21st Agents SDK

Accelerate AI-powered product development with open-source tools and managed infrastructure.

Overview

The 21st Agents SDK provides open-source UI components and developer tools for building and deploying AI agents faster. It's designed for frontend engineers, designers, product teams, and founders building AI applications. The SDK offers built-in UI, chat history, spend limits, and observability, alongside managed infrastructure for auto-retries and graceful recovery, significantly simplifying development.

What's New with 21st Agents SDK

Latest news, updates, and media coverage

Mar 8·95

AI Tools See Launch Surge, Funding, and Ecosystem Challenges

Mar 8·90

GPT-5.4, Adult Mode Delayed, Military Policy Shift Amid Broad AI Industry Pressures

Mar 7·90

Google AI boosts LLM dev tools, agent ecosystem with Workspace CLI, Android Bench

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Frequently asked questions about 21st Agents SDK

Yes, 21st Agents SDK offers a freemium plan. Accelerate AI-powered product development with open-source tools and managed infrastructure.

Key features of 21st Agents SDK include: Built-in UI and chat history, Spend limits and sandbox execution with isolated VMs, Observability including session replay and traces, Supports Claude and OpenAI models with token-by-token streaming.

21st Agents SDK is primarily designed for businesses and professionals. Accelerate AI-powered product development with open-source tools and managed infrastructure.

Popular alternatives to 21st Agents SDK include Cursor, Google AI Studio, Cohere. Compare their features on Decod.tech to find the best fit.

21st Agents SDK remains relevant in 2026. The 21st Agents SDK provides open-source UI components and developer tools for building and deploying AI agents faster. It's designed for frontend eng The pricing model is freemium. Check reviews and comparisons on Decod.tech to decide.

21st Agents SDK offers a freemium plan. You can start for free and upgrade as your needs grow. Visit the official pricing page for details.

Overview