sandbox-next

# Sandbox SDK — `@next` (1.0 preview) Isolated Linux environments on [Cloudflare Containers](https://developers.cloudflare.com/containers/), driven from Workers. **Prefer preview docs and installed `@next` types over memory.** APIs change; this skill is a gate, a contract, and a retrieval map—not a full manual. We recommend **new projects** on this line. Apps still on the default package use **`sandbox-stable`**. Port only when asked, via **`sandbox-migrate-to-next`**. ## 1. Gate — confirm the package line Before writing code, inspect the app: | Check | Must match | | ----- | ---------- | | npm dependency | `@cloudflare/sandbox@next` (or another preview tag) | | Container image | Same line (e.g. `cloudflare/sandbox:next`, `next-python`) | | If you find… | Action | | ------------ | ------ | | Default `@cloudflare/sandbox` (no `@next`) | **Stop.** Load **`sandbox-stable`**. Do not apply this skill’s APIs. | | User wants to port stable → `@next` | **Stop.** Load **`sandbox-migrate-to-next`**. | | Self-deployed **bridge** only | Bridge is **not** on the 1.0 preview line yet. Keep bridge on stable package + image. [Bridge (stable)](https://developers.cloudflare.com/sandbox/bridge/) | Never mix an `@next` Worker package with a stable container image (or the reverse). Skills install: [Agent setup](https://developers.cloudflare.com/agent-setup/) · [cloudflare/skills](https://github.com/cloudflare/skills) ## 2. Contract — non-negotiables - `sandbox.exec(argv)` takes an **ar...