3 Steps To Build ANY App with AI (ask, plan, agent)

Quick Overview

The video outlines a three-step workflow for building applications with AI assistance using the Cursor IDE: Ask, Plan, and Agent, demonstrated by fixing a Tailwind CSS v4 opacity syntax migration issue where modal overlays lost opacity after an upgrade from v3 to v4, which the AI model resolved by providing a comprehensive plan and executing the necessary code changes.

Key Points: The core workflow demonstrated for building apps with AI involves three modes: Ask for providing context, Plan for generating detailed steps, and Agent for automatic execution. The specific bug addressed was the loss of opacity on modal overlays after upgrading Tailwind CSS from v3 to v4, where deprecated utilities needed replacement with the new slash syntax (e.g., ). The AI model, Composer 1, successfully generated a detailed plan identifying 15 files requiring updates for modal overlays and 25+ instances for hover state opacity changes. The solution involved migrating modal overlay classes from to and updating hover states from to color-specific slash notations like . The presenter emphasizes that even without deep development experience, users can effectively use the Plan mode to understand the AI's proposed steps before execution. After the Agent successfully executed the fix, the modal overlays' opacity was restored, proving the efficacy of the Ask-Plan-Agent sequence for complex code fixes.

Context: The video features a developer demonstrating an advanced workflow within the Cursor AI IDE, utilizing its integrated agent capabilities to solve a specific coding issue related to a dependency upgrade. The issue stems from migrating the project's styling framework, Tailwind CSS, from version 3 to version 4, which introduced breaking changes in how opacity utility classes are declared, causing visual elements like confirmation dialogs and other pop-ups to render without the intended semi-transparency.

Detailed Analysis

The demonstration centers on using Cursor's AI capabilities through a three-stage process: Ask, Plan, and Agent. First, the user employs the Ask mode (0:47) to query the AI about a specific bug encountered after upgrading Tailwind CSS from v3 to v4: modal pop-ups losing opacity. The AI model, Composer 1, analyzes the context and provides a detailed Markdown summary of changes required, listing critical files like and (2:33). The user then switches to Plan mode (3:07) to generate a precise, executable roadmap, which includes updating modal overlays and hover states using the new Tailwind v4 syntax (2:51). Finally, switching to Agent mode (3:06) allows the AI to execute the entire plan automatically, modifying 15 files to correct the opacity issue (4:45). The presenter highlights that this systematic approach, akin to talking to a robot programmer, provides highly specific and context-aware solutions, allowing developers of any skill level to tackle complex migration tasks efficiently.