# Say what you want. Watch it take shape.

> Describe the look you want. Your agent edits the theme's templates and styles, checks each page and sends you the link. Every step can be undone.

A PixelGlass theme is Liquid templates and CSS that your agent reads and writes over MCP. **A change goes live only when the whole theme passes its checks**, and each one is a step in the theme's history.

## By hand, in the admin

1. Open **Settings › Design**.
2. Under **Brand**, set the logo, the icon and the cover, and pick the accent colour.
3. Under **Theme settings**, fill in the theme's own options: headings, lines, pictures, switches.
4. Press **Save**. The frame shows the accent and the settings before you save; a picture saves as soon as you pick it.

The admin has no code editor. A new layout, new templates or a new stylesheet is your agent's work.

## With your agent

> Copy Atlas as a theme called harbour, give it a navy masthead and a two-column story grid, and keep it off the site until I say so.

> The post pages feel cramped. Widen the column, raise the line height and show me a post.

> Show the reading time under every post title on the home page.

The tools it calls: `list_themes`, `create_theme`, `read_theme_file`, `edit_theme_file`, `write_theme_file`, `validate_theme`, `render_page`, `preview_theme`, `activate_theme`.

## Examples

- **A food writer's new masthead.** A food writer asks for a hand-drawn feel. Her agent changes the fonts, the masthead and the colours **one step at a time**, and sends the page after each.
- **A magazine of its own.** A cycling magazine starts from a copy of Atlas, renames it, and builds its own front page on it while the old theme stays live.
- **A fix in one request.** An analyst sees dates in the wrong order on post pages. The agent finds the line in the post template, changes it and renders a post to check.

## Questions

### Can AI design my blog theme on PixelGlass?

Yes. Connect Claude, ChatGPT or another MCP client and describe the look. The agent edits the theme's Liquid templates and CSS, renders pages to check its work and gives you the address.

### What happens if the agent breaks my theme?

The broken change does not reach readers. PixelGlass holds a change back while the theme has a validator error or, in a theme that builds, until its build succeeds. Every write is kept, so restore_theme_revision takes any of them back.

### Can my agent build a new design without changing the live site?

Yes. create_theme makes a copy under its own name, which the site does not wear until activate_theme. preview_theme gives you a link to see the copy on your own site, in your browser alone.

### Who can let an agent change the theme?

The owner or an admin. A PixelGlass agent acts with the role of the person who connected it, and an editor's agent can read the theme but not change it.

### Does my agent need build tools on my computer?

No. A PixelGlass theme that builds is built by PixelGlass after each write, and the agent follows the build with get_build. A theme with plain CSS needs no build.

## See also

- [Preview a theme before it goes live](https://pixelglass.co/guides/preview-a-theme-before-it-goes-live): See your own site in another theme, page by page, before readers do. Use the Design frame by hand, or a private preview link from your agent.
- [Undo a theme change](https://pixelglass.co/guides/undo-a-theme-change): Every change to a PixelGlass theme is kept. Look at any earlier version on your site, then restore it, in Settings › Design or with your agent.
- [Connect Claude](https://pixelglass.co/guides/connect-claude): Add your PixelGlass site to Claude as a custom connector and sign in. Claude then writes, publishes and designs as you, on web, desktop and mobile.
- [Themes](https://pixelglass.co/features/themes): Start from 9 themes made for magazines, newsletters, coaches and portfolios. Change the look in Settings, or ask your agent to redesign it.
- [MCP server](https://pixelglass.co/features/mcp-server): Every PixelGlass site is an MCP server with 68 tools. Claude, ChatGPT, Cursor and more write posts, design themes and run your publication.
- [Every guide](https://pixelglass.co/guides)
- [Pricing](https://pixelglass.co/pricing): every feature on every plan, 14 days free
- [Create your site](https://pixelglass.co/signup)