Migrate from @starbeam/core

@starbeam/core is a deprecated compatibility alias for @starbeam/universal.

This page is for existing projects that still depend on @starbeam/core. Do not start new code there. New framework-neutral Starbeam code should use @starbeam/universal, plus @starbeam/collections when state is object-shaped or collection-shaped.

What changed

Older Starbeam code imported framework-neutral APIs from @starbeam/core. The current package name for that surface is @starbeam/universal.

@starbeam/core remains available during the compatibility window so existing projects can migrate without combining an upgrade with an immediate source edit. Importing it emits a warning and re-exports @starbeam/universal.

Migration steps

1. Add @starbeam/universal to your dependencies.
2. Change imports that point at the deprecated compatibility package so they point at @starbeam/universal.
3. Run your tests and typecheck.
4. Remove @starbeam/core from your dependencies once no imports use it.

For the compatibility surface, this is a package rename. There is no separate @starbeam/core API to learn.

New code

Use current package entry points instead:

• @starbeam/collections for reactive versions of ordinary JavaScript objects and built-in collections;
• @starbeam/universal for framework-neutral resources and common authoring APIs;
• a framework adapter when a framework owns rendering.

See Install Starbeam for the package chooser and Reference for the current package map.