Claude Code or Cowork? Pick Code when the rules matter
Cowork is the easier way in. Claude Code is where work that has to follow your rules every time belongs, and it's what I built The Modern OS on.
I use both every day, and what decides it for me is how much the work depends on rules. Cowork is the easier way in. Open the Claude desktop app, point it at a folder, and describe what you want. For a one-off document, some research, or a teammate who has never touched a terminal, start there. But in my experience Cowork drifts on instructions. Tell it how you name files or which account to send from, and a few tasks later it’s doing things its own way.
Claude Code doesn’t drift like that, because the rules don’t live in the conversation. They live in a file in your project folder (CLAUDE.md), and Code reads it at the start of every session. For the rules that can’t break, Code also runs hooks: small scripts that check each action and stop the ones that break a rule, so the rule is enforced instead of remembered. Code also works on your actual files, and if you use Git every change can be undone. That’s why anything I’ll run more than once ends up in Code. You don’t need the terminal for it anymore either. The Code tab in the Claude desktop app does the same job.
What I built on top of it
That’s the foundation of The Modern OS, the system I run my own businesses on. ModernOS Core gives Claude a workspace that stays put between sessions: your conventions, your context, its memory and your saved conversations, kept as plain files in your own drive. ModernOS Core Team adds a chief of staff that reads the state of everything you have going and turns the day into one short queue of decisions, plus decision engines that argue a call out before you make it. The rules hold the same way they do in Code. Nothing client-facing sends, nothing publishes and no money moves without me.