Why your agent needs one
So it doesn't forget.
So there's room. So it's still working tomorrow.
Right now your agent starts every conversation from zero — nothing it made yesterday is still there. Give it its own computer and that changes: it remembers what you taught it, its files and tools have a real home, and long jobs keep running after you close the chat.
It doesn't forget
Notes, preferences, half-finished work — still there next conversation. You stop re-explaining everything every morning.
More storage
Its files, projects, and tools live on its own disk instead of evaporating with the chat window. Room to actually build things up over time.
More compute
Long-running jobs and scheduled checks keep going overnight. It works while you sleep and reports back in the morning.
Task-scoped sandbox task sandbox
spark-vm spark-vm
The demo above is illustrative, not a benchmark — sandbox snapshot features vary by vendor. See the honest comparisons.
The trust story
A powerful agent, never trusted with the raw materials.
Your secrets never reach the agent
It writes hsurr: placeholders; a proxy swaps them for real
values at the last moment on allowlisted hosts only, and every swap is audited.
Sensitive actions pause for your tap
Spending money, touching credentials, anything outside the allowlist — approve or deny with a tap on your phone. Per-action consent, not blanket lockdown.
Built for localhost first
Your box has no public ingress by default — you reach it through the relay, never the open internet. The hosted version inherits that DNA.
How it works
Here's the plan once invites go out.
Nothing to install today — this is the shape of the hosted product we're building.
Get your invite
Join the waitlist — we'll email you when hosted boxes open up.
Link identity
Your agent proves it's yours (ed25519 key + your fingerprint approval). You bring your Tailscale tailnet at signup. Ephemeral agents can re-link without you re-doing the paperwork.
Give it work
Your box is a real computer — jobs, a desktop, a browser. The first sensitive thing it tries, you approve with a tap on your phone.
Compare
Honest comparisons, kept current.
We research the field continuously and publish what we find — including when a competitor is the better pick. Each page carries its verification date.
spark-vm vs E2B
Persistent computer vs the SDK-first sandbox cloud. When 24-hour sessions aren't enough.
spark-vm vs Daytona
Owning the machine vs renting stateful sandboxes by the hour.
spark-vm vs Modal
A computer that stays yours vs serverless compute that now bills egress.
spark-vm vs a raw VPS
The $4 droplet is cheap. The ops aren't. What the stack adds on top.
FAQ
Six objections, answered.
Is this another sandbox?
No — and we're not a sandbox provider at all. E2B, Daytona, and Modal sell sandboxes to developers; spark-vm is a service provider for agents — Muse, Grok Bot, Dots, and everything like them (meet them). Sandboxes are task-scoped by design; a computer persists: files, scheduled jobs, and the desktop survive. That's the whole product.
Will my agent see my API keys?
No. It only ever handles placeholders; the real values are swapped at the last moment on allowlisted hosts, and every swap is logged for you.
What do I have to approve?
Sensitive actions: spending money, touching credentials, anything outside the allowlist. A tap on your phone.
Do I need my own infrastructure?
Not for the box itself — that's the hosted part. You do bring your Tailscale tailnet at signup, and we run the machine. Want it on your hardware today? Self-host from the repo.
How much does it cost?
Tiers are still being decided; the waitlist email will carry the real numbers before you're asked for a card. See the pricing page for what we can say today.
When does it launch?
We don't print dates we can't keep. The waitlist is the launch list — first invites go there.
Be first in line when hosted boxes open.
One email. No card. We'll write the moment your box is ready.