diff --git a/apps/server/src/index.ts b/apps/server/src/index.ts
index 11088a3c..755569de 100644
--- a/apps/server/src/index.ts
+++ b/apps/server/src/index.ts
@@ -53,6 +53,8 @@ import { SettingsService } from './services/settings-service.js';
 import { createSpecRegenerationRoutes } from './routes/app-spec/index.js';
 import { createClaudeRoutes } from './routes/claude/index.js';
 import { ClaudeUsageService } from './services/claude-usage-service.js';
+import { createCodexRoutes } from './routes/codex/index.js';
+import { CodexUsageService } from './services/codex-usage-service.js';
 import { createGitHubRoutes } from './routes/github/index.js';
 import { createContextRoutes } from './routes/context/index.js';
 import { createBacklogPlanRoutes } from './routes/backlog-plan/index.js';
@@ -166,6 +168,7 @@ const agentService = new AgentService(DATA_DIR, events, settingsService);
 const featureLoader = new FeatureLoader();
 const autoModeService = new AutoModeService(events, settingsService);
 const claudeUsageService = new ClaudeUsageService();
+const codexUsageService = new CodexUsageService();
 const mcpTestService = new MCPTestService(settingsService);
 const ideationService = new IdeationService(events, settingsService, featureLoader);
 
@@ -216,6 +219,7 @@ app.use('/api/templates', createTemplatesRoutes());
 app.use('/api/terminal', createTerminalRoutes());
 app.use('/api/settings', createSettingsRoutes(settingsService));
 app.use('/api/claude', createClaudeRoutes(claudeUsageService));
+app.use('/api/codex', createCodexRoutes(codexUsageService));
 app.use('/api/github', createGitHubRoutes(events, settingsService));
 app.use('/api/context', createContextRoutes(settingsService));
 app.use('/api/backlog-plan', createBacklogPlanRoutes(events, settingsService));
diff --git a/apps/server/src/routes/codex/index.ts b/apps/server/src/routes/codex/index.ts
new file mode 100644
index 00000000..34412256
--- /dev/null
+++ b/apps/server/src/routes/codex/index.ts
@@ -0,0 +1,52 @@
+import { Router, Request, Response } from 'express';
+import { CodexUsageService } from '../../services/codex-usage-service.js';
+import { createLogger } from '@automaker/utils';
+
+const logger = createLogger('Codex');
+
+export function createCodexRoutes(service: CodexUsageService): Router {
+  const router = Router();
+
+  // Get current usage (attempts to fetch from Codex CLI)
+  router.get('/usage', async (req: Request, res: Response) => {
+    try {
+      // Check if Codex CLI is available first
+      const isAvailable = await service.isAvailable();
+      if (!isAvailable) {
+        res.status(503).json({
+          error: 'Codex CLI not found',
+          message: "Please install Codex CLI and run 'codex login' to authenticate",
+        });
+        return;
+      }
+
+      const usage = await service.fetchUsageData();
+      res.json(usage);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : 'Unknown error';
+
+      if (message.includes('not authenticated') || message.includes('login')) {
+        res.status(401).json({
+          error: 'Authentication required',
+          message: "Please run 'codex login' to authenticate",
+        });
+      } else if (message.includes('not available') || message.includes('does not provide')) {
+        // This is the expected case - Codex doesn't provide usage stats
+        res.status(503).json({
+          error: 'Usage statistics not available',
+          message: message,
+        });
+      } else if (message.includes('timed out')) {
+        res.status(504).json({
+          error: 'Command timed out',
+          message: 'The Codex CLI took too long to respond',
+        });
+      } else {
+        logger.error('Error fetching usage:', error);
+        res.status(500).json({ error: message });
+      }
+    }
+  });
+
+  return router;
+}
diff --git a/apps/server/src/services/codex-usage-service.ts b/apps/server/src/services/codex-usage-service.ts
new file mode 100644
index 00000000..3697f5c9
--- /dev/null
+++ b/apps/server/src/services/codex-usage-service.ts
@@ -0,0 +1,112 @@
+import { spawn } from 'child_process';
+import * as os from 'os';
+
+export interface CodexRateLimitWindow {
+  limit: number;
+  used: number;
+  remaining: number;
+  usedPercent: number;
+  windowDurationMins: number;
+  resetsAt: number;
+}
+
+export interface CodexCreditsSnapshot {
+  balance?: string;
+  unlimited?: boolean;
+  hasCredits?: boolean;
+}
+
+export type CodexPlanType = 'free' | 'plus' | 'pro' | 'team' | 'enterprise' | 'edu' | 'unknown';
+
+export interface CodexUsageData {
+  rateLimits: {
+    primary?: CodexRateLimitWindow;
+    secondary?: CodexRateLimitWindow;
+    credits?: CodexCreditsSnapshot;
+    planType?: CodexPlanType;
+  } | null;
+  lastUpdated: string;
+}
+
+/**
+ * Codex Usage Service
+ *
+ * Unlike Claude Code CLI which provides a `/usage` command, Codex CLI
+ * does not expose usage statistics directly. This service returns a
+ * clear message explaining this limitation.
+ *
+ * Future enhancement: Could query OpenAI API headers for rate limit info.
+ */
+export class CodexUsageService {
+  private codexBinary = 'codex';
+  private isWindows = os.platform() === 'win32';
+
+  /**
+   * Check if Codex CLI is available on the system
+   */
+  async isAvailable(): Promise<boolean> {
+    return new Promise((resolve) => {
+      const checkCmd = this.isWindows ? 'where' : 'which';
+      const proc = spawn(checkCmd, [this.codexBinary]);
+      proc.on('close', (code) => {
+        resolve(code === 0);
+      });
+      proc.on('error', () => {
+        resolve(false);
+      });
+    });
+  }
+
+  /**
+   * Attempt to fetch usage data
+   *
+   * Note: Codex CLI doesn't provide usage statistics like Claude Code does.
+   * This method returns an error explaining this limitation.
+   */
+  async fetchUsageData(): Promise<CodexUsageData> {
+    // Check authentication status first
+    const isAuthenticated = await this.checkAuthentication();
+
+    if (!isAuthenticated) {
+      throw new Error("Codex is not authenticated. Please run 'codex login' to authenticate.");
+    }
+
+    // Codex CLI doesn't provide a usage command
+    // Return an error that will be caught and displayed
+    throw new Error(
+      'Codex usage statistics are not available. Unlike Claude Code, the Codex CLI does not provide a built-in usage command. ' +
+        'Usage limits are enforced by OpenAI but cannot be queried via the CLI. ' +
+        'Check your OpenAI dashboard at https://platform.openai.com/usage for detailed usage information.'
+    );
+  }
+
+  /**
+   * Check if Codex is authenticated
+   */
+  private async checkAuthentication(): Promise<boolean> {
+    return new Promise((resolve) => {
+      const proc = spawn(this.codexBinary, ['login', 'status'], {
+        env: {
+          ...process.env,
+          TERM: 'dumb', // Avoid interactive output
+        },
+      });
+
+      let output = '';
+
+      proc.stdout.on('data', (data) => {
+        output += data.toString();
+      });
+
+      proc.on('close', (code) => {
+        // Check if output indicates logged in
+        const isLoggedIn = output.toLowerCase().includes('logged in');
+        resolve(code === 0 && isLoggedIn);
+      });
+
+      proc.on('error', () => {
+        resolve(false);
+      });
+    });
+  }
+}
diff --git a/apps/ui/src/components/codex-usage-popover.tsx b/apps/ui/src/components/codex-usage-popover.tsx
new file mode 100644
index 00000000..f6005b6a
--- /dev/null
+++ b/apps/ui/src/components/codex-usage-popover.tsx
@@ -0,0 +1,405 @@
+import { useState, useEffect, useMemo, useCallback } from 'react';
+import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
+import { Button } from '@/components/ui/button';
+import { RefreshCw, AlertTriangle, CheckCircle, XCircle, Clock, ExternalLink } from 'lucide-react';
+import { cn } from '@/lib/utils';
+import { getElectronAPI } from '@/lib/electron';
+import { useAppStore } from '@/store/app-store';
+import { useSetupStore } from '@/store/setup-store';
+
+// Error codes for distinguishing failure modes
+const ERROR_CODES = {
+  API_BRIDGE_UNAVAILABLE: 'API_BRIDGE_UNAVAILABLE',
+  AUTH_ERROR: 'AUTH_ERROR',
+  NOT_AVAILABLE: 'NOT_AVAILABLE',
+  UNKNOWN: 'UNKNOWN',
+} as const;
+
+type ErrorCode = (typeof ERROR_CODES)[keyof typeof ERROR_CODES];
+
+type UsageError = {
+  code: ErrorCode;
+  message: string;
+};
+
+// Fixed refresh interval (45 seconds)
+const REFRESH_INTERVAL_SECONDS = 45;
+
+// Helper to format reset time
+function formatResetTime(unixTimestamp: number): string {
+  const date = new Date(unixTimestamp * 1000);
+  const now = new Date();
+  const diff = date.getTime() - now.getTime();
+
+  // If less than 1 hour, show minutes
+  if (diff < 3600000) {
+    const mins = Math.ceil(diff / 60000);
+    return `Resets in ${mins}m`;
+  }
+
+  // If less than 24 hours, show hours and minutes
+  if (diff < 86400000) {
+    const hours = Math.floor(diff / 3600000);
+    const mins = Math.ceil((diff % 3600000) / 60000);
+    return `Resets in ${hours}h ${mins > 0 ? `${mins}m` : ''}`;
+  }
+
+  // Otherwise show date
+  return `Resets ${date.toLocaleDateString()} at ${date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}`;
+}
+
+// Helper to format window duration
+function getWindowLabel(durationMins: number): { title: string; subtitle: string } {
+  if (durationMins < 60) {
+    return { title: `${durationMins}min Window`, subtitle: 'Rate limit' };
+  }
+  if (durationMins < 1440) {
+    const hours = Math.round(durationMins / 60);
+    return { title: `${hours}h Window`, subtitle: 'Rate limit' };
+  }
+  const days = Math.round(durationMins / 1440);
+  return { title: `${days}d Window`, subtitle: 'Rate limit' };
+}
+
+export function CodexUsagePopover() {
+  const { codexUsage, codexUsageLastUpdated, setCodexUsage } = useAppStore();
+  const codexAuthStatus = useSetupStore((state) => state.codexAuthStatus);
+  const [open, setOpen] = useState(false);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<UsageError | null>(null);
+
+  // Check if Codex is authenticated
+  const isCodexAuthenticated = codexAuthStatus?.authenticated;
+
+  // Check if data is stale (older than 2 minutes)
+  const isStale = useMemo(() => {
+    return !codexUsageLastUpdated || Date.now() - codexUsageLastUpdated > 2 * 60 * 1000;
+  }, [codexUsageLastUpdated]);
+
+  const fetchUsage = useCallback(
+    async (isAutoRefresh = false) => {
+      if (!isAutoRefresh) setLoading(true);
+      setError(null);
+      try {
+        const api = getElectronAPI();
+        if (!api.codex) {
+          setError({
+            code: ERROR_CODES.API_BRIDGE_UNAVAILABLE,
+            message: 'Codex API bridge not available',
+          });
+          return;
+        }
+        const data = await api.codex.getUsage();
+        if ('error' in data) {
+          // Check if it's the "not available" error
+          if (
+            data.message?.includes('not available') ||
+            data.message?.includes('does not provide')
+          ) {
+            setError({
+              code: ERROR_CODES.NOT_AVAILABLE,
+              message: data.message || data.error,
+            });
+          } else {
+            setError({
+              code: ERROR_CODES.AUTH_ERROR,
+              message: data.message || data.error,
+            });
+          }
+          return;
+        }
+        setCodexUsage(data);
+      } catch (err) {
+        setError({
+          code: ERROR_CODES.UNKNOWN,
+          message: err instanceof Error ? err.message : 'Failed to fetch usage',
+        });
+      } finally {
+        if (!isAutoRefresh) setLoading(false);
+      }
+    },
+    [setCodexUsage]
+  );
+
+  // Auto-fetch on mount if data is stale (only if authenticated)
+  useEffect(() => {
+    if (isStale && isCodexAuthenticated) {
+      fetchUsage(true);
+    }
+  }, [isStale, isCodexAuthenticated, fetchUsage]);
+
+  useEffect(() => {
+    // Skip if not authenticated
+    if (!isCodexAuthenticated) return;
+
+    // Initial fetch when opened
+    if (open) {
+      if (!codexUsage || isStale) {
+        fetchUsage();
+      }
+    }
+
+    // Auto-refresh interval (only when open)
+    let intervalId: NodeJS.Timeout | null = null;
+    if (open) {
+      intervalId = setInterval(() => {
+        fetchUsage(true);
+      }, REFRESH_INTERVAL_SECONDS * 1000);
+    }
+
+    return () => {
+      if (intervalId) clearInterval(intervalId);
+    };
+  }, [open, codexUsage, isStale, isCodexAuthenticated, fetchUsage]);
+
+  // Derived status color/icon helper
+  const getStatusInfo = (percentage: number) => {
+    if (percentage >= 75) return { color: 'text-red-500', icon: XCircle, bg: 'bg-red-500' };
+    if (percentage >= 50)
+      return { color: 'text-orange-500', icon: AlertTriangle, bg: 'bg-orange-500' };
+    return { color: 'text-green-500', icon: CheckCircle, bg: 'bg-green-500' };
+  };
+
+  // Helper component for the progress bar
+  const ProgressBar = ({ percentage, colorClass }: { percentage: number; colorClass: string }) => (
+    <div className="h-2 w-full bg-secondary/50 rounded-full overflow-hidden">
+      <div
+        className={cn('h-full transition-all duration-500', colorClass)}
+        style={{ width: `${Math.min(percentage, 100)}%` }}
+      />
+    </div>
+  );
+
+  const UsageCard = ({
+    title,
+    subtitle,
+    percentage,
+    resetText,
+    isPrimary = false,
+    stale = false,
+  }: {
+    title: string;
+    subtitle: string;
+    percentage: number;
+    resetText?: string;
+    isPrimary?: boolean;
+    stale?: boolean;
+  }) => {
+    const isValidPercentage =
+      typeof percentage === 'number' && !isNaN(percentage) && isFinite(percentage);
+    const safePercentage = isValidPercentage ? percentage : 0;
+
+    const status = getStatusInfo(safePercentage);
+    const StatusIcon = status.icon;
+
+    return (
+      <div
+        className={cn(
+          'rounded-xl border bg-card/50 p-4 transition-opacity',
+          isPrimary ? 'border-border/60 shadow-sm' : 'border-border/40',
+          (stale || !isValidPercentage) && 'opacity-50'
+        )}
+      >
+        <div className="flex items-start justify-between mb-3">
+          <div>
+            <h4 className={cn('font-semibold', isPrimary ? 'text-sm' : 'text-xs')}>{title}</h4>
+            <p className="text-[10px] text-muted-foreground">{subtitle}</p>
+          </div>
+          {isValidPercentage ? (
+            <div className="flex items-center gap-1.5">
+              <StatusIcon className={cn('w-3.5 h-3.5', status.color)} />
+              <span
+                className={cn(
+                  'font-mono font-bold',
+                  status.color,
+                  isPrimary ? 'text-base' : 'text-sm'
+                )}
+              >
+                {Math.round(safePercentage)}%
+              </span>
+            </div>
+          ) : (
+            <span className="text-xs text-muted-foreground">N/A</span>
+          )}
+        </div>
+        <ProgressBar
+          percentage={safePercentage}
+          colorClass={isValidPercentage ? status.bg : 'bg-muted-foreground/30'}
+        />
+        {resetText && (
+          <div className="mt-2 flex justify-end">
+            <p className="text-xs text-muted-foreground flex items-center gap-1">
+              <Clock className="w-3 h-3" />
+              {resetText}
+            </p>
+          </div>
+        )}
+      </div>
+    );
+  };
+
+  // Header Button
+  const maxPercentage = codexUsage?.rateLimits
+    ? Math.max(
+        codexUsage.rateLimits.primary?.usedPercent || 0,
+        codexUsage.rateLimits.secondary?.usedPercent || 0
+      )
+    : 0;
+
+  const getProgressBarColor = (percentage: number) => {
+    if (percentage >= 80) return 'bg-red-500';
+    if (percentage >= 50) return 'bg-yellow-500';
+    return 'bg-green-500';
+  };
+
+  const trigger = (
+    <Button variant="ghost" size="sm" className="h-9 gap-3 bg-secondary border border-border px-3">
+      <span className="text-sm font-medium">Codex</span>
+      {codexUsage && codexUsage.rateLimits && (
+        <div
+          className={cn(
+            'h-1.5 w-16 bg-muted-foreground/20 rounded-full overflow-hidden transition-opacity',
+            isStale && 'opacity-60'
+          )}
+        >
+          <div
+            className={cn('h-full transition-all duration-500', getProgressBarColor(maxPercentage))}
+            style={{ width: `${Math.min(maxPercentage, 100)}%` }}
+          />
+        </div>
+      )}
+    </Button>
+  );
+
+  return (
+    <Popover open={open} onOpenChange={setOpen}>
+      <PopoverTrigger asChild>{trigger}</PopoverTrigger>
+      <PopoverContent
+        className="w-80 p-0 overflow-hidden bg-background/95 backdrop-blur-xl border-border shadow-2xl"
+        align="end"
+        sideOffset={8}
+      >
+        {/* Header */}
+        <div className="flex items-center justify-between px-4 py-3 border-b border-border/50 bg-secondary/10">
+          <div className="flex items-center gap-2">
+            <span className="text-sm font-semibold">Codex Usage</span>
+          </div>
+          {error && error.code !== ERROR_CODES.NOT_AVAILABLE && (
+            <Button
+              variant="ghost"
+              size="icon"
+              className={cn('h-6 w-6', loading && 'opacity-80')}
+              onClick={() => !loading && fetchUsage(false)}
+            >
+              <RefreshCw className="w-3.5 h-3.5" />
+            </Button>
+          )}
+        </div>
+
+        {/* Content */}
+        <div className="p-4 space-y-4">
+          {error ? (
+            <div className="flex flex-col items-center justify-center py-6 text-center space-y-3">
+              <AlertTriangle className="w-8 h-8 text-yellow-500/80" />
+              <div className="space-y-1 flex flex-col items-center">
+                <p className="text-sm font-medium">
+                  {error.code === ERROR_CODES.NOT_AVAILABLE ? 'Usage not available' : error.message}
+                </p>
+                <p className="text-xs text-muted-foreground">
+                  {error.code === ERROR_CODES.API_BRIDGE_UNAVAILABLE ? (
+                    'Ensure the Electron bridge is running or restart the app'
+                  ) : error.code === ERROR_CODES.NOT_AVAILABLE ? (
+                    <>
+                      Codex CLI doesn't provide usage statistics. Check{' '}
+                      <a
+                        href="https://platform.openai.com/usage"
+                        target="_blank"
+                        rel="noreferrer"
+                        className="underline hover:text-foreground"
+                      >
+                        OpenAI dashboard
+                      </a>{' '}
+                      for usage details.
+                    </>
+                  ) : (
+                    <>
+                      Make sure Codex CLI is installed and authenticated via{' '}
+                      <code className="font-mono bg-muted px-1 rounded">codex login</code>
+                    </>
+                  )}
+                </p>
+              </div>
+            </div>
+          ) : !codexUsage ? (
+            // Loading state
+            <div className="flex flex-col items-center justify-center py-8 space-y-2">
+              <RefreshCw className="w-6 h-6 animate-spin text-muted-foreground/50" />
+              <p className="text-xs text-muted-foreground">Loading usage data...</p>
+            </div>
+          ) : codexUsage.rateLimits ? (
+            <>
+              {/* Primary Window Card */}
+              {codexUsage.rateLimits.primary && (
+                <UsageCard
+                  title={getWindowLabel(codexUsage.rateLimits.primary.windowDurationMins).title}
+                  subtitle={
+                    getWindowLabel(codexUsage.rateLimits.primary.windowDurationMins).subtitle
+                  }
+                  percentage={codexUsage.rateLimits.primary.usedPercent}
+                  resetText={formatResetTime(codexUsage.rateLimits.primary.resetsAt)}
+                  isPrimary={true}
+                  stale={isStale}
+                />
+              )}
+
+              {/* Secondary Window Card */}
+              {codexUsage.rateLimits.secondary && (
+                <UsageCard
+                  title={getWindowLabel(codexUsage.rateLimits.secondary.windowDurationMins).title}
+                  subtitle={
+                    getWindowLabel(codexUsage.rateLimits.secondary.windowDurationMins).subtitle
+                  }
+                  percentage={codexUsage.rateLimits.secondary.usedPercent}
+                  resetText={formatResetTime(codexUsage.rateLimits.secondary.resetsAt)}
+                  stale={isStale}
+                />
+              )}
+
+              {/* Plan Type */}
+              {codexUsage.rateLimits.planType && (
+                <div className="rounded-xl border border-border/40 bg-secondary/20 p-3">
+                  <p className="text-xs text-muted-foreground">
+                    Plan:{' '}
+                    <span className="text-foreground font-medium">
+                      {codexUsage.rateLimits.planType.charAt(0).toUpperCase() +
+                        codexUsage.rateLimits.planType.slice(1)}
+                    </span>
+                  </p>
+                </div>
+              )}
+            </>
+          ) : (
+            <div className="flex flex-col items-center justify-center py-6 text-center">
+              <AlertTriangle className="w-8 h-8 text-yellow-500/80" />
+              <p className="text-sm font-medium mt-3">No usage data available</p>
+            </div>
+          )}
+        </div>
+
+        {/* Footer */}
+        <div className="flex items-center justify-between px-4 py-2 bg-secondary/10 border-t border-border/50">
+          <a
+            href="https://platform.openai.com/usage"
+            target="_blank"
+            rel="noreferrer"
+            className="text-[10px] text-muted-foreground hover:text-foreground flex items-center gap-1 transition-colors"
+          >
+            OpenAI Dashboard <ExternalLink className="w-2.5 h-2.5" />
+          </a>
+
+          <span className="text-[10px] text-muted-foreground">Updates every minute</span>
+        </div>
+      </PopoverContent>
+    </Popover>
+  );
+}
diff --git a/apps/ui/src/components/usage-popover.tsx b/apps/ui/src/components/usage-popover.tsx
new file mode 100644
index 00000000..e772d48b
--- /dev/null
+++ b/apps/ui/src/components/usage-popover.tsx
@@ -0,0 +1,612 @@
+import { useState, useEffect, useMemo, useCallback } from 'react';
+import { Popover, PopoverContent, PopoverTrigger } from '@/components/ui/popover';
+import { Button } from '@/components/ui/button';
+import { Tabs, TabsContent, TabsList, TabsTrigger } from '@/components/ui/tabs';
+import { RefreshCw, AlertTriangle, CheckCircle, XCircle, Clock, ExternalLink } from 'lucide-react';
+import { cn } from '@/lib/utils';
+import { getElectronAPI } from '@/lib/electron';
+import { useAppStore } from '@/store/app-store';
+import { useSetupStore } from '@/store/setup-store';
+import { AnthropicIcon, OpenAIIcon } from '@/components/ui/provider-icon';
+
+// Error codes for distinguishing failure modes
+const ERROR_CODES = {
+  API_BRIDGE_UNAVAILABLE: 'API_BRIDGE_UNAVAILABLE',
+  AUTH_ERROR: 'AUTH_ERROR',
+  NOT_AVAILABLE: 'NOT_AVAILABLE',
+  UNKNOWN: 'UNKNOWN',
+} as const;
+
+type ErrorCode = (typeof ERROR_CODES)[keyof typeof ERROR_CODES];
+
+type UsageError = {
+  code: ErrorCode;
+  message: string;
+};
+
+// Fixed refresh interval (45 seconds)
+const REFRESH_INTERVAL_SECONDS = 45;
+
+// Helper to format reset time for Codex
+function formatCodexResetTime(unixTimestamp: number): string {
+  const date = new Date(unixTimestamp * 1000);
+  const now = new Date();
+  const diff = date.getTime() - now.getTime();
+
+  if (diff < 3600000) {
+    const mins = Math.ceil(diff / 60000);
+    return `Resets in ${mins}m`;
+  }
+  if (diff < 86400000) {
+    const hours = Math.floor(diff / 3600000);
+    const mins = Math.ceil((diff % 3600000) / 60000);
+    return `Resets in ${hours}h ${mins > 0 ? `${mins}m` : ''}`;
+  }
+  return `Resets ${date.toLocaleDateString()} at ${date.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}`;
+}
+
+// Helper to format window duration for Codex
+function getCodexWindowLabel(durationMins: number): { title: string; subtitle: string } {
+  if (durationMins < 60) {
+    return { title: `${durationMins}min Window`, subtitle: 'Rate limit' };
+  }
+  if (durationMins < 1440) {
+    const hours = Math.round(durationMins / 60);
+    return { title: `${hours}h Window`, subtitle: 'Rate limit' };
+  }
+  const days = Math.round(durationMins / 1440);
+  return { title: `${days}d Window`, subtitle: 'Rate limit' };
+}
+
+export function UsagePopover() {
+  const { claudeUsage, claudeUsageLastUpdated, setClaudeUsage } = useAppStore();
+  const { codexUsage, codexUsageLastUpdated, setCodexUsage } = useAppStore();
+  const claudeAuthStatus = useSetupStore((state) => state.claudeAuthStatus);
+  const codexAuthStatus = useSetupStore((state) => state.codexAuthStatus);
+
+  const [open, setOpen] = useState(false);
+  const [activeTab, setActiveTab] = useState<'claude' | 'codex'>('claude');
+  const [claudeLoading, setClaudeLoading] = useState(false);
+  const [codexLoading, setCodexLoading] = useState(false);
+  const [claudeError, setClaudeError] = useState<UsageError | null>(null);
+  const [codexError, setCodexError] = useState<UsageError | null>(null);
+
+  // Check authentication status
+  const isClaudeCliVerified =
+    claudeAuthStatus?.authenticated && claudeAuthStatus?.method === 'cli_authenticated';
+  const isCodexAuthenticated = codexAuthStatus?.authenticated;
+
+  // Determine which tab to show by default
+  useEffect(() => {
+    if (isClaudeCliVerified) {
+      setActiveTab('claude');
+    } else if (isCodexAuthenticated) {
+      setActiveTab('codex');
+    }
+  }, [isClaudeCliVerified, isCodexAuthenticated]);
+
+  // Check if data is stale (older than 2 minutes)
+  const isClaudeStale = useMemo(() => {
+    return !claudeUsageLastUpdated || Date.now() - claudeUsageLastUpdated > 2 * 60 * 1000;
+  }, [claudeUsageLastUpdated]);
+
+  const isCodexStale = useMemo(() => {
+    return !codexUsageLastUpdated || Date.now() - codexUsageLastUpdated > 2 * 60 * 1000;
+  }, [codexUsageLastUpdated]);
+
+  const fetchClaudeUsage = useCallback(
+    async (isAutoRefresh = false) => {
+      if (!isAutoRefresh) setClaudeLoading(true);
+      setClaudeError(null);
+      try {
+        const api = getElectronAPI();
+        if (!api.claude) {
+          setClaudeError({
+            code: ERROR_CODES.API_BRIDGE_UNAVAILABLE,
+            message: 'Claude API bridge not available',
+          });
+          return;
+        }
+        const data = await api.claude.getUsage();
+        if ('error' in data) {
+          setClaudeError({
+            code: ERROR_CODES.AUTH_ERROR,
+            message: data.message || data.error,
+          });
+          return;
+        }
+        setClaudeUsage(data);
+      } catch (err) {
+        setClaudeError({
+          code: ERROR_CODES.UNKNOWN,
+          message: err instanceof Error ? err.message : 'Failed to fetch usage',
+        });
+      } finally {
+        if (!isAutoRefresh) setClaudeLoading(false);
+      }
+    },
+    [setClaudeUsage]
+  );
+
+  const fetchCodexUsage = useCallback(
+    async (isAutoRefresh = false) => {
+      if (!isAutoRefresh) setCodexLoading(true);
+      setCodexError(null);
+      try {
+        const api = getElectronAPI();
+        if (!api.codex) {
+          setCodexError({
+            code: ERROR_CODES.API_BRIDGE_UNAVAILABLE,
+            message: 'Codex API bridge not available',
+          });
+          return;
+        }
+        const data = await api.codex.getUsage();
+        if ('error' in data) {
+          if (
+            data.message?.includes('not available') ||
+            data.message?.includes('does not provide')
+          ) {
+            setCodexError({
+              code: ERROR_CODES.NOT_AVAILABLE,
+              message: data.message || data.error,
+            });
+          } else {
+            setCodexError({
+              code: ERROR_CODES.AUTH_ERROR,
+              message: data.message || data.error,
+            });
+          }
+          return;
+        }
+        setCodexUsage(data);
+      } catch (err) {
+        setCodexError({
+          code: ERROR_CODES.UNKNOWN,
+          message: err instanceof Error ? err.message : 'Failed to fetch usage',
+        });
+      } finally {
+        if (!isAutoRefresh) setCodexLoading(false);
+      }
+    },
+    [setCodexUsage]
+  );
+
+  // Auto-fetch on mount if data is stale
+  useEffect(() => {
+    if (isClaudeStale && isClaudeCliVerified) {
+      fetchClaudeUsage(true);
+    }
+  }, [isClaudeStale, isClaudeCliVerified, fetchClaudeUsage]);
+
+  useEffect(() => {
+    if (isCodexStale && isCodexAuthenticated) {
+      fetchCodexUsage(true);
+    }
+  }, [isCodexStale, isCodexAuthenticated, fetchCodexUsage]);
+
+  // Auto-refresh when popover is open
+  useEffect(() => {
+    if (!open) return;
+
+    // Fetch based on active tab
+    if (activeTab === 'claude' && isClaudeCliVerified) {
+      if (!claudeUsage || isClaudeStale) {
+        fetchClaudeUsage();
+      }
+      const intervalId = setInterval(() => {
+        fetchClaudeUsage(true);
+      }, REFRESH_INTERVAL_SECONDS * 1000);
+      return () => clearInterval(intervalId);
+    }
+
+    if (activeTab === 'codex' && isCodexAuthenticated) {
+      if (!codexUsage || isCodexStale) {
+        fetchCodexUsage();
+      }
+      const intervalId = setInterval(() => {
+        fetchCodexUsage(true);
+      }, REFRESH_INTERVAL_SECONDS * 1000);
+      return () => clearInterval(intervalId);
+    }
+  }, [
+    open,
+    activeTab,
+    claudeUsage,
+    isClaudeStale,
+    isClaudeCliVerified,
+    codexUsage,
+    isCodexStale,
+    isCodexAuthenticated,
+    fetchClaudeUsage,
+    fetchCodexUsage,
+  ]);
+
+  // Derived status color/icon helper
+  const getStatusInfo = (percentage: number) => {
+    if (percentage >= 75) return { color: 'text-red-500', icon: XCircle, bg: 'bg-red-500' };
+    if (percentage >= 50)
+      return { color: 'text-orange-500', icon: AlertTriangle, bg: 'bg-orange-500' };
+    return { color: 'text-green-500', icon: CheckCircle, bg: 'bg-green-500' };
+  };
+
+  // Helper component for the progress bar
+  const ProgressBar = ({ percentage, colorClass }: { percentage: number; colorClass: string }) => (
+    <div className="h-2 w-full bg-secondary/50 rounded-full overflow-hidden">
+      <div
+        className={cn('h-full transition-all duration-500', colorClass)}
+        style={{ width: `${Math.min(percentage, 100)}%` }}
+      />
+    </div>
+  );
+
+  const UsageCard = ({
+    title,
+    subtitle,
+    percentage,
+    resetText,
+    isPrimary = false,
+    stale = false,
+  }: {
+    title: string;
+    subtitle: string;
+    percentage: number;
+    resetText?: string;
+    isPrimary?: boolean;
+    stale?: boolean;
+  }) => {
+    const isValidPercentage =
+      typeof percentage === 'number' && !isNaN(percentage) && isFinite(percentage);
+    const safePercentage = isValidPercentage ? percentage : 0;
+
+    const status = getStatusInfo(safePercentage);
+    const StatusIcon = status.icon;
+
+    return (
+      <div
+        className={cn(
+          'rounded-xl border bg-card/50 p-4 transition-opacity',
+          isPrimary ? 'border-border/60 shadow-sm' : 'border-border/40',
+          (stale || !isValidPercentage) && 'opacity-50'
+        )}
+      >
+        <div className="flex items-start justify-between mb-3">
+          <div>
+            <h4 className={cn('font-semibold', isPrimary ? 'text-sm' : 'text-xs')}>{title}</h4>
+            <p className="text-[10px] text-muted-foreground">{subtitle}</p>
+          </div>
+          {isValidPercentage ? (
+            <div className="flex items-center gap-1.5">
+              <StatusIcon className={cn('w-3.5 h-3.5', status.color)} />
+              <span
+                className={cn(
+                  'font-mono font-bold',
+                  status.color,
+                  isPrimary ? 'text-base' : 'text-sm'
+                )}
+              >
+                {Math.round(safePercentage)}%
+              </span>
+            </div>
+          ) : (
+            <span className="text-xs text-muted-foreground">N/A</span>
+          )}
+        </div>
+        <ProgressBar
+          percentage={safePercentage}
+          colorClass={isValidPercentage ? status.bg : 'bg-muted-foreground/30'}
+        />
+        {resetText && (
+          <div className="mt-2 flex justify-end">
+            <p className="text-xs text-muted-foreground flex items-center gap-1">
+              <Clock className="w-3 h-3" />
+              {resetText}
+            </p>
+          </div>
+        )}
+      </div>
+    );
+  };
+
+  // Calculate max percentage for header button
+  const claudeMaxPercentage = claudeUsage
+    ? Math.max(claudeUsage.sessionPercentage || 0, claudeUsage.weeklyPercentage || 0)
+    : 0;
+
+  const codexMaxPercentage = codexUsage?.rateLimits
+    ? Math.max(
+        codexUsage.rateLimits.primary?.usedPercent || 0,
+        codexUsage.rateLimits.secondary?.usedPercent || 0
+      )
+    : 0;
+
+  const maxPercentage = Math.max(claudeMaxPercentage, codexMaxPercentage);
+  const isStale = activeTab === 'claude' ? isClaudeStale : isCodexStale;
+
+  const getProgressBarColor = (percentage: number) => {
+    if (percentage >= 80) return 'bg-red-500';
+    if (percentage >= 50) return 'bg-yellow-500';
+    return 'bg-green-500';
+  };
+
+  const trigger = (
+    <Button variant="ghost" size="sm" className="h-9 gap-3 bg-secondary border border-border px-3">
+      <span className="text-sm font-medium">Usage</span>
+      {(claudeUsage || codexUsage) && (
+        <div
+          className={cn(
+            'h-1.5 w-16 bg-muted-foreground/20 rounded-full overflow-hidden transition-opacity',
+            isStale && 'opacity-60'
+          )}
+        >
+          <div
+            className={cn('h-full transition-all duration-500', getProgressBarColor(maxPercentage))}
+            style={{ width: `${Math.min(maxPercentage, 100)}%` }}
+          />
+        </div>
+      )}
+    </Button>
+  );
+
+  // Determine which tabs to show
+  const showClaudeTab = isClaudeCliVerified;
+  const showCodexTab = isCodexAuthenticated;
+
+  return (
+    <Popover open={open} onOpenChange={setOpen}>
+      <PopoverTrigger asChild>{trigger}</PopoverTrigger>
+      <PopoverContent
+        className="w-80 p-0 overflow-hidden bg-background/95 backdrop-blur-xl border-border shadow-2xl"
+        align="end"
+        sideOffset={8}
+      >
+        <Tabs value={activeTab} onValueChange={(v) => setActiveTab(v as 'claude' | 'codex')}>
+          {/* Tabs Header */}
+          {showClaudeTab && showCodexTab && (
+            <TabsList className="grid w-full grid-cols-2 rounded-none border-b border-border/50">
+              <TabsTrigger value="claude" className="gap-2">
+                <AnthropicIcon className="w-3.5 h-3.5" />
+                Claude
+              </TabsTrigger>
+              <TabsTrigger value="codex" className="gap-2">
+                <OpenAIIcon className="w-3.5 h-3.5" />
+                Codex
+              </TabsTrigger>
+            </TabsList>
+          )}
+
+          {/* Claude Tab Content */}
+          <TabsContent value="claude" className="m-0">
+            {/* Header */}
+            <div className="flex items-center justify-between px-4 py-3 border-b border-border/50 bg-secondary/10">
+              <div className="flex items-center gap-2">
+                <AnthropicIcon className="w-4 h-4" />
+                <span className="text-sm font-semibold">Claude Usage</span>
+              </div>
+              {claudeError && (
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className={cn('h-6 w-6', claudeLoading && 'opacity-80')}
+                  onClick={() => !claudeLoading && fetchClaudeUsage(false)}
+                >
+                  <RefreshCw className="w-3.5 h-3.5" />
+                </Button>
+              )}
+            </div>
+
+            {/* Content */}
+            <div className="p-4 space-y-4">
+              {claudeError ? (
+                <div className="flex flex-col items-center justify-center py-6 text-center space-y-3">
+                  <AlertTriangle className="w-8 h-8 text-yellow-500/80" />
+                  <div className="space-y-1 flex flex-col items-center">
+                    <p className="text-sm font-medium">{claudeError.message}</p>
+                    <p className="text-xs text-muted-foreground">
+                      {claudeError.code === ERROR_CODES.API_BRIDGE_UNAVAILABLE ? (
+                        'Ensure the Electron bridge is running or restart the app'
+                      ) : (
+                        <>
+                          Make sure Claude CLI is installed and authenticated via{' '}
+                          <code className="font-mono bg-muted px-1 rounded">claude login</code>
+                        </>
+                      )}
+                    </p>
+                  </div>
+                </div>
+              ) : !claudeUsage ? (
+                <div className="flex flex-col items-center justify-center py-8 space-y-2">
+                  <RefreshCw className="w-6 h-6 animate-spin text-muted-foreground/50" />
+                  <p className="text-xs text-muted-foreground">Loading usage data...</p>
+                </div>
+              ) : (
+                <>
+                  <UsageCard
+                    title="Session Usage"
+                    subtitle="5-hour rolling window"
+                    percentage={claudeUsage.sessionPercentage}
+                    resetText={claudeUsage.sessionResetText}
+                    isPrimary={true}
+                    stale={isClaudeStale}
+                  />
+
+                  <div className="grid grid-cols-2 gap-3">
+                    <UsageCard
+                      title="Weekly"
+                      subtitle="All models"
+                      percentage={claudeUsage.weeklyPercentage}
+                      resetText={claudeUsage.weeklyResetText}
+                      stale={isClaudeStale}
+                    />
+                    <UsageCard
+                      title="Sonnet"
+                      subtitle="Weekly"
+                      percentage={claudeUsage.sonnetWeeklyPercentage}
+                      resetText={claudeUsage.sonnetResetText}
+                      stale={isClaudeStale}
+                    />
+                  </div>
+
+                  {claudeUsage.costLimit && claudeUsage.costLimit > 0 && (
+                    <UsageCard
+                      title="Extra Usage"
+                      subtitle={`${claudeUsage.costUsed ?? 0} / ${claudeUsage.costLimit} ${claudeUsage.costCurrency ?? ''}`}
+                      percentage={
+                        claudeUsage.costLimit > 0
+                          ? ((claudeUsage.costUsed ?? 0) / claudeUsage.costLimit) * 100
+                          : 0
+                      }
+                      stale={isClaudeStale}
+                    />
+                  )}
+                </>
+              )}
+            </div>
+
+            {/* Footer */}
+            <div className="flex items-center justify-between px-4 py-2 bg-secondary/10 border-t border-border/50">
+              <a
+                href="https://status.claude.com"
+                target="_blank"
+                rel="noreferrer"
+                className="text-[10px] text-muted-foreground hover:text-foreground flex items-center gap-1 transition-colors"
+              >
+                Claude Status <ExternalLink className="w-2.5 h-2.5" />
+              </a>
+              <span className="text-[10px] text-muted-foreground">Updates every minute</span>
+            </div>
+          </TabsContent>
+
+          {/* Codex Tab Content */}
+          <TabsContent value="codex" className="m-0">
+            {/* Header */}
+            <div className="flex items-center justify-between px-4 py-3 border-b border-border/50 bg-secondary/10">
+              <div className="flex items-center gap-2">
+                <OpenAIIcon className="w-4 h-4" />
+                <span className="text-sm font-semibold">Codex Usage</span>
+              </div>
+              {codexError && codexError.code !== ERROR_CODES.NOT_AVAILABLE && (
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className={cn('h-6 w-6', codexLoading && 'opacity-80')}
+                  onClick={() => !codexLoading && fetchCodexUsage(false)}
+                >
+                  <RefreshCw className="w-3.5 h-3.5" />
+                </Button>
+              )}
+            </div>
+
+            {/* Content */}
+            <div className="p-4 space-y-4">
+              {codexError ? (
+                <div className="flex flex-col items-center justify-center py-6 text-center space-y-3">
+                  <AlertTriangle className="w-8 h-8 text-yellow-500/80" />
+                  <div className="space-y-1 flex flex-col items-center">
+                    <p className="text-sm font-medium">
+                      {codexError.code === ERROR_CODES.NOT_AVAILABLE
+                        ? 'Usage not available'
+                        : codexError.message}
+                    </p>
+                    <p className="text-xs text-muted-foreground">
+                      {codexError.code === ERROR_CODES.API_BRIDGE_UNAVAILABLE ? (
+                        'Ensure the Electron bridge is running or restart the app'
+                      ) : codexError.code === ERROR_CODES.NOT_AVAILABLE ? (
+                        <>
+                          Codex CLI doesn't provide usage statistics. Check{' '}
+                          <a
+                            href="https://platform.openai.com/usage"
+                            target="_blank"
+                            rel="noreferrer"
+                            className="underline hover:text-foreground"
+                          >
+                            OpenAI dashboard
+                          </a>{' '}
+                          for usage details.
+                        </>
+                      ) : (
+                        <>
+                          Make sure Codex CLI is installed and authenticated via{' '}
+                          <code className="font-mono bg-muted px-1 rounded">codex login</code>
+                        </>
+                      )}
+                    </p>
+                  </div>
+                </div>
+              ) : !codexUsage ? (
+                <div className="flex flex-col items-center justify-center py-8 space-y-2">
+                  <RefreshCw className="w-6 h-6 animate-spin text-muted-foreground/50" />
+                  <p className="text-xs text-muted-foreground">Loading usage data...</p>
+                </div>
+              ) : codexUsage.rateLimits ? (
+                <>
+                  {codexUsage.rateLimits.primary && (
+                    <UsageCard
+                      title={
+                        getCodexWindowLabel(codexUsage.rateLimits.primary.windowDurationMins).title
+                      }
+                      subtitle={
+                        getCodexWindowLabel(codexUsage.rateLimits.primary.windowDurationMins)
+                          .subtitle
+                      }
+                      percentage={codexUsage.rateLimits.primary.usedPercent}
+                      resetText={formatCodexResetTime(codexUsage.rateLimits.primary.resetsAt)}
+                      isPrimary={true}
+                      stale={isCodexStale}
+                    />
+                  )}
+
+                  {codexUsage.rateLimits.secondary && (
+                    <UsageCard
+                      title={
+                        getCodexWindowLabel(codexUsage.rateLimits.secondary.windowDurationMins)
+                          .title
+                      }
+                      subtitle={
+                        getCodexWindowLabel(codexUsage.rateLimits.secondary.windowDurationMins)
+                          .subtitle
+                      }
+                      percentage={codexUsage.rateLimits.secondary.usedPercent}
+                      resetText={formatCodexResetTime(codexUsage.rateLimits.secondary.resetsAt)}
+                      stale={isCodexStale}
+                    />
+                  )}
+
+                  {codexUsage.rateLimits.planType && (
+                    <div className="rounded-xl border border-border/40 bg-secondary/20 p-3">
+                      <p className="text-xs text-muted-foreground">
+                        Plan:{' '}
+                        <span className="text-foreground font-medium">
+                          {codexUsage.rateLimits.planType.charAt(0).toUpperCase() +
+                            codexUsage.rateLimits.planType.slice(1)}
+                        </span>
+                      </p>
+                    </div>
+                  )}
+                </>
+              ) : (
+                <div className="flex flex-col items-center justify-center py-6 text-center">
+                  <AlertTriangle className="w-8 h-8 text-yellow-500/80" />
+                  <p className="text-sm font-medium mt-3">No usage data available</p>
+                </div>
+              )}
+            </div>
+
+            {/* Footer */}
+            <div className="flex items-center justify-between px-4 py-2 bg-secondary/10 border-t border-border/50">
+              <a
+                href="https://platform.openai.com/usage"
+                target="_blank"
+                rel="noreferrer"
+                className="text-[10px] text-muted-foreground hover:text-foreground flex items-center gap-1 transition-colors"
+              >
+                OpenAI Dashboard <ExternalLink className="w-2.5 h-2.5" />
+              </a>
+              <span className="text-[10px] text-muted-foreground">Updates every minute</span>
+            </div>
+          </TabsContent>
+        </Tabs>
+      </PopoverContent>
+    </Popover>
+  );
+}
diff --git a/apps/ui/src/components/views/board-view/board-header.tsx b/apps/ui/src/components/views/board-view/board-header.tsx
index 884cf495..21f30bf2 100644
--- a/apps/ui/src/components/views/board-view/board-header.tsx
+++ b/apps/ui/src/components/views/board-view/board-header.tsx
@@ -5,7 +5,7 @@ import { Switch } from '@/components/ui/switch';
 import { Label } from '@/components/ui/label';
 import { Plus, Bot, Wand2 } from 'lucide-react';
 import { KeyboardShortcut } from '@/hooks/use-keyboard-shortcuts';
-import { ClaudeUsagePopover } from '@/components/claude-usage-popover';
+import { UsagePopover } from '@/components/usage-popover';
 import { useAppStore } from '@/store/app-store';
 import { useSetupStore } from '@/store/setup-store';
 
@@ -40,17 +40,21 @@ export function BoardHeader({
 }: BoardHeaderProps) {
   const apiKeys = useAppStore((state) => state.apiKeys);
   const claudeAuthStatus = useSetupStore((state) => state.claudeAuthStatus);
+  const codexAuthStatus = useSetupStore((state) => state.codexAuthStatus);
 
-  // Hide usage tracking when using API key (only show for Claude Code CLI users)
-  // Check both user-entered API key and environment variable ANTHROPIC_API_KEY
+  // Claude usage tracking visibility logic
+  // Hide when using API key (only show for Claude Code CLI users)
   // Also hide on Windows for now (CLI usage command not supported)
-  // Only show if CLI has been verified/authenticated
   const isWindows =
     typeof navigator !== 'undefined' && navigator.platform?.toLowerCase().includes('win');
-  const hasApiKey = !!apiKeys.anthropic || !!claudeAuthStatus?.hasEnvApiKey;
-  const isCliVerified =
+  const hasClaudeApiKey = !!apiKeys.anthropic || !!claudeAuthStatus?.hasEnvApiKey;
+  const isClaudeCliVerified =
     claudeAuthStatus?.authenticated && claudeAuthStatus?.method === 'cli_authenticated';
-  const showUsageTracking = !hasApiKey && !isWindows && isCliVerified;
+  const showClaudeUsage = !hasClaudeApiKey && !isWindows && isClaudeCliVerified;
+
+  // Codex usage tracking visibility logic
+  // Show if Codex is authenticated (CLI or API key)
+  const showCodexUsage = !!codexAuthStatus?.authenticated;
 
   return (
     <div className="flex items-center justify-between p-4 border-b border-border bg-glass backdrop-blur-md">
@@ -59,8 +63,8 @@ export function BoardHeader({
         <p className="text-sm text-muted-foreground">{projectName}</p>
       </div>
       <div className="flex gap-2 items-center">
-        {/* Usage Popover - only show for CLI users (not API key users) */}
-        {isMounted && showUsageTracking && <ClaudeUsagePopover />}
+        {/* Usage Popover - show if either provider is authenticated */}
+        {isMounted && (showClaudeUsage || showCodexUsage) && <UsagePopover />}
 
         {/* Concurrency Slider - only show after mount to prevent hydration issues */}
         {isMounted && (
diff --git a/apps/ui/src/lib/http-api-client.ts b/apps/ui/src/lib/http-api-client.ts
index d1e51992..ffb8aabc 100644
--- a/apps/ui/src/lib/http-api-client.ts
+++ b/apps/ui/src/lib/http-api-client.ts
@@ -36,7 +36,7 @@ import type {
   ConvertToFeatureOptions,
 } from './electron';
 import type { Message, SessionListItem } from '@/types/electron';
-import type { Feature, ClaudeUsageResponse } from '@/store/app-store';
+import type { Feature, ClaudeUsageResponse, CodexUsageResponse } from '@/store/app-store';
 import type { WorktreeAPI, GitAPI, ModelDefinition, ProviderStatus } from '@/types/electron';
 import { getGlobalFileBrowser } from '@/contexts/file-browser-context';
 
@@ -1834,6 +1834,11 @@ export class HttpApiClient implements ElectronAPI {
     getUsage: (): Promise<ClaudeUsageResponse> => this.get('/api/claude/usage'),
   };
 
+  // Codex API
+  codex = {
+    getUsage: (): Promise<CodexUsageResponse> => this.get('/api/codex/usage'),
+  };
+
   // Context API
   context = {
     describeImage: (
diff --git a/apps/ui/src/store/app-store.ts b/apps/ui/src/store/app-store.ts
index 960348c0..8abca72e 100644
--- a/apps/ui/src/store/app-store.ts
+++ b/apps/ui/src/store/app-store.ts
@@ -646,20 +646,24 @@ export interface CodexRateLimitWindow {
   limit: number;
   used: number;
   remaining: number;
-  window: number; // Duration in minutes
+  usedPercent: number; // Percentage used (0-100)
+  windowDurationMins: number; // Duration in minutes
   resetsAt: number; // Unix timestamp in seconds
 }
 
 export interface CodexUsage {
-  planType: CodexPlanType | null;
-  credits: CodexCreditsSnapshot | null;
   rateLimits: {
-    session?: CodexRateLimitWindow;
-    weekly?: CodexRateLimitWindow;
+    primary?: CodexRateLimitWindow;
+    secondary?: CodexRateLimitWindow;
+    credits?: CodexCreditsSnapshot;
+    planType?: CodexPlanType;
   } | null;
   lastUpdated: string;
 }
 
+// Response type for Codex usage API (can be success or error)
+export type CodexUsageResponse = CodexUsage | { error: string; message?: string };
+
 /**
  * Check if Claude usage is at its limit (any of: session >= 100%, weekly >= 100%, OR cost >= limit)
  * Returns true if any limit is reached, meaning auto mode should pause feature pickup.