Sandboxes FAQ

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Basics

What is a sandbox?

Sandboxes (beta) are Linux microVMs that your code creates, runs commands in, pauses, forks, and deletes through the API or the CLI. Unlike a box, the machine you work on every day, a sandbox is for one job at a time and lives 24 hours at most.

How fast is it?

A create is usually running in 4 to 5 seconds, a resume in about two, and a fork's copies within a few seconds. At busy moments a create can wait in starting while capacity is added, or answer 503 sandbox_capacity with Retry-After and bill nothing (Limits: Sandboxes).

What is inside one?

Ubuntu 24.04 with Python 3, Node.js 22, git, and build tools (prized-base-v1), or all of that plus Claude Code and Codex (prized-agent-v1). Each takes 1 to 8 vCPU, 1 to 16 GB of memory, and 10 to 100 GB of disk (Templates).

Where do sandboxes run?

In us-west-2 (Oregon). Other regions are not available yet.

Forking

What does a fork copy?

Each copy starts with the parent's memory, disk, and running processes as they were at the fork, and the parent keeps running after a brief pause, usually under a second. Copies are ordinary sandboxes, billed and counted against your quotas like any other (Fork).

How many copies can one fork make?

As many as fit on the parent's machine and in your workspace's quotas: at most 31 copies of a 1 vCPU sandbox, 15 of a 2 vCPU one, 7 of a 4 vCPU one, and 3 of an 8 vCPU one; more memory or disk, or a busy machine, fits fewer. A fork that does not fit makes nothing and answers 409 fork_capacity with fits, how many fit now: fork that many, or start a new sandbox and fork that.

Do copies share randomness or identity?

Each copy gets its own hostname, IP address, and /etc/machine-id, and a freshly reseeded kernel random number generator; its connections to other machines are closed, and loopback ones keep working. Process IDs and boot_id stay the parent's, and a process that was already running keeps the random state it holds in memory, so reseed or restart it after a fork before it makes keys, tokens, or IDs.

Security and isolation

How are sandboxes isolated, and what can they reach?

Each sandbox is its own microVM with its own kernel. It reaches the internet outbound, nothing reaches it from the internet, and sandboxes cannot reach each other (Security and trust).

Do I get root?

No: commands run as the user prized, without sudo, so there is no apt. pip installs into a venv, and npm install -g needs a user prefix (Inside a sandbox).

What can Prized see?

Commands and files pass through Prized's edge, which checks your API key on every request; the key never enters the sandbox, and the envVars you set are stored encrypted and never returned by any route. A running sandbox reports resource vitals, listening ports, and its top processes, never file names, file contents, or terminal output (Security and trust).

What happens to my data when a sandbox is deleted?

Deleting a sandbox, by hand or at the end of its lifetime, erases its disk, memory, and environment variables with no undo. What the workspace keeps after a delete, and what erasing the workspace removes, is on Data retention.

Pricing and limits

How much does it cost?

Per second, with no minimum: running, by vCPU, memory, and disk; paused, by disk and saved memory alone (Billing: Sandboxes).

What do I get for free?

New workspaces get $30 of free credit with no card. On the free credit alone you can run 4 sandboxes at once, each up to 2 vCPU, 4 GB, and 60 minutes, so a free fork is a parent plus 3 copies; a top-up or a plan lifts the workspace to the full quotas (Free tier).

How long can a sandbox live, and what does pausing do?

Up to 24 hours from the create, paused time included (60 minutes on the free tier), then it is deleted. A paused sandbox keeps its memory and disk and bills for storage alone, and on resume every process carries on where it stopped (Pause and resume).

What happens at a limit, or when my credit runs out?

A request past a quota makes nothing and answers 429 sandbox_quota_exceeded, naming the limit in reason (Limits: Sandboxes). At a zero balance, with overage off, running sandboxes pause until you add credit and resume them, and are still deleted when their lifetime ends (Billing: Sandboxes).

What's not there yet

Can I bring my own image?

Not yet: no templates from your own Dockerfile or image, and no saving a sandbox as a template. Install what you need once in a sandbox, then fork it for each job.

Is there an SDK?

No SDK packages are published yet. Use the Sandbox API from any HTTP client, a helper for Python or TypeScript, or prized sandbox from the CLI.

Can I stream a command's output?

Not yet: an exec answers when the command ends, with up to 4 MiB of each stream. For a long job, write its output to a file and read it with a later exec or a download (Run a command).

What else is missing?

Other regions, GPUs, egress allow and deny lists, SSH or a terminal into a sandbox, preview links to its ports, more than 8 vCPU or 16 GB, and lifetimes past 24 hours. Not yet lists each with what to use instead.

Getting help

Where do I get help?

Email team@prized.dev with the sandbox id and the error from the response; common errors and their fixes are on Troubleshooting: Sandboxes. Report a vulnerability to the same address, before publishing it if you can (Security and trust).