Several Claude accounts, side by side
Sessions from every account sit in one list. Group by state, project or account, and see each account’s 5-hour and weekly limit next to it.
Every session,
one calm board.
Mastlight is a Mac app where every Claude Code session, on every account you use, tells you what it needs. You answer it in one place.
Early previewComing soon
- Runs on your Mac
- No account, no telemetry
- Apple silicon
The main window
api-refactorA1
> Split the request handler into routes and services, then run the tests. ● I'll start with the handler. ⎿ Read src/server/handler.ts (318 lines) ● Edit src/server/routes.ts ⎿ Added 42 lines
Waiting on you api-refactor A1
Run a command
npm test -- --watch=false
Claude says: Run the unit tests once
one vocabulary
Every session is in one state, and the state has a word.
- Waiting on you A permission, plan or question is pending.
- Working A turn is running.
- Unread A turn ended after you last looked.
- Idle Finished, and you have seen it.
- Failed It stopped with an error.
- Ended Closed, and you can restore it.
features
What it does, and nothing more.
One inbox for every session
Whatever is waiting, on any account, lands in the inbox, oldest first. ⌘ J jumps to it. You answer in place, without hunting for the terminal.
The exact permission, plan or question
A card shows the real command, the plan, or the question with its options, built from what the session is asking. Answer with a key: 1 allows once, 3 denies. Each card is one decision. The Conversation view shows each session’s transcript as formatted Markdown: headings, lists, tables and code blocks.
Terminals that survive quitting
Each session runs in a built-in terminal owned by a small background helper, not by the window. Quit or update Mastlight and the sessions keep running. Open it again and every tab reattaches with its scrollback.
Restore after a crash or reboot
If the helper is killed or the Mac restarts, Mastlight offers “Restore 6 sessions” on the next launch. Each one resumes in its own folder and under its own account.
Sessions from other terminals show up too
A claude running in iTerm, Terminal or tmux appears on the board with an External tag, read-only, so nothing is hidden from you. When you want one here, choose “Bring into Mastlight” from the Mac window and confirm once. Claude exits in the old tab and the same conversation resumes inside Mastlight, with the same account and folder. If it is mid-turn, Mastlight can wait until it is idle first.
how it works
Three steps, about two minutes.
Install
Open the DMG and drag Mastlight onto Applications. The first time, right-click it and choose Open. Setup starts straight away.
Sign in with Claude’s own
/loginMastlight finds your Claude Code, offers the sign-ins already on your Mac, or opens a terminal where you run
/loginyourself. It never sees a credential.Start sessions
Press ⌘ N, pick a folder and an account. When a session needs you it moves to the top, and ⌘ J takes you there.
privacy
It stays on your Mac.
Everything runs here
The window, the sessions and the engine that watches them all run on your Mac.
No account, no telemetry, no relay
There is nothing to sign up for and no server of ours. The only request the app makes by itself is a daily check for a newer version, which you can switch off.
Your credentials stay with Claude
Sign-ins stay where Claude keeps them, in the macOS Keychain or its own folder. Mastlight reads only the email and plan from each account, never a token.
requirements
What you need.
- A Mac with Apple silicon
- Mastlight 1.0 is an arm64 build for macOS. Windows is planned, with no date.
- Claude Code 2.1.85 or newer
- That is the first version where a hook can answer a question. Setup checks the version it finds.
- A Claude subscription
- You sign in with your own. One account is enough.
questions
Questions people ask first.
macOS says it can’t open the app. What do I do?
The build is not signed with an Apple Developer ID yet, so macOS does not recognise it. The first time, right-click Mastlight in Applications, choose Open, then Open again in the dialog. After that it opens normally.
If macOS says the app is “damaged” and does not offer Open, run this once in Terminal: xattr -dr com.apple.quarantine /Applications/Mastlight.app
For the same reason, the app never updates itself. It can tell you a newer version exists. It never downloads or installs one.
Is Mastlight made by Anthropic?
No. Mastlight is an independent app. It is not affiliated with or endorsed by Anthropic, and it runs the unmodified claude you already have.
Does it change my Claude settings?
No. The hook that shows cards is passed to each session on its own command line (claude --settings <file>). Your own settings files are never edited.
Can I use more than one Claude account?
Yes. Add each one by signing in with Claude’s own /login in a terminal inside Mastlight, or import the sign-ins already on your Mac. Each account has to be your own. Mastlight never sees a credential, and it does not switch accounts for you: a session starts under the account you pick.
We read Anthropic’s Consumer Terms (effective October 8, 2025) and Usage Policy (September 15, 2025) on 5 October 2026. They do not mention a limit on how many accounts one person may hold, and they do not allow sharing a login. Read them yourself: Consumer Terms.
What does it send over the network?
Nothing to us: there is no server of ours. The one request the app makes by itself is a once-a-day check for a newer version, which you can switch off in Settings. Claude Code itself talks to Anthropic as it always does.
Is there a Windows version?
Windows is planned. There is no date.
How do I remove it?
In Settings, Uninstall Mastlight (two confirmations) removes the app’s data, its logs and its background helper, then moves the app to the Trash. It does not touch ~/.claude*, your Claude sign-ins or other apps.
All quiet. Nothing is waiting on you.
That is the point. Mastlight is in early preview.
Early previewComing soon