21st

21st

21st.dev
+
+

Related Products

  • Gemini Enterprise Agent Platform
    999 Ratings
    Visit Website
  • BAND
    3 Ratings
    Visit Website
  • Retool
    593 Ratings
    Visit Website
  • Google Cloud Run
    349 Ratings
    Visit Website
  • Apify
    1,714 Ratings
    Visit Website
  • Chainstack
    34 Ratings
    Visit Website
  • cside
    37 Ratings
    Visit Website
  • Checksum.ai
    1 Rating
    Visit Website
  • LM-Kit.NET
    29 Ratings
    Visit Website
  • Redlist
    64 Ratings
    Visit Website

About

21st is a developer platform that provides the fastest way to add AI agents directly into applications. The platform offers an SDK that allows developers to define, deploy, and run AI agents with minimal infrastructure setup. Developers can integrate agents using popular frameworks such as Next.js, React, TypeScript, Python, and Node.js. 21st includes built-in features like chat interfaces, session history, tool execution, memory, and real-time streaming responses. The platform also manages backend components such as sandboxed execution environments, authentication, rate limits, and observability. With support for Claude Code and Codex runtimes, developers can build agents that interact with tools, files, and APIs securely. By handling infrastructure and deployment automatically, 21st enables teams to launch production-ready AI agents quickly.

About

The Agents API lets developers build and run cloud agents with the same harness and infrastructure that powers Codex, fully managed by OpenAI. A production-ready agent can be created with a single API call by specifying the task, model, tools, and environment, while OpenAI hosts and maintains the agent harness. Developers can choose where agents run: in an OpenAI-hosted sandbox, on their own infrastructure, or through supported sandbox partners. OpenAI-hosted sandboxes provide secure environments where agents can run code, work with files, use packages, skills, and plugins, and produce artifacts. The API is designed for long-running work, with automatic context compaction that preserves relevant information as sessions span multiple context windows. Tool search loads relevant tool definitions only when needed, while programmatic tool calling lets agents run calls in parallel, chain related operations, and filter or combine results in code.

Platforms Supported

Windows Not Supported
Mac Not Supported
Linux Not Supported
Cloud Supported
On-Premises Not Supported
iPhone Not Supported
iPad Not Supported
Android Not Supported
Chromebook Not Supported

Platforms Supported

Windows Not Supported
Mac Not Supported
Linux Not Supported
Cloud Supported
On-Premises Not Supported
iPhone Not Supported
iPad Not Supported
Android Not Supported
Chromebook Not Supported

Audience

Software developers, startups, and product teams that want a fast and scalable way to build and deploy AI agents inside their applications

Audience

Developers and AI teams seeking to build reliable, long-running cloud agents with managed context, tools, sandboxes, and multi-agent orchestration

Support

Phone Support Not Supported
24/7 Live Support Not Supported
Online Supported

Support

Phone Support Not Supported
24/7 Live Support Not Supported
Online Supported

API

Offers API Not Supported

API

Offers API Supported

Screenshots and Videos

Screenshots and Videos

Pricing

Free
Free Version Supported
Free Trial Not Supported

Pricing

No information available.
Free Version Not Supported
Free Trial Not Supported

Reviews/Ratings

Overall 0.0 / 5
ease 0.0 / 5
features 0.0 / 5
design 0.0 / 5
support 0.0 / 5

This software hasn't been reviewed yet. Be the first to provide a review:

Review this Software

Reviews/Ratings

Overall 0.0 / 5
ease 0.0 / 5
features 0.0 / 5
design 0.0 / 5
support 0.0 / 5

This software hasn't been reviewed yet. Be the first to provide a review:

Review this Software

Training

Documentation Supported
Webinars Not Supported
Live Online Not Supported
In Person Not Supported

Training

Documentation Supported
Webinars Not Supported
Live Online Not Supported
In Person Not Supported

Company Information

21st.dev
21st.dev/

Company Information

OpenAI
Founded: 2015
United States
openai.com/index/introducing-the-agents-api/

Alternatives

Alternatives

Flowise

Flowise

Flowise AI

Categories

AI SDKs Supported
UI Design Supported

Categories

Integrations

AptiStockX Not Supported
ChatGPT Not Supported
ChatGPT Work Not Supported
OpenAI Not Supported
OpenAI Codex Not Supported
OpenAI Dots Not Supported
React Supported
Tailwind CSS Supported
shadcn/ui Supported

Integrations

AptiStockX Supported
ChatGPT Supported
ChatGPT Work Supported
OpenAI Supported
OpenAI Codex Supported
OpenAI Dots Supported
React Not Supported
Tailwind CSS Not Supported
shadcn/ui Not Supported
Claim 21st and update features and information
Claim 21st and update features and information
Claim OpenAI Agents API and update features and information
Claim OpenAI Agents API and update features and information