DevaiyDevaiy/Docs
← Back to app

Building Your App

How to get the most out of Devaiy when describing what you want to build, editing files directly, and choosing between AI model tiers.

Writing good prompts

The AI works best when you’re specific about WHAT you want, not HOW to build it. A few principles that help:

  • Describe the user, not the code. “A pricing page for a SaaS tool with three tiers and a comparison table” beats “a page with three cards”.
  • Mention the style if you care about it. “Clean and minimal, like Linear’s pricing”, or “vibrant gradients, playful animations”.
  • Front-load the detail — describe the whole app upfront. A long, structured first prompt that lists every page and what each section should contain produces far better results (and costs far fewer credits) than building the same app through dozens of small follow-ups. Each AI turn re-reads your project, so ten small prompts cost much more than one thorough prompt. Save the back-and-forth for genuine corrections (“the hero background is too dark”) rather than building the app one section at a time.
  • A good first prompt looks like a brief. Pages you want, the sections on each page, the tone/style, the data the app handles, who the user is. The starter prompts on the home page (luxury car website, beautiful dashboard, memory card game, designer portfolio, product launch page) are examples of this shape — click any of them to see how detailed the opening prompt should be, then edit before submitting.

The file editor (paid plans)

Sometimes you want to tweak a specific line of code directly — for example, to adjust a Tailwind class the AI keeps regenerating, or to fix a small typo without burning credits. Click any file in the file tree on the left side of the project view to open it in the Monaco editor.

Save with Cmd/Ctrl+S. The change is committed to your project immediately. To see your edit in the preview, click the refresh button on the preview panel — otherwise the preview keeps showing the previously built version.

The AI doesn’t automatically know that you edited a file. In your next prompt, mention what you changed (e.g. “I tweaked the header styles in Header.tsx — please keep those and add a logo on the left”). The AI usually reads the relevant file before making changes, so as long as you flag your edit it won’t accidentally overwrite your work.

File editing is available on all paid plans (Starter and above). On the Free plan, the editor is read-only.

AI model tiers

You can choose between two AI tiers in the chat input area:

  • Lite — faster and more economical. Great for simple changes, content edits, and iteration on smaller projects.
  • Pro — more capable, higher quality. Best for complex features, larger projects, and when you need the AI to reason about more code at once.

Pick the tier wisely at the start of your project based on its complexity.

Limits

  • Chat attachment size: 5 MB per file attached to a chat message (images, PDFs, text files).
  • File save size: 10 MB per file when editing in the file editor.
  • Asset storage per account: 10 MB on Free, 100 MB on Starter, 250 MB on Pro.
  • Credits: see Account & Billing.