# isketch

> isketch is a sketchpad for architecture and UI diagrams whose output is agent-ready: every sketch is also `.flow` text a coding agent reads exactly, and can edit back. Sketch the system, hand it to your agent, and the diagram stays true as the code changes.

Links:

- [The editor](https://isketch.online/new): start drawing, no account.
- [The .flow format](https://isketch.online/docs/format): the whole text format, with examples. This is the page an agent should read before writing a diagram.
- [The brief](https://isketch.online/#what-your-agent-receives): what "Copy for AI" puts on the clipboard.
- [MCP over stdio](https://github.com/raj-khan/flow#connect-your-agent-mcp): `isketch mcp` — list, read, write, render and diff the `.flow` files in a folder.
- [MCP over HTTP](https://github.com/raj-khan/flow#the-same-tools-over-http): the hosted server at `/mcp` — read a diagram by its link, publish, update with its edit token.
- [The CLI](https://github.com/raj-khan/flow#command-line): render, check, import and export from a terminal or CI.
- [Hosted links](https://github.com/raj-khan/flow#hosted-links-for-agents): every diagram behind one link, as a page, `.md`, `.flow`, `.svg`, `.json` or a PNG preview.

## The format in ten lines

```text
title: Web app architecture

browser = terminal "Browser" -- Single page app
api = process "API" -- REST, documented with OpenAPI
db = database "PostgreSQL"

browser -> api : HTTPS
api -> db : SQL
```

The full spec, including layouts, notes, wireframe shapes, ink and the sketch
style, is at [/docs/format](https://isketch.online/docs/format) and in
[llms-full.txt](https://isketch.online/llms-full.txt).

## The MCP tools

`list_diagrams`, `read_diagram` (brief or `.flow` text), `write_diagram`
(refuses invalid text, with line numbers), `render_diagram` (SVG),
`diff_diagrams` — the local server for the diagrams in a folder. The hosted
endpoint at `/mcp` answers `read_diagram` by link, `publish_diagram` and
`update_diagram` with the diagram's edit token. Setup lines for both are in
llms-full.txt.