Agent skill · cloudflare
sandbox-next
Build or maintain Cloudflare Sandbox apps on @cloudflare/sandbox@next (SDK 1.0 preview). Use sandbox-migrate-to-next when porting a stable app.
What it needs
About 3k tokens when loaded.
What this skill does
Sandbox SDK — @next (1.0 preview) Isolated Linux environments on Cloudflare 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) Never mix an @next Worker package with a stable container image (or the reverse). Skills install: Agent setup · cloudflare/skills 2. Contract — non-negotiables sandbox.exec(argv) takes an argv list and resolves when the process starts. It returns a handle, not a finished command result. Collect results with handle methods: output(), logs(), waitForExit(), waitForPort(), waitForLog(), kill(signal?). No implicit shell. Shell syntax needs an explicit shell, e.g. ["/bin/bash", "-lc", script]. Each launch is independent. A cd / export in one exec is not visible to the next. Pass cwd and env per launch, or one shell script. Process handles have no stdin. Interactive use → terminals (createTerminal + connect). Local wait timeout / AbortSignal cancel the wait only. They do not kill the process. Use kill or exec’s remote timeout. getProcess / listProcesses / getTerminal / listTerminals do not start a container; they return null / [] when none is up. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills cloudflare/sandbox-next