make esbuild run serverless

package-lock.json

@@ -1872,18 +1872,6 @@
         "node": ">= 0.4"
       }
     },
-    "node_modules/esbuild-wasm": {
-      "version": "0.25.12",
-      "resolved": "https://registry.npmjs.org/esbuild-wasm/-/esbuild-wasm-0.25.12.tgz",
-      "integrity": "sha512-rZqkjL3Y6FwLpSHzLnaEy8Ps6veCNo1kZa9EOfJvmWtBq5dJH4iVjfmOO6Mlkv9B0tt9WFPFmb/VxlgJOnueNg==",
-      "license": "MIT",
-      "bin": {
-        "esbuild": "bin/esbuild"
-      },
-      "engines": {
-        "node": ">=18"
-      }
-    },
     "node_modules/escalade": {
       "version": "3.2.0",
       "resolved": "https://registry.npmjs.org/escalade/-/escalade-3.2.0.tgz",
@@ -3538,7 +3526,7 @@
       "license": "MIT",
       "dependencies": {
         "@mcp-ui/server": "^5.15.0",
-        "esbuild-wasm": "^0.25.0"
+        "esbuild": "^0.25.0"
       },
       "devDependencies": {
         "@types/node": "^20.10.0",
@@ -3552,7 +3540,12 @@
         "node": ">=18.0.0"
       },
       "optionalDependencies": {
-        "esbuild": "^0.25.0"
+        "@esbuild/darwin-arm64": "^0.25.0",
+        "@esbuild/darwin-x64": "^0.25.0",
+        "@esbuild/linux-arm64": "^0.25.0",
+        "@esbuild/linux-x64": "^0.25.0",
+        "@esbuild/win32-arm64": "^0.25.0",
+        "@esbuild/win32-x64": "^0.25.0"
       },
       "peerDependencies": {
         "react": ">=18.0.0",
@@ -3599,7 +3592,6 @@
       "integrity": "sha512-bbPBYYrtZbkt6Os6FiTLCTFxvq4tt3JKall1vRwshA3fdVztsLAatFaZobhkBC8/BrPetoa0oksYoKXoG4ryJg==",
       "hasInstallScript": true,
       "license": "MIT",
-      "optional": true,
       "bin": {
         "esbuild": "bin/esbuild"
       },

packages/library/package.json

@@ -47,10 +47,15 @@
   "license": "MIT",
   "dependencies": {
     "@mcp-ui/server": "^5.15.0",
-    "esbuild-wasm": "^0.25.0"
+    "esbuild": "^0.25.0"
   },
   "optionalDependencies": {
-    "esbuild": "^0.25.0"
+    "@esbuild/linux-x64": "^0.25.0",
+    "@esbuild/linux-arm64": "^0.25.0",
+    "@esbuild/darwin-x64": "^0.25.0",
+    "@esbuild/darwin-arm64": "^0.25.0",
+    "@esbuild/win32-x64": "^0.25.0",
+    "@esbuild/win32-arm64": "^0.25.0"
   },
   "peerDependencies": {
     "react": ">=18.0.0",

packages/library/server/bundle.ts

@@ -1,38 +1,12 @@
+import * as esbuild from 'esbuild';
+
 // Cache bundled JS per entry path (only used in production)
 const bundleCache = new Map<string, string>();
 
 // In development mode, skip cache to allow hot-reloading of component changes
 const isDev = process.env.NODE_ENV !== 'production';
 
-// Dynamic esbuild loader - tries native first, falls back to wasm for serverless
+async function runBuild(entryPath: string): Promise<esbuild.BuildResult<{ write: false }>> {
-let esbuildModule: typeof import('esbuild') | null = null;
-let wasmInitialized = false;
-
-async function getEsbuild(): Promise<typeof import('esbuild')> {
-    if (esbuildModule) return esbuildModule;
-
-    // Try native esbuild first (faster, works locally)
-    try {
-        esbuildModule = await import('esbuild');
-        // Test if native binary works
-        await esbuildModule.transform('', { loader: 'js' });
-        return esbuildModule;
-    } catch {
-        // Fall back to wasm (works on serverless without native binaries)
-        const wasm = await import('esbuild-wasm');
-        if (!wasmInitialized) {
-            await wasm.initialize({
-                wasmURL: `https://unpkg.com/esbuild-wasm@${wasm.version}/esbuild.wasm`,
-            });
-            wasmInitialized = true;
-        }
-        esbuildModule = wasm as typeof import('esbuild');
-        return esbuildModule;
-    }
-}
-
-async function runBuild(entryPath: string): Promise<import('esbuild').BuildResult<{ write: false }>> {
-    const esbuild = await getEsbuild();
     return esbuild.build({
         entryPoints: [entryPath],
         bundle: true,
@@ -53,7 +27,7 @@ export async function bundleComponent(entryPath: string): Promise<string> {
         return bundleCache.get(entryPath)!;
     }
 
-    let result: import('esbuild').BuildResult<{ write: false }>;
+    let result: esbuild.BuildResult<{ write: false }>;
 
     try {
         result = await runBuild(entryPath);
@@ -67,7 +41,6 @@ export async function bundleComponent(entryPath: string): Promise<string> {
         );
         if (isServiceError) {
             // Force stop the dead service, then retry - esbuild will start fresh
-            const esbuild = await getEsbuild();
             await esbuild.stop();
             result = await runBuild(entryPath);
         } else {

yarn.lock

@@ -167,7 +167,7 @@
   dependencies:
     "@jridgewell/trace-mapping" "0.3.9"
 
-"@esbuild/darwin-x64@0.25.12":
+"@esbuild/darwin-x64@^0.25.0", "@esbuild/darwin-x64@0.25.12":
   version "0.25.12"
   resolved "https://registry.npmjs.org/@esbuild/darwin-x64/-/darwin-x64-0.25.12.tgz"
   integrity sha512-HQ9ka4Kx21qHXwtlTUVbKJOAnmG1ipXhdWTmNXiPzPfWKpXqASVcWdnf2bnL73wgjNrFXAa3yYvBSd9pzfEIpA==
@@ -711,11 +711,6 @@ es-object-atoms@^1.0.0, es-object-atoms@^1.1.1:
   dependencies:
     es-errors "^1.3.0"
 
-esbuild-wasm@^0.25.0:
-  version "0.25.12"
-  resolved "https://registry.npmjs.org/esbuild-wasm/-/esbuild-wasm-0.25.12.tgz"
-  integrity sha512-rZqkjL3Y6FwLpSHzLnaEy8Ps6veCNo1kZa9EOfJvmWtBq5dJH4iVjfmOO6Mlkv9B0tt9WFPFmb/VxlgJOnueNg==
-
 esbuild@^0.25.0:
   version "0.25.12"
   resolved "https://registry.npmjs.org/esbuild/-/esbuild-0.25.12.tgz"
@@ -1044,6 +1039,8 @@ mcp-ui-kit@*, "mcp-ui-kit@file:/Users/fedjens/projects/mcp-ui-kit/packages/libra
   resolved "file:packages/library"
   dependencies:
     "@mcp-ui/server" "^5.15.0"
+    esbuild-wasm "^0.25.0"
+  optionalDependencies:
     esbuild "^0.25.0"
 
 media-typer@^1.1.0: