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Why Sandboxes

Prime Sandboxes are disposable, isolated environments for AI-assisted coding, benchmarking, and quick experiments. They give agents and humans a clean workspace without touching production infrastructure. New sandboxes are VM sandboxes by default.
Container sandboxes are being deprecated. Sandboxes now run as virtual machines by default. You can still opt into the container runtime with --container on the CLI or vm=False in the SDK, but plan to migrate.
Sandbox Dashboard
  • Prototype quickly – launch a clean runtime and iterate without worrying about teardown.
  • Benchmark safely – run untrusted code or model evaluations in a locked-down environment.
  • Run AI agents securely – restrict where code can reach with network allow/deny lists.
  • Inject secrets safely – pass API keys, passwords, and tokens as encrypted secrets that never appear in logs or API responses.
  • Teach & demo – hand teammates a reproducible workspace that mirrors your setup.
  • Use custom images – push your own Docker images and use them in sandboxes with all your dependencies pre-installed.
  • Organize with labels – tag sandboxes by project, team, or environment for easy filtering and bulk cleanup.

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VM Sandboxes

VM sandboxes boot an OCI/Docker image as the root filesystem of a hardware-isolated microVM. Use them when you need a stronger isolation boundary or VM-only egress controls. VM sandboxes were built with agentic RL in mind. They offer:
  • Full VM fidelity - supports Docker, systemd, background services, and kernel-dependent workloads.
  • Fast startup - we can start thousands of concurrent sandboxes in seconds, with image-aware scheduling for heterogeneous training runs.
  • Latency – commands come back noticeably faster.
  • GPUs – GPU sandboxes are VM-only (coming soon).
  • Snapshots - save, restore, and fork a sandbox mid-run, preserving & branching your trajectories (coming soon).
VM sandboxes are used by default. To opt back into container sandboxes:

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First Run

Make sure you have an API key with the right permissions on hand (prime login) before running these commands.
Track usage limits and billing inside the Prime Billing dashboard.

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Pricing

Sandboxes are billed while running:
  • CPU: $0.05 per core per hour
  • Memory: $0.01 per GB per hour
  • Disk: $0.001 per GB per hour
Example: 1 CPU core, 2 GB RAM, 10 GB disk → $0.08/hour.

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Limits

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Per-sandbox — VM sandboxes

CPU is allocated in whole vCPUs; fractional values round up to 1. Idle timeout is coming soon to VM sandboxes. Use --container for now.

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Per-sandbox — container sandboxes

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Per-account

Account limits apply across all running sandboxes. If you need higher limits, contact support.

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Images

Sandboxes run standard Docker images. When you pass an image reference to prime sandbox create, it resolves in this order:
  1. Fully-qualified references go to the registry you name — docker.io/pytorch/pytorch:latest, ghcr.io/org/image:tag, quay.io/org/image:tag.
  2. Prime Images — references that start with prime/, like prime/<username>/<image>:<tag>, prime/<team-slug>/<image>:<tag>, or the id forms (prime/<userId>/<image>:<tag>, prime/team-<teamId>/<image>:<tag>), resolve to a Prime Image you can access: your own, your team’s, or one that’s been published.
  3. Docker Hub — any other reference with no registry host and no prime/ prefix resolves as a Docker Hub image, so official images like ubuntu:22.04 or pytorch/pytorch:latest work as usual.

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VM sandbox images

VM sandboxes can boot Prime Images and Docker Hub images. Support for any Docker-compatible registry (including private registries) is coming soon to VM sandboxes. Use --container for now. The first time a given image is launched as a VM sandbox, Prime converts it into a VM image. The sandbox stays PENDING while that runs, which can take a few minutes; later sandboxes from the same image start normally. To skip the wait, pre-build with prime images build-vm.

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Container sandbox images

Container sandboxes (--container) pull from any Docker-compatible registry, including private ones. For private images, add registry credentials via the dashboard, then switch to Settings in the toggle. Then pass --container --registry-credentials-id <id> when creating a sandbox. Use prime registry list to view saved credentials and prime registry check-image to verify an image is accessible.

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GPU Support

GPU-enabled sandboxes are coming soon. They run only on VM sandboxes and need an explicit grant from Prime, so --gpu-count above 0 returns an error until your account has access. We’ll announce as soon as GPU tiers open up.

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Next Steps