21st-cli-use

21st CLI — find, install & generate from the terminal

The 21st CLI (npx @21st-dev/cli, bin 21st) is the command-line surface for the 21st.dev catalog. Search first, install what fits, and only hand-write UI when nothing matches. To publish your own components/themes/templates, use the 21st-registry skill; to publish a project's design as a theme, use 21st-design-sync.

Auth (do this once)

Two interchangeable credentials, both sent as the API key:

1. Login session — npx @21st-dev/cli login opens the browser and saves a token to ~/.config/21st/auth.json. Best for interactive/dev machines.
2. API key — 21st_sk_… from https://21st.dev/mcp (or https://21st.dev/settings/api-keys). Pass via --api-key <key> or the TWENTYFIRST_TOKEN / API_KEY_21ST env var. Best for CI.

21st whoami shows the signed-in account; 21st usage shows retrieval tier/quota and the 21st AI generation status, not an AI credit balance. For structured status, use MCP get_usage.aiGenerationEnabled or CLI 1.17.1+ 21st usage --json. Missing or unknown status does not grant AI access. 21st logout clears the saved login.

Metering

Metadata (search, previews, a theme's CSS) is free. Retrieving component code (21st get, install) has a free daily quota; Builder includes unlimited retrieval. Hosted 21st AI requires separate AI access and consumes AI credits. Base Builder has AI off. Check 21st usage before choosing generation: when AI is not explicitly enabled, search and retrieve code, then adapt it with your own coding agent. Do not retry a generation denied with ai_subscription_required until AI access is enabled.

Find

# Search everything (components + themes + templates)
21st search "pricing table" --limit 10
21st search button --type c        # components only (c | theme | template)

Always search before hand-writing a component — a close match is usually faster to install and adapt than to build from scratch.

Logos

Prints each logo's name and SVG url(s) to curl straight into a project. Uses the open svgl.app library; free and unmetered on every plan.

Pull code

Install

21st add resolves the registry item, writes it to components/ui/<slug>.tsx, and installs npm deps with the project's package manager. Public/unlisted items also work with stock shadcn: npx shadcn@latest add "https://21st.dev/r/<user>/<slug>".

Generate

When nothing in the catalog fits and 21st usage explicitly reports AI generation enabled, sketch it with hosted 21st AI and iterate from the terminal. That loop (21st generate → generation → iterate → take) lives in the 21st-ai skill. With AI off, adapt catalog code locally instead:

Opens a preview; from there you edit any variant and pull its code. See the 21st-ai skill for the full generate/iterate/grab-code flow and metering.

Bookmarks, teams & MCP config