Fuseduo by HollowbitSafety
Nothing runs until you say so.
Fuseduo writes code that controls your apps, so it’s built to be careful by default and honest about what it does.
You approve every run
Scripts only run when you press Run. Nothing runs in the background, on a schedule or by itself.
Plain-English steps
Every fusion is explained step by step, so you know what it touches without reading code.
An honest risk rating
Low means it only reads, opens or creates new things. Medium means it changes something, like making a draft. Anything else is high.
Compile check
Each script is compiled before you see it. If it fails, Claude gets one try to fix it, and a script that still won’t compile can’t be run.
How to undo it
Every plan ends with how to reverse what it did. Fusions only create new files, never overwrite yours.
Runs on your Mac
Scripts run locally with macOS’s own tools, and macOS asks before an app can be controlled the first time.
The block-list
Some things it simply won’t run.
On top of Claude’s own rules, every script is screened before the Run button is enabled. If it matches any of these, it’s blocked.
It’s a safety net, not a sandbox. Reading the plan before you approve is still the main protection.
Privacy
What Claude sees.
Sent to Claude
- The names of the two apps you fused
- The idea you picked, or the one you typed
- If a script fails to compile, the script and the error, so it can be fixed
Never sent
- Your notes, emails, events, photos or files
- What a script reads or makes when it runs
- A list of all your apps
- Analytics or tracking of any kind
Questions
Can a fusion delete my stuff?
Fuseduo asks Claude never to delete, overwrite or move your files, and blocks scripts that try to delete things, move them to the Trash or empty it. Fusions create new things instead.
Can it send emails or messages as me?
No. It can open a draft for you to check, but scripts that send email or messages are blocked.
Why does macOS ask for permission?
macOS asks the first time any app wants to control another app, like Notes or Calendar. That prompt comes from macOS itself. You can change it later in System Settings › Privacy & Security › Automation.
Do I need to pay for an API key?
Not if you have Claude Code. Fuseduo can use your own Claude Code sign-in, and requests count towards your plan’s limits. If you’d rather, use an Anthropic API key instead. You choose in Settings, and Fuseduo never sees your Claude login.
Is there a Windows version?
Not yet. Fuseduo starts on Mac. Windows (with PowerShell) is planned.
Get Fuseduo.
Free for Mac. Drop one app on another and see what they can do together.
Version 1.0.0 · Free and open source · View on GitHub · All downloads
First launch: right-click Fuseduo in Applications and choose Open (it isn’t signed with a paid Apple certificate). You’ll need Claude Code or an Anthropic API key.