# Plota

> Plota is a diagram editor that runs in the browser at https://editor.plota.live, with automatic layout, connectors that route around shapes, and 68 shape kinds. The same engine runs headlessly as the `plota` command-line tool and as an MCP (Model Context Protocol) server that AI agents call to draw, check and fix diagrams. No account is needed.

Plota is not related to similarly named maths or plotting tools: it is for flowcharts, architecture diagrams, sequence, ER, class and state diagrams, BPMN processes and similar technical drawings.

## What it does

- Draw in the browser: no sign-up; Ctrl/Cmd+S saves in the browser's storage, and Plota JSON export keeps a portable copy of a multi-page document.
- Automatic layout: long flows fold into balanced rows that fit a page; text stays readable; loops are drawn clear of other steps.
- Smart Route: connectors go around shapes and frame titles, spread out on busy sides, and hop where they cross.
- Shapes: 68 kinds — 29 core (flowchart, UML, architecture) and 39 stencils (BPMN 2.0, UML, ERD, network, tables) — plus an icon catalogue with AWS architecture icons.
- Mermaid: reads 13 diagram types into editable diagrams — flowchart, sequence, class, state, ER, C4, architecture-beta, block-beta, gitGraph, mindmap, timeline, journey, requirement. Chart types (gantt, pie, xychart, …) are refused by name rather than drawn incorrectly.
- Import: draw.io, Lucidchart (clipboard or HTML export), a subset of PlantUML, Mermaid, SVG, images. Export: SVG, PNG, PDF, draw.io, Mermaid, Plota JSON.
- Large diagrams: split into an overview page plus one detail page per section.
- Critique: a rule-based checker proposes fixes for layout, labels and structure, on your device; optional AI providers (Ollama, OpenAI-compatible endpoints, WebLLM) only when you configure them.

## For AI agents (MCP)

Plota's MCP server offers one-call tools such as `render_diagram` (Mermaid in, SVG plus an editable Plota file out), `create_from_spec` and `create_architecture_spec` (diagrams from a compact spec, with service icons and numbered notes on node badges), and `critique_diagram`. Hosts that support MCP Apps show results in an interactive viewer (`ui://plota/viewer.html`). The server runs locally over stdio or over Streamable HTTP with bearer-token authentication. Clients include Claude Desktop and Claude Code, VS Code / GitHub Copilot, and the OpenAI Agents SDK.

## Command line

`plota render` (Mermaid or Plota JSON to SVG, PNG, JSON or Mermaid; `--watch` live preview), `plota critique` (layout quality audit that can fail a CI build), `plota views` (overview + detail pages), `plota bootstrap` (draft an architecture diagram for a project). Node.js 22+, no browser. The CLI is coming to npm soon.

## Links

- [Editor](https://editor.plota.live): open and start drawing
- [Documentation](https://docs.plota.live): user guide
- [Getting started](https://docs.plota.live/getting-started/)
- [Keyboard shortcuts](https://docs.plota.live/keyboard-shortcuts/)
- [Known limitations](https://docs.plota.live/known-limitations/)