What Lucian is
Lucian is a desktop assistant that lives on your Mac or PC. You tell it what you want in normal words. It does the task on your machine, shows you what it did, and asks before anything risky.
How it works
Lucian is a real app you install, not a website. A small local engine runs on your computer and does the actual work: opening folders, moving files, running apps, making captions. When you send a message, the engine asks an AI model what to do, carries out the steps locally, and reports back in plain language.
The AI model comes from one of two places. On BYOK plans you connect your own account with any supported provider; your key stays on your machine and requests go straight to that provider. On hosted plans (Pro, Max, Ultra) Lucian supplies the models through our service, so there is nothing to set up and your usage is measured in credits.
What it can do today
Files and folders
- Create, rename, move, and organize files and folders
- Find things by what they are, not just their name
- Safe delete to the Trash with one-click undo
- Results come back as clickable chips that open in Finder or Explorer
Media
- Create captions and subtitles for a video
- Burn captions into a video or extract existing ones
- Convert, trim, and resize with a plain request
Apps and the desktop
- Open apps, switch windows, and type for you
- See what is on your screen when you ask it to
- Sign in to sites you have saved
- Watch a folder or an app and act when something changes
Research and thinking
- Search the web and read pages for you
- Compare products, tools, or options side by side
- Spin up parallel helpers for big jobs, right in the chat
- Remember what worked so the next time is faster
Code
- Set up a new project with tests and a README
- Edit, run, and fix code in a rehearsed terminal
- Explain an unfamiliar codebase in plain English
Control and safety
- Asks before overwriting, deleting permanently, or running risky commands
- Shows every step it took and what it changed
- Offers choices when a request is ambiguous
- Stop any job, including helpers, with one click
Your keys, your data
BYOK plans
- ✓Your API keys are stored on your computer and never sent to us.
- ✓Your conversations go from your machine to your provider. We never see them.
- ✓You pay your provider at their rates. We do not mark up tokens.
Hosted plans
- ✓Model requests pass through our service only long enough to be answered.
- ✓We keep usage counts for billing, not the content of your requests.
- ✓Files, folders, and apps are still touched only on your machine.
Full details in the Privacy Policy.
AI providers you can bring
Hosted plans use Lucian Cloud and need no keys at all.
Who makes it
Lucian is built by Severn Systems, LLC. The macOS app is signed with an Apple Developer ID and notarized; the Windows app ships as a signed installer. Updates arrive automatically inside the app.