chore: changeset

.changeset/gentle-windows-enjoy.md

@@ -0,0 +1,46 @@
+---
+"@astrojs/react": minor
+"astro": minor
+---
+
+Add support for [the React 19 `useActionState()` hook](https://react.dev/reference/react/useActionState) when using Astro Actions. This introduces progressive enhancement when calling an Action with the `withState()` utility.
+
+This example calls a `like` action that accepts a `postId` and returns the number of likes. Pass this action to the `experimental_withState()` function to apply progressive enhancement info, and apply to `useActionState()` to track the result:
+
+```tsx
+import { actions } from 'astro:actions';
+import { experimental_withState } from '@astrojs/react/actions';
+
+export function Like({ postId }: { postId: string }) {
+	const [state, action, pending] = useActionState(
+		experimental_withState(actions.like),
+		0, // initial likes
+	);
+
+	return (
+		<form action={action}>
+			<input type="hidden" name="postId" value={postId} />
+      <button disabled={pending}>{state} ❤️</button>
+		</form>
+	);
+}
+```
+
+You can also access the state stored by `useActionState()` from your action `handler`. Call `experimental_getActionState()` with the API context, and optionally apply a type to the result:
+
+```ts
+import { defineAction, z } from 'astro:actions';
+import { experimental_getActionState } from '@astrojs/react/actions';
+
+export const server = {
+  like: defineAction({
+    input: z.object({
+      postId: z.string(),
+    }),
+    handler: async ({ postId }, ctx) => {
+      const currentLikes = experimental_getActionState<number>(ctx);
+      // write to database
+      return currentLikes + 1;
+    }
+  })
+}