Machine size and network

Pick a CPU and memory size for a sandbox, and limit which hosts it can reach. Both fail at creation when the provider can't enforce them.

Two options shape what a sandbox is allowed to be: size sets how much machine it gets, and network sets where it can connect. You set both when you create the sandbox. If the provider can’t do what you asked, createSandbox throws instead of giving you something different.

Size

import { createSandbox } from "@opencoredev/sandbox-sdk";
import { daytona } from "@opencoredev/sandbox-sdk/daytona";

await using small = await createSandbox(daytona(), { size: "small" });
await using custom = await createSandbox(daytona(), {
  size: { cpu: 4, memoryMb: 8192, diskGb: 20 },
});

size takes a preset ("small", "medium", or "large") or exact numbers. Each provider maps the presets to its own machine settings:

Exact numbers are less portable than presets. Some providers take any CPU, memory, and disk, some fix one of them or allow only certain steps, some take presets only, and some take no size at all because the template sets the machine. The Size presets and Exact size rows of the capability matrix say which provider does what, and each provider page lists its preset mapping.

When a provider can’t give you the size you asked for, creation fails with code unsupported, and the error message says what that provider allows. Vercel, for example, has no disk setting:

import { createSandbox, SandboxError } from "@opencoredev/sandbox-sdk";
import { vercel } from "@opencoredev/sandbox-sdk/vercel";

try {
  await using box = await createSandbox(vercel(), {
    size: { cpu: 64, memoryMb: 262_144, diskGb: 500 },
  });
} catch (error) {
  if (error instanceof SandboxError && error.code === "unsupported") {
    console.error(error.message, error.hint);
  }
}

Leave size out to get the provider’s default machine.

Network

import { createSandbox } from "@opencoredev/sandbox-sdk";
import { vercel } from "@opencoredev/sandbox-sdk/vercel";

await using box = await createSandbox(vercel(), {
  network: { allow: ["registry.npmjs.org", "github.com", "codeload.github.com"] },
});

const install = await box.run("npm install react");
const exfil = await box.run("curl -sS https://example.com");
console.log(install.ok, exfil.ok);

This prints true false. npm reaches its registry, and the request to any other host fails inside the sandbox.

Use an allow list whenever a model or a user’s code runs in the sandbox. A short list of package registries and your own API covers most apps.

When a provider can’t enforce it

A network policy is only useful if it holds. When a provider has no way to enforce "none" or an allow list, createSandbox throws SandboxError with code unsupported rather than create an open sandbox. The same goes for size.

Providers differ here. Some enforce both "none" and allow lists, some only one of them, and some accept only "all". The No network and Allow list rows of the capability matrix say which, and its Network note lists the host formats each allow list takes. Check ahead of time with box.capabilities, which includes "network-policy" and "size" when the provider supports them in some form.

Previews are inbound, so an allow list doesn’t block them. The exception is Local with network: "none", where the container has no network at all and previews fail.