castomUI
Open castomUI

The website builder for teams who have a deadline

Describe the website.Publish it tonight.

Start from a sentence, a sketch or the site you already have. castomUI drafts the pages, you shape them with components, your data and your team — and it goes live on cstmui.com, your own domain or GitHub.

Open castomUI See how it works

The whole thing,
in four moves.

Describe · Shape · Work together · Publish

Describe

Write what the website is for, or paste the address of the one it replaces. castomUI proposes a sitemap, drafts the pages from your components, writes META tags and fills the gaps with images from the media library — every page arriving as a draft, so nothing is public until somebody says so.

Shape

A page is a stack of blocks and every block is a component — your HTML, CSS and JavaScript with a data structure on top. Editing content is filling in a form; editing design is editing code, in the same window, with the live preview beside it.

Work together

Invite owners, editors and viewers. Leave a note on the exact block you mean, answer it in a thread, keep the conversation in the project chat instead of in forty e-mails. On the Team plan, share a screen and build the same page at the same time.

Publish

One page or the whole project, to a cstmui.com address, to your own domain, to a GitHub repository or to a publisher you define — minified, prefetched on hover and able to open offline, if you switch those on.
Every feature, part by part

Why this one

A website was never hard to draw.
It was hard to finish.

Every builder can put a hero on a page. What takes the quarter is everything after it: the forty subpages, the three languages, the product data that changes weekly, the client who wants the headline changed at 11 p.m., and the move off the old site without losing what it ranked for. castomUI is built around that part.

One workspace, many windows

The editor is not a row of tabs you click through. Pages, blocks, components, media, datasets, menus, settings, notes and the publisher each open as a window beside the live preview, so the thing you are editing and the result of the edit are on screen at the same time.

Arrange them the way the job needs, save the layout, and open it again tomorrow. The person doing SEO and the person writing components keep very different desks, and both are right.

Open windowsLayout · “Launch week”
  • 1Pages overviewTree of 42 pages, drafts marked, the homepage flagged.
  • 2Page preview · PricingNine blocks; the third one is hidden while the offer is agreed.
  • 3Component · Plan cardsHTML, CSS, JS and the data structure behind the form.
  • ✎Note on block 4“Can the Team price say ‘per seat’ in the heading?” — two replies.
  • 4PublishWhole project → your domain, when the note is resolved.

IllustrationLayouts are saved per person

Components you own, forms anyone can fill

A component is code you can read: HTML, CSS and JavaScript, plus a JSON data structure that says which fields it has. That structure is what becomes the editing form, so the marketing team changes a headline without meeting the markup, and the developer changes the markup without breaking the headline.

Write components by hand, clone one and adapt it, or describe the one you need and let AI draft it with your project's CSS and fonts as context. Templates carry the header, the footer and the fonts every page shares.

Component · Hero with offerData structure
  • TheadlineSimple text · translatable · mandatory
  • leadLonger text · translatable
  • ▣backgroundImage · from the media library
  • ↗cta_urlURL address
  • =BecomesA four-field form in every block that uses this component.

Illustration23 field types available

AI where the work is, and never the last word

AI in castomUI is not a separate chat window that hands you a file. It acts in place: generate a project from a prompt or a URL, a sitemap, a page from your own components, a block rewrite, a component, META tags for every page, an llms.txt, base CSS, an image, a translation.

You choose how much of the project it gets to read and which model does the work — per action, or as a project default. And every generated page lands as a draft, because a sentence you did not write should still be read by somebody before a customer does.

Generate page with AIDraft
  • 1Instructions“A page for the spring workshop series, three dates, booking form.”
  • 2Source URLLast year's page on the old site, to reuse what still applies.
  • 3ComponentsOnly from this project, rated ones first.
  • 4Existing blocksHide them, rather than remove, until the new version is approved.
  • !ResultSeven blocks, marked draft. Not publishable until unmarked.

IllustrationModel chosen per action

Your data, not a copy of it

Create datasets with typed fields — text, images, dates, relations, options, 23 types in all — or connect the MySQL or MongoDB database you already run. Connect a page to a dataset view and it becomes a template: one product, one event or one location per record, each with its own address.

When the catalogue changes, the pages change. Nobody retypes a price into a website again, which is the single most reliable way of getting a price wrong.

Dataset · WorkshopsConnected page
  • 1Fieldstitle, date, city, seats, price, cover image, description
  • 2ViewUpcoming only, ordered by date
  • 3Page template/workshops/{title} — one page per record
  • ↺ChangeA new record in the table is a new page on the next publish.

IllustrationMongoDB or MySQL

What people build with it

Eight kinds of website,
one editor.

The toolkit does not change between them. What changes is which part of it carries the weight — AI for the landing page due on Friday, datasets for the store, translation for the site in nine languages.

Landing pages

One page, one campaign, one deadline. Generated from a brief, shared through a private preview, published before the meeting ends.

See how it works

Company websites

The site every business needs: sitemap, shared header and footer, menus, contact, SEO and your own domain — editable by the people who know the company.

See how it works

Premium websites

Your own components, code, fonts and motion, with a builder underneath so the client can still change a headline without calling the studio.

See how it works

Online stores

A storefront built on your catalogue — in a dataset or read from the shop database you already run — with one page per product.

See how it works

Presentations

A deck that is a website: full-screen sections, a private link instead of an attachment, a copy per audience.

See how it works

Multilingual websites

Clone and translate a page, a block or a menu in one step; dictionaries for the interface strings; translatable data fields.

See how it works

All eight, including rebuilding the site you have

“We just need a simple website.”

Nobody has ever needed a simple website
for longer than a week.

So castomUI assumes the second week: more pages, more languages, more people, more data.

Inside the editor

Nine parts,
one project.

Pages and blocks

A page tree you drag into shape, drafts that cannot publish by accident, blocks you move, hide, clone and translate, menus built from anchors.

See how it works

Components and templates

HTML, CSS, JS and a data structure. Templates for the shared frame, fonts included. Written by hand or drafted by AI.

See how it works

AI generation

Projects, sitemaps, pages, blocks, components, META, llms.txt, CSS, images and translations — with the model and the context you choose.

See how it works

Datasets and content

23 field types, views, relations, dataset-driven pages, external MySQL and MongoDB, global variables, dictionaries.

See how it works

Media library

Uploads, AI images, five royalty-free stock libraries, ALT and TITLE, tags, EXIF and duplicate removal.

See how it works

SEO and migration

A crawler that reads the old site into the new one, META for every page at once, canonical, OpenGraph, redirects.

See how it works

Publishing

cstmui.com, your own domain, GitHub or a custom publisher — one page or the whole project, with speed switches.

See how it works

Collaboration

Roles, invitations, notes on elements, project chat, saved window layouts — and screen sharing on Team.

See how it works

Plugins

Mailing campaigns, Eclicks PRO, a matching system and a moderation console, running on your datasets.

See how it works

Pricing

Three plans,
priced per person who builds.

No free tier, no per-page fees, no surcharge for the tenth language. You pay for the seats that edit — monthly, or yearly with two months free — and the plan decides how far into data, plugins and co-working those seats go.

See pricing Talk to a person

The short versionMonthly, in euro
  • €100RegularThe whole builder, AI and publishing · one seat.
  • €300PROPlus datasets, external databases, plugins, GitHub and custom publishers.
  • €500TeamPer seat · everything, plus screen sharing and real-time co-working.

One castomo accountOne wallet across the family

Part of one family,
and useful on its own.

castomUI is where the castomo family makes websites. castomAPI runs underneath it — the AI models, the image generation and the royalty-free media library all come from there. castoMIND uses it for the website half of a product it assembles; FABLS writes the blog that sits on it; dash-b is where the numbers about it land.

One castomo account signs into all of them, and one wallet pays for all of them. None of which you need in order to build a website here: plenty of projects are one landing page, one domain and nothing else.

The honest bit: AI will give you a first version in minutes, and it will be a first version. The headline will be almost what you meant, and one photograph will be of a slightly wrong kind of office. That is why pages arrive as drafts — the minutes you save go into reading, which is still the cheapest part of building a website.

Today.
That is rather the point.

“When can it be live?” Open the editor, describe the website, and publish the first version to a cstmui.com address before anyone has finished the brief.

Open castomUI Watch it in six pictures

Illustrations by GetIllustrations.com (Ghost pack).