Design
Built from your parts
A layout carries header and footer, templates set the structure of each page type, modules hold the content, one theme sets colours, type and spacing. A button is the same button on page one and page fifty.
Open-source CMS for websites run with AI
Change your website by chat while Caelo keeps it in shape.
Point at anything on your live site and say what should change. Caelo updates a draft in your design, checks it with Lighthouse, and waits for your click to publish.
Harbour YogaClasses · Teachers · Visit
SelectedBreathe in. The harbour is right outside.
Small classes by the water, for every level. Your first class is on us.
- Mon · Slow Flow · 18:30
- Wed · Vinyasa · 07:00
- Sun · Gentle Morning · 10:00
Selected Hero headline
Make this warmer and add a Sunday class at 10.
Done. New headline, and Sunday 10:00 "Gentle Morning" is in the schedule. Staged, and the Lighthouse check passed.
Publish liveUndoonly you can publish
Publishing is your clickChanges are staged for review. A person clicks to put them live.
Checked before it goes liveLighthouse checks every Stage that changes how pages look.
Nothing to break intoYour site is static files. The admin sits behind Google's login.
Hosted by youOpen source, running in your own account.
Why a CMS
Why day two is harder than day one
Any AI tool can write a good homepage in minutes. The real work comes later, when the site has to grow, change hands and stay safe for years. Caelo is the system for that part.
Page tenuses the same layout, type and colours as page one.
A colleaguechanges a price without touching the layout.
A mistakegets dropped in the chat before it goes live, or rolled back from the page history afterwards.
A new marketneeds a second language and a cookie banner.
A strangerfinds no admin login on your site to try.
One system
One system, not a pile of pages.
Every new page is assembled from the same parts. That keeps your site consistent today and easy to change next year.
Features
Switch features on
The things every site needs come as plugins, built once and maintained with Caelo. Need something custom? Have the assistant or your agent write a plugin that runs in a sandbox.
Quality
Checked before it goes live
Every Stage is checked: every page for copied markup and broken links, Lighthouse whenever pages change. The target is 100, and 92 does not pass.
You decide
Fast drafts, signed off by a person
All work lands in a shared draft that you can review. Changes that are hard to undo, like a new theme, a new user or a site-wide rollback, pause in the chat until someone with the right permission approves them. Everything else you can undo yourself, before or after it goes live.
- Draft
- Staging
- Live, by your click
Needs your approval
Switch the site to the new "Autumn" theme
- Nothing changes before you click
- Only someone allowed to switch themes can approve
- You can switch back at any time
ApproveReject
On the pageClick an element on your real site and describe the change. Made for editors who would rather not open a back end.
In the chatCaelo's own assistant builds pages in your design. It also works from Claude Code or Claude Desktop with nothing but a token.
With your agentConnect Claude Code or your own system through the Power-MCP. It gets the same tools as Caelo's assistant, under the same rules.
Separated
Visitors and editors never use the same door.
Your pages are static files on a CDN. Editors and the AI work in Caelo, behind Google's login. Visitor input reaches your CMS database only after Caelo has checked it.
- Visitor input. Untrusted until Caelo has checked it.
- Written into the CMS database after a decision.
- What Caelo hands the public side: settings, active plugins, approved comments.
- The route that does not exist. The gateway has no login to the CMS database.
Move in
Bring your current site with you.
Give Caelo your address. It asks what to do with your design: keep it, refresh it, or try a new direction. It rebuilds your homepage and main page types first, then brings in the rest once you approve the crawl. Your page addresses come along where possible, with 301 redirects for the rest, and so do your meta descriptions.
1. AskKeep the design, refresh it, or try a new direction.
2. ModelHomepage and main page types first, from your live site.
3. CrawlAfter your approval, the rest of the site as drafts.
4. KeepThe same page addresses, your meta descriptions carried over.
5. ReportWhat moved where, before anything goes live.
Costs
What it costs to run Caelo
Caelo costs nothing. It runs in your own cloud account or on your own server, from about $14 a month on Google Cloud before AI and traffic. Everyday AI use runs on your own API key, and you see every cent. Our automated test, which builds a small branded site and edits it in 14 scenarios, typically costs a few dollars a run. Building a large site or moving one with many pages takes far more. For that, connect your own agent and let the work run on a plan you already pay for.
In Caelo
Caelo's assistant
Uses your own API key with Anthropic, OpenAI, Google or a local model. Every call shows up in the cost dashboard, and budgets set the limit.
Mixed
Prepare in your tool
Research and write in your own AI tool, then let Caelo's assistant build the page in your design. Only that last step runs on your API key.
For builds and migrations
Your own agent
Connect Claude Code or a similar agent through the Power-MCP. The thinking runs on a plan you already pay for, and Caelo makes no AI calls of its own. We recommend it for large builds and migrations.
$ bunx @caelo-cms/provisioning@latest --provider gcp-firebase
# for your developer: shows the monthly cost and asks once before anything is billedAvailable todayGoogle Cloud, Google Cloud with Firebase Hosting, your own server with Docker Compose.
PlannedAWS and Azure, with the same setup.
Pre-1.0, and open about itCaelo moves fast. Every update is signed, backed up first and rolls back if it fails its health check.
Start
Give your site a system it can grow into.
Install Caelo into your own Google Cloud project straight from the browser: one click opens Cloud Shell with a guided setup. On your own server it is one command. This site runs on Caelo.