---
title: "21st"
description: "Find and build UI, and create editable product videos from your project with 21st tools."
canonical: https://agentpluginsdirectory.com/plugins/21st--21st-dev
last-updated: 2026-10-10
---

# 21st
Find and build UI, and create editable product videos from your project with 21st tools.
- Slug: 21st--21st-dev
- Publisher: 21st.dev
- Repository: https://github.com/21st-dev/codex-plugin
- Manifest: plugin.json
- Version: 0.5.0
- License: MIT
- Category (editorial): other
- Skills: 8 (21st-ai, 21st-cli-use, 21st-design-sync, 21st-registry, 21st-ui-build, 21st-ui-explore, 21st-ui-review, 21st-video)
- MCP servers: 1 (21st)
- Stars: 8
- Repository created: 2026-07-03
- Repository last pushed: 2026-10-06
- Publisher type: Organization
- Listing: https://agentpluginsdirectory.com/plugins/21st--21st-dev
- Schema: https://agent-plugins.org/schemas/1.0.0/plugin.schema.json

## What 21st does, in the publisher's words

Find and install React components, build project-aware UI, and make editable product videos with the 21st MCP server. The video workflow uses the coding agent's own reasoning and the same project operations as the web editor.

The monorepo marketplace is.agents/plugins/marketplace.json at the repo root. It points to this directory, distribution/codex-plugin, so there is one canonical package instead of a duplicate under packages/.

- Run pnpm skills:build, pnpm skills:check, and pnpm plugin:check from the monorepo root.
- Register and install a cached package with the CLI:

bash codex plugin marketplace add./distribution/codex-plugin codex plugin add 21st@21st

- Connect the 21st account when prompted. The entry requests authentication on install; the endpoint advertises OAuth discovery.
- In a new chat, ask: "Make a launch video for this repo and open the editable project beside the chat."

From the project README, punctuation lightly normalized. Full text: https://raw.githubusercontent.com/21st-dev/codex-plugin/HEAD/README.md