Foldkit 0.159.0

Foldkit 0.159.0 is out. The main change is a portable fetch handler for server-rendered applications.

In 0.155.0, Foldkit moved the browser build, server build, and prerendering into one vite build. But the server build still asked you to choose a host entry: a Node HTTP process or a custom Worker.

@foldkit/vite-plugin 0.21.0 now builds a Web fetch handler. The same server module can run on Node or Workers:

foldkit({
  buildId,
  ssr: {
    serverEntry: '/src/entry.server.ts',
    build: true,
  },
})

Run vite build and the server output is dist/server/fetch.js, with a default export shaped as { fetch }. A Node host serves the built client assets and passes page requests to that handler. A Worker can default-export the same module.

This is a breaking change. Remove ssr.build.entry and keep ssr.serverEntry. Vite no longer builds your Node host. Use the SSR example's scripts/serve.ts as a reference, and start it with node scripts/serve.ts instead of node dist/server/main.js. Hosts importing dist/server/entry.server.js should import dist/server/fetch.js, which still exports renderPage.

The server rendering guide covers the build and host setup. New SSR projects from create-foldkit-app also pin @effect/platform-node-shared to their Effect version, so a fresh install cannot silently pick up an incompatible newer prerelease.

There are also several smaller updates:

• OnInput and OnChange support contenteditable hosts, with new beforeinput handlers and Scene steps for editor interactions.

• OnKeyDownSelf and OnKeyDownSelfPreventDefault ignore key events that bubble up from children.

• CustomElement events decode their payloads against the declared Schema before dispatching a Message.

• Domain and Route unions gain matchOrElse for handling selected variants with a shared fallback.

• Canceling a file picker inside a Dialog now keeps the Dialog open.

• Dialog and form controls now require an explicit opt-in for aria-describedby.

• Runtime.embed reports startup failures in the console.

• The DevTools MCP bin and oxlint plugin have smaller bundles built with Rolldown.

• The Model preservation API uses live reload terminology, including the renamed foldkit/model-preservation import.

• A new anti-patterns guide covers common Foldkit mistakes and what to do instead.

The 0.159.0 release notes have more context and the migration steps for the breaking changes.

Thank you to @filipfalcon for the portable server bundle, the Rolldown migration, and documentation improvements. Thank you also to @artile for correcting the documentation snippets and UI overview, and to @armancharan for the Runtime.embed startup reporting fix!

Thanks to everyone building with Foldkit!

Devin