Feat: Show Gemini Usage in usage dropdown and mobile sidebar

apps/server/src/index.ts

@@ -68,6 +68,7 @@ import { CodexAppServerService } from './services/codex-app-server-service.js';
 import { CodexModelCacheService } from './services/codex-model-cache-service.js';
 import { createZaiRoutes } from './routes/zai/index.js';
 import { ZaiUsageService } from './services/zai-usage-service.js';
+import { createGeminiRoutes } from './routes/gemini/index.js';
 import { createGitHubRoutes } from './routes/github/index.js';
 import { createContextRoutes } from './routes/context/index.js';
 import { createBacklogPlanRoutes } from './routes/backlog-plan/index.js';
@@ -438,6 +439,7 @@ app.use('/api/settings', createSettingsRoutes(settingsService));
 app.use('/api/claude', createClaudeRoutes(claudeUsageService));
 app.use('/api/codex', createCodexRoutes(codexUsageService, codexModelCacheService));
 app.use('/api/zai', createZaiRoutes(zaiUsageService, settingsService));
+app.use('/api/gemini', createGeminiRoutes());
 app.use('/api/github', createGitHubRoutes(events, settingsService));
 app.use('/api/context', createContextRoutes(settingsService));
 app.use('/api/backlog-plan', createBacklogPlanRoutes(events, settingsService));

apps/server/src/routes/gemini/index.ts

@@ -0,0 +1,60 @@
+import { Router, Request, Response } from 'express';
+import { GeminiProvider } from '../../providers/gemini-provider.js';
+import { getGeminiUsageService } from '../../services/gemini-usage-service.js';
+import { createLogger } from '@automaker/utils';
+
+const logger = createLogger('Gemini');
+
+export function createGeminiRoutes(): Router {
+  const router = Router();
+
+  // Get current usage/quota data from Google Cloud API
+  router.get('/usage', async (_req: Request, res: Response) => {
+    try {
+      const usageService = getGeminiUsageService();
+      const usageData = await usageService.fetchUsageData();
+
+      res.json(usageData);
+    } catch (error) {
+      const message = error instanceof Error ? error.message : 'Unknown error';
+      logger.error('Error fetching Gemini usage:', error);
+
+      // Return error in a format the UI expects
+      res.status(200).json({
+        authenticated: false,
+        authMethod: 'none',
+        usedPercent: 0,
+        remainingPercent: 100,
+        lastUpdated: new Date().toISOString(),
+        error: `Failed to fetch Gemini usage: ${message}`,
+      });
+    }
+  });
+
+  // Check if Gemini is available
+  router.get('/status', async (_req: Request, res: Response) => {
+    try {
+      const provider = new GeminiProvider();
+      const status = await provider.detectInstallation();
+
+      const authMethod =
+        (status as any).authMethod ||
+        (status.authenticated ? (status.hasApiKey ? 'api_key' : 'cli_login') : 'none');
+
+      res.json({
+        success: true,
+        installed: status.installed,
+        version: status.version || null,
+        path: status.path || null,
+        authenticated: status.authenticated || false,
+        authMethod,
+        hasCredentialsFile: (status as any).hasCredentialsFile || false,
+      });
+    } catch (error) {
+      const message = error instanceof Error ? error.message : 'Unknown error';
+      res.status(500).json({ success: false, error: message });
+    }
+  });
+
+  return router;
+}

apps/server/src/services/gemini-usage-service.ts

@@ -0,0 +1,761 @@
+/**
+ * Gemini Usage Service
+ *
+ * Service for tracking Gemini CLI usage and quota.
+ * Uses the internal Google Cloud quota API (same as CodexBar).
+ * See: https://github.com/steipete/CodexBar/blob/main/docs/gemini.md
+ *
+ * OAuth credentials are extracted from the Gemini CLI installation,
+ * not hardcoded, to ensure compatibility with CLI updates.
+ */
+
+import { createLogger } from '@automaker/utils';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as os from 'os';
+import { execSync } from 'child_process';
+
+const logger = createLogger('GeminiUsage');
+
+// Quota API endpoint (internal Google Cloud API)
+const QUOTA_API_URL = 'https://cloudcode-pa.googleapis.com/v1internal:retrieveUserQuota';
+
+// Code Assist endpoint for getting project ID and tier info
+const CODE_ASSIST_URL = 'https://cloudcode-pa.googleapis.com/v1internal:loadCodeAssist';
+
+// Google OAuth endpoints for token refresh
+const GOOGLE_TOKEN_URL = 'https://oauth2.googleapis.com/token';
+
+export interface GeminiQuotaBucket {
+  /** Model ID this quota applies to */
+  modelId: string;
+  /** Remaining fraction (0-1) */
+  remainingFraction: number;
+  /** ISO-8601 reset time */
+  resetTime: string;
+}
+
+/** Simplified quota info for a model tier (Flash or Pro) */
+export interface GeminiTierQuota {
+  /** Used percentage (0-100) */
+  usedPercent: number;
+  /** Remaining percentage (0-100) */
+  remainingPercent: number;
+  /** Reset time as human-readable string */
+  resetText?: string;
+  /** ISO-8601 reset time */
+  resetTime?: string;
+}
+
+export interface GeminiUsageData {
+  /** Whether authenticated via CLI */
+  authenticated: boolean;
+  /** Authentication method */
+  authMethod: 'cli_login' | 'api_key' | 'none';
+  /** Usage percentage (100 - remainingFraction * 100) - overall most constrained */
+  usedPercent: number;
+  /** Remaining percentage - overall most constrained */
+  remainingPercent: number;
+  /** Reset time as human-readable string */
+  resetText?: string;
+  /** ISO-8601 reset time */
+  resetTime?: string;
+  /** Model ID with lowest remaining quota */
+  constrainedModel?: string;
+  /** Flash tier quota (aggregated from all flash models) */
+  flashQuota?: GeminiTierQuota;
+  /** Pro tier quota (aggregated from all pro models) */
+  proQuota?: GeminiTierQuota;
+  /** Raw quota buckets for detailed view */
+  quotaBuckets?: GeminiQuotaBucket[];
+  /** When this data was last fetched */
+  lastUpdated: string;
+  /** Optional error message */
+  error?: string;
+}
+
+interface OAuthCredentials {
+  access_token?: string;
+  id_token?: string;
+  refresh_token?: string;
+  token_type?: string;
+  expiry_date?: number;
+  client_id?: string;
+  client_secret?: string;
+}
+
+interface OAuthClientCredentials {
+  clientId: string;
+  clientSecret: string;
+}
+
+interface QuotaResponse {
+  // The actual API returns 'buckets', not 'quotaBuckets'
+  buckets?: Array<{
+    modelId?: string;
+    remainingFraction?: number;
+    resetTime?: string;
+    tokenType?: string;
+  }>;
+  // Legacy field name (in case API changes)
+  quotaBuckets?: Array<{
+    modelId?: string;
+    remainingFraction?: number;
+    resetTime?: string;
+    tokenType?: string;
+  }>;
+}
+
+/**
+ * Gemini Usage Service
+ *
+ * Provides real usage/quota data for Gemini CLI users.
+ * Extracts OAuth credentials from the Gemini CLI installation.
+ */
+export class GeminiUsageService {
+  private cachedCredentials: OAuthCredentials | null = null;
+  private cachedClientCredentials: OAuthClientCredentials | null = null;
+  private credentialsPath: string;
+
+  constructor() {
+    // Default credentials path for Gemini CLI
+    this.credentialsPath = path.join(os.homedir(), '.gemini', 'oauth_creds.json');
+  }
+
+  /**
+   * Check if Gemini CLI is authenticated
+   */
+  async isAvailable(): Promise<boolean> {
+    const creds = await this.loadCredentials();
+    return Boolean(creds?.access_token || creds?.refresh_token);
+  }
+
+  /**
+   * Fetch quota/usage data from Google Cloud API
+   */
+  async fetchUsageData(): Promise<GeminiUsageData> {
+    logger.info('[fetchUsageData] Starting...');
+
+    const creds = await this.loadCredentials();
+
+    if (!creds || (!creds.access_token && !creds.refresh_token)) {
+      logger.info('[fetchUsageData] No credentials found');
+      return {
+        authenticated: false,
+        authMethod: 'none',
+        usedPercent: 0,
+        remainingPercent: 100,
+        lastUpdated: new Date().toISOString(),
+        error: 'Not authenticated. Run "gemini auth login" to authenticate.',
+      };
+    }
+
+    try {
+      // Get a valid access token (refresh if needed)
+      const accessToken = await this.getValidAccessToken(creds);
+
+      if (!accessToken) {
+        return {
+          authenticated: false,
+          authMethod: 'none',
+          usedPercent: 0,
+          remainingPercent: 100,
+          lastUpdated: new Date().toISOString(),
+          error: 'Failed to obtain access token. Try running "gemini auth login" again.',
+        };
+      }
+
+      // First, get the project ID from loadCodeAssist endpoint
+      // This is required to get accurate quota data
+      let projectId: string | undefined;
+      try {
+        const codeAssistResponse = await fetch(CODE_ASSIST_URL, {
+          method: 'POST',
+          headers: {
+            Authorization: `Bearer ${accessToken}`,
+            'Content-Type': 'application/json',
+          },
+          body: JSON.stringify({}),
+        });
+
+        if (codeAssistResponse.ok) {
+          const codeAssistData = (await codeAssistResponse.json()) as {
+            cloudaicompanionProject?: string;
+            currentTier?: { id?: string; name?: string };
+          };
+          projectId = codeAssistData.cloudaicompanionProject;
+          logger.debug('[fetchUsageData] Got project ID:', projectId);
+        }
+      } catch (e) {
+        logger.debug('[fetchUsageData] Failed to get project ID:', e);
+      }
+
+      // Fetch quota from Google Cloud API
+      // Pass project ID to get accurate quota (without it, returns default 100%)
+      const response = await fetch(QUOTA_API_URL, {
+        method: 'POST',
+        headers: {
+          Authorization: `Bearer ${accessToken}`,
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify(projectId ? { project: projectId } : {}),
+      });
+
+      if (!response.ok) {
+        const errorText = await response.text().catch(() => '');
+        logger.error('[fetchUsageData] Quota API error:', response.status, errorText);
+
+        // Still authenticated, but quota API failed
+        return {
+          authenticated: true,
+          authMethod: 'cli_login',
+          usedPercent: 0,
+          remainingPercent: 100,
+          lastUpdated: new Date().toISOString(),
+          error: `Quota API unavailable (${response.status})`,
+        };
+      }
+
+      const data = (await response.json()) as QuotaResponse;
+
+      // API returns 'buckets', with fallback to 'quotaBuckets' for compatibility
+      const apiBuckets = data.buckets || data.quotaBuckets;
+
+      logger.debug('[fetchUsageData] Raw buckets:', JSON.stringify(apiBuckets));
+
+      if (!apiBuckets || apiBuckets.length === 0) {
+        return {
+          authenticated: true,
+          authMethod: 'cli_login',
+          usedPercent: 0,
+          remainingPercent: 100,
+          lastUpdated: new Date().toISOString(),
+        };
+      }
+
+      // Group buckets into Flash and Pro tiers
+      // Flash: any model with "flash" in the name
+      // Pro: any model with "pro" in the name
+      let flashLowestRemaining = 1.0;
+      let flashResetTime: string | undefined;
+      let hasFlashModels = false;
+      let proLowestRemaining = 1.0;
+      let proResetTime: string | undefined;
+      let hasProModels = false;
+      let overallLowestRemaining = 1.0;
+      let constrainedModel: string | undefined;
+      let overallResetTime: string | undefined;
+
+      const quotaBuckets: GeminiQuotaBucket[] = apiBuckets.map((bucket) => {
+        const remaining = bucket.remainingFraction ?? 1.0;
+        const modelId = bucket.modelId?.toLowerCase() || '';
+
+        // Track overall lowest
+        if (remaining < overallLowestRemaining) {
+          overallLowestRemaining = remaining;
+          constrainedModel = bucket.modelId;
+          overallResetTime = bucket.resetTime;
+        }
+
+        // Group into Flash or Pro tier
+        if (modelId.includes('flash')) {
+          hasFlashModels = true;
+          if (remaining < flashLowestRemaining) {
+            flashLowestRemaining = remaining;
+            flashResetTime = bucket.resetTime;
+          }
+          // Also track reset time even if at 100%
+          if (!flashResetTime && bucket.resetTime) {
+            flashResetTime = bucket.resetTime;
+          }
+        } else if (modelId.includes('pro')) {
+          hasProModels = true;
+          if (remaining < proLowestRemaining) {
+            proLowestRemaining = remaining;
+            proResetTime = bucket.resetTime;
+          }
+          // Also track reset time even if at 100%
+          if (!proResetTime && bucket.resetTime) {
+            proResetTime = bucket.resetTime;
+          }
+        }
+
+        return {
+          modelId: bucket.modelId || 'unknown',
+          remainingFraction: remaining,
+          resetTime: bucket.resetTime || '',
+        };
+      });
+
+      const usedPercent = Math.round((1 - overallLowestRemaining) * 100);
+      const remainingPercent = Math.round(overallLowestRemaining * 100);
+
+      // Build tier quotas (only include if we found models for that tier)
+      const flashQuota: GeminiTierQuota | undefined = hasFlashModels
+        ? {
+            usedPercent: Math.round((1 - flashLowestRemaining) * 100),
+            remainingPercent: Math.round(flashLowestRemaining * 100),
+            resetText: flashResetTime ? this.formatResetTime(flashResetTime) : undefined,
+            resetTime: flashResetTime,
+          }
+        : undefined;
+
+      const proQuota: GeminiTierQuota | undefined = hasProModels
+        ? {
+            usedPercent: Math.round((1 - proLowestRemaining) * 100),
+            remainingPercent: Math.round(proLowestRemaining * 100),
+            resetText: proResetTime ? this.formatResetTime(proResetTime) : undefined,
+            resetTime: proResetTime,
+          }
+        : undefined;
+
+      return {
+        authenticated: true,
+        authMethod: 'cli_login',
+        usedPercent,
+        remainingPercent,
+        resetText: overallResetTime ? this.formatResetTime(overallResetTime) : undefined,
+        resetTime: overallResetTime,
+        constrainedModel,
+        flashQuota,
+        proQuota,
+        quotaBuckets,
+        lastUpdated: new Date().toISOString(),
+      };
+    } catch (error) {
+      const errorMsg = error instanceof Error ? error.message : 'Unknown error';
+      logger.error('[fetchUsageData] Error:', errorMsg);
+
+      return {
+        authenticated: true,
+        authMethod: 'cli_login',
+        usedPercent: 0,
+        remainingPercent: 100,
+        lastUpdated: new Date().toISOString(),
+        error: `Failed to fetch quota: ${errorMsg}`,
+      };
+    }
+  }
+
+  /**
+   * Load OAuth credentials from file
+   */
+  private async loadCredentials(): Promise<OAuthCredentials | null> {
+    if (this.cachedCredentials) {
+      return this.cachedCredentials;
+    }
+
+    // Check multiple possible paths
+    const possiblePaths = [
+      this.credentialsPath,
+      path.join(os.homedir(), '.gemini', 'oauth_creds.json'),
+      path.join(os.homedir(), '.config', 'gemini', 'oauth_creds.json'),
+    ];
+
+    for (const credPath of possiblePaths) {
+      try {
+        if (fs.existsSync(credPath)) {
+          const content = fs.readFileSync(credPath, 'utf8');
+          const creds = JSON.parse(content);
+
+          // Handle different credential formats
+          if (creds.access_token || creds.refresh_token) {
+            this.cachedCredentials = creds;
+            logger.info('[loadCredentials] Loaded from:', credPath);
+            return creds;
+          }
+
+          // Some formats nest credentials under 'web' or 'installed'
+          if (creds.web?.client_id || creds.installed?.client_id) {
+            const clientCreds = creds.web || creds.installed;
+            this.cachedCredentials = {
+              client_id: clientCreds.client_id,
+              client_secret: clientCreds.client_secret,
+            };
+            return this.cachedCredentials;
+          }
+        }
+      } catch (error) {
+        logger.debug('[loadCredentials] Failed to load from', credPath, error);
+      }
+    }
+
+    return null;
+  }
+
+  /**
+   * Find the Gemini CLI binary path
+   */
+  private findGeminiBinaryPath(): string | null {
+    try {
+      // Try 'which' on Unix-like systems
+      const whichResult = execSync('which gemini 2>/dev/null', { encoding: 'utf8' }).trim();
+      if (whichResult && fs.existsSync(whichResult)) {
+        return whichResult;
+      }
+    } catch {
+      // Ignore errors from 'which'
+    }
+
+    // Check common installation paths
+    const possiblePaths = [
+      // npm global installs
+      path.join(os.homedir(), '.npm-global', 'bin', 'gemini'),
+      '/usr/local/bin/gemini',
+      '/usr/bin/gemini',
+      // Homebrew
+      '/opt/homebrew/bin/gemini',
+      '/usr/local/opt/gemini/bin/gemini',
+      // nvm/fnm node installs
+      path.join(os.homedir(), '.nvm', 'versions', 'node'),
+      path.join(os.homedir(), '.fnm', 'node-versions'),
+      // Windows
+      path.join(os.homedir(), 'AppData', 'Roaming', 'npm', 'gemini.cmd'),
+      path.join(os.homedir(), 'AppData', 'Roaming', 'npm', 'gemini'),
+    ];
+
+    for (const p of possiblePaths) {
+      if (fs.existsSync(p)) {
+        return p;
+      }
+    }
+
+    return null;
+  }
+
+  /**
+   * Extract OAuth client credentials from Gemini CLI installation
+   * This mimics CodexBar's approach of finding oauth2.js in the CLI
+   */
+  private extractOAuthClientCredentials(): OAuthClientCredentials | null {
+    if (this.cachedClientCredentials) {
+      return this.cachedClientCredentials;
+    }
+
+    const geminiBinary = this.findGeminiBinaryPath();
+    if (!geminiBinary) {
+      logger.debug('[extractOAuthClientCredentials] Gemini binary not found');
+      return null;
+    }
+
+    // Resolve symlinks to find actual location
+    let resolvedPath = geminiBinary;
+    try {
+      resolvedPath = fs.realpathSync(geminiBinary);
+    } catch {
+      // Use original path if realpath fails
+    }
+
+    const baseDir = path.dirname(resolvedPath);
+    logger.debug('[extractOAuthClientCredentials] Base dir:', baseDir);
+
+    // Possible locations for oauth2.js relative to the binary
+    // Based on CodexBar's search patterns
+    const possibleOAuth2Paths = [
+      // npm global install structure
+      path.join(
+        baseDir,
+        '..',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+      path.join(
+        baseDir,
+        '..',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli-core',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+      // Homebrew/libexec structure
+      path.join(
+        baseDir,
+        '..',
+        'libexec',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+      path.join(
+        baseDir,
+        '..',
+        'libexec',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli-core',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+      // Direct sibling
+      path.join(baseDir, '..', 'gemini-cli-core', 'dist', 'src', 'code_assist', 'oauth2.js'),
+      path.join(baseDir, '..', 'gemini-cli', 'dist', 'src', 'code_assist', 'oauth2.js'),
+      // Alternative node_modules structures
+      path.join(
+        baseDir,
+        '..',
+        '..',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+      path.join(
+        baseDir,
+        '..',
+        '..',
+        'lib',
+        'node_modules',
+        '@google',
+        'gemini-cli-core',
+        'dist',
+        'src',
+        'code_assist',
+        'oauth2.js'
+      ),
+    ];
+
+    for (const oauth2Path of possibleOAuth2Paths) {
+      try {
+        const normalizedPath = path.normalize(oauth2Path);
+        if (fs.existsSync(normalizedPath)) {
+          logger.debug('[extractOAuthClientCredentials] Found oauth2.js at:', normalizedPath);
+          const content = fs.readFileSync(normalizedPath, 'utf8');
+          const creds = this.parseOAuthCredentialsFromSource(content);
+          if (creds) {
+            this.cachedClientCredentials = creds;
+            logger.info('[extractOAuthClientCredentials] Extracted credentials from CLI');
+            return creds;
+          }
+        }
+      } catch (error) {
+        logger.debug('[extractOAuthClientCredentials] Failed to read', oauth2Path, error);
+      }
+    }
+
+    // Try finding oauth2.js by searching in node_modules
+    try {
+      const searchResult = execSync(
+        `find ${baseDir}/.. -name "oauth2.js" -path "*gemini*" -path "*code_assist*" 2>/dev/null | head -1`,
+        { encoding: 'utf8', timeout: 5000 }
+      ).trim();
+
+      if (searchResult && fs.existsSync(searchResult)) {
+        logger.debug('[extractOAuthClientCredentials] Found via search:', searchResult);
+        const content = fs.readFileSync(searchResult, 'utf8');
+        const creds = this.parseOAuthCredentialsFromSource(content);
+        if (creds) {
+          this.cachedClientCredentials = creds;
+          logger.info(
+            '[extractOAuthClientCredentials] Extracted credentials from CLI (via search)'
+          );
+          return creds;
+        }
+      }
+    } catch {
+      // Ignore search errors
+    }
+
+    logger.warn('[extractOAuthClientCredentials] Could not extract credentials from CLI');
+    return null;
+  }
+
+  /**
+   * Parse OAuth client credentials from oauth2.js source code
+   */
+  private parseOAuthCredentialsFromSource(content: string): OAuthClientCredentials | null {
+    // Patterns based on CodexBar's regex extraction
+    // Look for: OAUTH_CLIENT_ID = "..." or const clientId = "..."
+    const clientIdPatterns = [
+      /OAUTH_CLIENT_ID\s*=\s*["']([^"']+)["']/,
+      /clientId\s*[:=]\s*["']([^"']+)["']/,
+      /client_id\s*[:=]\s*["']([^"']+)["']/,
+      /"clientId"\s*:\s*["']([^"']+)["']/,
+    ];
+
+    const clientSecretPatterns = [
+      /OAUTH_CLIENT_SECRET\s*=\s*["']([^"']+)["']/,
+      /clientSecret\s*[:=]\s*["']([^"']+)["']/,
+      /client_secret\s*[:=]\s*["']([^"']+)["']/,
+      /"clientSecret"\s*:\s*["']([^"']+)["']/,
+    ];
+
+    let clientId: string | null = null;
+    let clientSecret: string | null = null;
+
+    for (const pattern of clientIdPatterns) {
+      const match = content.match(pattern);
+      if (match && match[1]) {
+        clientId = match[1];
+        break;
+      }
+    }
+
+    for (const pattern of clientSecretPatterns) {
+      const match = content.match(pattern);
+      if (match && match[1]) {
+        clientSecret = match[1];
+        break;
+      }
+    }
+
+    if (clientId && clientSecret) {
+      logger.debug('[parseOAuthCredentialsFromSource] Found client credentials');
+      return { clientId, clientSecret };
+    }
+
+    return null;
+  }
+
+  /**
+   * Get a valid access token, refreshing if necessary
+   */
+  private async getValidAccessToken(creds: OAuthCredentials): Promise<string | null> {
+    // Check if current token is still valid (with 5 min buffer)
+    if (creds.access_token && creds.expiry_date) {
+      const now = Date.now();
+      if (creds.expiry_date > now + 5 * 60 * 1000) {
+        logger.debug('[getValidAccessToken] Using existing token (not expired)');
+        return creds.access_token;
+      }
+    }
+
+    // If we have a refresh token, try to refresh
+    if (creds.refresh_token) {
+      // Try to extract credentials from CLI first
+      const extractedCreds = this.extractOAuthClientCredentials();
+
+      // Use extracted credentials, then fall back to credentials in file
+      const clientId = extractedCreds?.clientId || creds.client_id;
+      const clientSecret = extractedCreds?.clientSecret || creds.client_secret;
+
+      if (!clientId || !clientSecret) {
+        logger.error('[getValidAccessToken] No client credentials available for token refresh');
+        // Return existing token even if expired - it might still work
+        return creds.access_token || null;
+      }
+
+      try {
+        logger.debug('[getValidAccessToken] Refreshing token...');
+        const response = await fetch(GOOGLE_TOKEN_URL, {
+          method: 'POST',
+          headers: {
+            'Content-Type': 'application/x-www-form-urlencoded',
+          },
+          body: new URLSearchParams({
+            client_id: clientId,
+            client_secret: clientSecret,
+            refresh_token: creds.refresh_token,
+            grant_type: 'refresh_token',
+          }),
+        });
+
+        if (response.ok) {
+          const data = (await response.json()) as { access_token?: string; expires_in?: number };
+          const newAccessToken = data.access_token;
+          const expiresIn = data.expires_in || 3600;
+
+          if (newAccessToken) {
+            logger.info('[getValidAccessToken] Token refreshed successfully');
+
+            // Update cached credentials
+            this.cachedCredentials = {
+              ...creds,
+              access_token: newAccessToken,
+              expiry_date: Date.now() + expiresIn * 1000,
+            };
+
+            // Save back to file
+            try {
+              fs.writeFileSync(
+                this.credentialsPath,
+                JSON.stringify(this.cachedCredentials, null, 2)
+              );
+            } catch (e) {
+              logger.debug('[getValidAccessToken] Could not save refreshed token:', e);
+            }
+
+            return newAccessToken;
+          }
+        } else {
+          const errorText = await response.text().catch(() => '');
+          logger.error('[getValidAccessToken] Token refresh failed:', response.status, errorText);
+        }
+      } catch (error) {
+        logger.error('[getValidAccessToken] Token refresh error:', error);
+      }
+    }
+
+    // Return current access token even if it might be expired
+    return creds.access_token || null;
+  }
+
+  /**
+   * Format reset time as human-readable string
+   */
+  private formatResetTime(isoTime: string): string {
+    try {
+      const resetDate = new Date(isoTime);
+      const now = new Date();
+      const diff = resetDate.getTime() - now.getTime();
+
+      if (diff < 0) {
+        return 'Resetting soon';
+      }
+
+      const minutes = Math.floor(diff / 60000);
+      const hours = Math.floor(minutes / 60);
+
+      if (hours > 0) {
+        const remainingMins = minutes % 60;
+        return remainingMins > 0 ? `Resets in ${hours}h ${remainingMins}m` : `Resets in ${hours}h`;
+      }
+
+      return `Resets in ${minutes}m`;
+    } catch {
+      return '';
+    }
+  }
+
+  /**
+   * Clear cached credentials (useful after logout)
+   */
+  clearCache(): void {
+    this.cachedCredentials = null;
+    this.cachedClientCredentials = null;
+  }
+}
+
+// Singleton instance
+let usageServiceInstance: GeminiUsageService | null = null;
+
+/**
+ * Get the singleton instance of GeminiUsageService
+ */
+export function getGeminiUsageService(): GeminiUsageService {
+  if (!usageServiceInstance) {
+    usageServiceInstance = new GeminiUsageService();
+  }
+  return usageServiceInstance;
+}

apps/ui/src/components/usage-popover.tsx

@@ -6,8 +6,8 @@ import { RefreshCw, AlertTriangle, CheckCircle, XCircle, Clock, ExternalLink } f
 import { Spinner } from '@/components/ui/spinner';
 import { cn } from '@/lib/utils';
 import { useSetupStore } from '@/store/setup-store';
-import { AnthropicIcon, OpenAIIcon, ZaiIcon } from '@/components/ui/provider-icon';
-import { useClaudeUsage, useCodexUsage, useZaiUsage } from '@/hooks/queries';
+import { AnthropicIcon, OpenAIIcon, ZaiIcon, GeminiIcon } from '@/components/ui/provider-icon';
+import { useClaudeUsage, useCodexUsage, useZaiUsage, useGeminiUsage } from '@/hooks/queries';
 
 // Error codes for distinguishing failure modes
 const ERROR_CODES = {
@@ -81,14 +81,16 @@ export function UsagePopover() {
   const claudeAuthStatus = useSetupStore((state) => state.claudeAuthStatus);
   const codexAuthStatus = useSetupStore((state) => state.codexAuthStatus);
   const zaiAuthStatus = useSetupStore((state) => state.zaiAuthStatus);
+  const geminiAuthStatus = useSetupStore((state) => state.geminiAuthStatus);
 
   const [open, setOpen] = useState(false);
-  const [activeTab, setActiveTab] = useState<'claude' | 'codex' | 'zai'>('claude');
+  const [activeTab, setActiveTab] = useState<'claude' | 'codex' | 'zai' | 'gemini'>('claude');
 
   // Check authentication status
   const isClaudeAuthenticated = !!claudeAuthStatus?.authenticated;
   const isCodexAuthenticated = codexAuthStatus?.authenticated;
   const isZaiAuthenticated = zaiAuthStatus?.authenticated;
+  const isGeminiAuthenticated = geminiAuthStatus?.authenticated;
 
   // Use React Query hooks for usage data
   // Only enable polling when popover is open AND the tab is active
@@ -116,6 +118,14 @@ export function UsagePopover() {
     refetch: refetchZai,
   } = useZaiUsage(open && activeTab === 'zai' && isZaiAuthenticated);
 
+  const {
+    data: geminiUsage,
+    isLoading: geminiLoading,
+    error: geminiQueryError,
+    dataUpdatedAt: geminiUsageLastUpdated,
+    refetch: refetchGemini,
+  } = useGeminiUsage(open && activeTab === 'gemini' && isGeminiAuthenticated);
+
   // Parse errors into structured format
   const claudeError = useMemo((): UsageError | null => {
     if (!claudeQueryError) return null;
@@ -157,6 +167,19 @@ export function UsagePopover() {
     return { code: ERROR_CODES.AUTH_ERROR, message };
   }, [zaiQueryError]);
 
+  const geminiError = useMemo((): UsageError | null => {
+    if (!geminiQueryError) return null;
+    const message =
+      geminiQueryError instanceof Error ? geminiQueryError.message : String(geminiQueryError);
+    if (message.includes('not configured') || message.includes('not authenticated')) {
+      return { code: ERROR_CODES.NOT_AVAILABLE, message };
+    }
+    if (message.includes('API bridge')) {
+      return { code: ERROR_CODES.API_BRIDGE_UNAVAILABLE, message };
+    }
+    return { code: ERROR_CODES.AUTH_ERROR, message };
+  }, [geminiQueryError]);
+
   // Determine which tab to show by default
   useEffect(() => {
     if (isClaudeAuthenticated) {
@@ -165,8 +188,10 @@ export function UsagePopover() {
       setActiveTab('codex');
     } else if (isZaiAuthenticated) {
       setActiveTab('zai');
+    } else if (isGeminiAuthenticated) {
+      setActiveTab('gemini');
     }
-  }, [isClaudeAuthenticated, isCodexAuthenticated, isZaiAuthenticated]);
+  }, [isClaudeAuthenticated, isCodexAuthenticated, isZaiAuthenticated, isGeminiAuthenticated]);
 
   // Check if data is stale (older than 2 minutes)
   const isClaudeStale = useMemo(() => {
@@ -181,10 +206,15 @@ export function UsagePopover() {
     return !zaiUsageLastUpdated || Date.now() - zaiUsageLastUpdated > 2 * 60 * 1000;
   }, [zaiUsageLastUpdated]);
 
+  const isGeminiStale = useMemo(() => {
+    return !geminiUsageLastUpdated || Date.now() - geminiUsageLastUpdated > 2 * 60 * 1000;
+  }, [geminiUsageLastUpdated]);
+
   // Refetch functions for manual refresh
   const fetchClaudeUsage = () => refetchClaude();
   const fetchCodexUsage = () => refetchCodex();
   const fetchZaiUsage = () => refetchZai();
+  const fetchGeminiUsage = () => refetchGemini();
 
   // Derived status color/icon helper
   const getStatusInfo = (percentage: number) => {
@@ -275,6 +305,23 @@ export function UsagePopover() {
   // Calculate max percentage for header button
   const claudeSessionPercentage = claudeUsage?.sessionPercentage || 0;
 
+  const codexMaxPercentage = codexUsage?.rateLimits
+    ? Math.max(
+        codexUsage.rateLimits.primary?.usedPercent || 0,
+        codexUsage.rateLimits.secondary?.usedPercent || 0
+      )
+    : 0;
+
+  const zaiMaxPercentage = zaiUsage?.quotaLimits
+    ? Math.max(
+        zaiUsage.quotaLimits.tokens?.usedPercent || 0,
+        zaiUsage.quotaLimits.mcp?.usedPercent || 0
+      )
+    : 0;
+
+  // Gemini quota from Google Cloud API (if available)
+  const geminiMaxPercentage = geminiUsage?.usedPercent ?? (geminiUsage?.authenticated ? 0 : 100);
+
   const getProgressBarColor = (percentage: number) => {
     if (percentage >= 80) return 'bg-red-500';
     if (percentage >= 50) return 'bg-yellow-500';
@@ -299,33 +346,43 @@ export function UsagePopover() {
   const indicatorInfo =
     activeTab === 'claude'
       ? {
-        icon: AnthropicIcon,
-        percentage: claudeSessionPercentage,
-        isStale: isClaudeStale,
-        title: `Session usage (${CLAUDE_SESSION_WINDOW_HOURS}h window)`,
-      }
-      : activeTab === 'codex' ? {
-        icon: OpenAIIcon,
-        percentage: codexWindowUsage ?? 0,
-        isStale: isCodexStale,
-        title: `Usage (${codexWindowLabel})`,
-      } : activeTab === 'zai' ? {
-        icon: ZaiIcon,
-        percentage: zaiMaxPercentage,
-        isStale: isZaiStale,
-        title: `Usage (z.ai)`,
-      } : null;
+          icon: AnthropicIcon,
+          percentage: claudeSessionPercentage,
+          isStale: isClaudeStale,
+          title: `Session usage (${CLAUDE_SESSION_WINDOW_HOURS}h window)`,
+        }
+      : activeTab === 'codex'
+        ? {
+            icon: OpenAIIcon,
+            percentage: codexWindowUsage ?? 0,
+            isStale: isCodexStale,
+          }
+        : activeTab === 'zai'
+          ? {
+              icon: ZaiIcon,
+              percentage: zaiMaxPercentage,
+              isStale: isZaiStale,
+              title: `Usage (z.ai)`,
+            }
+          : activeTab === 'gemini'
+            ? {
+                icon: GeminiIcon,
+                percentage: geminiMaxPercentage,
+                isStale: isGeminiStale,
+                title: `Usage (Gemini)`,
+              }
+            : null;
 
   const statusColor = getStatusInfo(indicatorInfo.percentage).color;
   const ProviderIcon = indicatorInfo.icon;
 
   const trigger = (
     <Button variant="ghost" size="sm" className="h-9 gap-2 bg-secondary border border-border px-3">
-      {(claudeUsage || codexUsage || zaiUsage) && (
+      {(claudeUsage || codexUsage || zaiUsage || geminiUsage) && (
         <ProviderIcon className={cn('w-4 h-4', statusColor)} />
       )}
       <span className="text-sm font-medium">Usage</span>
-      {(claudeUsage || codexUsage || zaiUsage) && (
+      {(claudeUsage || codexUsage || zaiUsage || geminiUsage) && (
         <div
           title={indicatorInfo.title}
           className={cn(
@@ -349,7 +406,8 @@ export function UsagePopover() {
   const showClaudeTab = isClaudeAuthenticated;
   const showCodexTab = isCodexAuthenticated;
   const showZaiTab = isZaiAuthenticated;
-  const tabCount = [showClaudeTab, showCodexTab, showZaiTab].filter(Boolean).length;
+  const showGeminiTab = isGeminiAuthenticated;
+  const tabCount = [showClaudeTab, showCodexTab, showZaiTab, showGeminiTab].filter(Boolean).length;
 
   return (
     <Popover open={open} onOpenChange={setOpen}>
@@ -361,7 +419,7 @@ export function UsagePopover() {
       >
         <Tabs
           value={activeTab}
-          onValueChange={(v) => setActiveTab(v as 'claude' | 'codex' | 'zai')}
+          onValueChange={(v) => setActiveTab(v as 'claude' | 'codex' | 'zai' | 'gemini')}
         >
           {/* Tabs Header */}
           {tabCount > 1 && (
@@ -369,7 +427,8 @@ export function UsagePopover() {
               className={cn(
                 'grid w-full rounded-none border-b border-border/50',
                 tabCount === 2 && 'grid-cols-2',
-                tabCount === 3 && 'grid-cols-3'
+                tabCount === 3 && 'grid-cols-3',
+                tabCount === 4 && 'grid-cols-4'
               )}
             >
               {showClaudeTab && (
@@ -390,6 +449,12 @@ export function UsagePopover() {
                   z.ai
                 </TabsTrigger>
               )}
+              {showGeminiTab && (
+                <TabsTrigger value="gemini" className="gap-2">
+                  <GeminiIcon className="w-3.5 h-3.5" />
+                  Gemini
+                </TabsTrigger>
+              )}
             </TabsList>
           )}
 
@@ -454,13 +519,6 @@ export function UsagePopover() {
                   />
 
                   <div className="grid grid-cols-2 gap-3">
-                    <UsageCard
-                      title="Sonnet"
-                      subtitle="Weekly"
-                      percentage={claudeUsage.sonnetWeeklyPercentage}
-                      resetText={claudeUsage.sonnetResetText}
-                      stale={isClaudeStale}
-                    />
                     <UsageCard
                       title="Weekly"
                       subtitle="All models"
@@ -744,6 +802,143 @@ export function UsagePopover() {
               <span className="text-[10px] text-muted-foreground">Updates every minute</span>
             </div>
           </TabsContent>
+
+          {/* Gemini Tab Content */}
+          <TabsContent value="gemini" 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">
+                <GeminiIcon className="w-4 h-4" />
+                <span className="text-sm font-semibold">Gemini Usage</span>
+              </div>
+              {geminiError && geminiError.code !== ERROR_CODES.NOT_AVAILABLE && (
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className={cn('h-6 w-6', geminiLoading && 'opacity-80')}
+                  onClick={() => !geminiLoading && fetchGeminiUsage()}
+                >
+                  <RefreshCw className="w-3.5 h-3.5" />
+                </Button>
+              )}
+            </div>
+
+            {/* Content */}
+            <div className="p-4 space-y-4">
+              {geminiError ? (
+                <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">
+                      {geminiError.code === ERROR_CODES.NOT_AVAILABLE
+                        ? 'Gemini not configured'
+                        : geminiError.message}
+                    </p>
+                    <p className="text-xs text-muted-foreground">
+                      {geminiError.code === ERROR_CODES.API_BRIDGE_UNAVAILABLE ? (
+                        'Ensure the Electron bridge is running or restart the app'
+                      ) : geminiError.code === ERROR_CODES.NOT_AVAILABLE ? (
+                        <>
+                          Run{' '}
+                          <code className="font-mono bg-muted px-1 rounded">gemini auth login</code>{' '}
+                          to authenticate with your Google account
+                        </>
+                      ) : (
+                        <>Check your Gemini CLI configuration</>
+                      )}
+                    </p>
+                  </div>
+                </div>
+              ) : !geminiUsage ? (
+                <div className="flex flex-col items-center justify-center py-8 space-y-2">
+                  <Spinner size="lg" />
+                  <p className="text-xs text-muted-foreground">Loading usage data...</p>
+                </div>
+              ) : geminiUsage.authenticated ? (
+                <>
+                  {/* Show Flash and Pro quota tiers */}
+                  {geminiUsage.flashQuota || geminiUsage.proQuota ? (
+                    <div className="grid grid-cols-2 gap-3">
+                      {geminiUsage.flashQuota && (
+                        <UsageCard
+                          title="Flash"
+                          subtitle="Flash models"
+                          percentage={geminiUsage.flashQuota.usedPercent}
+                          resetText={geminiUsage.flashQuota.resetText}
+                          stale={isGeminiStale}
+                        />
+                      )}
+                      {geminiUsage.proQuota && (
+                        <UsageCard
+                          title="Pro"
+                          subtitle="Pro models"
+                          percentage={geminiUsage.proQuota.usedPercent}
+                          resetText={geminiUsage.proQuota.resetText}
+                          stale={isGeminiStale}
+                        />
+                      )}
+                    </div>
+                  ) : (
+                    <>
+                      {/* No quota data available - show connected status */}
+                      <div className="flex items-center gap-3 p-4 rounded-xl bg-emerald-500/10 border border-emerald-500/20">
+                        <div className="w-10 h-10 rounded-xl bg-emerald-500/15 flex items-center justify-center border border-emerald-500/20 shrink-0">
+                          <CheckCircle className="w-5 h-5 text-emerald-500" />
+                        </div>
+                        <div className="flex-1 min-w-0">
+                          <p className="text-sm font-medium text-emerald-400">Connected</p>
+                          <p className="text-xs text-emerald-400/70 mt-0.5">
+                            Authenticated via{' '}
+                            <span className="font-mono">
+                              {geminiUsage.authMethod === 'cli_login'
+                                ? 'CLI Login'
+                                : geminiUsage.authMethod === 'api_key_env'
+                                  ? 'API Key (Environment)'
+                                  : geminiUsage.authMethod === 'api_key'
+                                    ? 'API Key'
+                                    : 'Unknown'}
+                            </span>
+                          </p>
+                        </div>
+                      </div>
+
+                      <div className="rounded-xl border border-border/40 bg-secondary/20 p-3">
+                        <p className="text-xs text-muted-foreground">
+                          {geminiUsage.error ? (
+                            <>Quota API: {geminiUsage.error}</>
+                          ) : (
+                            <>No usage yet or quota data unavailable</>
+                          )}
+                        </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">Not authenticated</p>
+                  <p className="text-xs text-muted-foreground mt-1">
+                    Run <code className="font-mono bg-muted px-1 rounded">gemini auth login</code>{' '}
+                    to authenticate
+                  </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://ai.google.dev"
+                target="_blank"
+                rel="noreferrer"
+                className="text-[10px] text-muted-foreground hover:text-foreground flex items-center gap-1 transition-colors"
+              >
+                Google AI <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>

apps/ui/src/components/views/board-view/board-header.tsx

@@ -82,6 +82,7 @@ export function BoardHeader({
   );
   const codexAuthStatus = useSetupStore((state) => state.codexAuthStatus);
   const zaiAuthStatus = useSetupStore((state) => state.zaiAuthStatus);
+  const geminiAuthStatus = useSetupStore((state) => state.geminiAuthStatus);
 
   // Worktree panel visibility (per-project)
   const worktreePanelVisibleByProject = useAppStore((state) => state.worktreePanelVisibleByProject);
@@ -116,6 +117,9 @@ export function BoardHeader({
   // z.ai usage tracking visibility logic
   const showZaiUsage = !!zaiAuthStatus?.authenticated;
 
+  // Gemini usage tracking visibility logic
+  const showGeminiUsage = !!geminiAuthStatus?.authenticated;
+
   // State for mobile actions panel
   const [showActionsPanel, setShowActionsPanel] = useState(false);
   const [isRefreshingBoard, setIsRefreshingBoard] = useState(false);
@@ -163,9 +167,11 @@ export function BoardHeader({
           </Tooltip>
         )}
         {/* Usage Popover - show if any provider is authenticated, only on desktop */}
-        {isMounted && !isTablet && (showClaudeUsage || showCodexUsage || showZaiUsage) && (
-          <UsagePopover />
-        )}
+        {isMounted &&
+          !isTablet &&
+          (showClaudeUsage || showCodexUsage || showZaiUsage || showGeminiUsage) && (
+            <UsagePopover />
+          )}
 
         {/* Tablet/Mobile view: show hamburger menu with all controls */}
         {isMounted && isTablet && (
@@ -185,6 +191,7 @@ export function BoardHeader({
             showClaudeUsage={showClaudeUsage}
             showCodexUsage={showCodexUsage}
             showZaiUsage={showZaiUsage}
+            showGeminiUsage={showGeminiUsage}
           />
         )}
 

apps/ui/src/components/views/board-view/header-mobile-menu.tsx

@@ -31,6 +31,7 @@ interface HeaderMobileMenuProps {
   showClaudeUsage: boolean;
   showCodexUsage: boolean;
   showZaiUsage?: boolean;
+  showGeminiUsage?: boolean;
 }
 
 export function HeaderMobileMenu({
@@ -49,13 +50,14 @@ export function HeaderMobileMenu({
   showClaudeUsage,
   showCodexUsage,
   showZaiUsage = false,
+  showGeminiUsage = false,
 }: HeaderMobileMenuProps) {
   return (
     <>
       <HeaderActionsPanelTrigger isOpen={isOpen} onToggle={onToggle} />
       <HeaderActionsPanel isOpen={isOpen} onClose={onToggle} title="Board Controls">
         {/* Usage Bar - show if any provider is authenticated */}
-        {(showClaudeUsage || showCodexUsage || showZaiUsage) && (
+        {(showClaudeUsage || showCodexUsage || showZaiUsage || showGeminiUsage) && (
           <div className="space-y-2">
             <span className="text-xs font-medium text-muted-foreground uppercase tracking-wide">
               Usage
@@ -64,6 +66,7 @@ export function HeaderMobileMenu({
               showClaudeUsage={showClaudeUsage}
               showCodexUsage={showCodexUsage}
               showZaiUsage={showZaiUsage}
+              showGeminiUsage={showGeminiUsage}
             />
           </div>
         )}

apps/ui/src/components/views/board-view/mobile-usage-bar.tsx

@@ -4,12 +4,14 @@ import { cn } from '@/lib/utils';
 import { Spinner } from '@/components/ui/spinner';
 import { getElectronAPI } from '@/lib/electron';
 import { useAppStore } from '@/store/app-store';
-import { AnthropicIcon, OpenAIIcon, ZaiIcon } from '@/components/ui/provider-icon';
+import { AnthropicIcon, OpenAIIcon, ZaiIcon, GeminiIcon } from '@/components/ui/provider-icon';
+import type { GeminiUsage } from '@/store/app-store';
 
 interface MobileUsageBarProps {
   showClaudeUsage: boolean;
   showCodexUsage: boolean;
   showZaiUsage?: boolean;
+  showGeminiUsage?: boolean;
 }
 
 // Helper to get progress bar color based on percentage
@@ -152,6 +154,7 @@ export function MobileUsageBar({
   showClaudeUsage,
   showCodexUsage,
   showZaiUsage = false,
+  showGeminiUsage = false,
 }: MobileUsageBarProps) {
   const { claudeUsage, claudeUsageLastUpdated, setClaudeUsage } = useAppStore();
   const { codexUsage, codexUsageLastUpdated, setCodexUsage } = useAppStore();
@@ -159,12 +162,17 @@ export function MobileUsageBar({
   const [isClaudeLoading, setIsClaudeLoading] = useState(false);
   const [isCodexLoading, setIsCodexLoading] = useState(false);
   const [isZaiLoading, setIsZaiLoading] = useState(false);
+  const [isGeminiLoading, setIsGeminiLoading] = useState(false);
+  const [geminiUsage, setGeminiUsage] = useState<GeminiUsage | null>(null);
+  const [geminiUsageLastUpdated, setGeminiUsageLastUpdated] = useState<number | null>(null);
 
   // Check if data is stale (older than 2 minutes)
   const isClaudeStale =
     !claudeUsageLastUpdated || Date.now() - claudeUsageLastUpdated > 2 * 60 * 1000;
   const isCodexStale = !codexUsageLastUpdated || Date.now() - codexUsageLastUpdated > 2 * 60 * 1000;
   const isZaiStale = !zaiUsageLastUpdated || Date.now() - zaiUsageLastUpdated > 2 * 60 * 1000;
+  const isGeminiStale =
+    !geminiUsageLastUpdated || Date.now() - geminiUsageLastUpdated > 2 * 60 * 1000;
 
   const fetchClaudeUsage = useCallback(async () => {
     setIsClaudeLoading(true);
@@ -214,6 +222,23 @@ export function MobileUsageBar({
     }
   }, [setZaiUsage]);
 
+  const fetchGeminiUsage = useCallback(async () => {
+    setIsGeminiLoading(true);
+    try {
+      const api = getElectronAPI();
+      if (!api.gemini) return;
+      const data = await api.gemini.getUsage();
+      if (!('error' in data)) {
+        setGeminiUsage(data);
+        setGeminiUsageLastUpdated(Date.now());
+      }
+    } catch {
+      // Silently fail - usage display is optional
+    } finally {
+      setIsGeminiLoading(false);
+    }
+  }, []);
+
   const getCodexWindowLabel = (durationMins: number) => {
     if (durationMins < 60) return `${durationMins}m Window`;
     if (durationMins < 1440) return `${Math.round(durationMins / 60)}h Window`;
@@ -239,8 +264,14 @@ export function MobileUsageBar({
     }
   }, [showZaiUsage, isZaiStale, fetchZaiUsage]);
 
+  useEffect(() => {
+    if (showGeminiUsage && isGeminiStale) {
+      fetchGeminiUsage();
+    }
+  }, [showGeminiUsage, isGeminiStale, fetchGeminiUsage]);
+
   // Don't render if there's nothing to show
-  if (!showClaudeUsage && !showCodexUsage && !showZaiUsage) {
+  if (!showClaudeUsage && !showCodexUsage && !showZaiUsage && !showGeminiUsage) {
     return null;
   }
 
@@ -340,6 +371,58 @@ export function MobileUsageBar({
           )}
         </UsageItem>
       )}
+
+      {showGeminiUsage && (
+        <UsageItem
+          icon={GeminiIcon}
+          label="Gemini"
+          isLoading={isGeminiLoading}
+          onRefresh={fetchGeminiUsage}
+        >
+          {geminiUsage ? (
+            geminiUsage.authenticated ? (
+              geminiUsage.flashQuota || geminiUsage.proQuota ? (
+                <>
+                  {geminiUsage.flashQuota && (
+                    <UsageBar
+                      label="Flash"
+                      percentage={geminiUsage.flashQuota.usedPercent}
+                      isStale={isGeminiStale}
+                      resetText={geminiUsage.flashQuota.resetText}
+                    />
+                  )}
+                  {geminiUsage.proQuota && (
+                    <UsageBar
+                      label="Pro"
+                      percentage={geminiUsage.proQuota.usedPercent}
+                      isStale={isGeminiStale}
+                      resetText={geminiUsage.proQuota.resetText}
+                    />
+                  )}
+                </>
+              ) : (
+                <div className="text-[10px]">
+                  <p className="text-green-500 font-medium">
+                    Connected via{' '}
+                    {geminiUsage.authMethod === 'cli_login'
+                      ? 'CLI Login'
+                      : geminiUsage.authMethod === 'api_key'
+                        ? 'API Key'
+                        : geminiUsage.authMethod}
+                  </p>
+                  <p className="text-muted-foreground italic mt-0.5">
+                    {geminiUsage.error || 'No usage yet'}
+                  </p>
+                </div>
+              )
+            ) : (
+              <p className="text-[10px] text-yellow-500">Not authenticated</p>
+            )
+          ) : (
+            <p className="text-[10px] text-muted-foreground italic">Loading usage data...</p>
+          )}
+        </UsageItem>
+      )}
     </div>
   );
 }

apps/ui/src/hooks/queries/index.ts

@@ -23,7 +23,7 @@ export {
 } from './use-github';
 
 // Usage
-export { useClaudeUsage, useCodexUsage, useZaiUsage } from './use-usage';
+export { useClaudeUsage, useCodexUsage, useZaiUsage, useGeminiUsage } from './use-usage';
 
 // Running Agents
 export { useRunningAgents, useRunningAgentsCount } from './use-running-agents';

apps/ui/src/hooks/queries/use-usage.ts

@@ -1,7 +1,7 @@
 /**
  * Usage Query Hooks
  *
- * React Query hooks for fetching Claude, Codex, and z.ai API usage data.
+ * React Query hooks for fetching Claude, Codex, z.ai, and Gemini API usage data.
  * These hooks include automatic polling for real-time usage updates.
  */
 
@@ -9,7 +9,7 @@ import { useQuery } from '@tanstack/react-query';
 import { getElectronAPI } from '@/lib/electron';
 import { queryKeys } from '@/lib/query-keys';
 import { STALE_TIMES } from '@/lib/query-client';
-import type { ClaudeUsage, CodexUsage, ZaiUsage } from '@/store/app-store';
+import type { ClaudeUsage, CodexUsage, ZaiUsage, GeminiUsage } from '@/store/app-store';
 
 /** Polling interval for usage data (60 seconds) */
 const USAGE_POLLING_INTERVAL = 60 * 1000;
@@ -33,7 +33,7 @@ export function useClaudeUsage(enabled = true) {
     queryFn: async (): Promise<ClaudeUsage> => {
       const api = getElectronAPI();
       if (!api.claude) {
-        throw new Error('Claude API not available');
+        throw new Error('Claude API bridge unavailable');
       }
       const result = await api.claude.getUsage();
       // Check if result is an error response
@@ -69,7 +69,7 @@ export function useCodexUsage(enabled = true) {
     queryFn: async (): Promise<CodexUsage> => {
       const api = getElectronAPI();
       if (!api.codex) {
-        throw new Error('Codex API not available');
+        throw new Error('Codex API bridge unavailable');
       }
       const result = await api.codex.getUsage();
       // Check if result is an error response
@@ -104,6 +104,9 @@ export function useZaiUsage(enabled = true) {
     queryKey: queryKeys.usage.zai(),
     queryFn: async (): Promise<ZaiUsage> => {
       const api = getElectronAPI();
+      if (!api.zai) {
+        throw new Error('z.ai API bridge unavailable');
+      }
       const result = await api.zai.getUsage();
       // Check if result is an error response
       if ('error' in result) {
@@ -120,3 +123,37 @@ export function useZaiUsage(enabled = true) {
     refetchOnReconnect: USAGE_REFETCH_ON_RECONNECT,
   });
 }
+
+/**
+ * Fetch Gemini API usage/status data
+ *
+ * @param enabled - Whether the query should run (default: true)
+ * @returns Query result with Gemini usage data
+ *
+ * @example
+ * ```tsx
+ * const { data: usage, isLoading } = useGeminiUsage(isPopoverOpen);
+ * ```
+ */
+export function useGeminiUsage(enabled = true) {
+  return useQuery({
+    queryKey: queryKeys.usage.gemini(),
+    queryFn: async (): Promise<GeminiUsage> => {
+      const api = getElectronAPI();
+      if (!api.gemini) {
+        throw new Error('Gemini API bridge unavailable');
+      }
+      const result = await api.gemini.getUsage();
+      // Server always returns a response with 'authenticated' field, even on error
+      // So we can safely cast to GeminiUsage
+      return result as GeminiUsage;
+    },
+    enabled,
+    staleTime: STALE_TIMES.USAGE,
+    refetchInterval: enabled ? USAGE_POLLING_INTERVAL : false,
+    // Keep previous data while refetching
+    placeholderData: (previousData) => previousData,
+    refetchOnWindowFocus: USAGE_REFETCH_ON_FOCUS,
+    refetchOnReconnect: USAGE_REFETCH_ON_RECONNECT,
+  });
+}

apps/ui/src/hooks/use-provider-auth-init.ts

@@ -4,6 +4,7 @@ import {
   type ClaudeAuthMethod,
   type CodexAuthMethod,
   type ZaiAuthMethod,
+  type GeminiAuthMethod,
 } from '@/store/setup-store';
 import { getHttpApiClient } from '@/lib/http-api-client';
 import { createLogger } from '@automaker/utils/logger';
@@ -11,7 +12,7 @@ import { createLogger } from '@automaker/utils/logger';
 const logger = createLogger('ProviderAuthInit');
 
 /**
- * Hook to initialize Claude, Codex, and z.ai authentication statuses on app startup.
+ * Hook to initialize Claude, Codex, z.ai, and Gemini authentication statuses on app startup.
  * This ensures that usage tracking information is available in the board header
  * without needing to visit the settings page first.
  */
@@ -20,9 +21,12 @@ export function useProviderAuthInit() {
     setClaudeAuthStatus,
     setCodexAuthStatus,
     setZaiAuthStatus,
+    setGeminiCliStatus,
+    setGeminiAuthStatus,
     claudeAuthStatus,
     codexAuthStatus,
     zaiAuthStatus,
+    geminiAuthStatus,
   } = useSetupStore();
   const initialized = useRef(false);
 
@@ -121,18 +125,74 @@ export function useProviderAuthInit() {
     } catch (error) {
       logger.error('Failed to init z.ai auth status:', error);
     }
-  }, [setClaudeAuthStatus, setCodexAuthStatus, setZaiAuthStatus]);
+
+    // 4. Gemini Auth Status
+    try {
+      const result = await api.setup.getGeminiStatus();
+      if (result.success) {
+        // Set CLI status
+        setGeminiCliStatus({
+          installed: result.installed ?? false,
+          version: result.version,
+          path: result.status,
+        });
+
+        // Set Auth status - always set a status to mark initialization as complete
+        if (result.auth) {
+          const auth = result.auth;
+          const validMethods: GeminiAuthMethod[] = ['cli_login', 'api_key_env', 'api_key', 'none'];
+
+          const method = validMethods.includes(auth.method as GeminiAuthMethod)
+            ? (auth.method as GeminiAuthMethod)
+            : ((auth.authenticated ? 'cli_login' : 'none') as GeminiAuthMethod);
+
+          setGeminiAuthStatus({
+            authenticated: auth.authenticated,
+            method,
+            hasApiKey: auth.hasApiKey ?? false,
+            hasEnvApiKey: auth.hasEnvApiKey ?? false,
+          });
+        } else {
+          // No auth info available, set default unauthenticated status
+          setGeminiAuthStatus({
+            authenticated: false,
+            method: 'none',
+            hasApiKey: false,
+            hasEnvApiKey: false,
+          });
+        }
+      }
+    } catch (error) {
+      logger.error('Failed to init Gemini auth status:', error);
+      // Set default status on error to prevent infinite retries
+      setGeminiAuthStatus({
+        authenticated: false,
+        method: 'none',
+        hasApiKey: false,
+        hasEnvApiKey: false,
+      });
+    }
+  }, [
+    setClaudeAuthStatus,
+    setCodexAuthStatus,
+    setZaiAuthStatus,
+    setGeminiCliStatus,
+    setGeminiAuthStatus,
+  ]);
 
   useEffect(() => {
     // Only initialize once per session if not already set
     if (
       initialized.current ||
-      (claudeAuthStatus !== null && codexAuthStatus !== null && zaiAuthStatus !== null)
+      (claudeAuthStatus !== null &&
+        codexAuthStatus !== null &&
+        zaiAuthStatus !== null &&
+        geminiAuthStatus !== null)
     ) {
       return;
     }
     initialized.current = true;
 
     void refreshStatuses();
-  }, [refreshStatuses, claudeAuthStatus, codexAuthStatus, zaiAuthStatus]);
+  }, [refreshStatuses, claudeAuthStatus, codexAuthStatus, zaiAuthStatus, geminiAuthStatus]);
 }

apps/ui/src/lib/electron.ts

@@ -1,6 +1,11 @@
 // Type definitions for Electron IPC API
 import type { SessionListItem, Message } from '@/types/electron';
-import type { ClaudeUsageResponse, CodexUsageResponse, ZaiUsageResponse } from '@/store/app-store';
+import type {
+  ClaudeUsageResponse,
+  CodexUsageResponse,
+  ZaiUsageResponse,
+  GeminiUsageResponse,
+} from '@/store/app-store';
 import type {
   IssueValidationVerdict,
   IssueValidationConfidence,
@@ -874,6 +879,9 @@ export interface ElectronAPI {
       error?: string;
     }>;
   };
+  gemini?: {
+    getUsage: () => Promise<GeminiUsageResponse>;
+  };
   settings?: {
     getStatus: () => Promise<{
       success: boolean;
@@ -1418,6 +1426,20 @@ const _getMockElectronAPI = (): ElectronAPI => {
         };
       },
     },
+
+    // Mock Gemini API
+    gemini: {
+      getUsage: async () => {
+        console.log('[Mock] Getting Gemini usage');
+        return {
+          authenticated: true,
+          authMethod: 'cli_login',
+          usedPercent: 0,
+          remainingPercent: 100,
+          lastUpdated: new Date().toISOString(),
+        };
+      },
+    },
   };
 };
 

apps/ui/src/lib/http-api-client.ts

@@ -41,7 +41,11 @@ import type {
   Notification,
 } from '@automaker/types';
 import type { Message, SessionListItem } from '@/types/electron';
-import type { ClaudeUsageResponse, CodexUsageResponse } from '@/store/app-store';
+import type {
+  ClaudeUsageResponse,
+  CodexUsageResponse,
+  GeminiUsage,
+} from '@/store/app-store';
 import type { WorktreeAPI, GitAPI, ModelDefinition, ProviderStatus } from '@/types/electron';
 import type { ModelId, ThinkingLevel, ReasoningEffort, Feature } from '@automaker/types';
 import { getGlobalFileBrowser } from '@/contexts/file-browser-context';
@@ -2688,6 +2692,11 @@ export class HttpApiClient implements ElectronAPI {
     },
   };
 
+  // Gemini API
+  gemini = {
+    getUsage: (): Promise<GeminiUsage> => this.get('/api/gemini/usage'),
+  };
+
   // Context API
   context = {
     describeImage: (

apps/ui/src/lib/query-keys.ts

@@ -101,6 +101,8 @@ export const queryKeys = {
     codex: () => ['usage', 'codex'] as const,
     /** z.ai API usage */
     zai: () => ['usage', 'zai'] as const,
+    /** Gemini API usage */
+    gemini: () => ['usage', 'gemini'] as const,
   },
 
   // ============================================

apps/ui/src/store/app-store.ts

@@ -98,6 +98,10 @@ import {
   type ZaiQuotaLimit,
   type ZaiUsage,
   type ZaiUsageResponse,
+  type GeminiQuotaBucket,
+  type GeminiTierQuota,
+  type GeminiUsage,
+  type GeminiUsageResponse,
 } from './types';
 
 // Import utility functions from modular utils files
@@ -181,6 +185,10 @@ export type {
   ZaiQuotaLimit,
   ZaiUsage,
   ZaiUsageResponse,
+  GeminiQuotaBucket,
+  GeminiTierQuota,
+  GeminiUsage,
+  GeminiUsageResponse,
 };
 
 // Re-export values from ./types for backward compatibility
@@ -210,7 +218,7 @@ export { defaultBackgroundSettings, defaultTerminalState, MAX_INIT_OUTPUT_LINES
 // - Terminal types (./types/terminal-types.ts)
 // - ClaudeModel, Feature, FileTreeNode, ProjectAnalysis (./types/project-types.ts)
 // - InitScriptState, AutoModeActivity, AppState, AppActions (./types/state-types.ts)
-// - Claude/Codex usage types (./types/usage-types.ts)
+// - Claude/Codex/Zai/Gemini usage types (./types/usage-types.ts)
 // The following utility functions have been moved to ./utils/:
 // - Theme utilities: THEME_STORAGE_KEY, getStoredTheme, getStoredFontSans, getStoredFontMono, etc. (./utils/theme-utils.ts)
 // - Shortcut utilities: parseShortcut, formatShortcut, DEFAULT_KEYBOARD_SHORTCUTS (./utils/shortcut-utils.ts)
@@ -220,6 +228,9 @@ export { defaultBackgroundSettings, defaultTerminalState, MAX_INIT_OUTPUT_LINES
 // - defaultBackgroundSettings (./defaults/background-settings.ts)
 // - defaultTerminalState (./defaults/terminal-defaults.ts)
 
+// Type definitions are imported from ./types/state-types.ts
+// AppActions interface is defined in ./types/state-types.ts
+
 const initialState: AppState = {
   projects: [],
   currentProject: null,

apps/ui/src/store/setup-store.ts

@@ -127,6 +127,22 @@ export interface ZaiAuthStatus {
   error?: string;
 }
 
+// Gemini Auth Method
+export type GeminiAuthMethod =
+  | 'cli_login' // Gemini CLI is installed and authenticated
+  | 'api_key_env' // GOOGLE_API_KEY or GEMINI_API_KEY environment variable
+  | 'api_key' // Manually stored API key
+  | 'none';
+
+// Gemini Auth Status
+export interface GeminiAuthStatus {
+  authenticated: boolean;
+  method: GeminiAuthMethod;
+  hasApiKey?: boolean;
+  hasEnvApiKey?: boolean;
+  error?: string;
+}
+
 // Claude Auth Method - all possible authentication sources
 export type ClaudeAuthMethod =
   | 'oauth_token_env'
@@ -200,6 +216,7 @@ export interface SetupState {
 
   // Gemini CLI state
   geminiCliStatus: GeminiCliStatus | null;
+  geminiAuthStatus: GeminiAuthStatus | null;
 
   // Copilot SDK state
   copilotCliStatus: CopilotCliStatus | null;
@@ -243,6 +260,7 @@ export interface SetupActions {
 
   // Gemini CLI
   setGeminiCliStatus: (status: GeminiCliStatus | null) => void;
+  setGeminiAuthStatus: (status: GeminiAuthStatus | null) => void;
 
   // Copilot SDK
   setCopilotCliStatus: (status: CopilotCliStatus | null) => void;
@@ -284,6 +302,7 @@ const initialState: SetupState = {
   opencodeCliStatus: null,
 
   geminiCliStatus: null,
+  geminiAuthStatus: null,
 
   copilotCliStatus: null,
 
@@ -363,6 +382,7 @@ export const useSetupStore = create<SetupState & SetupActions>()((set, get) => (
 
   // Gemini CLI
   setGeminiCliStatus: (status) => set({ geminiCliStatus: status }),
+  setGeminiAuthStatus: (status) => set({ geminiAuthStatus: status }),
 
   // Copilot SDK
   setCopilotCliStatus: (status) => set({ copilotCliStatus: status }),

apps/ui/src/store/types/usage-types.ts

@@ -82,3 +82,55 @@ export interface ZaiUsage {
 
 // Response type for z.ai usage API (can be success or error)
 export type ZaiUsageResponse = ZaiUsage | { error: string; message?: string };
+
+// Gemini Usage types - uses internal Google Cloud quota API
+export interface GeminiQuotaBucket {
+  /** Model ID this quota applies to */
+  modelId: string;
+  /** Remaining fraction (0-1) */
+  remainingFraction: number;
+  /** ISO-8601 reset time */
+  resetTime: string;
+}
+
+/** Simplified quota info for a model tier (Flash or Pro) */
+export interface GeminiTierQuota {
+  /** Used percentage (0-100) */
+  usedPercent: number;
+  /** Remaining percentage (0-100) */
+  remainingPercent: number;
+  /** Reset time as human-readable string */
+  resetText?: string;
+  /** ISO-8601 reset time */
+  resetTime?: string;
+}
+
+export interface GeminiUsage {
+  /** Whether the user is authenticated (via CLI or API key) */
+  authenticated: boolean;
+  /** Authentication method: 'cli_login' | 'api_key' | 'api_key_env' | 'none' */
+  authMethod: string;
+  /** Usage percentage (100 - remainingFraction * 100) - overall most constrained */
+  usedPercent: number;
+  /** Remaining percentage - overall most constrained */
+  remainingPercent: number;
+  /** Reset time as human-readable string */
+  resetText?: string;
+  /** ISO-8601 reset time */
+  resetTime?: string;
+  /** Model ID with lowest remaining quota */
+  constrainedModel?: string;
+  /** Flash tier quota (aggregated from all flash models) */
+  flashQuota?: GeminiTierQuota;
+  /** Pro tier quota (aggregated from all pro models) */
+  proQuota?: GeminiTierQuota;
+  /** Raw quota buckets for detailed view */
+  quotaBuckets?: GeminiQuotaBucket[];
+  /** When this data was last fetched */
+  lastUpdated: string;
+  /** Optional error message */
+  error?: string;
+}
+
+// Response type for Gemini usage API (can be success or error)
+export type GeminiUsageResponse = GeminiUsage | { error: string; message?: string };

package-lock.json

@@ -11475,7 +11475,6 @@
       "os": [
         "android"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11497,7 +11496,6 @@
       "os": [
         "darwin"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11519,7 +11517,6 @@
       "os": [
         "darwin"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11541,7 +11538,6 @@
       "os": [
         "freebsd"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11563,7 +11559,6 @@
       "os": [
         "linux"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11585,7 +11580,6 @@
       "os": [
         "linux"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11607,7 +11601,6 @@
       "os": [
         "linux"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11629,7 +11622,6 @@
       "os": [
         "linux"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11651,7 +11643,6 @@
       "os": [
         "linux"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11673,7 +11664,6 @@
       "os": [
         "win32"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },
@@ -11695,7 +11685,6 @@
       "os": [
         "win32"
       ],
-      "peer": true,
       "engines": {
         "node": ">= 12.0.0"
       },