diff --git a/app.js b/app.js
index b997d49e..ada97f20 100644
--- a/app.js
+++ b/app.js
@@ -37,7 +37,6 @@ let util;
 let dir;
 let log;
 let pre;
-let alt;
 
 const EventEmitter = require('events');
 class AppEmitter extends EventEmitter {}
@@ -65,7 +64,6 @@ function init(mod) {
     startTime = time();
     lastmod = mod.util.lastmod;
     logger = mod.log;
-    alt = ENV.alt;
     pre = ENV.pre || mod.meta.pre;
     debug = ENV.debug || mod.meta.debug;
     oversion = ENV.over || mod.meta.over;
@@ -80,10 +78,6 @@ function init(mod) {
     dversion = debug ? `_${version}` : version;
     forceUseCache = ENV.cache ? true : false;
 
-    if (!ENV.electron) {
-        generateDevices();
-    }
-
     if (pre) {
         for (let [k,v] of Object.entries(productionMap)) {
             productionMap[`${pre}${k}`] = `${pre}${v}`;
@@ -142,7 +136,8 @@ function init(mod) {
             return "reload";
         });
     }
-    mod.add(rewriteHtmlVersion);
+    mod.add(addAppHeaders);
+    mod.static("/lib/", "alt");
     mod.static("/lib/", "src");
     mod.static("/obj/", "web/obj");
     mod.static("/font/", "web/font");
@@ -194,28 +189,26 @@ function init(mod) {
         }
     }
 
-    if (alt) {
-        for (let [ key, val ] of Object.entries(append)) {
-            let src = `src/main/${key}.js`;
-            if (!fs.existsSync(src)) {
-                logger.log('missing:', src);
-                continue;
-            }
-            fs.mkdirSync(`alt/main`, { recursive: true });
-            let body = fs.readFileSync(src);
-            fs.writeFileSync(`alt/main/${key}.js`, body + val);
-            if (true) {
-                // packed
-                src= `src/pack/${key}-main.js`;
-                if (!fs.existsSync(src)) {
-                    logger.log('missing:', src);
-                    continue;
-                }
-                fs.mkdirSync(`alt/pack`, { recursive: true });
-                body = fs.readFileSync(src);
-                fs.writeFileSync(`alt/pack/${key}-main.js`, body + val);
-            }
+    // create alt artifacts with module extensions
+    logger.log('create alt artifacts');
+    for (let [ key, val ] of Object.entries(append)) {
+        let src = `src/main/${key}.js`;
+        if (!fs.existsSync(src)) {
+            logger.log('missing:', src);
+            continue;
         }
+        fs.mkdirSync(`alt/main`, { recursive: true });
+        let body = fs.readFileSync(src);
+        fs.writeFileSync(`alt/main/${key}.js`, body + val);
+
+        src= `src/pack/${key}-main.js`;
+        if (!fs.existsSync(src)) {
+            logger.log('missing:', src);
+            continue;
+        }
+        fs.mkdirSync(`alt/pack`, { recursive: true });
+        body = fs.readFileSync(src);
+        fs.writeFileSync(`alt/pack/${key}-main.js`, body + val);
     }
 };
 
@@ -440,28 +433,6 @@ function serveWasm(req, res, next) {
     }
 }
 
-// pack/concat device script strings to inject into /code/ scripts
-function generateDevices() {
-    let root = PATH.join(dir,"src","kiri","dev");
-    let devs = {};
-    fs.readdirSync(root).forEach(type => {
-        let map = devs[type] = devs[type] || {};
-        fs.readdirSync(PATH.join(root,type)).forEach(device => {
-            let deviceName = device.endsWith('.json')
-                ? device.substring(0,device.length-5)
-                : device;
-            map[deviceName] = JSON.parse(fs.readFileSync(PATH.join(root,type,device)));
-        });
-    });
-    let dstr = JSON.stringify(devs);
-    util.mkdir(PATH.join(dir,"src","pack"));
-    fs.writeFileSync(PATH.join(dir,"src","pack","kiri-devs.js"), `export const devices = ${dstr};`);
-    if (alt) {
-        fs.mkdirSync('alt/pack', { recursive: true });
-        fs.writeFileSync(PATH.join(dir,"alt","pack","kiri-devs.js"), `export const devices = ${dstr};`);
-    }
-}
-
 function minify(code) {
     let mini = uglify.minify(code.toString(), {
         compress: {
@@ -585,7 +556,7 @@ function cookieValue(cookie,key) {
     }
 }
 
-function rewriteHtmlVersion(req, res, next) {
+function addAppHeaders(req, res, next) {
     if ([
         "/kiri/",
         "/mesh/",
@@ -599,37 +570,6 @@ function rewriteHtmlVersion(req, res, next) {
     ].indexOf(req.app.path) >= 0) {
         addCorsHeaders(req, res);
     }
-    if ([
-        "/lib/main/kiri.js",
-        "/lib/main/mesh.js"
-    ].indexOf(req.app.path) >= 0) {
-        addCorsHeaders(req, res);
-        // const data = append[req.app.path.split('/')[3].split('.')[0]];
-        const data = append[req.app.path.split('.')[0].split('/').pop()];
-
-        if (!data) return next();
-        if (debug) logger.log({ append: req.app.path, data: data.length });
-
-        const real_write = res.write;
-        const real_end = res.end;
-        let body = '';
-
-        res.write = function (chunk, encoding) {
-            body += chunk.toString(encoding);
-        };
-
-        res.end = function (chunk, encoding) {
-            if (chunk) {
-                body += chunk.toString(encoding);
-            }
-            body += data;
-            res.setHeader('Content-Length', Buffer.byteLength(body));
-            res.setHeader('Content-Type', "application/javascript; charset=utf-8");
-            real_write.call(res, body);
-            real_end.call(res);
-        };
-    }
-
     next();
 }
 
diff --git a/bin/esbuild.config.mjs b/bin/esbuild.config.mjs
index 26a4315a..1a55e3e8 100644
--- a/bin/esbuild.config.mjs
+++ b/bin/esbuild.config.mjs
@@ -1,5 +1,6 @@
 import { build, transform } from 'esbuild';
 import fs from 'fs/promises';
+import path from 'path';
 import glob from 'fast-glob';
 
 // Get build mode from command line argument
@@ -38,6 +39,30 @@ async function appendExtraModules(extras, outfile, minify = false) {
     console.log(`Appended ${files.length} module(s) to ${outfile}`);
 }
 
+async function generateDevices(dir = '') {
+    let root = path.join(dir, "src", "kiri", "dev");
+    let devs = {};
+    let files = await fs.readdir(root);
+    for (let type of files) {
+        let map = devs[type] = devs[type] || {};
+        let devices = await fs.readdir(path.join(root, type));
+        for (let device of devices) {
+            let deviceName = device.endsWith('.json')
+                ? device.substring(0, device.length - 5)
+                : device;
+            map[deviceName] = JSON.parse(await fs.readFile(path.join(root, type, device)));
+        }
+    }
+    let dstr = JSON.stringify(devs);
+    fs.mkdir(path.join(dir, "src", "pack"), { recursive: true });
+    await fs.writeFile(path.join(dir, "src", "pack", "kiri-devs.js"), `export const devices = ${dstr};`);
+    if (true) {
+        // create alt artifacts
+        await fs.mkdir('alt/pack', { recursive: true });
+        await fs.writeFile(path.join(dir, "alt", "pack", "kiri-devs.js"), `export const devices = ${dstr};`);
+    }
+}
+
 const logOverride = {
     'duplicate-class-member': 'silent',
     'duplicate-object-key': 'silent',
@@ -72,6 +97,9 @@ const rec = {
 
 async function buildApp() {
     try {
+        // Concatenate kiri devices
+        generateDevices();
+
         // Bundle mesh main app
         await build(Object.assign({}, rec, {
             entryPoints: [ 'src/main/mesh.js' ],
diff --git a/package.json b/package.json
index bedc9966..23ee11a5 100644
--- a/package.json
+++ b/package.json
@@ -36,7 +36,7 @@
     },
     "dependencies": {
         "@fortawesome/fontawesome-free": "^6.1.1",
-        "@gridspace/app-server": "github:gridspace/app-server#v0.0.19",
+        "@gridspace/app-server": "github:gridspace/app-server#v0.0.20",
         "@gridspace/basic-ftp": "github:gridspace/basic-ftp#v5.0.5-gridspace",
         "@gridspace/net-level-client": "^0.2.3",
         "@gridspace/raster-path": "^1.0.6",
@@ -57,7 +57,7 @@
         "npm": "^11.4.2",
         "prettier": "^3.5.3",
         "react-responsive-carousel": "^3.2.23",
-        "serve-static": "^1.14.1",
+        "serve-static": "^2.2.0",
         "three": "^0.178.0",
         "three-mesh-bvh": "^0.7.6",
         "uglify-js": "3.14.5",
@@ -103,8 +103,8 @@
         "dryrun": "gs-app-server --debug --single --alt --dryrun",
         "mac-verify": "spctl --assess -vv --type install dist/*/*.app",
         "mk-links": "find src web -type l | xargs -I{} sh -c 'echo \"{},$(readlink {})\"' > conf/links.csv",
-        "pack-dev": "npm run dryrun && npm run webpack-src && npm run dryrun && npm run bundle:dev",
-        "pack-prod": "npm run dryrun && npm run webpack-src prod && npm run dryrun && npm run bundle",
+        "pack-dev": "npm run webpack-src && npm run dryrun && npm run bundle:dev",
+        "pack-prod": "npm run webpack-src prod && npm run dryrun && npm run bundle",
         "postbuild": "node bin/electron-post.js",
         "prebuild": "npm run setup && npm run pack-dev prod && node bin/electron-pre.js",
         "preinstall": "node bin/install-pre.js",