@tupper/mastra

A Mastra WorkspaceSandbox backed by Tupper. Give a Mastra workspace an isolated Tupper sandbox (Apple Containers today; Firecracker/WSL planned) for command execution.

Install

bun add @tupper/mastra @tupper/sdk @tupper/container @mastra/core

@mastra/core is a peer dependency; install the Tupper backend for your platform (@tupper/container on macOS).

Usage

import { Workspace } from "@mastra/core/workspace";
import { TupperSandbox } from "@tupper/mastra";

const workspace = new Workspace({
  sandbox: new TupperSandbox({ image: "docker.io/library/alpine:latest" }),
});

// Mastra calls sandbox.start() on init and sandbox.destroy() on cleanup.

TupperSandbox implements Mastra's WorkspaceSandbox (start / destroy / getInfo / executeCommand) over @tupper/sdk.

Filesystem mounting

Mount host directories into the sandbox at creation (bind mounts, applied at launch):

const sandbox = new TupperSandbox({
  image: "docker.io/library/alpine:latest",
  mounts: [{ source: "/host/project", target: "/work", readonly: true }],
});

Mastra's runtime sandbox.mount(filesystem, path) — FUSE / cloud mounts into a running sandbox — isn't supported by container or microVM backends (Mastra reports MountNotSupportedError). Pass host mounts at create time instead.