# Tenon > Tenon is a small, text-based, parametric CAD language for 3D-printed parts, furniture from > dimensional lumber and sheet goods, and welded steel frames. It is new: read the reference > card before writing Tenon. This site is a browser playground (the page runs Tenon in > WebAssembly, so its HTML has no docs in it). ## Docs for writing Tenon - [Tenon AI docs, one file](ai/tenon-ai.md): reference card + packages card (language 0.3); the same as a web page: [ai/tenon-ai.html](ai/tenon-ai.html) - [Reference card](ai/reference-card.md): the whole core language, conventions and common mistakes - [Packages card](ai/packages-card.md): `print3d` and `stock` (lumber, plywood, steel, cut lists) - [Agent guide](ai/README.md): system prompt and workflow for models with a shell ## Optional - [Eval prompts](ai/eval/): one complete prompt per benchmark task - [Example designs](examples/index.json): `.tenon` files under examples/