diff --git a/.changeset/fast-sync-temp-server.md b/.changeset/fast-sync-temp-server.md
new file mode 100644
index 000000000000..bd170c55b6c7
--- /dev/null
+++ b/.changeset/fast-sync-temp-server.md
@@ -0,0 +1,5 @@
+---
+"astro": patch
+---
+
+Skips adapter `configureServer` hooks and per-environment dependency pre-bundling during the temporary Vite server used by `astro build` for type generation. The temp server only resolves virtual modules — it never serves HTTP requests — so starting adapter runtimes (e.g. miniflare/workerd via `@astrojs/cloudflare`) and pre-bundling adapter `optimizeDeps.include` lists were both unnecessary. On a representative project this reduces the “Types Generated” phase from ~3.6 s to ~125 ms.
diff --git a/packages/astro/src/core/sync/index.ts b/packages/astro/src/core/sync/index.ts
index bf04261585f1..bcec400b72d3 100644
--- a/packages/astro/src/core/sync/index.ts
+++ b/packages/astro/src/core/sync/index.ts
@@ -234,6 +234,12 @@ async function createTempViteServer(
 		{ dev: true },
 	);
 
+	// Disable dependency optimization for all environments. The temp server only needs
+	// to resolve virtual modules for type generation, not pre-bundle dependencies.
+	// Setting this per-environment ensures adapter plugins (e.g. Cloudflare) see the
+	// flag and skip injecting their own optimizeDeps.include lists.
+	const noOptimize = { optimizeDeps: { noDiscovery: true, include: [] } };
+
 	const tempViteServer = await createServer(
 		await createVite(
 			{
@@ -241,6 +247,32 @@ async function createTempViteServer(
 				optimizeDeps: { noDiscovery: true },
 				ssr: { external: [] },
 				logLevel: 'silent',
+				environments: {
+					client: noOptimize,
+					ssr: noOptimize,
+					astro: noOptimize,
+					prerender: noOptimize,
+				},
+				plugins: [
+					// Strip `configureServer` hooks from non-Astro plugins. The temp
+					// server is only used to resolve modules for type generation — it
+					// never serves HTTP requests. Removing these hooks prevents adapter
+					// plugins from starting heavy runtimes (e.g. miniflare/workerd for
+					// Cloudflare). Astro's own plugins (prefixed with `astro:`) are
+					// preserved because some rely on configureServer to set up state
+					// needed by their other hooks.
+					{
+						name: 'astro:sync:strip-server-hooks',
+						enforce: 'pre',
+						configResolved(config) {
+							for (const plugin of config.plugins) {
+								if (plugin.configureServer && !plugin.name.startsWith('astro:')) {
+									delete plugin.configureServer;
+								}
+							}
+						},
+					},
+				],
 			},
 			{
 				routesList,