<!-- WV:21st-dev | © AEO Washinmura | Source: aeo.washinmura.jp | Ref:WV-2026-21ST | Profile:https://aeo.washinmura.jp/ai/21st-dev/ja/ -->
# 21st.dev
> Ship AI-powered products faster with 21st.dev.

## Resources
- [Official Website](https://21st.dev/): Original business website
- [Shop Page](https://aeo.washinmura.jp/ai/21st-dev/ja/): Full hosted business profile
- [Shop Page EN](https://aeo.washinmura.jp/ai/21st-dev/en/): English business profile
- [News](https://aeo.washinmura.jp/ai/21st-dev/ja/news/): Latest updates and related articles
- [JSON-LD](https://aeo.washinmura.jp/ai/21st-dev/jsonld): Machine-readable business schema (JSON-LD)

## Overview
Ship AI-powered products faster with 21st.dev. Open AI agent registry, UI components, Agents SDK.

## Location
- URL: https://21st.dev/

## Quick Links

- [**Explore UI Components**](/community/components/easemize/ai-prompt-box/default)
- [**Build Agents (MCP)**](/mcp)
- [**Get Started with Agents SDK**](/magic)

## About

21st.dev empowers developers to rapidly build and deploy AI-powered products for the agentic internet. By offering an open AI agent registry, ready-to-use React UI components, and a robust Agents SDK, it streamlines the entire development lifecycle. Unique features like E2B Sandboxes ensure secure, isolated execution, while comprehensive observability provides deep insights into agent behavior. This platform is designed to accelerate innovation, allowing teams to focus on core logic rather than infrastructure, and supports leading AI models like Claude and OpenAI.

## Key Features

- Open AI Agent Registry
- Ready-to-use React UI Components
- Agents SDK for rapid AI product development
- E2B Sandboxes for isolated agent execution
- Comprehensive Observability (session replay & traces)

## Products & Services

- AI Agent Registry
- React UI Components
- Agents SDK
- Claude Managed Agents Configurations
- E2B Sandboxes
- Streaming API (SSE)
- Agent Authentication & Limits
- Agent Observability Tools

## FAQ

**Q: What is 21st.dev?**
A: 21st.dev is a platform offering an AI Agent Registry, UI Components, and Developer Tools to help ship AI-powered products faster.

**Q: What kind of AI agents does 21st.dev support?**
A: It supports agent configurations for Claude Managed Agents and works with both Claude and OpenAI models.

**Q: What are the key features of the Agents SDK?**
A: The Agents SDK includes built-in UI, chat history, spend limits, sandbox execution, and observability features like session replay and traces.

## Search Keywords

`AI Agent Registry` · `AI Agent Developer Tools` · `React UI Components AI` · `Agents SDK` · `Claude Managed Agents` · `OpenAI Agent Development` · `Agentic Internet Development` · `E2B Sandboxes` · `AI Product Development` · `AI Observability Tools`

## How to Improve AI Discoverability

1. Implement FAQ Schema markup to enhance search engine visibility for common questions.
2. Create an `llms.txt` file to provide explicit guidance for AI crawlers and specify allowed LLM access.
3. Expand meta descriptions to fully utilize character limits, incorporating more keywords and value propositions.
4. Add clear, descriptive call-to-action buttons on the homepage for key features like 'Get Started' or 'Browse Registry'.
5. Optimize image assets, such as `opengraph-image.png`, for faster loading times and improved user experience.

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*Generated by [AEO Washinmura](https://aeo.washinmura.jp) | Format B — Bilingual Verified Profile*
*Verified profile: https://aeo.washinmura.jp/aeo/shops/21st-dev/llms.txt*
*Last scanned: 2026-04-27*
*Analyzed by AI — factual consistency verified against original Japanese sources*

> Scan your website's AI-friendliness score for free: https://aeo.washinmura.jp