diff --git a/src/components/common/SecondaryScreenShell.module.scss b/src/components/common/SecondaryScreenShell.module.scss
index 1f86817..23889e6 100644
--- a/src/components/common/SecondaryScreenShell.module.scss
+++ b/src/components/common/SecondaryScreenShell.module.scss
@@ -82,3 +82,51 @@
   gap: $spacing-lg;
 }
 
+.contentWithFloatingAction {
+  padding-bottom: calc(
+    var(--secondary-shell-floating-action-height, 56px) + 12px + env(safe-area-inset-bottom)
+  );
+}
+
+.floatingActionContainer {
+  position: fixed;
+  left: var(--content-center-x, 50%);
+  bottom: calc(12px + env(safe-area-inset-bottom));
+  transform: translateX(-50%);
+  z-index: 50;
+  pointer-events: none;
+  width: fit-content;
+  max-width: calc(100vw - 24px);
+}
+
+.floatingActionSurface {
+  pointer-events: auto;
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  padding: 10px 12px;
+  border-radius: 999px;
+  background: color-mix(in srgb, var(--bg-primary) 82%, transparent);
+  backdrop-filter: blur(12px);
+  -webkit-backdrop-filter: blur(12px);
+  border: 1px solid color-mix(in srgb, var(--border-color) 60%, transparent);
+  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
+}
+
+:global([data-theme='dark']) {
+  .floatingActionSurface {
+    background: color-mix(in srgb, var(--bg-primary) 82%, transparent);
+    border-color: color-mix(in srgb, var(--border-color) 55%, transparent);
+    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
+  }
+}
+
+@media (max-width: 1200px) {
+  .floatingActionContainer {
+    max-width: calc(100vw - 16px);
+  }
+
+  .floatingActionSurface {
+    padding: 8px 10px;
+  }
+}
diff --git a/src/components/common/SecondaryScreenShell.tsx b/src/components/common/SecondaryScreenShell.tsx
index 177a29f..f14e3f2 100644
--- a/src/components/common/SecondaryScreenShell.tsx
+++ b/src/components/common/SecondaryScreenShell.tsx
@@ -1,7 +1,9 @@
-import { forwardRef, type ReactNode } from 'react';
+import { forwardRef, useLayoutEffect, useRef, type ReactNode } from 'react';
+import { createPortal } from 'react-dom';
 import { Button } from '@/components/ui/Button';
 import { LoadingSpinner } from '@/components/ui/LoadingSpinner';
 import { IconChevronLeft } from '@/components/ui/icons';
+import { usePageTransitionLayer } from './PageTransitionLayer';
 import styles from './SecondaryScreenShell.module.scss';
 
 export type SecondaryScreenShellProps = {
@@ -10,6 +12,9 @@ export type SecondaryScreenShellProps = {
   backLabel?: string;
   backAriaLabel?: string;
   rightAction?: ReactNode;
+  hideTopBarBackButton?: boolean;
+  hideTopBarRightAction?: boolean;
+  floatingAction?: ReactNode;
   isLoading?: boolean;
   loadingLabel?: ReactNode;
   className?: string;
@@ -25,6 +30,9 @@ export const SecondaryScreenShell = forwardRef<HTMLDivElement, SecondaryScreenSh
       backLabel = 'Back',
       backAriaLabel,
       rightAction,
+      hideTopBarBackButton = false,
+      hideTopBarRightAction = false,
+      floatingAction,
       isLoading = false,
       loadingLabel = 'Loading...',
       className = '',
@@ -34,45 +42,94 @@ export const SecondaryScreenShell = forwardRef<HTMLDivElement, SecondaryScreenSh
     ref
   ) {
     const containerClassName = [styles.container, className].filter(Boolean).join(' ');
-    const contentClasses = [styles.content, contentClassName].filter(Boolean).join(' ');
+    const contentClasses = [
+      styles.content,
+      floatingAction ? styles.contentWithFloatingAction : '',
+      contentClassName,
+    ]
+      .filter(Boolean)
+      .join(' ');
     const titleTooltip = typeof title === 'string' ? title : undefined;
     const resolvedBackAriaLabel = backAriaLabel ?? backLabel;
+    const pageTransitionLayer = usePageTransitionLayer();
+    const isCurrentLayer = pageTransitionLayer ? pageTransitionLayer.status === 'current' : true;
+    const shouldRenderFloatingAction = Boolean(floatingAction) && isCurrentLayer;
+    const floatingActionRef = useRef<HTMLDivElement | null>(null);
+
+    useLayoutEffect(() => {
+      if (!shouldRenderFloatingAction) return;
+
+      const element = floatingActionRef.current;
+      if (!element) return;
+
+      const updateHeight = () => {
+        const height = element.getBoundingClientRect().height;
+        document.documentElement.style.setProperty(
+          '--secondary-shell-floating-action-height',
+          `${height}px`
+        );
+      };
+
+      updateHeight();
+      window.addEventListener('resize', updateHeight);
+
+      const resizeObserver =
+        typeof ResizeObserver === 'undefined' ? null : new ResizeObserver(updateHeight);
+      resizeObserver?.observe(element);
+
+      return () => {
+        resizeObserver?.disconnect();
+        window.removeEventListener('resize', updateHeight);
+        document.documentElement.style.removeProperty('--secondary-shell-floating-action-height');
+      };
+    }, [shouldRenderFloatingAction]);
 
     return (
-      <div className={containerClassName} ref={ref}>
-        <div className={styles.topBar}>
-          {onBack ? (
-            <Button
-              variant="ghost"
-              size="sm"
-              onClick={onBack}
-              className={styles.backButton}
-              aria-label={resolvedBackAriaLabel}
-            >
-              <span className={styles.backIcon}>
-                <IconChevronLeft size={18} />
-              </span>
-              <span className={styles.backText}>{backLabel}</span>
-            </Button>
-          ) : (
-            <div />
-          )}
-          <div className={styles.topBarTitle} title={titleTooltip}>
-            {title}
+      <>
+        <div className={containerClassName} ref={ref}>
+          <div className={styles.topBar}>
+            {onBack && !hideTopBarBackButton ? (
+              <Button
+                variant="ghost"
+                size="sm"
+                onClick={onBack}
+                className={styles.backButton}
+                aria-label={resolvedBackAriaLabel}
+              >
+                <span className={styles.backIcon}>
+                  <IconChevronLeft size={18} />
+                </span>
+                <span className={styles.backText}>{backLabel}</span>
+              </Button>
+            ) : (
+              <div />
+            )}
+            <div className={styles.topBarTitle} title={titleTooltip}>
+              {title}
+            </div>
+            <div className={styles.rightSlot}>{hideTopBarRightAction ? null : rightAction}</div>
           </div>
-          <div className={styles.rightSlot}>{rightAction}</div>
-        </div>
 
-        {isLoading ? (
-          <div className={styles.loadingState}>
-            <LoadingSpinner size={16} />
-            <span>{loadingLabel}</span>
-          </div>
-        ) : (
-          <div className={contentClasses}>{children}</div>
-        )}
-      </div>
+          {isLoading ? (
+            <div className={styles.loadingState}>
+              <LoadingSpinner size={16} />
+              <span>{loadingLabel}</span>
+            </div>
+          ) : (
+            <div className={contentClasses}>{children}</div>
+          )}
+        </div>
+        {shouldRenderFloatingAction && typeof document !== 'undefined'
+          ? createPortal(
+              <div className={styles.floatingActionContainer}>
+                <div className={styles.floatingActionSurface} ref={floatingActionRef}>
+                  {floatingAction}
+                </div>
+              </div>,
+              document.body
+            )
+          : null}
+      </>
     );
   }
 );
-
diff --git a/src/pages/AiProvidersAmpcodeEditPage.tsx b/src/pages/AiProvidersAmpcodeEditPage.tsx
index fc98a27..a90e54e 100644
--- a/src/pages/AiProvidersAmpcodeEditPage.tsx
+++ b/src/pages/AiProvidersAmpcodeEditPage.tsx
@@ -271,10 +271,28 @@ export function AiProvidersAmpcodeEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={() => void saveAmpcode()} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={() => void saveAmpcode()}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersClaudeEditPage.tsx b/src/pages/AiProvidersClaudeEditPage.tsx
index 5916ff4..7c73d3b 100644
--- a/src/pages/AiProvidersClaudeEditPage.tsx
+++ b/src/pages/AiProvidersClaudeEditPage.tsx
@@ -272,10 +272,28 @@ export function AiProvidersClaudeEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={() => void handleSave()} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={() => void handleSave()}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersClaudeModelsPage.tsx b/src/pages/AiProvidersClaudeModelsPage.tsx
index c6cb923..b26e9da 100644
--- a/src/pages/AiProvidersClaudeModelsPage.tsx
+++ b/src/pages/AiProvidersClaudeModelsPage.tsx
@@ -163,10 +163,27 @@ export function AiProvidersClaudeModelsPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={handleApply} disabled={!canApply}>
-          {t('ai_providers.claude_models_fetch_apply')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={handleApply}
+            disabled={!canApply}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('ai_providers.claude_models_fetch_apply')}
+          </Button>
+        </div>
       }
       isLoading={initialLoading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersCodexEditPage.tsx b/src/pages/AiProvidersCodexEditPage.tsx
index 43f4d2b..2fe2418 100644
--- a/src/pages/AiProvidersCodexEditPage.tsx
+++ b/src/pages/AiProvidersCodexEditPage.tsx
@@ -417,10 +417,28 @@ export function AiProvidersCodexEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={handleSave} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={handleSave}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersEditLayout.module.scss b/src/pages/AiProvidersEditLayout.module.scss
index 4166476..84d97dc 100644
--- a/src/pages/AiProvidersEditLayout.module.scss
+++ b/src/pages/AiProvidersEditLayout.module.scss
@@ -4,6 +4,20 @@
   margin: 0 auto;
 }
 
+.floatingActions {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.floatingBackButton {
+  min-width: 82px;
+}
+
+.floatingSaveButton {
+  min-width: 88px;
+}
+
 .upstreamApiKeyRow {
   display: flex;
   align-items: center;
diff --git a/src/pages/AiProvidersGeminiEditPage.tsx b/src/pages/AiProvidersGeminiEditPage.tsx
index 027acd5..95e40b1 100644
--- a/src/pages/AiProvidersGeminiEditPage.tsx
+++ b/src/pages/AiProvidersGeminiEditPage.tsx
@@ -411,10 +411,28 @@ export function AiProvidersGeminiEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={handleSave} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={handleSave}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersOpenAIEditPage.tsx b/src/pages/AiProvidersOpenAIEditPage.tsx
index 7302cf9..4bf9039 100644
--- a/src/pages/AiProvidersOpenAIEditPage.tsx
+++ b/src/pages/AiProvidersOpenAIEditPage.tsx
@@ -501,10 +501,28 @@ export function AiProvidersOpenAIEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={() => void handleSave()} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={() => void handleSave()}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersOpenAIModelsPage.tsx b/src/pages/AiProvidersOpenAIModelsPage.tsx
index 4ef43de..34cb38e 100644
--- a/src/pages/AiProvidersOpenAIModelsPage.tsx
+++ b/src/pages/AiProvidersOpenAIModelsPage.tsx
@@ -144,10 +144,27 @@ export function AiProvidersOpenAIModelsPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={handleApply} disabled={!canApply}>
-          {t('ai_providers.openai_models_fetch_apply')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={handleApply}
+            disabled={!canApply}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('ai_providers.openai_models_fetch_apply')}
+          </Button>
+        </div>
       }
       isLoading={initialLoading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/AiProvidersVertexEditPage.tsx b/src/pages/AiProvidersVertexEditPage.tsx
index 3c36ca7..90cb9ea 100644
--- a/src/pages/AiProvidersVertexEditPage.tsx
+++ b/src/pages/AiProvidersVertexEditPage.tsx
@@ -258,10 +258,28 @@ export function AiProvidersVertexEditPage() {
       onBack={handleBack}
       backLabel={t('common.back')}
       backAriaLabel={t('common.back')}
-      rightAction={
-        <Button size="sm" onClick={handleSave} loading={saving} disabled={!canSave}>
-          {t('common.save')}
-        </Button>
+      hideTopBarBackButton
+      hideTopBarRightAction
+      floatingAction={
+        <div className={layoutStyles.floatingActions}>
+          <Button
+            variant="secondary"
+            size="sm"
+            onClick={handleBack}
+            className={layoutStyles.floatingBackButton}
+          >
+            {t('common.back')}
+          </Button>
+          <Button
+            size="sm"
+            onClick={handleSave}
+            loading={saving}
+            disabled={!canSave}
+            className={layoutStyles.floatingSaveButton}
+          >
+            {t('common.save')}
+          </Button>
+        </div>
       }
       isLoading={loading}
       loadingLabel={t('common.loading')}
diff --git a/src/pages/LogsPage.module.scss b/src/pages/LogsPage.module.scss
index 7c54d7a..a88bccd 100644
--- a/src/pages/LogsPage.module.scss
+++ b/src/pages/LogsPage.module.scss
@@ -612,6 +612,13 @@
   color: var(--text-primary);
 }
 
+.traceCandidatesHeader {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+}
+
 .traceInfoGrid {
   display: grid;
   grid-template-columns: repeat(2, minmax(0, 1fr));
diff --git a/src/pages/LogsPage.tsx b/src/pages/LogsPage.tsx
index 2c00887..86dfa12 100644
--- a/src/pages/LogsPage.tsx
+++ b/src/pages/LogsPage.tsx
@@ -947,7 +947,20 @@ export function LogsPage() {
               </div>
             </div>
 
-            <h3 className={styles.traceSectionTitle}>{t('logs.trace_candidates_title')}</h3>
+            <div className={styles.traceCandidatesHeader}>
+              <h3 className={styles.traceSectionTitle}>{t('logs.trace_candidates_title')}</h3>
+              <Button
+                variant="secondary"
+                size="sm"
+                onClick={() => {
+                  void trace.refreshTraceUsageDetails().catch(() => {});
+                }}
+                loading={trace.traceLoading}
+                disabled={requestLogDownloading}
+              >
+                {t('common.refresh')}
+              </Button>
+            </div>
             {trace.traceLoading ? (
               <div className="hint">{t('logs.trace_loading')}</div>
             ) : trace.traceError ? (
diff --git a/src/pages/hooks/useTraceResolver.ts b/src/pages/hooks/useTraceResolver.ts
index 6b74191..6b2f90b 100644
--- a/src/pages/hooks/useTraceResolver.ts
+++ b/src/pages/hooks/useTraceResolver.ts
@@ -1,7 +1,7 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import { useTranslation } from 'react-i18next';
 import { authFilesApi } from '@/services/api/authFiles';
-import { usageApi } from '@/services/api/usage';
+import { USAGE_STATS_STALE_TIME_MS, useUsageStatsStore } from '@/stores';
 import type { AuthFileItem, Config } from '@/types';
 import type { CredentialInfo, SourceInfo } from '@/types/sourceInfo';
 import { buildSourceInfoMap, resolveSourceDisplay } from '@/utils/sourceResolver';
@@ -21,7 +21,7 @@ export type TraceCandidate = {
   timeDeltaMs: number | null;
 };
 
-const TRACE_USAGE_CACHE_MS = 60 * 1000;
+const TRACE_AUTH_CACHE_MS = 60 * 1000;
 const TRACE_MATCH_STRONG_WINDOW_MS = 3 * 1000;
 const TRACE_MATCH_WINDOW_MS = 10 * 1000;
 const TRACE_MATCH_MAX_WINDOW_MS = 30 * 1000;
@@ -138,6 +138,7 @@ interface UseTraceResolverReturn {
   traceCandidates: TraceCandidate[];
   resolveTraceSourceInfo: (sourceRaw: string, authIndex: unknown) => SourceInfo;
   loadTraceUsageDetails: () => Promise<void>;
+  refreshTraceUsageDetails: () => Promise<void>;
   openTraceModal: (line: ParsedLogLine) => void;
   closeTraceModal: () => void;
 }
@@ -145,25 +146,30 @@ interface UseTraceResolverReturn {
 export function useTraceResolver(options: UseTraceResolverOptions): UseTraceResolverReturn {
   const { traceScopeKey, connectionStatus, config, requestLogDownloading } = options;
   const { t } = useTranslation();
+  const usageSnapshot = useUsageStatsStore((state) => state.usage);
+  const usageScopeKey = useUsageStatsStore((state) => state.scopeKey);
+  const loadUsageStats = useUsageStatsStore((state) => state.loadUsageStats);
 
   const [traceLogLine, setTraceLogLine] = useState<ParsedLogLine | null>(null);
-  const [traceUsageDetails, setTraceUsageDetails] = useState<UsageDetailWithEndpoint[]>([]);
   const [traceAuthFileMap, setTraceAuthFileMap] = useState<Map<string, CredentialInfo>>(new Map());
   const [traceLoading, setTraceLoading] = useState(false);
   const [traceError, setTraceError] = useState('');
 
-  const traceUsageLoadedAtRef = useRef(0);
   const traceAuthLoadedAtRef = useRef(0);
   const traceScopeKeyRef = useRef('');
 
+  const scopedUsageSnapshot = usageScopeKey === traceScopeKey ? usageSnapshot : null;
+  const traceUsageDetails = useMemo<UsageDetailWithEndpoint[]>(
+    () => collectUsageDetailsWithEndpoint(scopedUsageSnapshot),
+    [scopedUsageSnapshot]
+  );
+
   const traceSourceInfoMap = useMemo(() => buildSourceInfoMap(config ?? {}), [config]);
 
-  const loadTraceUsageDetails = useCallback(async () => {
+  const loadTraceUsageDetailsInternal = useCallback(async (forceUsage: boolean) => {
     if (traceScopeKeyRef.current !== traceScopeKey) {
       traceScopeKeyRef.current = traceScopeKey;
-      traceUsageLoadedAtRef.current = 0;
       traceAuthLoadedAtRef.current = 0;
-      setTraceUsageDetails([]);
       setTraceAuthFileMap(new Map());
       setTraceError('');
     }
@@ -171,27 +177,20 @@ export function useTraceResolver(options: UseTraceResolverOptions): UseTraceReso
     if (traceLoading) return;
 
     const now = Date.now();
-    const usageFresh =
-      traceUsageLoadedAtRef.current > 0 && now - traceUsageLoadedAtRef.current < TRACE_USAGE_CACHE_MS;
     const authFresh =
-      traceAuthLoadedAtRef.current > 0 && now - traceAuthLoadedAtRef.current < TRACE_USAGE_CACHE_MS;
-    if (usageFresh && authFresh) return;
+      traceAuthLoadedAtRef.current > 0 && now - traceAuthLoadedAtRef.current < TRACE_AUTH_CACHE_MS;
 
     setTraceLoading(true);
     setTraceError('');
     try {
-      const [usageResponse, authFilesResponse] = await Promise.all([
-        usageFresh ? Promise.resolve(null) : usageApi.getUsage(),
+      const [, authFilesResponse] = await Promise.all([
+        loadUsageStats({
+          force: forceUsage,
+          staleTimeMs: USAGE_STATS_STALE_TIME_MS
+        }),
         authFresh ? Promise.resolve(null) : authFilesApi.list().catch(() => null)
       ]);
 
-      if (usageResponse !== null) {
-        const usageData = usageResponse?.usage ?? usageResponse;
-        const details = collectUsageDetailsWithEndpoint(usageData);
-        setTraceUsageDetails(details);
-        traceUsageLoadedAtRef.current = now;
-      }
-
       if (authFilesResponse !== null) {
         const files = Array.isArray(authFilesResponse)
           ? authFilesResponse
@@ -207,7 +206,7 @@ export function useTraceResolver(options: UseTraceResolverOptions): UseTraceReso
             });
           });
           setTraceAuthFileMap(map);
-          traceAuthLoadedAtRef.current = now;
+          traceAuthLoadedAtRef.current = Date.now();
         }
       }
     } catch (err: unknown) {
@@ -215,14 +214,20 @@ export function useTraceResolver(options: UseTraceResolverOptions): UseTraceReso
     } finally {
       setTraceLoading(false);
     }
-  }, [t, traceLoading, traceScopeKey]);
+  }, [loadUsageStats, t, traceLoading, traceScopeKey]);
+
+  const loadTraceUsageDetails = useCallback(async () => {
+    await loadTraceUsageDetailsInternal(false);
+  }, [loadTraceUsageDetailsInternal]);
+
+  const refreshTraceUsageDetails = useCallback(async () => {
+    await loadTraceUsageDetailsInternal(true);
+  }, [loadTraceUsageDetailsInternal]);
 
   useEffect(() => {
     if (connectionStatus === 'connected') {
       traceScopeKeyRef.current = traceScopeKey;
-      traceUsageLoadedAtRef.current = 0;
       traceAuthLoadedAtRef.current = 0;
-      setTraceUsageDetails([]);
       setTraceAuthFileMap(new Map());
       setTraceLoading(false);
       setTraceError('');
@@ -271,6 +276,7 @@ export function useTraceResolver(options: UseTraceResolverOptions): UseTraceReso
     traceCandidates,
     resolveTraceSourceInfo,
     loadTraceUsageDetails,
+    refreshTraceUsageDetails,
     openTraceModal,
     closeTraceModal
   };