Chartdown

Write TTRPG maps as plain text in your notes; see them as maps. Chartdown is a Markdown-inspired language for battlemaps, hex charts, and region maps — this plugin renders every ```chartdown fence in place, entirely on your machine.

```chartdown
# Ambush at Redford Crossing
map: battlemap
grid: square 20x15
scale: 5ft
[terrain]
river redford "The Redford" : path A9 F9 K9 P10 T10 width=2
road tollroad "Old Toll Road" : path K1 K15
ford : on redford on tollroad difficult
[tokens]
goblins g1 g2 : C12 E13
ogre "Gruk" : G9 size=2 hidden
party start : J14..L15
```

What you get

• Maps in your prep notes — versionable, diffable, no graphical editor. Edit the fence, reopen the note, the map follows.
• GM/player split, fail-closed — hidden tokens, [gm] notes, and triggers render only in GM view. Each map has a toolbar toggle; the settings tab sets the default.
• Export SVG — one click writes the map (in the current view) next to the note and reveals it in your system file explorer.
• Export UVTT — one .dd2vtt per map level, with walls, doors, windows, and lights mapped for VTT import (Foundry, Roll20 via importers, Arkenforge, …) and the map image rasterized in-app. Note: .dd2vtt files are hidden in Obsidian's own file explorer (unknown extension) — they're real files in your vault folder, and the export reveals them.
• .cd files open to their map — keep a map as its own file, not only as a fence inside a note. Opening one shows the rendered map with the same toolbar; a Source button swaps to the text, and edits save in place. Exports take the file's own name, so sunless-hollow.cd writes sunless-hollow.svg beside it. While this plugin is enabled it claims the .cd extension for the vault; disable it and those files go back to being unopenable, since nothing else knows what they are.
• Multi-level battlemaps, themes, light and sight — the full Chartdown language.

Try the language first in the playground — no install, runs in your browser.

Long source? Fold it with a callout

A detailed map is a long fence, and a long fence disrupts the read. Wrap it in a collapsed callout — the - after the type is what starts it folded:

> [!note]- Map source (Chartdown)
> ```chartdown
> # Garl's Estate
> map: battlemap
> grid: square 30x22
> …
> ```

The map renders when you expand it, toolbar and all.

Not <details>. You will see that idiom recommended for GitHub, where it folds properly — but Obsidian does not parse a fence inside a raw HTML block, so the map never renders and you get the source as text (Chartdown#225). A callout is the one that works in both, which matters if the same file is read here and on GitHub.

Co-write your maps with an AI assistant

Chartdown is plain text, which means any LLM you already use can write it with you: describe the scene in prose ("the estate has a treasury, a ballroom, slave cells below…"), get a ```chartdown fence back, paste it in your note, and it renders. The plugin ships no AI, no API keys, and makes no network calls — you bring the assistant; you just have to teach it the language once per conversation:

• Chat assistants (ChatGPT, Claude, …): give it the single-file language reference — https://nossimonov.github.io/Chartdown/llms-full.txt — by pasting it into the chat (or just the link, for assistants that browse). Then describe your scene, or paste an existing map and describe the changes; ask it to reply with one ```chartdown block.

• Tool-using agents (Claude Code and other MCP clients): the @chartdown/mcp server hands the agent the whole loop — the spec, fail-loud validation, and PNG rendering, so it can check its own work before you see it:

  claude mcp add chartdown -- npx -y @chartdown/mcp
  

Each map's toolbar closes the round trip: Copy Chartdown puts the map's source on your clipboard, opening with a comment that points at the language reference — so wherever you paste it, an LLM chat included, the reader knows what it's looking at and where the spec lives. Paste Chartdown brings the reply back: it accepts a bare document or a ```chartdown fence straight from the chat, validates it, and only then replaces the map in your note — an invalid paste changes nothing and tells you the offending line. (The paste button grays out while the clipboard is empty; the check looks only at clipboard format metadata, never the content — your clipboard is read exactly once, on an explicit paste click.)

Manual installation

Until the plugin is in the community store: download main.js, manifest.json, and styles.css from the latest release, place them in <your vault>/.obsidian/plugins/chartdown/, then enable Chartdown under Settings → Community plugins. (Or point BRAT at Nossimonov/obsidian-chartdown.)

Development

Development happens in the Chartdown monorepo (packages/obsidian), which is where the tests and issue tracker live — please file issues and PRs there. This repository carries the store-facing artifact: src/ and styles.css are synced verbatim from the monorepo by the release workflow (every release commit pins the exact source it was built from), and release assets carry build-provenance attestations. The plugin imports @chartdown/core and @chartdown/render-svg, published from the same monorepo.

License

MIT. The Chartdown language specification is CC-BY-4.0.