Hi It’s Sergey and Serafim from 21st.dev, in the last 10 months we’ve built and launched 9 products, getting over 1 millions total users, $200k in revenue, and 10k GitHub stars.

Motivation:

Claude Code has been our go-to for 4 months. When Opus 4.5 dropped, parallel agents stopped needing babysitting.

You could finally run multiple and trust them. But the more agents we ran, the more the CLI felt like a limitation, not a feature.

So we built 1Code.dev

Whats 1Code?

An app to run your Claude Code agents in parallel that works on Mac and Web.

On Mac - run locally, with or without worktrees.

On Web - run in remote sandboxes with live previews of your app, mobile included, so you can check on agents from anywhere.

Running multiple Claude Codes in parallel dramatically sped up how we build features.

What’s next: Bug bot for identifying issues based on your changes; QA Agent, that check that new features dont break anything

Adding OpenCode, Codex, other models and coding agents.

API for starting Claude Codes in remote sandboxes. Debugging and spotting errors in AI Coding Era is more critical than ever

Try it: We're open-source, so you can just bun build it.

Paid tiers exist too - for us it’s gonna be highest signal that we're on the right track.

Either way, we'd love to hear your feedback!