ArchLang for VS Code

Write floor plans as code. ArchLang is an open-source language that compiles .arch text into SVG, DXF or PDF floor plans, and this extension gives .arch files full editor support.

Try it

Floor plans as code. Your AI writes ArchLang; the compiler draws a precise, dimensioned plan and tells it what's wrong.

ChatGPT, no install: ArchLang app in ChatGPT, then ask, for example: "Draw a two-bedroom flat of about 75 m² as an ArchLang plan, and check it."
claude.ai, no install: add https://mcp.archlang.uk/mcp as a custom connector (the steps)
Coding agent: claude mcp add --transport http archlang https://mcp.archlang.uk/mcp; locally, claude mcp add archlang -- npx -y @chanmeng666/archlang-mcp; skills, npx -y skills add ChanMeng666/archlang --yes (skills.sh)
Playground, in the browser: https://playground.archlang.uk

_Plan

_{3D preview}

Same source, plan and 3D preview. The 3D preview is extruded from the same .arch file by the separate archlang-3d package, and checked against the plan. What the 3D preview shows →

3D preview: walls, openings, floors, stairs and furniture in flat colours; no pitched roofs yet, and no sections, elevations or BIM.

Features

Syntax highlighting for .arch files, including metric unit suffixes such as 4m, 40cm and 20mm.
Live diagnostics: compiler errors and warnings appear as squiggles and in the Problems panel as you type.
Hover: documentation for the element or keyword under the cursor.
Completion: context-aware suggestions.
Go to definition: jump to where an id, binding or component is defined.
Rename: rename an id across the document.
Signature help: parameter hints for functions and components.
Quick fixes: apply a diagnostic's suggested fix with one action.

Floor plans in Markdown preview

A fenced block tagged arch renders as the compiled floor plan in VS Code's built-in Markdown preview (Ctrl+Shift+V, or Cmd+Shift+V on macOS). archlang works as a fence tag too. If the plan has an error, the preview shows the error and your source instead.

```arch
plan "Studio" {
  units mm
  wall exterior thickness 200 { (0, 0) (5000, 0) (5000, 4000) (0, 4000) close }
  room id=r_living at (0, 0) size 5000x4000 label "Living" uses living
}
```

Install

Search for "ArchLang" in the Extensions view, or run:

code --install-extension ChanMeng.archlang

Open any file ending in .arch and the extension activates. Everything runs locally; no account or API key is needed.

Compile from the command line

The extension edits; the archlang CLI renders. No install is needed:

npx -y @chanmeng666/archlang compile plan.arch -o plan.svg

Use with an AI agent

ArchLang ships an MCP server so agents can write, check and render plans:

npx -y @chanmeng666/archlang-mcp

See archlang.uk/agents for setup. Language docs and a live playground are at archlang.uk.

ArchLang

Chan Meng