Kaleta
An open-source CMS for business websites – services, testimonials, team, careers, contact and news. A visual page builder whose output reads like hand-written HTML, an AI assistant, Claude over MCP, and a WordPress importer. Česky

Project website: kaletacms.com · guide: kaletacms.com/guide · latest version: GitHub Releases · what comes next: roadmap · release policy
Features
- Page builder – the canvas is the real page. Drag elements and ready-made sections into place, style them separately for desktop, tablet, mobile and hover. Drafts save continuously and go live only when you publish; older versions can be restored.
- Library of 40 ready-made sections (heroes, services, pricing, testimonials, team, gallery, contact with a form…) and three starter sites at installation. Texts follow the page language.
- Design system – one-click styles, colours with a readability (WCAG) check, dark mode, fonts, fluid sizes and spacing – all tokens, so changing a colour restyles the whole site.
- Site parts – header, footer and wrappers for the news item, news list and 404 page in the builder, including variants for selected pages (a landing page without navigation).
- Pop-ups – windows, slide-in panels and bars built in the builder, with triggers (time, scrolling, exit intent, idle time, page count), rules by page, language, period, device and campaign, and cookie-free views and conversions.
- Components – reusable blocks with properties; editing a component updates it everywhere.
- Collections – custom content types (testimonials, team, products, branches…) with their own fields, listed in the
builder with
{{field}}tags, filters, sorting and pagination, and item pages with a builder template. - Forms and enquiries – an enquiry form without CAPTCHA or cookies, enquiries in the admin, email notifications, CSV export and automatic deletion of personal data.
- Newsletter – double opt-in sign-up; send your latest news in an e-mail styled by the design system (through SMTP), or pass confirmed subscribers to Brevo, MailerLite, Mailchimp, Ecomail, SmartEmailing or any service via a webhook.
- Company details – address, company ID, opening hours and map once in Settings; the site shows them and search engines get LocalBusiness structured data.
- AI – the assistant drafts a new section from a description, rewrites element text, suggests headlines, SEO descriptions, proofreading and translation (Claude, OpenAI, Google Gemini or Mistral). Claude can also build the site over MCP: it turns HTML into builder content and edits site parts, collections and the design – always as a draft to approve.
- News (blog), sites in around forty languages, the admin in Czech, English, German and Spanish, SEO and llms.txt, cookie-free analytics, redirects, backups and signed updates, WordPress import (straight into the builder, too).
Principles
- No technical debt: plain PHP 8.3+, no framework, Composer or build step; no third-party plugins.
- Clean output: one builder element = one HTML tag, CSS only for what the page uses, in cascade layers (
@layer); JavaScript only where it is really needed. Tests enforce it. - Web 2026: fluid type and spacing, container queries, OKLCH colours (
color-mix), the Popover API, view transitions. - AI as a first-class user: whatever works in the editor works over MCP – same schema, validation and permissions.
- Privacy and accessibility by default: no third-party scripts or fonts, colour contrast checks.
- FTP installation, signed updates.
Installation
- Download
kaleta-X.Y.Z.zipfrom Releases and upload its contents (including the hidden.htaccessfiles) to hosting with PHP 8.3+ and MySQL 8 / MariaDB 10.6+. On PHP 8.3 with the JIT on, keep PHP's defaultopcache.jit = tracing: the per-function mode (1235) has a crash bug in 8.3 that System status points out. - Create an empty database.
- Open
https://your-site.com/install.php, fill in the form and choose a starter site.
Later versions are downloaded and installed by the site itself (Settings → Backups and updates); packages are signed by the publisher.
Nginx does not read .htaccess – use the example in system/nginx.example.conf. The user guide is in docs/guide.md.
Development
php -S localhost:8080 system/dev-router.php
Tests: php tools/unit-tests.php (unit, no database) and tools/test.sh (clean install plus a walk through the site, admin,
builder and MCP; needs MySQL; WEB=remeslo tools/test.sh tests another starter site). tools/test-lighthouse.sh holds every
starter site to the output budget; php tools/contracts.php shows changes of the public contracts (MCP tools, design tokens,
builder elements); static analysis is PHPStan with phpstan.neon.dist. How to contribute is in
CONTRIBUTING.md; architecture notes are in CLAUDE.md (Czech).
Support
Kaleta is free, with no ads, paid tiers or licence keys. If it saves you time, you can support its development on Buy Me a Coffee – see why Kaleta is free.
Licence
GNU GPL version 2 or later. The licence text is in LICENSE.