01 · Your own machine
One server. Yours alone.
A cloud server in the EU that nobody else uses. It's created when you join, runs around the clock, and is deleted when you leave. Your code and your agents' work live there, not in our database.
Private alpha · invite only
Your agents.
Your machine.
Always on.
Quartz is a private cloud computer that never sleeps. Send a coding task from your Mac or iPhone, and the agent you already pay for works on it while you're away. It comes back as a pull request.
Works with Claude Code / Codex / Cursor
Task in, pull request out
Send it at midnight.
Review it with coffee.
Every task gets its own sandbox and its own branch on your machine. Quartz runs your tests, pushes the work and opens the pull request. Then it tells you.
Rate-limit the login endpoint
acme/webClaude CodeDraft PR
“Add rate limiting to POST /login: 5 attempts a minute per IP, then a 429 with Retry-After. Add tests.”
- Task sent from iPhone
- Sandbox started on
quartz/rate-limit-login-7f3a2c - Claude Code read 14 files
- Edited 3 files +84 −12
- Tests passed · 212 of 212
- Draft pull request #142 opened
Quartznow
PR #142 ready · 3 files · tests pass
Rate-limit the login endpoint
What you get
A computer,
not a chatbot.
We supply the machine, the apps and the plumbing that turns a task into a pull request. You supply the AI. That's the whole deal.
02 · Your own AI
Bring the agent you pay for.
Sign in with your own subscription or API key. Prompts go from your machine straight to your provider. We never see, store or meter them.
03 · Nothing hidden
Follow every step.
Each task streams its timeline as it runs. On the Mac you can open a terminal on your machine and look around yourself.
04 · Follow-ups that remember
Keep the conversation going.
Not quite right? A follow-up resumes the same agent session, in the same working copy, and pushes on top of the same branch. No starting over.
How it works
Four steps,
then it runs itself.
- 01
Sign in with GitHub
Quartz asks GitHub who you are, and nothing more. Your machine is created for you. Connecting repositories is a separate, explicit step.
- 02
Connect your agent
Sign in to Claude Code, Codex or Cursor on your machine. The credential goes into an encrypted vault there, never to our servers.
- 03
Send a task
A repo, a prompt and an agent, from your Mac or iPhone. Several run at once. The rest wait their turn.
- 04
Review the pull request
The notification brings the PR. Review it on GitHub, or send a follow-up from the app and the same agent picks it back up.
Any agent, per task
Pick the agent. Pick how it ships.
Use Claude Code for one task and Codex for the next. Then decide how far each one goes. The default is a draft pull request, so nothing lands without you.
Quartz never runs a model of its own. Each agent is the vendor's official CLI, signed in with your account.
Security
Agents write code.
Quartz ships it.
Agents run unattended, so every boundary sits outside their reach. They can change files in their sandbox. Everything that leaves the machine goes through Quartz.
A sandbox per task
Each task runs in its own gVisor sandbox with its own copy of the repo. Tasks can't see each other or the host. If a task can't run sandboxed, it fails. It never falls back to something weaker.
Your GitHub token stays out of reach
Quartz's own daemon holds it and does the pushing. Agents never see it, and they can only ever push to their own
quartz/branch.Risky moves ask first
A force-push, or the first auto-merge on a repo, waits for you. Force-pushes can be answered right from the lock screen. No answer in 24 hours counts as a no.
A network mode you choose
Open lets agents reach anything, and the app says plainly that's the higher-risk choice. Restricted allows only package registries, GitHub, your AI vendor and hosts you add.
QuartzNeeds you
Force-push quartz/squash-migrations?
This drops 2 commits that are on GitHub but not in the task's work.
Try it. Approvals are answered from the notification.
Said plainly
Prompt injection can be contained, not prevented. A tricked agent can leak its own AI sign-in, the code in its working copy and any build secrets you gave it. It can't reach your GitHub write access, other tasks, or the machine itself.
Mac and iPhone
On your desk.
In your pocket.
macOS
Quartz for Mac
Start tasks, watch them run, review the results, and open a terminal on your machine.
iOS
Quartz for iPhone
Send a task from anywhere, answer approvals from the lock screen, and follow up on what comes back.
In the alpha now
- Tasks to pull requests, with all four ship options
- Claude Code, Codex and Cursor
- Sandboxed agents and the network modes
- Approvals from a notification
- Follow-ups in the same session
- A terminal on your machine, from the Mac
Coming next
- Watch the desktop live, and take over
- Preview links for dev servers
- Quartz chat and scheduled tasks
- Machine backups
- A web console
What does it cost?
Nothing during the alpha. Paid plans come later, and we'll publish prices well before anyone is charged. Your AI usage is between you and your provider, as it is today.
How do I get in?
Quartz is invite-only for now. Email us with your GitHub username. Invites are tied to your GitHub account, and sign-in is with GitHub.
Do you see my code or prompts?
No. Your code, prompts and transcripts stay on your machine. Our servers keep a small index of each task (status, repo and pull request link) so the apps can list them. The details are in our privacy policy.
Which agents work?
Claude Code, Codex and Cursor, through each vendor's official CLI. Sign in with your subscription or use an API key. Using them on Quartz has to be allowed by your agreement with that vendor.
Where does my machine run?
On Hetzner, in its EU data centres. It's a server for you alone, running all the time, and it's deleted when you delete your account.
Is my work backed up?
Not during the alpha. Keep your work pushed to GitHub, which is where Quartz sends it anyway. When backups arrive we'll say where they're kept and for how long first.
What happens when I leave?
Delete your account in Settings, on either app. It's immediate: you're signed out everywhere, your machine is deleted, our GitHub access is revoked and your records are erased.
Always on.
Always clear.
The alpha is small and free. Tell us your GitHub username and what you'd hand off first.