feat: recognize provider cost data from usage.cost_details block

packages/backend/src/services/inspectors/usage-logging.ts

@@ -10,9 +10,10 @@ import {
   normalizeGeminiUsage,
   normalizeOpenAIChatUsage,
   normalizeOpenAIResponsesUsage,
+  extractUsageCostDetails,
 } from '../../utils/usage-normalizer';
 import { estimateKwhUsed } from '../inference-energy';
-import { applyProviderReportedCost } from '../../utils/provider-cost';
+import { applyProviderReportedCost, applyUsageCostDetails } from '../../utils/provider-cost';
 import { DEFAULT_MODEL, DEFAULT_GPU_PARAMS } from '@plexus/shared';
 import { recordQuotaUsage } from '../quota/quota-middleware';
 
@@ -149,6 +150,15 @@ export class UsageInspector extends PassThrough {
         applyProviderReportedCost(this.usageRecord, reconstructed.providerReportedCost);
       }
 
+      // Override with provider-reported cost from usage.cost_details if available
+      // Some providers include detailed cost breakdowns in the usage block
+      if (!this.usageRecord.providerReportedCost && reconstructed?.usage) {
+        const usageCostDetails = extractUsageCostDetails(reconstructed.usage);
+        if (usageCostDetails) {
+          applyUsageCostDetails(this.usageRecord, usageCostDetails);
+        }
+      }
+
       // Use provider-reported energy if available, otherwise estimate
       // Some providers emit `: energy {"energy_kwh": ...}` as SSE comments
       if (reconstructed?.providerReportedEnergy?.energy_kwh != null) {

packages/backend/src/services/response-handler.ts

@@ -10,7 +10,8 @@ import { DebugLoggingInspector, UsageInspector } from './inspectors';
 import { Readable } from 'stream';
 import { DebugManager } from './debug-manager';
 import { estimateKwhUsed } from './inference-energy';
-import { applyProviderReportedCost } from '../utils/provider-cost';
+import { applyProviderReportedCost, applyUsageCostDetails } from '../utils/provider-cost';
+import { extractUsageCostDetails } from '../utils/usage-normalizer';
 import { StallInspector, type StallConfig } from './inspectors/stall-inspector';
 import { DEFAULT_GPU_PARAMS, DEFAULT_MODEL } from '@plexus/shared';
 import type { GpuParams } from '@plexus/shared';
@@ -502,6 +503,14 @@ async function finalizeUsage(
   if (reconstructed?.providerReportedCost) {
     applyProviderReportedCost(usageRecord, reconstructed.providerReportedCost);
   }
+
+  // Also check for cost_details in the usage block (some providers embed costs there)
+  if (!usageRecord.providerReportedCost && reconstructed?.usage) {
+    const usageCostDetails = extractUsageCostDetails(reconstructed.usage);
+    if (usageCostDetails) {
+      applyUsageCostDetails(usageRecord, usageCostDetails);
+    }
+  }
   usageRecord.responseStatus = 'success';
   usageRecord.durationMs = Date.now() - startTime;