21st Agents Infrastructure
Officially listedA YC-backed production infrastructure platform for deploying AI agents, with multi-model runtime, E2B sandboxes, streaming, and React UI components.
21st Agents Infrastructure
21st Agents Infrastructure is a Y Combinator-backed production-grade AI agent infrastructure platform that removes infrastructure complexity from agent deployment for developers. Through a simplified "create-deploy-integrate" workflow, teams can focus on agent configuration and business logic instead of building plumbing from scratch.
Core Capabilities
- Multi-model runtime: Supports Claude Code and OpenAI Codex with dynamic model switching
- E2B sandbox execution: Isolated code execution environment safeguarding production
- Streaming: SSE-based real-time responses, compatible with the AI SDK
- Built-in toolset: Web search, file handling, code execution, and custom actions
- UI component library: Preset themes (Notion, Cursor, Minimal) and React components
- Session management: Persistent project IDs, conversation history, and replay
Use Cases Next.js/React developers quickly adding AI agent capabilities to their apps, startup teams validating AI agent products, and enterprise developers needing a secure code execution environment and production-grade deployment.
Unique Advantages Compared with LangChain's logic orchestration or E2B's standalone sandbox, 21st offers an all-in-one solution from agent definition to deployment to UI — out-of-the-box security and multi-model support are the core differentiators.
Editor's Review The technical architecture is complete and sensible, especially for the Next.js ecosystem. But as an early product (only 45 GitHub stars), its community ecosystem and documentation examples still need to mature. A good bet for teams comfortable with new technology; projects demanding high stability should wait and watch.
Pricing
### 💰 定价模式：未公开 **起步价**：未公开 #### 主要方案 官方未公开具体定价信息，采用基于使用量的计费模式（按对话轮次和 token 计数）。 #### 试用/其他信息 需通过 API Key 进行身份验证，具体价格需联系官方获取。
FAQ
Is 21st Agents Infrastructure free?
Official pricing is not published; it uses usage-based billing (by conversation turns and token counts) — contact the vendor for specific prices.
What are 21st Agents Infrastructure's main features?
Core features include multi-model runtime management, E2B sandbox execution environments, streaming, a built-in toolset (web search, file handling, code execution), a UI component library, and session management.
How does 21st Agents Infrastructure differ from LangChain?
LangChain focuses on agent logic orchestration and toolchains, while 21st provides complete deployment and runtime infrastructure — a one-stop solution including sandboxed execution, UI components, and streaming.
Which programming languages does 21st Agents Infrastructure support?
It provides JavaScript/TypeScript SDKs (@21st-sdk/agent, @21st-sdk/react, @21st-sdk/nextjs) and a Python SDK (21st-sdk), especially suited to Next.js and React developers.
Is 21st Agents Infrastructure's sandbox environment secure?
It uses E2B's isolated sandbox execution environment with configurable permission modes, supporting file operations and Git repository cloning — suitable for running untrusted code and keeping production safe.
Is 21st Agents Infrastructure suitable for startups?
Yes. Backed by Y Combinator, it offers CLI tools and multi-language SDKs that lower integration barriers. But note the product is in an early stage with a thin community ecosystem.