withastro · florian-lefebvre · Oct 2, 2025 · Sep 30, 2025 · Oct 2, 2025 · Oct 2, 2025
diff --git a/.changeset/cyan-crews-cross.md b/.changeset/cyan-crews-cross.md
@@ -0,0 +1,19 @@
+---
+'astro': major
+---
+
+Removes the old `app.render()` signature (Adapter API)
+
+In Astro 4.0, the `app.render()` signature that allowed passing `routeData` and `locals` as optional arguments was deprecated in favor of a single optional `renderOptions` argument.
+
+Astro 6.0 removes this signature entirely. Attempting to pass these separate arguments will now cause an error in your project.
+
+#### What should I do?
+
+Review your `app.render` calls and pass `routeData` and `locals` as properties of an object instead of as multiple independent arguments:
+
+```diff
+// my-adapter/entrypoint.ts
+-app.render(request, routeData, locals)
++app.render(request, { routeData, locals })
+```
diff --git a/.changeset/dull-mangos-travel.md b/.changeset/dull-mangos-travel.md
@@ -0,0 +1,20 @@
+---
+'astro': major
+---
+
+Removes `prefetch()` `with` option
+
+In Astro 4.8.4, the `with` option of the programmatic `prefetch()` function was deprecated in favor of a more sensible default behavior that no longer required specifying the priority of prefetching for each page.
+
+Astro 6.0 removes this option entirely and it is no longer possible to configure the priority of prefetching by passing the `with` option. Attempting to do so will now cause errors.
+
+By default, Astro's prefetching now uses an automatic approach that will always try to use `<link rel="prefetch>` if supported, or will fall back to `fetch()`.
+
+#### What should I do?
+
+Review your `prefetch()` calls and remove the `with` option if it still exists:
+
+```diff
+-prefetch('/about', { with: 'fetch' });
++prefetch('/about');
+```
diff --git a/.changeset/pretty-forks-smash.md b/.changeset/pretty-forks-smash.md
@@ -0,0 +1,29 @@
+---
+'astro': major
+---
+
+Removes the `handleForms` prop for the `<ClientRouter />` component
+
+In Astro 4.0, the `handleForms` prop of the `<ClientRouter />` component was deprecated, as it was no longer necessary to opt in to handling `submit` events for `form` elements. This functionality has been built in by default and the property, if still included in your project, silently had no impact on form submission.
+
+Astro 6.0 removes this prop entirely and it now must be removed to avoid errors in your project.
+
+#### What should I do?
+
+Remove the `handleForms` property from your `<ClientRouter />` component if it exists. It has provided no additional functionality, and so removing it should not change any behavior in your project:
+
+```diff
+---
+// title="src/pages/index.astro
+import { ClientRouter } from "astro:transitions";
+---
+<html>
+  <head>
+-    <ClientRouter handleForms />
++    <ClientRouter />
+  </head>
+  <body>
+    <!-- stuff here -->
+  </body>
+</html>
+```
diff --git a/packages/astro/components/ClientRouter.astro b/packages/astro/components/ClientRouter.astro
@@ -3,11 +3,6 @@ type Fallback = 'none' | 'animate' | 'swap';
 
 export interface Props {
 	fallback?: Fallback;
-	/** @deprecated handleForms is enabled by default in Astro 4.0
-	 *
-	 * Set `data-astro-reload` on your form to opt-out of the default behavior.
-	 */
-	handleForms?: boolean;
 }
 
 const { fallback = 'animate' } = Astro.props;

diff --git a/packages/astro/e2e/fixtures/prefetch/src/pages/index.astro b/packages/astro/e2e/fixtures/prefetch/src/pages/index.astro
@@ -27,7 +27,7 @@
       // @ts-nocheck
       import { prefetch } from 'astro:prefetch'
       document.getElementById('prefetch-manual').addEventListener('click', () => {
-        prefetch('/prefetch-manual', { with: 'link' })
+        prefetch('/prefetch-manual')
       })
     </script>
   </body>

diff --git a/packages/astro/src/content/data-store.ts b/packages/astro/src/content/data-store.ts
@@ -34,8 +34,6 @@ export interface DataEntry<TData extends Record<string, unknown> = Record<string
 	 */
 	deferredRender?: boolean;
 	assetImports?: Array<string>;
-	/** @deprecated */
-	legacyId?: string;
 }
 
 /**

diff --git a/packages/astro/src/content/mutable-data-store.ts b/packages/astro/src/content/mutable-data-store.ts
@@ -291,17 +291,7 @@ export default new Map([\n${lines.join(',\n')}]);
 			entries: () => this.entries(collectionName),
 			values: () => this.values(collectionName),
 			keys: () => this.keys(collectionName),
-			set: ({
-				id: key,
-				data,
-				body,
-				filePath,
-				deferredRender,
-				digest,
-				rendered,
-				assetImports,
-				legacyId,
-			}) => {
+			set: ({ id: key, data, body, filePath, deferredRender, digest, rendered, assetImports }) => {
 				if (!key) {
 					throw new Error(`ID must be a non-empty string`);
 				}
@@ -348,9 +338,6 @@ export default new Map([\n${lines.join(',\n')}]);
 				if (rendered) {
 					entry.rendered = rendered;
 				}
-				if (legacyId) {
-					entry.legacyId = legacyId;
-				}
 				if (deferredRender) {
 					entry.deferredRender = deferredRender;
 					if (filePath) {

diff --git a/packages/astro/src/core/app/index.ts b/packages/astro/src/core/app/index.ts
@@ -320,14 +320,18 @@ export class App {
 		return pathname;
 	}
 
-	async render(request: Request, renderOptions?: RenderOptions): Promise<Response> {
-		let routeData: RouteData | undefined;
-		let locals: object | undefined;
-		let clientAddress: string | undefined;
-		let addCookieHeader: boolean | undefined;
+	async render(
+		request: Request,
+		{
+			addCookieHeader,
+			clientAddress = Reflect.get(request, clientAddressSymbol),
+			locals,
+			prerenderedErrorPageFetch = fetch,
+			routeData,
+		}: RenderOptions = {},
+	): Promise<Response> {
 		const url = new URL(request.url);
 		const redirect = this.#redirectTrailingSlash(url.pathname);
-		const prerenderedErrorPageFetch = renderOptions?.prerenderedErrorPageFetch ?? fetch;
 
 		if (redirect !== url.pathname) {
 			const status = request.method === 'GET' ? 301 : 308;
@@ -347,11 +351,6 @@ export class App {
 			);
 		}
 
-		addCookieHeader = renderOptions?.addCookieHeader;
-		clientAddress = renderOptions?.clientAddress ?? Reflect.get(request, clientAddressSymbol);
-		routeData = renderOptions?.routeData;
-		locals = renderOptions?.locals;
-
 		if (routeData) {
 			this.#logger.debug(
 				'router',

diff --git a/packages/astro/src/core/app/node.ts b/packages/astro/src/core/app/node.ts
@@ -2,7 +2,6 @@ import fs from 'node:fs';
 import type { IncomingMessage, ServerResponse } from 'node:http';
 import { Http2ServerResponse } from 'node:http2';
 import type { Socket } from 'node:net';
-import type { RouteData } from '../../types/public/internal.js';
 import { clientAddressSymbol, nodeRequestAbortControllerCleanupSymbol } from '../constants.js';
 import { deserializeManifest } from './common.js';
 import { createOutgoingHttpHeaders } from './createOutgoingHttpHeaders.js';
@@ -33,22 +32,12 @@ export class NodeApp extends App {
 		}
 		return super.match(req, allowPrerenderedRoutes);
 	}
-	render(request: NodeRequest | Request, options?: RenderOptions): Promise<Response>;
-	/**
-	 * @deprecated Instead of passing `RouteData` and locals individually, pass an object with `routeData` and `locals` properties.
-	 * See https://github.com/withastro/astro/pull/9199 for more information.
-	 */
-	render(request: NodeRequest | Request, routeData?: RouteData, locals?: object): Promise<Response>;
-	render(
-		req: NodeRequest | Request,
-		routeDataOrOptions?: RouteData | RenderOptions,
-		maybeLocals?: object,
-	) {
-		if (!(req instanceof Request)) {
-			req = NodeApp.createRequest(req);
+
+	render(request: NodeRequest | Request, options?: RenderOptions): Promise<Response> {
+		if (!(request instanceof Request)) {
+			request = NodeApp.createRequest(request);
 		}
-		// @ts-expect-error The call would have succeeded against the implementation, but implementation signatures of overloads are not externally visible.
-		return super.render(req, routeDataOrOptions, maybeLocals);
+		return super.render(request, options);
 	}
 
 	/**

diff --git a/packages/astro/src/prefetch/index.ts b/packages/astro/src/prefetch/index.ts
@@ -186,16 +186,6 @@ function initLoadStrategy() {
 }
 
 export interface PrefetchOptions {
-	/**
-	 * How the prefetch should prioritize the URL. (default `'link'`)
-	 * - `'link'`: use `<link rel="prefetch">`.
-	 * - `'fetch'`: use `fetch()`.
-	 *
-	 * @deprecated It is recommended to not use this option, and let prefetch use `'link'` whenever it's supported,
-	 * or otherwise fall back to `'fetch'`. `'link'` works better if the URL doesn't set an appropriate cache header,
-	 * as the browser will continue to cache it as long as it's used subsequently.
-	 */
-	with?: 'link' | 'fetch';
 	/**
 	 * Should prefetch even on data saver mode or slow connection. (default `false`)
 	 */
@@ -236,10 +226,7 @@ export function prefetch(url: string, opts?: PrefetchOptions) {
 		appendSpeculationRules(url, opts?.eagerness ?? 'immediate');
 	}
 	// Prefetch with link if supported
-	else if (
-		document.createElement('link').relList?.supports?.('prefetch') &&
-		opts?.with !== 'fetch'
-	) {
+	else if (document.createElement('link').relList?.supports?.('prefetch')) {
 		debug?.(`[astro] Prefetching ${url} with <link rel="prefetch">`);
 		const link = document.createElement('link');
 		link.rel = 'prefetch';