feat: add Gemini CLI provider integration (#647)

* feat: add Gemini CLI provider for AI model execution - Add GeminiProvider class extending CliProvider for Gemini CLI integration - Add Gemini models (Gemini 3 Pro/Flash Preview, 2.5 Pro/Flash/Flash-Lite) - Add gemini-models.ts with model definitions and types - Update ModelProvider type to include 'gemini' - Add isGeminiModel() to provider-utils.ts for model detection - Register Gemini provider in provider-factory with priority 4 - Add Gemini setup detection routes (status, auth, deauth) - Add GeminiCliStatus to setup store for UI state management - Add Gemini to PROVIDER_ICON_COMPONENTS for UI icon display - Add GEMINI_MODELS to model-display for dropdown population - Support thinking levels: off, low, medium, high Based on https://github.com/google-gemini/gemini-cli * chore: update package-lock.json * feat(ui): add Gemini provider to settings and setup wizard - Add GeminiCliStatus component for CLI detection display - Add GeminiSettingsTab component for global settings - Update provider-tabs.tsx to include Gemini as 5th tab - Update providers-setup-step.tsx with Gemini provider detection - Add useGeminiCliStatus hook for querying CLI status - Add getGeminiStatus, authGemini, deauthGemini to HTTP API client - Add gemini query key for React Query - Fix GeminiModelId type to not double-prefix model IDs * feat(ui): add Gemini to settings sidebar navigation - Add 'gemini-provider' to SettingsViewId type - Add GeminiIcon and gemini-provider to navigation config - Add gemini-provider to NAV_ID_TO_PROVIDER mapping - Add gemini-provider case in settings-view switch - Export GeminiSettingsTab from providers index This fixes the missing Gemini entry in the AI Providers sidebar menu. * feat(ui): add Gemini model configuration in settings - Create GeminiModelConfiguration component for model selection - Add enabledGeminiModels and geminiDefaultModel state to app-store - Add setEnabledGeminiModels, setGeminiDefaultModel, toggleGeminiModel actions - Update GeminiSettingsTab to show model configuration when CLI is installed - Import GeminiModelId and getAllGeminiModelIds from types This adds the ability to configure which Gemini models are available in the feature modal, similar to other providers like Codex and OpenCode. * feat(ui): add Gemini models to all model dropdowns - Add GEMINI_MODELS to model-constants.ts for UI dropdowns - Add Gemini to ALL_MODELS array used throughout the app - Add GeminiIcon to PROFILE_ICONS mapping - Fix GEMINI_MODELS in model-display.ts to use correct model IDs - Update getModelDisplayName to handle Gemini models correctly Gemini models now appear in all model selection dropdowns including Model Defaults, Feature Defaults, and feature card settings. * fix(gemini): fix CLI integration and event handling - Fix model ID prefix handling: strip gemini- prefix in agent-service, add it back in buildCliArgs for CLI invocation - Fix event normalization to match actual Gemini CLI output format: - type: 'init' (not 'system') - type: 'message' with role (not 'assistant') - tool_name/tool_id/parameters/output field names - Add --sandbox false and --approval-mode yolo for faster execution - Remove thinking level selector from UI (Gemini CLI doesn't support it) - Update auth status to show errors properly * test: update provider-factory tests for Gemini provider - Add GeminiProvider import and spy mock - Update expected provider count from 4 to 5 - Add test for GeminiProvider inclusion - Add gemini key to checkAllProviders test * fix(gemini): address PR review feedback - Fix npm package name from @anthropic-ai/gemini-cli to @google/gemini-cli - Fix comments in gemini-provider.ts to match actual CLI output format - Convert sync fs operations to async using fs/promises * fix(settings): add Gemini and Codex settings to sync Add enabledGeminiModels, geminiDefaultModel, enabledCodexModels, and codexDefaultModel to SETTINGS_FIELDS_TO_SYNC for persistence across sessions. * fix(gemini): address additional PR review feedback - Use 'Speed' badge for non-thinking Gemini models (consistency) - Fix installCommand mapping in gemini-settings-tab.tsx - Add hasEnvApiKey to GeminiCliStatus interface for API parity - Clarify GeminiThinkingLevel comment (CLI doesn't support --thinking-level) * fix(settings): restore Codex and Gemini settings from server Add sanitization and restoration logic for enabledCodexModels, codexDefaultModel, enabledGeminiModels, and geminiDefaultModel in refreshSettingsFromServer() to match the fields in SETTINGS_FIELDS_TO_SYNC. * feat(gemini): normalize tool names and fix workspace restrictions - Add tool name mapping to normalize Gemini CLI tool names to standard names (e.g., write_todos -> TodoWrite, read_file -> Read) - Add normalizeGeminiToolInput to convert write_todos format to TodoWrite format (description -> content, handle cancelled status) - Pass --include-directories with cwd to fix workspace restriction errors when Gemini CLI has a different cached workspace from previous sessions --------- Co-authored-by: Claude <noreply@anthropic.com>
2026-01-31 06:42:03 +00:00 · 2026-01-23 01:42:17 +01:00
parent 7773db559d
commit f480386905
33 changed files with 2408 additions and 27 deletions
--- a/apps/server/src/providers/gemini-provider.ts
+++ b/apps/server/src/providers/gemini-provider.ts
@@ -0,0 +1,815 @@
+/**
+ * Gemini Provider - Executes queries using the Gemini CLI
+ *
+ * Extends CliProvider with Gemini-specific:
+ * - Event normalization for Gemini's JSONL streaming format
+ * - Google account and API key authentication support
+ * - Thinking level configuration
+ *
+ * Based on https://github.com/google-gemini/gemini-cli
+ */
+
+import { execSync } from 'child_process';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import * as os from 'os';
+import { CliProvider, type CliSpawnConfig, type CliErrorInfo } from './cli-provider.js';
+import type {
+  ProviderConfig,
+  ExecuteOptions,
+  ProviderMessage,
+  InstallationStatus,
+  ModelDefinition,
+  ContentBlock,
+} from './types.js';
+import { validateBareModelId } from '@automaker/types';
+import { GEMINI_MODEL_MAP, type GeminiAuthStatus } from '@automaker/types';
+import { createLogger, isAbortError } from '@automaker/utils';
+import { spawnJSONLProcess } from '@automaker/platform';
+
+// Create logger for this module
+const logger = createLogger('GeminiProvider');
+
+// =============================================================================
+// Gemini Stream Event Types
+// =============================================================================
+
+/**
+ * Base event structure from Gemini CLI --output-format stream-json
+ *
+ * Actual CLI output format:
+ * {"type":"init","timestamp":"...","session_id":"...","model":"..."}
+ * {"type":"message","timestamp":"...","role":"user","content":"..."}
+ * {"type":"message","timestamp":"...","role":"assistant","content":"...","delta":true}
+ * {"type":"tool_use","timestamp":"...","tool_name":"...","tool_id":"...","parameters":{...}}
+ * {"type":"tool_result","timestamp":"...","tool_id":"...","status":"success","output":"..."}
+ * {"type":"result","timestamp":"...","status":"success","stats":{...}}
+ */
+interface GeminiStreamEvent {
+  type: 'init' | 'message' | 'tool_use' | 'tool_result' | 'result' | 'error';
+  timestamp?: string;
+  session_id?: string;
+}
+
+interface GeminiInitEvent extends GeminiStreamEvent {
+  type: 'init';
+  session_id: string;
+  model: string;
+}
+
+interface GeminiMessageEvent extends GeminiStreamEvent {
+  type: 'message';
+  role: 'user' | 'assistant';
+  content: string;
+  delta?: boolean;
+  session_id?: string;
+}
+
+interface GeminiToolUseEvent extends GeminiStreamEvent {
+  type: 'tool_use';
+  tool_id: string;
+  tool_name: string;
+  parameters: Record<string, unknown>;
+  session_id?: string;
+}
+
+interface GeminiToolResultEvent extends GeminiStreamEvent {
+  type: 'tool_result';
+  tool_id: string;
+  status: 'success' | 'error';
+  output: string;
+  session_id?: string;
+}
+
+interface GeminiResultEvent extends GeminiStreamEvent {
+  type: 'result';
+  status: 'success' | 'error';
+  stats?: {
+    total_tokens?: number;
+    input_tokens?: number;
+    output_tokens?: number;
+    cached?: number;
+    input?: number;
+    duration_ms?: number;
+    tool_calls?: number;
+  };
+  error?: string;
+  session_id?: string;
+}
+
+// =============================================================================
+// Error Codes
+// =============================================================================
+
+export enum GeminiErrorCode {
+  NOT_INSTALLED = 'GEMINI_NOT_INSTALLED',
+  NOT_AUTHENTICATED = 'GEMINI_NOT_AUTHENTICATED',
+  RATE_LIMITED = 'GEMINI_RATE_LIMITED',
+  MODEL_UNAVAILABLE = 'GEMINI_MODEL_UNAVAILABLE',
+  NETWORK_ERROR = 'GEMINI_NETWORK_ERROR',
+  PROCESS_CRASHED = 'GEMINI_PROCESS_CRASHED',
+  TIMEOUT = 'GEMINI_TIMEOUT',
+  UNKNOWN = 'GEMINI_UNKNOWN_ERROR',
+}
+
+export interface GeminiError extends Error {
+  code: GeminiErrorCode;
+  recoverable: boolean;
+  suggestion?: string;
+}
+
+// =============================================================================
+// Tool Name Normalization
+// =============================================================================
+
+/**
+ * Gemini CLI tool name to standard tool name mapping
+ * This allows the UI to properly categorize and display Gemini tool calls
+ */
+const GEMINI_TOOL_NAME_MAP: Record<string, string> = {
+  write_todos: 'TodoWrite',
+  read_file: 'Read',
+  read_many_files: 'Read',
+  replace: 'Edit',
+  write_file: 'Write',
+  run_shell_command: 'Bash',
+  search_file_content: 'Grep',
+  glob: 'Glob',
+  list_directory: 'Ls',
+  web_fetch: 'WebFetch',
+  google_web_search: 'WebSearch',
+};
+
+/**
+ * Normalize Gemini tool names to standard tool names
+ */
+function normalizeGeminiToolName(geminiToolName: string): string {
+  return GEMINI_TOOL_NAME_MAP[geminiToolName] || geminiToolName;
+}
+
+/**
+ * Normalize Gemini tool input parameters to standard format
+ *
+ * Gemini `write_todos` format:
+ * {"todos": [{"description": "Task text", "status": "pending|in_progress|completed|cancelled"}]}
+ *
+ * Claude `TodoWrite` format:
+ * {"todos": [{"content": "Task text", "status": "pending|in_progress|completed", "activeForm": "..."}]}
+ */
+function normalizeGeminiToolInput(
+  toolName: string,
+  input: Record<string, unknown>
+): Record<string, unknown> {
+  // Normalize write_todos: map 'description' to 'content', handle 'cancelled' status
+  if (toolName === 'write_todos' && Array.isArray(input.todos)) {
+    return {
+      todos: input.todos.map((todo: { description?: string; status?: string }) => ({
+        content: todo.description || '',
+        // Map 'cancelled' to 'completed' since Claude doesn't have cancelled status
+        status: todo.status === 'cancelled' ? 'completed' : todo.status,
+        // Use description as activeForm since Gemini doesn't have it
+        activeForm: todo.description || '',
+      })),
+    };
+  }
+  return input;
+}
+
+/**
+ * GeminiProvider - Integrates Gemini CLI as an AI provider
+ *
+ * Features:
+ * - Google account OAuth login support
+ * - API key authentication (GEMINI_API_KEY)
+ * - Vertex AI support
+ * - Thinking level configuration
+ * - Streaming JSON output
+ */
+export class GeminiProvider extends CliProvider {
+  constructor(config: ProviderConfig = {}) {
+    super(config);
+    // Trigger CLI detection on construction
+    this.ensureCliDetected();
+  }
+
+  // ==========================================================================
+  // CliProvider Abstract Method Implementations
+  // ==========================================================================
+
+  getName(): string {
+    return 'gemini';
+  }
+
+  getCliName(): string {
+    return 'gemini';
+  }
+
+  getSpawnConfig(): CliSpawnConfig {
+    return {
+      windowsStrategy: 'npx', // Gemini CLI can be run via npx
+      npxPackage: '@google/gemini-cli', // Official Google Gemini CLI package
+      commonPaths: {
+        linux: [
+          path.join(os.homedir(), '.local/bin/gemini'),
+          '/usr/local/bin/gemini',
+          path.join(os.homedir(), '.npm-global/bin/gemini'),
+        ],
+        darwin: [
+          path.join(os.homedir(), '.local/bin/gemini'),
+          '/usr/local/bin/gemini',
+          '/opt/homebrew/bin/gemini',
+          path.join(os.homedir(), '.npm-global/bin/gemini'),
+        ],
+        win32: [
+          path.join(os.homedir(), 'AppData', 'Roaming', 'npm', 'gemini.cmd'),
+          path.join(os.homedir(), '.npm-global', 'gemini.cmd'),
+        ],
+      },
+    };
+  }
+
+  /**
+   * Extract prompt text from ExecuteOptions
+   */
+  private extractPromptText(options: ExecuteOptions): string {
+    if (typeof options.prompt === 'string') {
+      return options.prompt;
+    } else if (Array.isArray(options.prompt)) {
+      return options.prompt
+        .filter((p) => p.type === 'text' && p.text)
+        .map((p) => p.text)
+        .join('\n');
+    } else {
+      throw new Error('Invalid prompt format');
+    }
+  }
+
+  buildCliArgs(options: ExecuteOptions): string[] {
+    // Model comes in stripped of provider prefix (e.g., '2.5-flash' from 'gemini-2.5-flash')
+    // We need to add 'gemini-' back since it's part of the actual CLI model name
+    const bareModel = options.model || '2.5-flash';
+    const cliArgs: string[] = [];
+
+    // Streaming JSON output format for real-time updates
+    cliArgs.push('--output-format', 'stream-json');
+
+    // Model selection - Gemini CLI expects full model names like "gemini-2.5-flash"
+    // Unlike Cursor CLI where 'cursor-' is just a routing prefix, for Gemini CLI
+    // the 'gemini-' is part of the actual model name Google expects
+    if (bareModel && bareModel !== 'auto') {
+      // Add gemini- prefix if not already present (handles edge cases)
+      const cliModel = bareModel.startsWith('gemini-') ? bareModel : `gemini-${bareModel}`;
+      cliArgs.push('--model', cliModel);
+    }
+
+    // Disable sandbox mode for faster execution (sandbox adds overhead)
+    cliArgs.push('--sandbox', 'false');
+
+    // YOLO mode for automatic approval (required for non-interactive use)
+    // Use explicit approval-mode for clearer semantics
+    cliArgs.push('--approval-mode', 'yolo');
+
+    // Explicitly include the working directory in allowed workspace directories
+    // This ensures Gemini CLI allows file operations in the project directory,
+    // even if it has a different workspace cached from a previous session
+    if (options.cwd) {
+      cliArgs.push('--include-directories', options.cwd);
+    }
+
+    // Note: Gemini CLI doesn't have a --thinking-level flag.
+    // Thinking capabilities are determined by the model selection (e.g., gemini-2.5-pro).
+    // The model handles thinking internally based on the task complexity.
+
+    // The prompt will be passed as the last positional argument
+    // We'll append it in executeQuery after extracting the text
+
+    return cliArgs;
+  }
+
+  /**
+   * Convert Gemini event to AutoMaker ProviderMessage format
+   */
+  normalizeEvent(event: unknown): ProviderMessage | null {
+    const geminiEvent = event as GeminiStreamEvent;
+
+    switch (geminiEvent.type) {
+      case 'init': {
+        // Init event - capture session but don't yield a message
+        const initEvent = geminiEvent as GeminiInitEvent;
+        logger.debug(
+          `Gemini init event: session=${initEvent.session_id}, model=${initEvent.model}`
+        );
+        return null;
+      }
+
+      case 'message': {
+        const messageEvent = geminiEvent as GeminiMessageEvent;
+
+        // Skip user messages - already handled by caller
+        if (messageEvent.role === 'user') {
+          return null;
+        }
+
+        // Handle assistant messages
+        if (messageEvent.role === 'assistant') {
+          return {
+            type: 'assistant',
+            session_id: messageEvent.session_id,
+            message: {
+              role: 'assistant',
+              content: [{ type: 'text', text: messageEvent.content }],
+            },
+          };
+        }
+
+        return null;
+      }
+
+      case 'tool_use': {
+        const toolEvent = geminiEvent as GeminiToolUseEvent;
+        const normalizedName = normalizeGeminiToolName(toolEvent.tool_name);
+        const normalizedInput = normalizeGeminiToolInput(
+          toolEvent.tool_name,
+          toolEvent.parameters as Record<string, unknown>
+        );
+
+        return {
+          type: 'assistant',
+          session_id: toolEvent.session_id,
+          message: {
+            role: 'assistant',
+            content: [
+              {
+                type: 'tool_use',
+                name: normalizedName,
+                tool_use_id: toolEvent.tool_id,
+                input: normalizedInput,
+              },
+            ],
+          },
+        };
+      }
+
+      case 'tool_result': {
+        const toolResultEvent = geminiEvent as GeminiToolResultEvent;
+        // If tool result is an error, prefix with error indicator
+        const content =
+          toolResultEvent.status === 'error'
+            ? `[ERROR] ${toolResultEvent.output}`
+            : toolResultEvent.output;
+        return {
+          type: 'assistant',
+          session_id: toolResultEvent.session_id,
+          message: {
+            role: 'assistant',
+            content: [
+              {
+                type: 'tool_result',
+                tool_use_id: toolResultEvent.tool_id,
+                content,
+              },
+            ],
+          },
+        };
+      }
+
+      case 'result': {
+        const resultEvent = geminiEvent as GeminiResultEvent;
+
+        if (resultEvent.status === 'error') {
+          return {
+            type: 'error',
+            session_id: resultEvent.session_id,
+            error: resultEvent.error || 'Unknown error',
+          };
+        }
+
+        // Success result - include stats for logging
+        logger.debug(
+          `Gemini result: status=${resultEvent.status}, tokens=${resultEvent.stats?.total_tokens}`
+        );
+        return {
+          type: 'result',
+          subtype: 'success',
+          session_id: resultEvent.session_id,
+        };
+      }
+
+      case 'error': {
+        const errorEvent = geminiEvent as GeminiResultEvent;
+        return {
+          type: 'error',
+          session_id: errorEvent.session_id,
+          error: errorEvent.error || 'Unknown error',
+        };
+      }
+
+      default:
+        logger.debug(`Unknown Gemini event type: ${geminiEvent.type}`);
+        return null;
+    }
+  }
+
+  // ==========================================================================
+  // CliProvider Overrides
+  // ==========================================================================
+
+  /**
+   * Override error mapping for Gemini-specific error codes
+   */
+  protected mapError(stderr: string, exitCode: number | null): CliErrorInfo {
+    const lower = stderr.toLowerCase();
+
+    if (
+      lower.includes('not authenticated') ||
+      lower.includes('please log in') ||
+      lower.includes('unauthorized') ||
+      lower.includes('login required') ||
+      lower.includes('error authenticating') ||
+      lower.includes('loadcodeassist') ||
+      (lower.includes('econnrefused') && lower.includes('8888'))
+    ) {
+      return {
+        code: GeminiErrorCode.NOT_AUTHENTICATED,
+        message: 'Gemini CLI is not authenticated',
+        recoverable: true,
+        suggestion:
+          'Run "gemini" interactively to log in, or set GEMINI_API_KEY environment variable',
+      };
+    }
+
+    if (
+      lower.includes('rate limit') ||
+      lower.includes('too many requests') ||
+      lower.includes('429') ||
+      lower.includes('quota exceeded')
+    ) {
+      return {
+        code: GeminiErrorCode.RATE_LIMITED,
+        message: 'Gemini API rate limit exceeded',
+        recoverable: true,
+        suggestion: 'Wait a few minutes and try again. Free tier: 60 req/min, 1000 req/day',
+      };
+    }
+
+    if (
+      lower.includes('model not available') ||
+      lower.includes('invalid model') ||
+      lower.includes('unknown model') ||
+      lower.includes('modelnotfounderror') ||
+      lower.includes('model not found') ||
+      (lower.includes('not found') && lower.includes('404'))
+    ) {
+      return {
+        code: GeminiErrorCode.MODEL_UNAVAILABLE,
+        message: 'Requested model is not available',
+        recoverable: true,
+        suggestion: 'Try using "gemini-2.5-flash" or select a different model',
+      };
+    }
+
+    if (
+      lower.includes('network') ||
+      lower.includes('connection') ||
+      lower.includes('econnrefused') ||
+      lower.includes('timeout')
+    ) {
+      return {
+        code: GeminiErrorCode.NETWORK_ERROR,
+        message: 'Network connection error',
+        recoverable: true,
+        suggestion: 'Check your internet connection and try again',
+      };
+    }
+
+    if (exitCode === 137 || lower.includes('killed') || lower.includes('sigterm')) {
+      return {
+        code: GeminiErrorCode.PROCESS_CRASHED,
+        message: 'Gemini CLI process was terminated',
+        recoverable: true,
+        suggestion: 'The process may have run out of memory. Try a simpler task.',
+      };
+    }
+
+    return {
+      code: GeminiErrorCode.UNKNOWN,
+      message: stderr || `Gemini CLI exited with code ${exitCode}`,
+      recoverable: false,
+    };
+  }
+
+  /**
+   * Override install instructions for Gemini-specific guidance
+   */
+  protected getInstallInstructions(): string {
+    return 'Install with: npm install -g @google/gemini-cli (or visit https://github.com/google-gemini/gemini-cli)';
+  }
+
+  /**
+   * Execute a prompt using Gemini CLI with streaming
+   */
+  async *executeQuery(options: ExecuteOptions): AsyncGenerator<ProviderMessage> {
+    this.ensureCliDetected();
+
+    // Validate that model doesn't have a provider prefix
+    validateBareModelId(options.model, 'GeminiProvider');
+
+    if (!this.cliPath) {
+      throw this.createError(
+        GeminiErrorCode.NOT_INSTALLED,
+        'Gemini CLI is not installed',
+        true,
+        this.getInstallInstructions()
+      );
+    }
+
+    // Extract prompt text to pass as positional argument
+    const promptText = this.extractPromptText(options);
+
+    // Build CLI args and append the prompt as the last positional argument
+    const cliArgs = this.buildCliArgs(options);
+    cliArgs.push(promptText); // Gemini CLI uses positional args for the prompt
+
+    const subprocessOptions = this.buildSubprocessOptions(options, cliArgs);
+
+    let sessionId: string | undefined;
+
+    logger.debug(`GeminiProvider.executeQuery called with model: "${options.model}"`);
+
+    try {
+      for await (const rawEvent of spawnJSONLProcess(subprocessOptions)) {
+        const event = rawEvent as GeminiStreamEvent;
+
+        // Capture session ID from init event
+        if (event.type === 'init') {
+          const initEvent = event as GeminiInitEvent;
+          sessionId = initEvent.session_id;
+          logger.debug(`Session started: ${sessionId}, model: ${initEvent.model}`);
+        }
+
+        // Normalize and yield the event
+        const normalized = this.normalizeEvent(event);
+        if (normalized) {
+          if (!normalized.session_id && sessionId) {
+            normalized.session_id = sessionId;
+          }
+          yield normalized;
+        }
+      }
+    } catch (error) {
+      if (isAbortError(error)) {
+        logger.debug('Query aborted');
+        return;
+      }
+
+      // Map CLI errors to GeminiError
+      if (error instanceof Error && 'stderr' in error) {
+        const errorInfo = this.mapError(
+          (error as { stderr?: string }).stderr || error.message,
+          (error as { exitCode?: number | null }).exitCode ?? null
+        );
+        throw this.createError(
+          errorInfo.code as GeminiErrorCode,
+          errorInfo.message,
+          errorInfo.recoverable,
+          errorInfo.suggestion
+        );
+      }
+      throw error;
+    }
+  }
+
+  // ==========================================================================
+  // Gemini-Specific Methods
+  // ==========================================================================
+
+  /**
+   * Create a GeminiError with details
+   */
+  private createError(
+    code: GeminiErrorCode,
+    message: string,
+    recoverable: boolean = false,
+    suggestion?: string
+  ): GeminiError {
+    const error = new Error(message) as GeminiError;
+    error.code = code;
+    error.recoverable = recoverable;
+    error.suggestion = suggestion;
+    error.name = 'GeminiError';
+    return error;
+  }
+
+  /**
+   * Get Gemini CLI version
+   */
+  async getVersion(): Promise<string | null> {
+    this.ensureCliDetected();
+    if (!this.cliPath) return null;
+
+    try {
+      const result = execSync(`"${this.cliPath}" --version`, {
+        encoding: 'utf8',
+        timeout: 5000,
+        stdio: 'pipe',
+      }).trim();
+      return result;
+    } catch {
+      return null;
+    }
+  }
+
+  /**
+   * Check authentication status
+   *
+   * Uses a fast credential check approach:
+   * 1. Check for GEMINI_API_KEY environment variable
+   * 2. Check for Google Cloud credentials
+   * 3. Check for Gemini settings file with stored credentials
+   * 4. Quick CLI auth test with --help (fast, doesn't make API calls)
+   */
+  async checkAuth(): Promise<GeminiAuthStatus> {
+    this.ensureCliDetected();
+    if (!this.cliPath) {
+      logger.debug('checkAuth: CLI not found');
+      return { authenticated: false, method: 'none' };
+    }
+
+    logger.debug('checkAuth: Starting credential check');
+
+    // Determine the likely auth method based on environment
+    const hasApiKey = !!process.env.GEMINI_API_KEY;
+    const hasEnvApiKey = hasApiKey;
+    const hasVertexAi = !!(
+      process.env.GOOGLE_APPLICATION_CREDENTIALS || process.env.GOOGLE_CLOUD_PROJECT
+    );
+
+    logger.debug(`checkAuth: hasApiKey=${hasApiKey}, hasVertexAi=${hasVertexAi}`);
+
+    // Check for Gemini credentials file (~/.gemini/settings.json)
+    const geminiConfigDir = path.join(os.homedir(), '.gemini');
+    const settingsPath = path.join(geminiConfigDir, 'settings.json');
+    let hasCredentialsFile = false;
+    let authType: string | null = null;
+
+    try {
+      await fs.access(settingsPath);
+      logger.debug(`checkAuth: Found settings file at ${settingsPath}`);
+      try {
+        const content = await fs.readFile(settingsPath, 'utf8');
+        const settings = JSON.parse(content);
+
+        // Auth config is at security.auth.selectedType (e.g., "oauth-personal", "oauth-adc", "api-key")
+        const selectedType = settings?.security?.auth?.selectedType;
+        if (selectedType) {
+          hasCredentialsFile = true;
+          authType = selectedType;
+          logger.debug(`checkAuth: Settings file has auth config, selectedType=${selectedType}`);
+        } else {
+          logger.debug(`checkAuth: Settings file found but no auth type configured`);
+        }
+      } catch (e) {
+        logger.debug(`checkAuth: Failed to parse settings file: ${e}`);
+      }
+    } catch {
+      logger.debug('checkAuth: No settings file found');
+    }
+
+    // If we have an API key, we're authenticated
+    if (hasApiKey) {
+      logger.debug('checkAuth: Using API key authentication');
+      return {
+        authenticated: true,
+        method: 'api_key',
+        hasApiKey,
+        hasEnvApiKey,
+        hasCredentialsFile,
+      };
+    }
+
+    // If we have Vertex AI credentials, we're authenticated
+    if (hasVertexAi) {
+      logger.debug('checkAuth: Using Vertex AI authentication');
+      return {
+        authenticated: true,
+        method: 'vertex_ai',
+        hasApiKey,
+        hasEnvApiKey,
+        hasCredentialsFile,
+      };
+    }
+
+    // Check if settings file indicates configured authentication
+    if (hasCredentialsFile && authType) {
+      // OAuth types: "oauth-personal", "oauth-adc"
+      // API key type: "api-key"
+      // Code assist: "code-assist" (requires IDE integration)
+      if (authType.startsWith('oauth')) {
+        logger.debug(`checkAuth: OAuth authentication configured (${authType})`);
+        return {
+          authenticated: true,
+          method: 'google_login',
+          hasApiKey,
+          hasEnvApiKey,
+          hasCredentialsFile,
+        };
+      }
+
+      if (authType === 'api-key') {
+        logger.debug('checkAuth: API key authentication configured in settings');
+        return {
+          authenticated: true,
+          method: 'api_key',
+          hasApiKey,
+          hasEnvApiKey,
+          hasCredentialsFile,
+        };
+      }
+
+      if (authType === 'code-assist' || authType === 'codeassist') {
+        logger.debug('checkAuth: Code Assist auth configured but requires local server');
+        return {
+          authenticated: false,
+          method: 'google_login',
+          hasApiKey,
+          hasEnvApiKey,
+          hasCredentialsFile,
+          error:
+            'Code Assist authentication requires IDE integration. Please use "gemini" CLI to log in with a different method, or set GEMINI_API_KEY.',
+        };
+      }
+
+      // Unknown auth type but something is configured
+      logger.debug(`checkAuth: Unknown auth type configured: ${authType}`);
+      return {
+        authenticated: true,
+        method: 'google_login',
+        hasApiKey,
+        hasEnvApiKey,
+        hasCredentialsFile,
+      };
+    }
+
+    // No credentials found
+    logger.debug('checkAuth: No valid credentials found');
+    return {
+      authenticated: false,
+      method: 'none',
+      hasApiKey,
+      hasEnvApiKey,
+      hasCredentialsFile,
+      error:
+        'No authentication configured. Run "gemini" interactively to log in, or set GEMINI_API_KEY.',
+    };
+  }
+
+  /**
+   * Detect installation status (required by BaseProvider)
+   */
+  async detectInstallation(): Promise<InstallationStatus> {
+    const installed = await this.isInstalled();
+    const version = installed ? await this.getVersion() : undefined;
+    const auth = await this.checkAuth();
+
+    return {
+      installed,
+      version: version || undefined,
+      path: this.cliPath || undefined,
+      method: 'cli',
+      hasApiKey: !!process.env.GEMINI_API_KEY,
+      authenticated: auth.authenticated,
+    };
+  }
+
+  /**
+   * Get the detected CLI path (public accessor for status endpoints)
+   */
+  getCliPath(): string | null {
+    this.ensureCliDetected();
+    return this.cliPath;
+  }
+
+  /**
+   * Get available Gemini models
+   */
+  getAvailableModels(): ModelDefinition[] {
+    return Object.entries(GEMINI_MODEL_MAP).map(([id, config]) => ({
+      id, // Full model ID with gemini- prefix (e.g., 'gemini-2.5-flash')
+      name: config.label,
+      modelString: id, // Same as id - CLI uses the full model name
+      provider: 'gemini',
+      description: config.description,
+      supportsTools: true,
+      supportsVision: config.supportsVision,
+      contextWindow: config.contextWindow,
+    }));
+  }
+
+  /**
+   * Check if a feature is supported
+   */
+  supportsFeature(feature: string): boolean {
+    const supported = ['tools', 'text', 'streaming', 'vision', 'thinking'];
+    return supported.includes(feature);
+  }
+}
--- a/apps/server/src/providers/provider-factory.ts
+++ b/apps/server/src/providers/provider-factory.ts
@@ -7,7 +7,13 @@

 import { BaseProvider } from './base-provider.js';
 import type { InstallationStatus, ModelDefinition } from './types.js';
-import { isCursorModel, isCodexModel, isOpencodeModel, type ModelProvider } from '@automaker/types';
+import {
+  isCursorModel,
+  isCodexModel,
+  isOpencodeModel,
+  isGeminiModel,
+  type ModelProvider,
+} from '@automaker/types';
 import * as fs from 'fs';
 import * as path from 'path';

@@ -16,6 +22,7 @@ const DISCONNECTED_MARKERS: Record<string, string> = {
  codex: '.codex-disconnected',
  cursor: '.cursor-disconnected',
  opencode: '.opencode-disconnected',
+  gemini: '.gemini-disconnected',
 };

 /**
@@ -239,8 +246,8 @@ export class ProviderFactory {
        model.modelString === modelId ||
        model.id.endsWith(`-${modelId}`) ||
        model.modelString.endsWith(`-${modelId}`) ||
-        model.modelString === modelId.replace(/^(claude|cursor|codex)-/, '') ||
-        model.modelString === modelId.replace(/-(claude|cursor|codex)$/, '')
+        model.modelString === modelId.replace(/^(claude|cursor|codex|gemini)-/, '') ||
+        model.modelString === modelId.replace(/-(claude|cursor|codex|gemini)$/, '')
      ) {
        return model.supportsVision ?? true;
      }
@@ -267,6 +274,7 @@ import { ClaudeProvider } from './claude-provider.js';
 import { CursorProvider } from './cursor-provider.js';
 import { CodexProvider } from './codex-provider.js';
 import { OpencodeProvider } from './opencode-provider.js';
+import { GeminiProvider } from './gemini-provider.js';

 // Register Claude provider
 registerProvider('claude', {
@@ -301,3 +309,11 @@ registerProvider('opencode', {
  canHandleModel: (model: string) => isOpencodeModel(model),
  priority: 3, // Between codex (5) and claude (0)
 });
+
+// Register Gemini provider
+registerProvider('gemini', {
+  factory: () => new GeminiProvider(),
+  aliases: ['google'],
+  canHandleModel: (model: string) => isGeminiModel(model),
+  priority: 4, // Between opencode (3) and codex (5)
+});
--- a/apps/server/src/routes/setup/index.ts
+++ b/apps/server/src/routes/setup/index.ts
@@ -24,6 +24,9 @@ import { createDeauthCursorHandler } from './routes/deauth-cursor.js';
 import { createAuthOpencodeHandler } from './routes/auth-opencode.js';
 import { createDeauthOpencodeHandler } from './routes/deauth-opencode.js';
 import { createOpencodeStatusHandler } from './routes/opencode-status.js';
+import { createGeminiStatusHandler } from './routes/gemini-status.js';
+import { createAuthGeminiHandler } from './routes/auth-gemini.js';
+import { createDeauthGeminiHandler } from './routes/deauth-gemini.js';
 import {
  createGetOpencodeModelsHandler,
  createRefreshOpencodeModelsHandler,
@@ -72,6 +75,11 @@ export function createSetupRoutes(): Router {
  router.post('/auth-opencode', createAuthOpencodeHandler());
  router.post('/deauth-opencode', createDeauthOpencodeHandler());

+  // Gemini CLI routes
+  router.get('/gemini-status', createGeminiStatusHandler());
+  router.post('/auth-gemini', createAuthGeminiHandler());
+  router.post('/deauth-gemini', createDeauthGeminiHandler());
+
  // OpenCode Dynamic Model Discovery routes
  router.get('/opencode/models', createGetOpencodeModelsHandler());
  router.post('/opencode/models/refresh', createRefreshOpencodeModelsHandler());
--- a/apps/server/src/routes/setup/routes/auth-gemini.ts
+++ b/apps/server/src/routes/setup/routes/auth-gemini.ts
@@ -0,0 +1,42 @@
+/**
+ * POST /auth-gemini endpoint - Connect Gemini CLI to the app
+ */
+
+import type { Request, Response } from 'express';
+import { getErrorMessage, logError } from '../common.js';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+
+const DISCONNECTED_MARKER_FILE = '.gemini-disconnected';
+
+/**
+ * Creates handler for POST /api/setup/auth-gemini
+ * Removes the disconnection marker to allow Gemini CLI to be used
+ */
+export function createAuthGeminiHandler() {
+  return async (_req: Request, res: Response): Promise<void> => {
+    try {
+      const projectRoot = process.cwd();
+      const automakerDir = path.join(projectRoot, '.automaker');
+      const markerPath = path.join(automakerDir, DISCONNECTED_MARKER_FILE);
+
+      // Remove the disconnection marker if it exists
+      try {
+        await fs.unlink(markerPath);
+      } catch {
+        // File doesn't exist, nothing to remove
+      }
+
+      res.json({
+        success: true,
+        message: 'Gemini CLI connected to app',
+      });
+    } catch (error) {
+      logError(error, 'Auth Gemini failed');
+      res.status(500).json({
+        success: false,
+        error: getErrorMessage(error),
+      });
+    }
+  };
+}
--- a/apps/server/src/routes/setup/routes/deauth-gemini.ts
+++ b/apps/server/src/routes/setup/routes/deauth-gemini.ts
@@ -0,0 +1,42 @@
+/**
+ * POST /deauth-gemini endpoint - Disconnect Gemini CLI from the app
+ */
+
+import type { Request, Response } from 'express';
+import { getErrorMessage, logError } from '../common.js';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+
+const DISCONNECTED_MARKER_FILE = '.gemini-disconnected';
+
+/**
+ * Creates handler for POST /api/setup/deauth-gemini
+ * Creates a marker file to disconnect Gemini CLI from the app
+ */
+export function createDeauthGeminiHandler() {
+  return async (_req: Request, res: Response): Promise<void> => {
+    try {
+      const projectRoot = process.cwd();
+      const automakerDir = path.join(projectRoot, '.automaker');
+
+      // Ensure .automaker directory exists
+      await fs.mkdir(automakerDir, { recursive: true });
+
+      const markerPath = path.join(automakerDir, DISCONNECTED_MARKER_FILE);
+
+      // Create the disconnection marker
+      await fs.writeFile(markerPath, 'Gemini CLI disconnected from app');
+
+      res.json({
+        success: true,
+        message: 'Gemini CLI disconnected from app',
+      });
+    } catch (error) {
+      logError(error, 'Deauth Gemini failed');
+      res.status(500).json({
+        success: false,
+        error: getErrorMessage(error),
+      });
+    }
+  };
+}
--- a/apps/server/src/routes/setup/routes/gemini-status.ts
+++ b/apps/server/src/routes/setup/routes/gemini-status.ts
@@ -0,0 +1,79 @@
+/**
+ * GET /gemini-status endpoint - Get Gemini CLI installation and auth status
+ */
+
+import type { Request, Response } from 'express';
+import { GeminiProvider } from '../../../providers/gemini-provider.js';
+import { getErrorMessage, logError } from '../common.js';
+import * as fs from 'fs/promises';
+import * as path from 'path';
+
+const DISCONNECTED_MARKER_FILE = '.gemini-disconnected';
+
+async function isGeminiDisconnectedFromApp(): Promise<boolean> {
+  try {
+    const projectRoot = process.cwd();
+    const markerPath = path.join(projectRoot, '.automaker', DISCONNECTED_MARKER_FILE);
+    await fs.access(markerPath);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+/**
+ * Creates handler for GET /api/setup/gemini-status
+ * Returns Gemini CLI installation and authentication status
+ */
+export function createGeminiStatusHandler() {
+  const installCommand = 'npm install -g @google/gemini-cli';
+  const loginCommand = 'gemini';
+
+  return async (_req: Request, res: Response): Promise<void> => {
+    try {
+      // Check if user has manually disconnected from the app
+      if (await isGeminiDisconnectedFromApp()) {
+        res.json({
+          success: true,
+          installed: true,
+          version: null,
+          path: null,
+          auth: {
+            authenticated: false,
+            method: 'none',
+            hasApiKey: false,
+          },
+          installCommand,
+          loginCommand,
+        });
+        return;
+      }
+
+      const provider = new GeminiProvider();
+      const status = await provider.detectInstallation();
+      const auth = await provider.checkAuth();
+
+      res.json({
+        success: true,
+        installed: status.installed,
+        version: status.version || null,
+        path: status.path || null,
+        auth: {
+          authenticated: auth.authenticated,
+          method: auth.method,
+          hasApiKey: auth.hasApiKey || false,
+          hasEnvApiKey: auth.hasEnvApiKey || false,
+          error: auth.error,
+        },
+        installCommand,
+        loginCommand,
+      });
+    } catch (error) {
+      logError(error, 'Get Gemini status failed');
+      res.status(500).json({
+        success: false,
+        error: getErrorMessage(error),
+      });
+    }
+  };
+}