Stuck on Where to Start a Complex Feature? Design Deeply in the Cloud with /ultraplan

When starting a big task like a payment feature, have you ever dived in with "let's just write the code first" and then watched the structure get tangled halfway through? The more complex the feature, the harder it is to know where to begin, and a bad start is hard to undo. /ultraplan is a command that lets you build a plan first, and deeply at that, before writing any code. The heavy design work happens in the cloud, and you review that plan calmly in your browser before starting. It is an advanced feature, so if you are just getting started, it is enough to know that "there is a way to handle big tasks like this."

Definition

/ultraplan is a command that builds a plan for a big task in the cloud, lets you review it in the browser, and then runs it remotely or pulls it into the terminal.

What makes it different from ordinary planning is its "depth" and "location."

• Design in the cloud: Heavy planning work is handled not on your PC but in the cloud (a server across the internet). That lets it handle bigger, deeper designs.
• Review in the browser: You can open and refine the finished plan on a web browser screen. Instead of the narrow terminal window, you review it across a wide view.
• Execute after review: Once you are happy with the plan, you run it directly in the cloud, or pull it into the terminal and continue.

Put simply, it is a tool that says "for important work, draw the blueprint properly and then start."

How to Use (by difficulty)

Basics — Delegating a Large Plan

Type the task you want designed into the chat box.

/ultraplan 결제 기능 설계해줘

Once you enter it, Claude starts building a plan for this feature in the cloud. A moment later, you are given a link or screen where you can review that plan in the browser. There you open the step-by-step design, refine it by saying "let's change this part like so," and then move on to execution.

Common Pitfall — It Goes Up to "Planning," Not Writing Code Right Away

This is an easy point to confuse. /ultraplan is fundamentally the stage that creates a plan (design). Code is not written out the instant you enter the command.

The flow goes like this.

1. Build the plan in the cloud with /ultraplan.
2. In the browser, a human reviews and refines that plan.
3. Only after the review is done do you move on to execution (writing code).

In other words, the human step of "review" being inserted in the middle is the core of this command. Skipping the review defeats the purpose of using /ultraplan. The more important the task, the more this review step prevents accidents.

Real-World Example

When I was assigned a large new feature, jumping straight into code as usual looked risky. So I had it designed first with /ultraplan.

/ultraplan 새 알림 시스템 전체 설계해줘

When I opened the plan built in the cloud in my browser, the missing cases and the structures that needed fixing were visible at a glance. I refined a few spots there and then moved on to execution. Had I written code right away, the structure would have tangled midway and I would have had to scrap it, but thanks to reviewing the design first, it went cleanly in one pass.

Using It Further

• Cloud design: Handle heavy, large plans with the power of the cloud.
• Browser review: Open the plan wide on the web and refine it.
• Paired with detailed review: If you want a deep code review on top of the design, it pairs well with the detailed review feature.
• For large features: Especially suited to designing big features that touch the codebase broadly.

Tip: You do not need to use /ultraplan for every small, simple task. Ordinary planning is enough for light work. It is more efficient to save it for "critical tasks" that are hard to undo or structurally complex.

Summary

The core fits in one sentence. For important work, do not rush; build and review a deep design first, then start. Big features are hard to undo if you start them wrong. By firmly building the plan in the cloud with /ultraplan and reviewing it in the browser, you can start critical work far more safely.

Based on: Claude Code v2.1.154 (2026.05)