21st-ai
21st AI — sketch, iterate & grab code from the terminal
21st AI is a fast UI-drafting board. Mental model: draft it here, then finish
it — sketch a few variants from a prompt, preview them, refine the one you like
with plain-English edits, and pull its code into the repo. The whole loop runs
from the 21st CLI (or the matching MCP tools), so you never leave the editor.
Sketch mode produces self-contained HTML + Tailwind drafts (fast, no build). The recommended handoff is the copy-prompt: a spec that tells you to rebuild the design in the target project's real stack — not paste raw HTML verbatim.
Auth
Same credential as the rest of the CLI: 21st login (saved token) or a
21st_sk_ key via --api-key / TWENTYFIRST_TOKEN. 21st usage shows tier +
remaining quota. (See the 21st-cli-use skill for the full auth notes.)