MCP Server for iOS Simulator

Implementation Reference

• src/mcp/mcp-server.ts:763-800 (registration)

  MCP tool registration for 'shutdown-simulator'. Includes Zod input schema requiring 'sessionId' and handler function that calls simulatorManager.shutdownSimulator and returns formatted text response.

  this.server.tool(
    'shutdown-simulator',
    {
      sessionId: z.string()
    },
    async ({ sessionId }) => {
      fileLogger.info(`Shutting down simulator: ${sessionId}`);
      try {
        const success = await simulatorManager.shutdownSimulator(sessionId);
        
        if (!success) {
          return {
            content: [{
              type: 'text',
              text: `Failed to shutdown simulator for session: ${sessionId}`
            }],
            isError: true
          };
        }
        
        return {
          content: [{
            type: 'text',
            text: `Simulator shutdown for session: ${sessionId}`
          }]
        };
      } catch (error) {
        fileLogger.error(`Failed to shutdown simulator for session: ${sessionId}`, { error });
        return {
          content: [{
            type: 'text',
            text: `Error: ${error instanceof Error ? error.message : String(error)}`
          }],
          isError: true
        };
      }
    }
  );

• src/simulator/simulator-manager.ts:364-405 (handler)

  Main handler logic for shutting down a simulator session. Attempts shutdown via appium-ios-simulator API first, falls back to 'xcrun simctl shutdown' CLI command if needed, and verifies the simulator is no longer booted.

  async shutdownSimulator(sessionId: string): Promise<boolean> {
    const session = this.sessions.get(sessionId);
    if (!session) {
      fileLogger.warn(`Session not found: ${sessionId}`);
      return false;
    }
  
    try {
      // Try the simulator object method first
      fileLogger.info(`Attempting to shut down simulator (via API) for session: ${sessionId}, UDID: ${session.udid}`);
      
      try {
        await session.simulator.shutdown();
        fileLogger.info(`Simulator API shutdown successful for session: ${sessionId}`);
      } catch (innerError) {
        fileLogger.warn(`API shutdown failed, falling back to CLI for session: ${sessionId}`, { innerError });
        // If the simulator object method fails, try direct CLI
        await this.directShutdownByUDID(session.udid);
      }
      
      // Verify the shutdown was successful
      let verifySuccess = await this.verifySimulatorShutdown(session.udid);
      
      // If not, try the CLI approach as a fallback
      if (!verifySuccess) {
        fileLogger.warn(`Simulator still running, trying direct CLI shutdown for session: ${sessionId}`);
        await this.directShutdownByUDID(session.udid);
        verifySuccess = await this.verifySimulatorShutdown(session.udid);
      }
      
      if (verifySuccess) {
        fileLogger.info(`Simulator successfully shutdown for session: ${sessionId}`);
        return true;
      } else {
        fileLogger.warn(`Simulator may still be running for session: ${sessionId}`);
        return false;
      }
    } catch (error) {
      fileLogger.error(`Failed to shutdown simulator for session: ${sessionId}`, { error });
      return false;
    }
  }

• src/simulator/simulator-manager.ts:410-421 (helper)

  Helper function that executes the direct CLI shutdown command 'xcrun simctl shutdown ${udid}' used as fallback in shutdownSimulator.

  async directShutdownByUDID(udid: string): Promise<boolean> {
    fileLogger.info(`Attempting direct CLI shutdown for simulator: ${udid}`);
    try {
      const execAsync = promisify(exec);
      await execAsync(`xcrun simctl shutdown ${udid}`);
      fileLogger.info(`Direct CLI shutdown command completed for simulator: ${udid}`);
      return true;
    } catch (error) {
      fileLogger.error(`Failed direct CLI shutdown for simulator: ${udid}`, { error });
      return false;
    }
  }