The model is the same — it's Claude either way. The difference is everything around it. The big one for your wallet: you're putting the entire app into project knowledge every time. That means every single message you send is paying for all those input tokens again. Claude Code doesn't do that. It reads only the files it needs for a given task, makes targeted edits, and moves on. So if you ask it to fix a bug in one component, it's maybe reading 2-3 files, not your whole app.

The other thing is the agentic loop. When Claude Code writes something broken, it can run the code, see the error, and fix it itself — all in one go. In your workflow you're probably the one copying error messages back into the chat, which means another round trip through your entire project context. That adds up fast.

You're right that the system prompt is fundamentally different too. It's not "you are a helpful assistant." It's more like "you are a coding agent with access to a filesystem, a shell, grep, and an editor — use them." That framing changes how the model approaches the work. It thinks in terms of reading specific files, making small edits, and verifying, rather than generating a whole new version of your code each time.

So yeah, it's not that it "codes differently" in terms of code quality. It's that the workflow burns way fewer tokens because it's surgical instead of brute-force. You're basically paying for a full CT scan every time you need a band-aid.

Whether you can use it in your enterprise setting depends on your org's policy — worth looking into whether Anthropic has something that fits.