make actionBodySizeLimit configurable

.changeset/young-cougars-mix.md

@@ -0,0 +1,6 @@
+---
+'@astrojs/node': patch
+'astro': patch
+---
+
+Make the body request limit a configurable

packages/astro/src/actions/runtime/server.ts

@@ -323,9 +323,10 @@ export function getActionContext(context: APIContext): AstroActionContext {
 					throw error;
 				}
 
+				const bodySizeLimit = pipeline.manifest.actionBodySizeLimit;
 				let input;
 				try {
-					input = await parseRequestBody(context.request);
+					input = await parseRequestBody(context.request, bodySizeLimit);
 				} catch (e) {
 					if (e instanceof ActionError) {
 						return { data: undefined, error: e };
@@ -381,24 +382,22 @@ function getCallerInfo(ctx: APIContext) {
 	return undefined;
 }
 
-const DEFAULT_ACTION_BODY_SIZE_LIMIT = 1024 * 1024;
-
-async function parseRequestBody(request: Request) {
+async function parseRequestBody(request: Request, bodySizeLimit: number) {
 	const contentType = request.headers.get('content-type');
 	const contentLengthHeader = request.headers.get('content-length');
 	const contentLength = contentLengthHeader ? Number.parseInt(contentLengthHeader, 10) : undefined;
 	const hasContentLength = typeof contentLength === 'number' && Number.isFinite(contentLength);
 
 	if (!contentType) return undefined;
-	if (hasContentLength && contentLength > DEFAULT_ACTION_BODY_SIZE_LIMIT) {
+	if (hasContentLength && contentLength > bodySizeLimit) {
 		throw new ActionError({
 			code: 'CONTENT_TOO_LARGE',
-			message: `Request body exceeds ${DEFAULT_ACTION_BODY_SIZE_LIMIT} bytes`,
+			message: `Request body exceeds ${bodySizeLimit} bytes`,
 		});
 	}
 	if (hasContentType(contentType, formContentTypes)) {
 		if (!hasContentLength) {
-			const body = await readRequestBodyWithLimit(request.clone(), DEFAULT_ACTION_BODY_SIZE_LIMIT);
+			const body = await readRequestBodyWithLimit(request.clone(), bodySizeLimit);
 			const formRequest = new Request(request.url, {
 				method: request.method,
 				headers: request.headers,
@@ -411,7 +410,7 @@ async function parseRequestBody(request: Request) {
 	if (hasContentType(contentType, ['application/json'])) {
 		if (contentLength === 0) return undefined;
 		if (!hasContentLength) {
-			const body = await readRequestBodyWithLimit(request.clone(), DEFAULT_ACTION_BODY_SIZE_LIMIT);
+			const body = await readRequestBodyWithLimit(request.clone(), bodySizeLimit);
 			if (body.byteLength === 0) return undefined;
 			return JSON.parse(new TextDecoder().decode(body));
 		}

packages/astro/src/container/index.ts

@@ -162,6 +162,7 @@ function createManifest(
 		i18n: manifest?.i18n,
 		checkOrigin: false,
 		allowedDomains: manifest?.allowedDomains ?? [],
+		actionBodySizeLimit: 1024 * 1024,
 		middleware: manifest?.middleware ?? middlewareInstance,
 		key: createKey(),
 		csp: manifest?.csp,

packages/astro/src/core/app/types.ts

@@ -87,6 +87,7 @@ export type SSRManifest = {
 	actions?: () => Promise<SSRActions> | SSRActions;
 	checkOrigin: boolean;
 	allowedDomains?: Partial<RemotePattern>[];
+	actionBodySizeLimit: number;
 	sessionConfig?: ResolvedSessionConfig<any>;
 	cacheDir: string | URL;
 	srcDir: string | URL;

packages/astro/src/core/build/generate.ts

@@ -775,6 +775,7 @@ async function createBuildManifest(
 		actions: () => actions,
 		checkOrigin:
 			(settings.config.security?.checkOrigin && settings.buildOutput === 'server') ?? false,
+		actionBodySizeLimit: settings.config.security.actionBodySizeLimit,
 		key,
 		csp,
 	};

packages/astro/src/core/build/plugins/plugin-manifest.ts

@@ -388,6 +388,7 @@ async function buildManifest(
 		checkOrigin:
 			(settings.config.security?.checkOrigin && settings.buildOutput === 'server') ?? false,
 		allowedDomains: settings.config.security?.allowedDomains,
+		actionBodySizeLimit: settings.config.security.actionBodySizeLimit,
 		serverIslandNameMap: Array.from(settings.serverIslandNameMap),
 		key: encodedKey,
 		sessionConfig: settings.config.session,

packages/astro/src/core/config/schemas/base.ts

@@ -91,6 +91,7 @@ export const ASTRO_CONFIG_DEFAULTS = {
 	security: {
 		checkOrigin: true,
 		allowedDomains: [],
+		actionBodySizeLimit: 1024 * 1024,
 	},
 	env: {
 		schema: {},
@@ -440,6 +441,10 @@ export const AstroConfigSchema = z.object({
 				)
 				.optional()
 				.default(ASTRO_CONFIG_DEFAULTS.security.allowedDomains),
+			actionBodySizeLimit: z
+				.number()
+				.optional()
+				.default(ASTRO_CONFIG_DEFAULTS.security.actionBodySizeLimit),
 		})
 		.optional()
 		.default(ASTRO_CONFIG_DEFAULTS.security),

packages/astro/src/types/public/config.ts

@@ -633,6 +633,31 @@ export interface AstroUserConfig<
 		 * When not configured, `X-Forwarded-Host` headers are not trusted and will be ignored.
 		 */
 		allowedDomains?: Partial<RemotePattern>[];
+
+		/**
+		 * @docs
+		 * @name security.actionBodySizeLimit
+		 * @kind h4
+		 * @type {number}
+		 * @default `1048576` (1 MB)
+		 * @version 5.x.0
+		 * @description
+		 *
+		 * Sets the maximum size in bytes allowed for action request bodies.
+		 *
+		 * By default, action request bodies are limited to 1 MB (1048576 bytes) to prevent abuse.
+		 * You can increase this limit if your actions need to accept larger payloads, for example when handling file uploads.
+		 *
+		 * ```js
+		 * // astro.config.mjs
+		 * export default defineConfig({
+		 *   security: {
+		 *     actionBodySizeLimit: 10 * 1024 * 1024 // 10 MB
+		 *   }
+		 * })
+		 * ```
+		 */
+		actionBodySizeLimit?: number;
 	};
 
 	/**

packages/astro/src/vite-plugin-astro-server/plugin.ts

@@ -130,6 +130,8 @@ export default function createVitePluginAstroServer({
 				warnMissingAdapter(logger, settings);
 				pipeline.manifest.checkOrigin =
 					settings.config.security.checkOrigin && settings.buildOutput === 'server';
+				pipeline.manifest.actionBodySizeLimit =
+					settings.config.security.actionBodySizeLimit;
 				pipeline.setManifestData(routesList);
 			}
 
@@ -311,6 +313,7 @@ export function createDevelopmentManifest(settings: AstroSettings): SSRManifest
 		i18n: i18nManifest,
 		checkOrigin:
 			(settings.config.security?.checkOrigin && settings.buildOutput === 'server') ?? false,
+		actionBodySizeLimit: settings.config.security.actionBodySizeLimit,
 		key: hasEnvironmentKey() ? getEnvironmentKey() : createKey(),
 		middleware() {
 			return {