diff --git a/astro.config.mjs b/astro.config.mjs
index 0ba1893..b70d622 100644
--- a/astro.config.mjs
+++ b/astro.config.mjs
@@ -1,10 +1,7 @@
 import { defineConfig } from "astro/config";
+import cozyBuild from './plugins/cozy-build.ts';
 
 import node from "@astrojs/node";
-import { readFile, writeFile } from 'node:fs/promises';
-import { fileURLToPath } from 'node:url';
-
-let assets = []
 
 // https://astro.build/config
 export default defineConfig({
@@ -13,19 +10,6 @@ export default defineConfig({
     mode: "middleware"
   }),
   integrations: [
-    {
-      'name': 'astro-cozy-build',
-      'hooks': {
-        'astro:build:ssr': (options) => {
-          assets = options.manifest.assets.filter(ass => !ass.includes('sw.js'))
-          console.log('build-cozy', assets)
-        },
-        'astro:build:done': async ({dir}) => {
-          const outFile = fileURLToPath(new URL('./sw.js', dir));
-          const originalScript = await readFile(outFile);
-          await writeFile(outFile, 'const assets = ' + JSON.stringify(assets) + ';' + originalScript);
-        }
-      }
-    }
+    cozyBuild()
   ]
 });
\ No newline at end of file
diff --git a/plugins/cozy-build.ts b/plugins/cozy-build.ts
new file mode 100644
index 0000000..1cb9041
--- /dev/null
+++ b/plugins/cozy-build.ts
@@ -0,0 +1,34 @@
+import { AstroIntegration } from 'astro';
+import { readFile, writeFile } from 'node:fs/promises';
+import { fileURLToPath } from 'node:url';
+
+let assets: string[] = [];
+
+function getBuildTime() {
+    const today = new Date();
+    const dd = String(today.getDate()).padStart(2, '0');
+    const mm = String(today.getMonth() + 1).padStart(2, '0'); //January is 0!
+    const yyyy = today.getFullYear();
+    const time = today.getTime();
+
+    return mm + dd + yyyy + time;
+}
+
+const config: AstroIntegration = {
+    'name': 'astro-cozy-build',
+    'hooks': {
+        'astro:build:ssr': ({ manifest }) => {
+            assets = manifest.assets.filter(ass => !ass.includes('sw.js'))
+            console.log('build-cozy', assets)
+        },
+        'astro:build:done': async ({ dir }) => {
+            const outFile = fileURLToPath(new URL('./sw.js', dir));
+            const originalScript = await readFile(outFile);
+            const assetsDeclaration = `const assets = ${JSON.stringify(assets)};\n`;
+            const versionDeclaration = `const version = ${JSON.stringify(getBuildTime())};\n`;
+            await writeFile(outFile, assetsDeclaration + versionDeclaration  + originalScript);
+        }
+    }
+}
+
+export default (): AstroIntegration => config;
\ No newline at end of file
diff --git a/public/sw.js b/public/sw.js
index ea45902..3a7a8c5 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -1,12 +1,13 @@
 
+const cacheName = 'cozy-reader-app-v' + (version ?? '000')
 const addResourcesToCache = async (resources) => {
-    const cache = await caches.open('cozy-reader-app-v1');
+    const cache = await caches.open(cacheName);
     console.log('adding resources to cache...', resources)
     await cache.addAll(resources);
 };
 
 const putInCache = async (request, response) => {
-    const cache = await caches.open('cozy-reader-app-v1');
+    const cache = await caches.open(cacheName);
     console.log('adding one response to cache...', request)
     await cache.put(request, response);
 };