Software Alternatives, Accelerators & Startups

21 Days VS CloudCLI

Compare 21 Days VS CloudCLI and see what are their differences

21 Days logo 21 Days

21 Days app enables the user to track their habits to take challenges to adopt good habits.

CloudCLI logo CloudCLI

Shared cloud environments for AI coding agents. Run Claude Code, Cursor CLI, Codex, and Gemini CLI from any device, API, or automation tool.
Visit Website
  • 21 Days Landing page
    Landing page //
    2020-04-04
  • CloudCLI CloudCLI Dashboard
    CloudCLI Dashboard //
    2026-04-01
  • CloudCLI CloudCLI Web IDE
    CloudCLI Web IDE //
    2026-04-01
  • CloudCLI Opening your dev environment on VSCode
    Opening your dev environment on VSCode //
    2026-04-01
  • CloudCLI Opening an environment on your mobile
    Opening an environment on your mobile //
    2026-04-01

Most engineering teams run AI coding agents on individual laptops. Close the lid, lose the session. When a new developer joins, they spend hours recreating the same setup.

CloudCLI gives your team shared cloud environments where AI agents run 24/7. Every developer gets their own isolated container, but the team shares MCP servers, context files, and configurations across all projects. Onboarding takes minutes.

Sessions can be started through a full REST API, so workflows in Linear, Jira, or n8n can trigger background coding agents programmatically. A ticket gets filed, an agent starts coding, the developer reviews the PR in the morning.

The web UI and mobile interface include a file explorer, git explorer, and full shell access. Review PRs on your iPad, make fixes from your phone, then pick up in VS Code over SSH.

Unlike GitHub Codespaces, CloudCLI is purpose-built for agentic development. Claude Code, Cursor CLI, Codex, and Gemini CLI come pre-installed. Sessions survive laptop closure. Teams bring their own API keys with no vendor lock-in.

Built on an open-source core (AGPL-3, 9,000+ GitHub stars). Self-host for data sovereignty or use the managed service from โ‚ฌ7/month.

21 Days

Website
21days.com
Pricing URL
-
$ Details
-
Platforms
-

CloudCLI

$ Details
paid Free Trial โ‚ฌ7.0 / Monthly
Platforms
Web Mobile
Startup details
Country
Netherlands
State
Zuid Holland
Founder(s)
Simos Mikelatos
Employees
1 - 9

21 Days features and specs

  • Structured Program
    The 21 Days program provides a structured approach to forming new habits, making it easier for participants to stay on track.
  • Time-Bound Commitment
    With a specific 21-day timeframe, participants are motivated to commit to the program and potentially see faster results.
  • Habit Formation
    Focusing on repeating tasks over 21 days aligns with conventional wisdom about the time it takes to form new habits.
  • Community Support
    Participants often have access to a community of like-minded individuals, providing support and motivation throughout the process.
  • Variety of Programs
    21 Days offers a variety of programs catering to different goals, such as fitness, mindfulness, and productivity.

Possible disadvantages of 21 Days

  • Limited Flexibility
    A strict 21-days timeframe may not suit everyone, and could be challenging for those with unpredictable schedules.
  • One-Size-Fits-All Approach
    The program might not accommodate specific personal needs or adapt to varying levels of individual progress.
  • Sustainability Concerns
    After the initial 21 days, participants may struggle to maintain their new habits without continued guidance and support.
  • Pressure to Succeed
    The fixed duration can create pressure, leading to stress if individuals feel they are not progressing as expected.
  • Cost Implications
    Access to certain features or programs within the 21 Days platform may require a financial investment, which might not be feasible for all users.

CloudCLI features and specs

  • Multi-Agent Support
    Run Claude Code, Cursor CLI, OpenAI Codex, and Gemini CLI side by side. Bring your own API keys. No vendor lock-in.
  • Git Integration
    Manage branches, view commit history, and browse files with syntax highlighting directly from the browser or mobile app.
  • Persistent Cloud Sessions
    agents keep running 24/7. Close your laptop, switch devices, or walk away entirely and your session survives with full context intact
  • Web UI & Mobile App
    Chat with agents, browse files, manage git branches, and monitor sessions from a browser or phone. No VS Code required.
  • Cross-Device Sync
    Start planning a feature on your phone, pick up the same session in VS Code at your desk, or kick off from a Linear ticket and continue in your IDE.
  • Plugin Ecosystem
    Extend your workflow with plugins and MCP integrations. Customize how your agents work to fit your team's process.
  • Shared Team Environments
    Every developer gets their own isolated container while the team shares MCP servers, context files, and configurations. Onboard new developers in minutes, not hours.
  • API-Driven Session Management
    Start, stop, and manage environments through a full API. Trigger coding agents programmatically from Linear, Jira, n8n, or any automation tool.

Category Popularity

0-100% (relative to 21 Days and CloudCLI)
Health And Fitness
100 100%
0% 0
Developer Tools
0 0%
100% 100
Lifestyle
100 100%
0% 0
Productivity
63 63%
37% 37

Questions & Answers

As answered by people managing 21 Days and CloudCLI.

Which are the primary technologies used for building your product?

CloudCLI's answer:

CloudCLI is built with a modern JavaScript/TypeScript stack:

  • Frontend: React with Vite for fast builds, Tailwind CSS for styling, and CodeMirror for the in-browser code editor with syntax highlighting
  • Backend: Node.js powering the server and session management
  • Infrastructure: Docker for containerized cloud sessions, with support for self-hosting
  • Mobile: A dedicated mobile app for managing sessions on the go

The entire codebase is open source under AGPL-3 and available on GitHub.

Why should a person choose your product over its competitors?

CloudCLI's answer:

Compared to tools like GitHub Codespaces, CloudCLI is purpose-built for agentic development rather than traditional coding. Here's what sets it apart:

  • AI-agent-first: While competitors give you a cloud IDE, CloudCLI gives your AI agents a persistent home in the cloud. Your agents keep working even when your laptop is closed.
  • Open-source web UI and mobile app: No other CDE ships with both a browser-based UI and a native mobile app for managing sessions on the go. And it's all open source.
  • Cross-device continuity: Start planning on your phone, continue in VS Code at your desk, or kick off from a Linear ticket. Your session context carries over seamlessly.
  • Multi-agent support: Run Claude Code, Cursor CLI, OpenAI Codex, and Gemini CLI from one platform instead of managing separate setups.
  • Affordable: Starting at โ‚ฌ7/month for the managed service, or self-host for free with Docker.

What makes your product unique?

CloudCLI's answer:

CloudCLI is one of the only cloud development environments built specifically for AI coding agents. Where Codespaces and Gitpod give you a cloud editor, CloudCLI gives your agents a persistent home that stays alive 24/7. What makes it particularly valuable for teams: shared MCP servers and environment configs mean every developer starts from the same baseline. A full REST API means sessions can be triggered from automation tools, not just opened manually. Background agents can run overnight and produce PRs for review in the morning. And the entire platform is open source (AGPL-3) so teams can self-host on their own infrastructure.

How would you describe the primary audience of your product?

CloudCLI's answer:

CloudCLI is built for engineering teams that use AI coding agents as part of their daily workflow. This includes teams adopting agentic development practices with tools like Claude Code, Cursor CLI, or Codex who need shared environments where MCP servers, context files, and configurations stay consistent across every developer. It also serves engineering managers looking to integrate AI agents into existing workflows through API-driven automation with tools like Linear, Jira, and n8n. Solo developers and open-source contributors who want persistent remote access from any device are also a core audience, along with organizations that need to self-host for data sovereignty or regulatory compliance.

What's the story behind your product?

CloudCLI's answer:

CloudCLI started as an open-source project to solve a problem every developer using AI coding agents hits: your agent ties up your terminal and stops working when your laptop sleeps. We built a cloud-native environment where agents run persistently, paired with an open-source web UI so anyone could manage sessions from a browser or phone. As teams started adopting it, the focus shifted to shared environments, where team-wide MCP servers, configurations, and context files could be maintained in one place instead of duplicated across every developer's machine. The project grew to 9,000+ GitHub stars organically with no marketing. Today CloudCLI offers both a free self-hosted option and a managed cloud service starting at โ‚ฌ7/month.

User comments

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What are some alternatives?

When comparing 21 Days and CloudCLI, you can also consider the following products

YourHour - YourHour is an app by Mindefy labs through which you can easily overcome with your phone addiction by monitoring your phone usage.

GitHub Codespaces - GItHub Codespaces is a hosted remote coding environment by GitHub based on Visual Studio Codespaces integrated directly for GitHub.

myPoli - Gameified to-do list and habit tracker.

Gitpod - One click dev environment for GitHub

Goalie - Track your daily goals

Qoder IDE - Qoder is an AI-powered agentic coding platform and IDE that automates complex software development tasks using autonomous AI agents.