# Build from a prompt (/docs/guides/build-from-a-prompt)



# Build from a prompt [#build-from-a-prompt]

Have an idea for an app that doesn't exist yet? You can build it from scratch by describing it in plain words, and AI puts together a first version for you to try. From there, you shape it one change at a time until it's just what you pictured. No coding needed.

## Before you start [#before-you-start]

Check Discover first. If an app is already close, [remixing it](./remix-an-app.mdx) is usually faster.

## How to do it [#how-to-do-it]

. Open **Discover** from the sidebar, then click **+ Create**, at the right of the Apps heading.
. Make sure **App** is selected. It is by default. Want to make an agent instead? Switch to **Agent** and see [Create an agent](./create-agent.md).
. Pick where to build it:
  * **Robutler agent** builds it right here, with nothing to set up. Good for small apps.
  * **Claude Code**, **Codex**, **Antigravity**, or **Cursor** opens that tool. We strongly recommend one of these for bigger builds.
. Describe the app you want. The tips below help.
. A first version opens on your screen. Try it out, then ask for changes, one at a time, until it's right.
. Happy with it? [Publish it](./publish-and-share.mdx) so others can use it, or keep it just for you.

<GuideFigure name="create" alt="The Create pop-up. A switch at the top chooses App or Agent. Browse apps to remix is the faster start. Under Pick where to build it, the first row, Robutler agent, builds right here with no setup, and the rows below it, Claude Code, Codex, Antigravity and Cursor, each open in that app." />

*Have an app in mind that's already close? Click **Browse apps to remix** instead. It's usually faster.*

## What happens after you pick [#what-happens-after-you-pick]

**With your Robutler agent.** Your agent opens with this already typed: "Build me a new app. First check whether one already exists or can be remixed. It should:" Finish the sentence with your idea and send. Your agent looks at the apps that already exist first. If one is close, it offers to remix that instead of starting over. Otherwise it builds a new private app and opens it on your screen.

**With a coding tool.** The tool opens with ready-made instructions, which are also on your clipboard. They tell it to connect to Robutler, look at the apps that already exist, and then ask you what to build. So your idea goes in when it asks, not before.

## How to describe your idea [#how-to-describe-your-idea]

Answer three questions, and you're most of the way there.

* **Who's it for?** "My book club."
* **What should it do?** "Log what we're reading and rate each book."
* **How should it look?** "Simple and bright, with big buttons."

Put together: "A simple, bright tracker where my book club can log what we're reading and rate each book, with big buttons."

## Try one of these [#try-one-of-these]

Copy a prompt, then make it yours.

* "A packing list for a beach weekend that I can check off on my phone."
* "A chore chart for three kids, with points and a weekly winner."
* "A countdown to our wedding, with photos and a to-do list."

## Not quite what you pictured? [#not-quite-what-you-pictured]

Totally normal on the first try. Say what's off, in plain words: "make the buttons bigger," "add a dark mode," "remove the timer." Each round gets closer.

## Good to know [#good-to-know]

* **Building uses credits only with your Robutler.** Bigger apps take more. A coding tool uses its own plan instead. See [What things cost](./what-things-cost.md).
* **Small apps suit your Robutler. Bigger builds suit a coding tool.** If your idea has lots of screens or moving parts, start in Claude Code, Codex, Antigravity, or Cursor.
* **Start small.** Get the basics working, then add more.
* **Your app stays private** until you publish or share it.
* **It's easy to find again.** It shows up under **Mine** in **Discover** and in **My files**.

## Building with a coding tool [#building-with-a-coding-tool]

If you already work in a coding tool, the loop looks like this:

. Connect it to Robutler. See [Connect your AI](./connect-ai-app.mdx).
. Ask it to start a new app.
. Ask for changes, and try each one as you go.
. Publish when you're ready.

```text
You:   Start a Robutler app called "habit-heatmap", then add a weekly grid.
Tool:  (creates the app, edits the files, shows you the result)
You:   Make today's square stand out.
Tool:  (edits the files and reloads the app)
```

For the full walkthrough, see the [developer quickstart](/develop/quickstart).

Next: [Publish and share](./publish-and-share.mdx), so others can use what you made.