DOP TAREAS | Jairo Vélez | ChatGPT + Codex https://deotroplaneta.com/en/blog/build-task-app-chatgpt-codex Before you start: what you need - An account with access to Codex and an environment where it can work on project files. A text conversation alone does not host an application. - A list of people, roles and rules: who assigns work, who can see each task and who administers the system. Define what completing a task means. - A computer for reviewing the preview and phones for real-device testing. Start with fictional examples, not confidential client information. - Hosting with a backend and database, plus HTTPS for the live version. A custom domain is optional; we used a subdomain. - Someone responsible for reviewing security, costs, backups and maintenance before onboarding the team. Never put private keys into prompts. 1. Describe the work, not just the screen Build a task platform for [company] with [number] people. I need administrator and adviser roles; advisers can assign tasks to one another. Each task needs a title, context, client, owner, deadline, priority and status. Include My day, list, board and comments. Use fictional data. Inspect any existing project first and show a mobile-friendly preview. Do not publish or replace existing data. Explain costs and limitations before choosing services. 2. Keep data outside the browser Connect the preview to a persistent database. Validate on the server what each role may read or change. Protect passwords and sessions, limit login attempts and keep secrets out of public code. Test with two users in different browsers. Add task export and explain backup and recovery. Do not use production accounts or the production database for testing. 3. Turn a routine into a recurring task Add task frequency: every day, Monday to Friday or selected weekdays. Each occurrence must keep its own status and history and must not duplicate on refresh. Use Colombia's time zone. Add a client dropdown and an Other option with manual entry. Preserve existing tasks and test in an isolated copy before publishing. 4. Bring the notification to the phone Implement Web Push with HTTPS, a service worker and VAPID keys protected on the server. Each user must be able to enable, disable and test notifications on their device. Do not expose sensitive information on the lock screen. Keep test and production data separate. Test on iPhone and Chrome for Android before publishing, and distinguish provider acceptance from actual receipt by a person. 5. Improve the software without erasing the work Before updating production, create and verify a recoverable backup. Compare users, tasks, statuses, recurrence rules and history before and after. Apply only necessary migrations and never reset or seed demonstration data in production. Document changes, files, configuration and rollback to a stable version. Stop if information is at risk and wait for my approval before publishing. Android and iPhone: notifications and a home-screen icon On Android these are separate actions. For DOP Tareas notifications: open the site in Chrome, go to your profile, enable notifications, accept the browser permission and select Send test. Keep Chrome notifications enabled in your phone settings. Installation was not needed for this workflow. To add the Android icon as well: open the site in Chrome, tap the three-dot menu and choose Install and create shortcut. Then choose Install if available, or Create shortcut, and confirm Add. Labels vary by version. An installed app may open in its own window; a simple shortcut opens the site in Chrome. Neither option is a task widget. On iPhone with iOS 16.4 or later: open the site in Safari, select Share and Add to Home Screen. Open the app from that icon, sign in and enable notifications in your profile. Accept the permission and send a test. Adding the app to the home screen is required for this Web Push workflow. If a notification does not appear, check site and system permissions, focus modes and the account session. Never share credentials or screenshots of private data when requesting help. Adding an icon does not make this platform work offline. What we learned, costs and limitations The first push test did not arrive. We found a network option incompatible with the execution environment and corrected it. The lesson was specific: passing a simulated test does not mean a notification reaches a phone. Test the real server environment and confirm receipt on real devices. Building with AI does not mean running AI for every task. This version does not call an OpenAI model to create tasks, change statuses or send push notifications. Budget for the development plan, domain, hosting, database, usage limits and maintenance. We do not promise it will be free forever or give a universal price. The profile email is contact information: it does not automatically enable email alerts, Google sign-in or WhatsApp messages. Those integrations need implementation and a review of costs and permissions. Fixed-time alarms, offline work and the complete feature set of an established enterprise task manager are also outside this version. Keeping source code and backups helps you change providers; it does not keep a cancelled hosting service running without migration. An existing tool may still be a better choice for a team without technical support. Start with one small need, verify the solution and grow without risking the data.