# Not a picture of a chart. The chart.

> Ask your agent for a chart, a calculator or a small program, and it lands in the post as a block readers use on the page. In the editor or with your agent.

A block is a small program your agent writes into a post: a chart, a calculator, a map. **Readers use it right there on the page**, in a sandboxed frame that cannot touch your site.

## By hand, in the admin

1. Open the post in the editor. A block shows as a live card, Interactive block, where your agent put it.
2. Click the block to select it. Its frame then answers the pointer, as it will for a reader.
3. Press **Remove** in its box to take it out of the post.
4. Before the post is out, press **Preview** to see the block in your theme, on a desktop or a phone.

Your agent makes a block; the editor shows it and removes it. To change what a block shows, ask your agent.

## With your agent

> Add a bar chart of the visitor numbers in my table to the post “A year at the gallery”, after the second paragraph.

> Put a mortgage calculator at the end of my post about first homes, in the site's fonts and accent colour.

> Make the chart in my rainfall post taller, and give the bars my accent colour.

The tools it calls: `list_posts`, `get_post`, `create_block`, `update_block`, `delete_block`.

## Examples

- **A coach's training zones.** A running coach asks for a calculator: **a reader types a race time and reads their paces**, inside the post.
- **A council budget, read clearly.** A local reporter pastes a spreadsheet into the chat. Her agent bakes the figures into a chart that sits after the third paragraph.
- **A price history for a review.** A watch writer's agent charts a model's price over ten years and names the source and the last date under the chart.

## Questions

### How do I add an interactive chart to a post on PixelGlass?

Ask your agent. It writes the chart as one self-contained HTML document and puts it into the post with create_block, after the paragraph you name or at the end.

### Can a block reach my site, my readers or their cookies?

No. A block runs in a sandboxed frame with an opaque origin: no cookies, no access to the page, and nothing shared with the site.

### Where does a block's data come from?

The agent bakes the data into the block. A block can also fetch from a public source that allows CORS. It may load one script library from cdnjs.cloudflare.com or cdn.jsdelivr.net.

### What happens to a block in the newsletter?

No email client runs a program, so the email shows a line that leads to the interactive block on your site.

### Can I undo a block my agent added?

Yes. Remove it in the editor, or restore the version before it in Post history. Each write an agent makes is a version you can undo.

## See also

- [Write alongside your agent](https://pixelglass.co/guides/write-alongside-your-agent): Your agent says in the editor that it is writing a post, and holds off while you have the post open. Every change it makes is a version you can undo.
- [Add images and video](https://pixelglass.co/guides/add-images-and-video): Add pictures, YouTube or Vimeo video and your own films to a post, set their width, and give it a cover. In the editor, or ask your agent for the pictures.
- [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.
- [The editor](https://pixelglass.co/features/editor): A calm editor for serious writing: cards for images, video, callouts and buttons, autosave, a history of 50 versions, scheduling and meta data.
- [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)