Cella Sandbox: fast enough to throw away, durable enough to keep

April 23, 2026

We are announcing Latere Cella. Cella is Latin for inner chamber: a small, private room for your work. The job is narrow on purpose:

A named runtime where code can run safely, state can persist when useful, compute can disappear when idle, and every action stays observable.

The two shapes that don't fit

Today you can rent cloud computing in two shapes. One is a quick task that vanishes the moment it finishes. The other is a full machine you have to look after yourself. Both work for what they were built for. Neither fits the kind of work AI assistants and developers actually do now. Cella sits in between.

A test run that takes ninety minutes shouldn't have to squeeze inside a quick task. A workspace where you track down a bug against last Tuesday's version, step out for lunch, and come back to find everything exactly as you left it shouldn't have to live on a machine you're paying to babysit. An AI assistant working through a project for an hour needs real files, a real place to run things, and somewhere lasting to keep what it figured out. Quick tasks are too short. Full machines are too much.

The market sells the wrong second

Private workspaces are a crowded market. Most of the competition is fought over startup speed: who gets the first command running fastest. That number matters. It is also the wrong number to chase once the work gets real.

The harder problem is not the first second. It is everything after the demo works.

• Where do the passwords and keys live, and who can see them.
• What happens to the work when the job ends.
• How do you know what the AI assistant actually did.
• Who is allowed to start new workspaces, against what limits, on whose budget.
• Can you stop a workload that's gone wrong without waking someone up at 3am.

The startup-speed number does not answer any of these.

The separation

Cella's design is one decision repeated through the product: separate what you want to keep from what you can throw away.

A workspace you keep. Files, saved downloads, the half-built project, the code you copied down three days ago. It is still there after you stop it, restart it, or leave it idle long enough to shut itself off. Whether to keep it is a choice you make when you create it. Throwaway workspaces are also available, and clean themselves up when you're done.

Computing power you can throw away. It stops when idle and starts back up in under half a second. Your work doesn't live in the computing power itself, so losing it costs nothing.

Passwords and keys that never sit in plain sight inside the workspace. Real secrets stay in a private, locked store that belongs to you. Read-only entries show up inside each cella at a known spot. Values needed for a single command are slipped in only at the moment they're used, never show up in command listings, and are wiped before your own code runs. Asking the store what's inside never reveals the values themselves. Updating a key takes effect without restarting your work.

Network access that's blocked unless you allow it. An approved list travels with the workspace. The same rules apply across every cella tied to the same account, all visible and easy to review.

A single record of everything. Every command, every use of a key, every start and stop is logged against whoever caused it. You can make sense of cost and behavior from one place.

That is the whole primitive. Everything else is policy.

What it is for

Four kinds of work pulled this design out:

Work that runs in the background. Jobs that take minutes to hours: a big test run, crunching data, training a model, a long download. Kick it off, walk away, come back to the results.

Trying things out. A workspace with real files and real tools. Try a new tool. Track down a bug against a specific version. Let an AI assistant work through a project for an hour. You set it up once.

AI assistants that touch real systems. Coding and research assistants that hold real keys and need to be watched over and controlled by a team. The locked store of keys, the activity record, and the controls stop being optional after the first time something goes wrong.

Named workspaces that stick around. Every cella has a short name. Stop it and it is still there tomorrow, with the same files, the same saved downloads, the same work in progress.

Try it

The command-line tool and public API are live. The getting-started guide walks you through it from start to finish. Early-access pricing is on the Cella page.

If any of this reads like it removes a problem you are currently solving by hand, reach out. We are especially interested in talking with teams building agent platforms or developer-environment tools.

Cella is a product of Latere. Founded by Dr. Changkun Ou.