From 87149a2aa065e9957cc4a8bae714c74b64f07b48 Mon Sep 17 00:00:00 2001
From: michalgrezel <michal.grezel@jti.com>
Date: Fri, 24 Oct 2025 13:02:44 +0200
Subject: [PATCH] feat: add serverExternals option to CloudflareOverrides and
 update build process

---
 packages/cloudflare/src/api/config.ts              | 8 ++++++++
 packages/cloudflare/src/cli/build/build.ts         | 3 ++-
 packages/cloudflare/src/cli/build/bundle-server.ts | 5 +++--
 packages/cloudflare/src/cli/commands/utils.ts      | 7 ++++++-
 4 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/packages/cloudflare/src/api/config.ts b/packages/cloudflare/src/api/config.ts
index d625f8bd8..2fc8af060 100644
--- a/packages/cloudflare/src/api/config.ts
+++ b/packages/cloudflare/src/api/config.ts
@@ -55,6 +55,11 @@ export type CloudflareOverrides = {
 	 * @default "none"
 	 */
 	routePreloadingBehavior?: RoutePreloadingBehavior;
+
+	/**
+	 * List of external modules to exclude from the server bundle.
+	 */
+	serverExternals?: string[];
 };
 
 /**
@@ -71,6 +76,7 @@ export function defineCloudflareConfig(config: CloudflareOverrides = {}): OpenNe
 		cachePurge,
 		enableCacheInterception = false,
 		routePreloadingBehavior = "none",
+		serverExternals = [],
 	} = config;
 
 	return {
@@ -106,6 +112,7 @@ export function defineCloudflareConfig(config: CloudflareOverrides = {}): OpenNe
 			},
 			assetResolver: () => assetResolver,
 		},
+		serverExternals,
 	};
 }
 
@@ -180,6 +187,7 @@ interface OpenNextConfig extends AwsOpenNextConfig {
 			maxVersionAgeDays?: number;
 		};
 	};
+	serverExternals?: string[];
 }
 
 /**
diff --git a/packages/cloudflare/src/cli/build/build.ts b/packages/cloudflare/src/cli/build/build.ts
index 8f88f637d..5b2187ea5 100644
--- a/packages/cloudflare/src/cli/build/build.ts
+++ b/packages/cloudflare/src/cli/build/build.ts
@@ -8,6 +8,7 @@ import logger from "@opennextjs/aws/logger.js";
 import type { Unstable_Config } from "wrangler";
 
 import { OpenNextConfig } from "../../api/config.js";
+import { BuildOptions } from "../commands/utils.js";
 import type { ProjectOptions } from "../project-options.js";
 import { bundleServer } from "./bundle-server.js";
 import { compileCacheAssetsManifestSqlFile } from "./open-next/compile-cache-assets-manifest.js";
@@ -29,7 +30,7 @@ import { getVersion } from "./utils/version.js";
  * @param projectOpts The options for the project
  */
 export async function build(
-	options: buildHelper.BuildOptions,
+	options: BuildOptions,
 	config: OpenNextConfig,
 	projectOpts: ProjectOptions,
 	wranglerConfig: Unstable_Config
diff --git a/packages/cloudflare/src/cli/build/bundle-server.ts b/packages/cloudflare/src/cli/build/bundle-server.ts
index 954024513..96fa8efbe 100644
--- a/packages/cloudflare/src/cli/build/bundle-server.ts
+++ b/packages/cloudflare/src/cli/build/bundle-server.ts
@@ -3,11 +3,12 @@ import { readFile, writeFile } from "node:fs/promises";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 
-import { type BuildOptions, getPackagePath } from "@opennextjs/aws/build/helper.js";
+import { getPackagePath } from "@opennextjs/aws/build/helper.js";
 import { ContentUpdater } from "@opennextjs/aws/plugins/content-updater.js";
 import { build, type Plugin } from "esbuild";
 
 import { getOpenNextConfig } from "../../api/config.js";
+import { BuildOptions } from "../commands/utils.js";
 import type { ProjectOptions } from "../project-options.js";
 import { patchVercelOgLibrary } from "./patches/ast/patch-vercel-og-library.js";
 import { patchWebpackRuntime } from "./patches/ast/webpack-runtime.js";
@@ -111,7 +112,7 @@ export async function bundleServer(buildOpts: BuildOptions, projectOpts: Project
 			// Apply updater updates, must be the last plugin
 			updater.plugin,
 		] as Plugin[],
-		external: ["./middleware/handler.mjs"],
+		external: ["./middleware/handler.mjs", ...buildOpts.config.serverExternals || []],
 		alias: {
 			// Workers have `fetch` so the `node-fetch` polyfill is not needed
 			"next/dist/compiled/node-fetch": path.join(buildOpts.outputDir, "cloudflare-templates/shims/fetch.js"),
diff --git a/packages/cloudflare/src/cli/commands/utils.ts b/packages/cloudflare/src/cli/commands/utils.ts
index 232b74373..485051f24 100644
--- a/packages/cloudflare/src/cli/commands/utils.ts
+++ b/packages/cloudflare/src/cli/commands/utils.ts
@@ -91,9 +91,14 @@ export function getNormalizedOptions(config: OpenNextConfig, buildDir = nextAppD
 	const options = normalizeOptions(config, openNextDistDir, buildDir);
 	logger.setLevel(options.debug ? "debug" : "info");
 
-	return options;
+	return {
+		...options,
+		config,
+	};
 }
 
+export type BuildOptions = ReturnType<typeof getNormalizedOptions>;
+
 /**
  * Read the Wrangler config.
  *