astro/.changeset/tricky-candles-suffer.md

astro	@astrojs/vercel
major	minor

The configuration build.split and build.excludeMiddleware are deprecated.

Configuration that were inside the astro configuration, are now moved inside the adapter:

import {defineConfig} from "astro/config";
import vercel from "@astrojs/vercel/serverless";

export default defineConfig({
-    build: {
-        excludeMiddleware: true
-    },
-    adapter: vercel()
+    adapter: vercel({
+        edgeMiddleware: true
+    })
})

import {defineConfig} from "astro/config";
import vercel from "@astrojs/vercel/serverless";

export default defineConfig({
-    build: {
-        split: true
-    },
-    adapter: vercel()
+    adapter: vercel({
+        functionPerRoute: true
+    })
})