdowns) {
-          const breakdownKey = getModelBreakdownKey(breakdown);
+          const breakdownKey = getProviderModelKey(breakdown);
           const existingBreakdown = existing.modelBreakdowns.find(
-            (b) => getModelBreakdownKey(b) === breakdownKey
+            (b) => getProviderModelKey(b) === breakdownKey
           );
           if (existingBreakdown) {
             existingBreakdown.inputTokens += breakdown.inputTokens;
@@ -152,12 +146,14 @@ export function mergeDailyData(sources: DailyUsage[][]): DailyUsage[] {
             existing.modelBreakdowns.push({ ...breakdown });
           }
         }
+        existing.modelsUsed = getModelsUsed(existing.modelBreakdowns);
       } else {
         // Clone to avoid mutating original
+        const modelBreakdowns = day.modelBreakdowns.map((b) => ({ ...b }));
         dateMap.set(day.date, {
           ...day,
-          modelsUsed: [...day.modelsUsed],
+          modelsUsed: getModelsUsed(modelBreakdowns),
-          modelBreakdowns: day.modelBreakdowns.map((b) => ({ ...b })),
+          modelBreakdowns,
         });
       }
     }
@@ -181,12 +177,10 @@ export function mergeMonthlyData(sources: MonthlyUsage[][]): MonthlyUsage[] {
         existing.cacheCreationTokens += month.cacheCreationTokens;
         existing.cacheReadTokens += month.cacheReadTokens;
         existing.totalCost += month.totalCost;
-        const modelSet = new Set([...existing.modelsUsed, ...month.modelsUsed]);
-        existing.modelsUsed = Array.from(modelSet);
         for (const breakdown of month.modelBreakdowns) {
-          const breakdownKey = getModelBreakdownKey(breakdown);
+          const breakdownKey = getProviderModelKey(breakdown);
           const existingBreakdown = existing.modelBreakdowns.find(
-            (item) => getModelBreakdownKey(item) === breakdownKey
+            (item) => getProviderModelKey(item) === breakdownKey
           );
           if (existingBreakdown) {
             existingBreakdown.inputTokens += breakdown.inputTokens;
@@ -198,11 +192,13 @@ export function mergeMonthlyData(sources: MonthlyUsage[][]): MonthlyUsage[] {
             existing.modelBreakdowns.push({ ...breakdown });
           }
         }
+        existing.modelsUsed = getModelsUsed(existing.modelBreakdowns);
       } else {
+        const modelBreakdowns = month.modelBreakdowns.map((breakdown) => ({ ...breakdown }));
         monthMap.set(month.month, {
           ...month,
-          modelsUsed: [...month.modelsUsed],
+          modelsUsed: getModelsUsed(modelBreakdowns),
-          modelBreakdowns: month.modelBreakdowns.map((breakdown) => ({ ...breakdown })),
+          modelBreakdowns,
         });
       }
     }
@@ -228,13 +224,11 @@ export function mergeHourlyData(sources: HourlyUsage[][]): HourlyUsage[] {
         existing.cacheReadTokens += hour.cacheReadTokens;
         existing.totalCost += hour.totalCost;
         existing.requestCount = getHourlyRequestCount(existing) + getHourlyRequestCount(hour);
-        const modelSet = new Set([...existing.modelsUsed, ...hour.modelsUsed]);
-        existing.modelsUsed = Array.from(modelSet);
         // Merge model breakdowns
         for (const breakdown of hour.modelBreakdowns) {
-          const breakdownKey = getModelBreakdownKey(breakdown);
+          const breakdownKey = getProviderModelKey(breakdown);
           const existingBreakdown = existing.modelBreakdowns.find(
-            (b) => getModelBreakdownKey(b) === breakdownKey
+            (b) => getProviderModelKey(b) === breakdownKey
           );
           if (existingBreakdown) {
             existingBreakdown.inputTokens += breakdown.inputTokens;
@@ -246,11 +240,13 @@ export function mergeHourlyData(sources: HourlyUsage[][]): HourlyUsage[] {
             existing.modelBreakdowns.push({ ...breakdown });
           }
         }
+        existing.modelsUsed = getModelsUsed(existing.modelBreakdowns);
       } else {
+        const modelBreakdowns = hour.modelBreakdowns.map((b) => ({ ...b }));
         hourMap.set(hour.hour, {
           ...hour,
-          modelsUsed: [...hour.modelsUsed],
+          modelsUsed: getModelsUsed(modelBreakdowns),
-          modelBreakdowns: hour.modelBreakdowns.map((b) => ({ ...b })),
+          modelBreakdowns,
           requestCount: getHourlyRequestCount(hour),
         });
       }
@@ -356,9 +352,9 @@ async function refreshFromSource(): Promise<{
   monthly: MonthlyUsage[];
   session: SessionUsage[];
 }> {
-  // Refresh model metadata before cost derivation. This is best-effort and
+  // Keep model metadata warming off the analytics request path. Current
-  // falls back to stale cache/static pricing when models.dev is unavailable.
+  // refreshes use cached/static pricing; the background result helps future runs.
-  await refreshModelsDevRegistry();
+  void startModelsDevRegistryRefresh();
 
   // Try to sync CLIProxy snapshot before reading it.
   // Non-fatal: syncer handles unavailability and stale fallback.

src/web-server/usage/cliproxy-usage-transformer.ts

@@ -8,6 +8,7 @@
 import type { CliproxyUsageApiResponse, CliproxyRequestDetail } from '../../cliproxy/stats-fetcher';
 import { calculateCost } from '../model-pricing';
 import type { ModelBreakdown, DailyUsage, HourlyUsage, MonthlyUsage } from './types';
+import { getModelsUsed } from './model-identity';
 
 // ============================================================================
 // INTERNAL HELPERS
@@ -257,10 +258,6 @@ function sumField(breakdowns: ModelBreakdown[], field: keyof ModelBreakdown): nu
   return breakdowns.reduce((acc, b) => acc + (b[field] as number), 0);
 }
 
-function getModelsUsed(breakdowns: ModelBreakdown[]): string[] {
-  return [...new Set(breakdowns.map((breakdown) => breakdown.modelName))];
-}
-
 // ============================================================================
 // TRANSFORMS
 // ============================================================================

src/web-server/usage/data-aggregator.ts

@@ -14,6 +14,7 @@ import {
   type MonthlyUsage,
   type SessionUsage,
 } from './types';
+import { getModelsUsed } from './model-identity';
 
 // ============================================================================
 // HELPER FUNCTIONS
@@ -91,10 +92,6 @@ function createModelAccumulator(entry: RawUsageEntry): ModelAccumulator {
   };
 }
 
-function getModelsUsed(modelMap: Map<string, ModelAccumulator>): string[] {
-  return [...new Set(Array.from(modelMap.values()).map((acc) => acc.modelName))];
-}
-
 // ============================================================================
 // DAILY AGGREGATION
 // ============================================================================
@@ -173,7 +170,7 @@ export function aggregateDailyUsage(
       cacheReadTokens: totalCacheRead,
       cost: totalCost,
       totalCost,
-      modelsUsed: getModelsUsed(modelMap),
+      modelsUsed: getModelsUsed(modelBreakdowns),
       modelBreakdowns,
     });
   }
@@ -262,7 +259,7 @@ export function aggregateHourlyUsage(
       cacheReadTokens: totalCacheRead,
       cost: totalCost,
       totalCost,
-      modelsUsed: getModelsUsed(modelMap),
+      modelsUsed: getModelsUsed(modelBreakdowns),
       modelBreakdowns,
       requestCount: hourEntries.length,
     });
@@ -351,7 +348,7 @@ export function aggregateMonthlyUsage(
       cacheCreationTokens: totalCacheCreation,
       cacheReadTokens: totalCacheRead,
       totalCost,
-      modelsUsed: getModelsUsed(modelMap),
+      modelsUsed: getModelsUsed(modelBreakdowns),
       modelBreakdowns,
     });
   }
@@ -469,7 +466,7 @@ export function aggregateSessionUsage(
       totalCost,
       lastActivity,
       versions: Array.from(versions),
-      modelsUsed: getModelsUsed(modelMap),
+      modelsUsed: getModelsUsed(modelBreakdowns),
       modelBreakdowns,
       source,
       target,

src/web-server/usage/handlers.ts

@@ -17,6 +17,7 @@ import {
   getLastFetchTimestamp,
   refreshUsageCache,
 } from './aggregator';
+import { getModelsUsed } from './model-identity';
 
 // ============================================================================
 // Types
@@ -716,7 +717,6 @@ export async function handleMonthly(
           cacheCreationTokens: number;
           cacheReadTokens: number;
           totalCost: number;
-          modelsUsed: Set<string>;
           modelBreakdowns: Map<
             string,
             {
@@ -741,7 +741,6 @@ export async function handleMonthly(
           cacheCreationTokens: 0,
           cacheReadTokens: 0,
           totalCost: 0,
-          modelsUsed: new Set<string>(),
           modelBreakdowns: new Map(),
         };
 
@@ -750,9 +749,6 @@ export async function handleMonthly(
         existing.cacheCreationTokens += day.cacheCreationTokens;
         existing.cacheReadTokens += day.cacheReadTokens;
         existing.totalCost += day.totalCost;
-        for (const model of day.modelsUsed) {
-          existing.modelsUsed.add(model);
-        }
         for (const breakdown of day.modelBreakdowns) {
           const breakdownKey = getBreakdownKey(breakdown);
           const existingBreakdown = existing.modelBreakdowns.get(breakdownKey) ?? {
@@ -783,8 +779,8 @@ export async function handleMonthly(
           cacheCreationTokens: month.cacheCreationTokens,
           cacheReadTokens: month.cacheReadTokens,
           totalCost: month.totalCost,
-          modelsUsed: Array.from(month.modelsUsed),
           modelBreakdowns: Array.from(month.modelBreakdowns.values()),
+          modelsUsed: getModelsUsed(Array.from(month.modelBreakdowns.values())),
         }))
         .sort((a, b) => a.month.localeCompare(b.month));
     } else {

src/web-server/usage/model-identity.ts

@@ -0,0 +1,37 @@
+export interface ProviderModelIdentity {
+  modelName: string;
+  provider?: string;
+}
+
+function getProviderKey(provider: string | undefined): string {
+  return provider?.trim().toLowerCase() ?? '';
+}
+
+function getModelUsageLabel(item: ProviderModelIdentity, ambiguousModelNames: Set<string>): string {
+  const provider = getProviderKey(item.provider);
+  if (provider && ambiguousModelNames.has(item.modelName)) {
+    return `${provider}/${item.modelName}`;
+  }
+  return item.modelName;
+}
+
+export function getProviderModelKey(item: ProviderModelIdentity): string {
+  return `${getProviderKey(item.provider)}\u0000${item.modelName}`;
+}
+
+export function getModelsUsed(items: ProviderModelIdentity[]): string[] {
+  const providersByModel = new Map<string, Set<string>>();
+  for (const item of items) {
+    const providers = providersByModel.get(item.modelName) ?? new Set<string>();
+    providers.add(getProviderKey(item.provider));
+    providersByModel.set(item.modelName, providers);
+  }
+
+  const ambiguousModelNames = new Set(
+    Array.from(providersByModel.entries())
+      .filter(([, providers]) => providers.size > 1)
+      .map(([modelName]) => modelName)
+  );
+
+  return [...new Set(items.map((item) => getModelUsageLabel(item, ambiguousModelNames)))];
+}

tests/integration/proxy/daemon-lifecycle.test.ts

@@ -395,13 +395,13 @@ describe('openai proxy daemon lifecycle', () => {
   });
 
   it('keeps the existing proxy running if replacement startup fails', async () => {
-    const firstPort = await getPort();
     const busyServer = Bun.serve({
       port: 0,
       hostname: '127.0.0.1',
       fetch: () => new Response('busy'),
     });
     const occupiedPort = busyServer.port;
+    const firstPort = await getPort({ exclude: [occupiedPort] });
 
     try {
       const settingsPath = path.join(tempDir, 'rollback.settings.json');

tests/unit/data-aggregator.test.ts

@@ -5,6 +5,7 @@
 import { describe, expect, test } from 'bun:test';
 import {
   aggregateDailyUsage,
+  aggregateHourlyUsage,
   aggregateMonthlyUsage,
   aggregateSessionUsage,
 } from '../../src/web-server/data-aggregator';
@@ -107,6 +108,36 @@ describe('aggregateDailyUsage', () => {
     const result = aggregateDailyUsage(entries, 'test-source');
     expect(result[0].source).toBe('test-source');
   });
+
+  test('keeps provider identity when same model appears under multiple providers', () => {
+    const entries: RawUsageEntry[] = [
+      createEntry({ model: 'gpt-5.5', target: 'openai' }),
+      createEntry({ model: 'gpt-5.5', target: 'github-copilot' }),
+    ];
+
+    const daily = aggregateDailyUsage(entries);
+    const hourly = aggregateHourlyUsage(entries);
+    const monthly = aggregateMonthlyUsage(entries);
+    const session = aggregateSessionUsage(entries);
+
+    expect(daily[0].modelsUsed).toEqual(['openai/gpt-5.5', 'github-copilot/gpt-5.5']);
+    expect(hourly[0].modelsUsed).toEqual(['openai/gpt-5.5', 'github-copilot/gpt-5.5']);
+    expect(monthly[0].modelsUsed).toEqual(['openai/gpt-5.5', 'github-copilot/gpt-5.5']);
+    expect(session[0].modelsUsed).toEqual(['openai/gpt-5.5', 'github-copilot/gpt-5.5']);
+    expect(daily[0].modelBreakdowns.map((item) => item.provider)).toEqual([
+      'openai',
+      'github-copilot',
+    ]);
+  });
+
+  test('preserves model-only modelsUsed entries when provider is unambiguous', () => {
+    const result = aggregateDailyUsage([
+      createEntry({ model: 'gpt-5.5', target: 'openai' }),
+      createEntry({ model: 'gpt-5.5', target: 'openai' }),
+    ]);
+
+    expect(result[0].modelsUsed).toEqual(['gpt-5.5']);
+  });
 });
 
 // ============================================================================

tests/unit/models-dev-registry-cache.test.ts

@@ -8,6 +8,7 @@ import {
   getCachedModelsDevRegistry,
   refreshModelsDevRegistry,
   setCachedModelsDevRegistry,
+  startModelsDevRegistryRefresh,
 } from '../../src/web-server/models-dev/registry-cache';
 
 describe('models.dev registry cache', () => {
@@ -90,4 +91,48 @@ describe('models.dev registry cache', () => {
     fs.writeFileSync(path.join(getCcsDir(), 'models-dev-registry-cache.json'), '{not json');
     expect(getCachedModelsDevRegistry({ allowStale: true })).toBeNull();
   });
+
+  it('starts and coalesces background refreshes without requiring callers to await', async () => {
+    let fetchCalls = 0;
+    let resolveResponse: (response: Response) => void = () => undefined;
+    const responsePromise = new Promise<Response>((resolve) => {
+      resolveResponse = resolve;
+    });
+    const fetchImpl: typeof fetch = async () => {
+      fetchCalls += 1;
+      return responsePromise;
+    };
+
+    const first = startModelsDevRegistryRefresh({
+      force: true,
+      fetchImpl,
+      now: () => 456,
+    });
+    const second = startModelsDevRegistryRefresh({
+      force: true,
+      fetchImpl,
+      now: () => 789,
+    });
+
+    expect(first).toBe(second);
+    expect(fetchCalls).toBe(1);
+    expect(getCachedModelsDevRegistry({ allowStale: true })).toBeNull();
+
+    resolveResponse(
+      new Response(
+        JSON.stringify({
+          openai: {
+            id: 'openai',
+            models: {
+              'gpt-5.5': { id: 'gpt-5.5', cost: { input: 5, output: 30 } },
+            },
+          },
+        }),
+        { status: 200 }
+      )
+    );
+
+    await first;
+    expect(getCachedModelsDevRegistry({ allowStale: true })?.openai.id).toBe('openai');
+  });
 });