In-Memory

Installation

The in-memory adapter has no peer dependencies and no runtime requirements — it's pure JavaScript backed by Maps, so it runs unchanged in Node, Bun, Deno, the browser, and edge runtimes. It's built in and is the zero-config default for createSandboxClient().

pnpm add sbox-sdk

Usage

The in-memory provider implements the same adapter contract as every cloud provider, but stores files and runs a tiny built-in shell in process instead of touching a network. That makes it the near-universal choice for testing code that uses sbox SDK without standing up a real sandbox — and it doubles as the reference adapter for the conformance suite.

import { createSandboxClient } from "sbox-sdk";
import { memory } from "sbox-sdk/memory";

// A fresh, empty sandbox. Same surface as the cloud adapters,
// so you can swap it in for tests without changing any call sites.
const client = createSandboxClient({ provider: memory() });
const sandbox = await client.create();

await sandbox.files.write("/app/hello.txt", "hi");
const text = await (await sandbox.files.read("/app/hello.txt")).text(); // "hi"

const res = await sandbox.commands.run("echo hi", { cwd: "/app" });
res.exitCode; // 0

Exercising the filesystem polyfills

Pass bareFs: true to hide the native filesystem methods, forcing the core's exec-based polyfills (ls, mkdir, rm, mv, stat) to run instead — useful for testing how the core behaves against providers that have no native fs primitives.

import { memory } from "sbox-sdk/memory";

const client = createSandboxClient({ provider: memory({ bareFs: true }) });

Authentication

Options

Behavior notes

• Non-persistent. State lives in the process. Two clients built from separate memory() calls don't share data. Not for production.
• Built-in mini-shell. commands.run interprets a small set of POSIX commands (echo, cat, ls, mkdir, rm, mv, stat, env, …). It is not a full shell — there's no &&, pipes, or subshells.
• The raw() escape hatch is the backing in-memory store, so a test can read or reset it directly.

Capabilities