sandbox-migrate-to-next

name	sandbox-migrate-to-next
description	Use when porting a Cloudflare Sandbox app from stable @cloudflare/sandbox to @cloudflare/sandbox@next (Sandbox SDK 1.0 preview), or when the user asks to migrate or upgrade to Sandbox 1.0 / @next. Not for day-to-day stable work (sandbox-stable) or new @next apps (sandbox-next).

Migrate stable → Sandbox SDK 1.0 preview (@next)

Perform the port. Follow the steps in order. Depth lives in docs—fetch the linked page when a step needs detail.

Human guide: Migrate · 1.0 preview

New projects should start on @next (sandbox-next), not this skill. Day-to-day stable work → sandbox-stable. Deprecated-API cleanup without moving to @next → 2026 deprecation guide first if needed.

Existing apps should migrate when you can, so you are ready when 1.0 becomes the stable release. Do not force production cutover without the user agreeing.

Prefer installed @next types and the migrate doc over memory.

Workflow

1. Review hard rules and the replacement map
2. Audit the codebase; list hits and target shapes
3. Clarify with the user (cutover, bridge, Python image, unclear sites)
4. Upgrade package, image, and code
5. Validate

Stop after any step that needs a user decision.

Hard rules