21st

21st

21st.dev
+
+

Related Products

  • Gemini Enterprise Agent Platform
    1,161 Ratings
    Visit Website
  • BAND
    3 Ratings
    Visit Website
  • Retool
    598 Ratings
    Visit Website
  • Google Cloud Run
    349 Ratings
    Visit Website
  • Apify
    1,800 Ratings
    Visit Website
  • Chainstack
    34 Ratings
    Visit Website
  • cside
    37 Ratings
    Visit Website
  • Checksum.ai
    2 Ratings
    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

Codex is an AI-powered coding agent from OpenAI designed to help developers build, manage, and ship software more efficiently across the entire development lifecycle. It acts as an intelligent pair programmer that can understand codebases, generate features, and deliver production-ready pull requests. Codex can safely execute commands in sandboxed environments while assisting with debugging, refactoring, and testing. A key advancement is its computer use capability, allowing it to operate your computer by seeing, clicking, and typing across applications. This enables Codex to interact with tools that don’t have APIs, making it useful for tasks like frontend testing and app navigation. The platform also includes an in-app browser and integrations with various developer tools for a more unified workflow. Codex supports automation by handling ongoing tasks such as monitoring, issue triage, and follow-ups.

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

Codex is ideal for software developers, engineering teams, and tech organizations that want to automate coding tasks, leverage AI-driven workflows, and utilize computer-based automation to accelerate software development

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

$20/month
Free Version Supported
Free Trial 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 5.0 / 5
ease 5.0 / 5
features 5.0 / 5
design 5.0 / 5
support 5.0 / 5

Pros & Cons from Real Users

Pros

  • OpenAI Codex feels less like a coding assistant and more like a junior developer that can execute tasks independently. For knowledge workers juggling technical and non technical work, this shift is powerful because it can take a task, work through it, and return with usable results. Its ability to operate across full codebases is a major strength, allowing it to write, debug, test, and manage multiple files in a way that fits real world development workflows. The multi agent and automation capabilities are particularly useful since you can run parallel tasks and orchestrate work efficiently, which significantly improves productivity on complex projects. It is also expanding beyond pure coding with features that allow interaction with software environments, making it feel like a broader work assistant.

Cons

  • Codex can still struggle with very large or highly complex projects without iteration, and outputs often need refinement through multiple passes. The setup and workflow can feel heavier compared to simpler tools, especially when integrating with repositories or managing environments. There is also strong competition, and in some advanced or highly structured coding scenarios other tools may feel more precise.

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

Alternatives

Alternatives

Perplexity Computer

Perplexity Computer

Perplexity AI
Bolt.new

Bolt.new

StackBlitz
Codex CLI

Codex CLI

OpenAI
Claude Code

Claude Code

Anthropic

Categories

AI SDKs Supported
UI Design Supported

Categories

Agentic AI Supported
AI Agents Supported
AI Code Generators Supported
AI Coding Agents Supported
AI Tools Supported
Vibe Coding Supported

Integrations

React Supported
Burp Suite Not Supported
C++ Not Supported
Cursor Not Supported
GPT-4 Not Supported
GPT-5.5 Pro Not Supported
GPT-6 Astra Not Supported
GitHub Not Supported
Harden Not Supported
JavaScript Not Supported
MachinesFluent Not Supported
Overmind Not Supported
PHP Not Supported
PlatformPilot Not Supported
Snyk Not Supported
SourceAI Not Supported
SuperBased Not Supported
T3 Code Not Supported
Vibe Island Not Supported
Visual Studio Code Not Supported

Integrations

React Supported
Burp Suite Supported
C++ Supported
Cursor Supported
GPT-4 Supported
GPT-5.5 Pro Supported
GPT-6 Astra Supported
GitHub Supported
Harden Supported
JavaScript Supported
MachinesFluent Supported
Overmind Supported
PHP Supported
PlatformPilot Supported
Snyk Supported
SourceAI Supported
SuperBased Supported
T3 Code Supported
Vibe Island Supported
Visual Studio Code Supported
Claim 21st and update features and information
Claim 21st and update features and information
Claim OpenAI Codex and update features and information
Claim OpenAI Codex and update features and information