Resize Window

Instructions

Implementation Reference

• src/system/tools.ts:704-711 (handler)

  The handler function for the resize_window tool. It accepts appName, width, height, and optional windowTitle, then executes a JXA script to resize the window.

    async ({ appName, width, height, windowTitle }) => {
      try {
        return ok(await runJxa(resizeWindowScript(appName, width, height, windowTitle)));
      } catch (e) {
        return errJxaFor("resize window", e);
      }
    },
  );

• src/system/tools.ts:693-701 (schema)

  Input schema definition for the resize_window tool using Zod validation.

    appName: z.string().min(1).max(500).describe("Application name (e.g. 'Safari')"),
    width: z.number().int().min(1).describe("Window width in pixels"),
    height: z.number().int().min(1).describe("Window height in pixels"),
    windowTitle: z
      .string()
      .max(500)
      .optional()
      .describe("Specific window title. If omitted, targets the first window."),
  },

• src/system/tools.ts:687-711 (registration)

  Registration of the 'resize_window' tool on the MCP server.

  server.registerTool(
    "resize_window",
    {
      title: "Resize Window",
      description: "Resize a window to specific dimensions.",
      inputSchema: {
        appName: z.string().min(1).max(500).describe("Application name (e.g. 'Safari')"),
        width: z.number().int().min(1).describe("Window width in pixels"),
        height: z.number().int().min(1).describe("Window height in pixels"),
        windowTitle: z
          .string()
          .max(500)
          .optional()
          .describe("Specific window title. If omitted, targets the first window."),
      },
      annotations: { readOnlyHint: false, destructiveHint: false, idempotentHint: true, openWorldHint: false },
    },
    async ({ appName, width, height, windowTitle }) => {
      try {
        return ok(await runJxa(resizeWindowScript(appName, width, height, windowTitle)));
      } catch (e) {
        return errJxaFor("resize window", e);
      }
    },
  );

• src/system/scripts.ts:387-394 (helper)

  Helper function that generates a JXA (JavaScript for Automation) script string to resize a window using System Events.

  export function resizeWindowScript(appName: string, width: number, height: number, windowTitle?: string): string {
    return `
      const se = Application('System Events');
      ${windowSelector(appName, windowTitle)}
      win.size = [${width}, ${height}];
      JSON.stringify({resized: true, app: '${esc(appName)}', size: win.size()});
    `;
  }

• src/system/scripts.ts:365-375 (helper)

  Helper function that generates JXA code to select a window by app name and optional title.

  function windowSelector(appName: string, windowTitle?: string): string {
    if (windowTitle) {
      return `const proc = se.processes.byName('${esc(appName)}');
      const wins = proc.windows.whose({name: '${esc(windowTitle)}'})();
      if (wins.length === 0) throw new Error('No window found: ${esc(windowTitle)}');
      const win = wins[0];`;
    }
    return `const proc = se.processes.byName('${esc(appName)}');
      const wins = proc.windows();
      if (wins.length === 0) throw new Error('No windows found for ${esc(appName)}');
      const win = wins[0];`;