---
title: "21st.dev Agent Elements"
description: "Open registry of agent UI primitives: chat shell, tool-call cards for bash/edit/search/todo, clarifying questions and streaming markdown."
canonical: "https://vibing.inc/library/21st-dev-agent-elements-vg-1797"
category: "UI Components & Libraries"
subcategory: "Agent UI"
license: "open-source"
author: "21st.dev (@21stdev)"
source: "https://agent-elements.21st.dev"
---

# 21st.dev Agent Elements
Open registry of agent UI primitives: chat shell, tool-call cards for bash/edit/search/todo, clarifying questions and streaming markdown.
## Facts
- Source: https://agent-elements.21st.dev
- Category: UI Components & Libraries / Agent UI
- Author: 21st.dev (@21stdev)
- Licence: open-source
- Tags: agent-ui, react, chat, tool-calls
## Why it's a gem
Tool-call card primitives are the hardest part of an agent UI and nobody else ships them
---
Listed in The Vibeary: https://vibing.inc/library/21st-dev-agent-elements-vg-1797 · JSON: https://vibing.inc/api/public/library/gems/21st-dev-agent-elements-vg-1797