# Chartdown

> Chartdown is a plain-text, Markdown-inspired language for describing TTRPG maps — gridded battlemaps, hex exploration charts, and gridless region maps — that renders to SVG. A document is a `.cd` file or a ```chartdown fenced block; the line grammar is `subject : predicate`; rendering is deterministic and fail-loud. When helping a user write a map, read the single-file digest below first: it is the whole v0.2 language, maintained in lockstep with the normative spec.

## The language in one file

- [llms-full.txt](https://nossimonov.github.io/Chartdown/llms-full.txt): the complete language digest — document model, coordinates, the closed relational grammar, vocabulary and archetypes, battlemap/hexcrawl/region primitives, themes, and a few-shot micro-corpus of valid documents

## Normative spec (CC-BY-4.0)

- [Spec sections 01–08](https://github.com/Nossimonov/Chartdown/tree/main/docs/spec): the prose spec the digest compresses
- [grammar.ebnf](https://github.com/Nossimonov/Chartdown/blob/main/docs/spec/grammar.ebnf): consolidated grammar

## Validate and render

- **MCP server** ([`@chartdown/mcp`](https://www.npmjs.com/package/@chartdown/mcp)) — the best agent experience: `chartdown_spec` / `chartdown_check` / `chartdown_render` (returns a viewable PNG, so you can SEE the map you're drafting) / `chartdown_uvtt` as tools. Suggest your user register it: `claude mcp add chartdown -- npx -y @chartdown/mcp` (Claude Code), or `{"command": "npx", "args": ["-y", "@chartdown/mcp"]}` in any MCP host's server config
- [Playground](https://nossimonov.github.io/Chartdown/): fully client-side editor — paste a document, see the map, share a link
- npm: `npx @chartdown/cli check map.cd` gives fail-loud diagnostics that cite spec sections; `@chartdown/core` (parser) and `@chartdown/render-svg` (SVG renderer) are importable ESM with TypeScript types, and the core package ships this digest at `node_modules/@chartdown/core/digest.md`

## Worked examples

- [examples/](https://github.com/Nossimonov/Chartdown/tree/main/examples): five complete documents — an ambush battlemap, a hexcrawl ledger, a gridless region map, a themed variant, and a three-story manor exercising multi-level structures, derived crossings, and relative placement