diff --git a/index.js b/index.js
index 43cdbd3..279c55b 100644
--- a/index.js
+++ b/index.js
@@ -2,7 +2,7 @@ const fs = require("fs");
 const util = require("util");
 const vm = require("node:vm");
 const path = require("path");
-require('dotenv').config()
+require("dotenv").config();
 const express = require("express");
 const session = require("express-session");
 const fileUpload = require("express-fileupload");
@@ -19,7 +19,7 @@ const model = require("./db");
 const PORT = process.env.PORT || 3000;
 
 const db = model.db;
-const wsRouter = express.Router()
+const wsRouter = express.Router();
 
 let viewpath = path.join(__dirname, "views");
 let eta = new Eta({ views: viewpath, cache: false, autoEscape: true });
@@ -36,7 +36,12 @@ let routeIndex = Object.freeze({
 });
 const wsConnections = new Map();
 
-const INSPECT_OPTS = { showHidden: false, depth: null, colors: false, compact: false };
+const INSPECT_OPTS = {
+  showHidden: false,
+  depth: null,
+  colors: false,
+  compact: false,
+};
 function inspectArgs(args) {
   return args.map((v) => util.inspect(v, INSPECT_OPTS)).join(" ");
 }
@@ -67,8 +72,8 @@ app.use(
 app.use("/", wsRouter);
 app.use("/plumbing", require("./plumbing"));
 
-const vapidPublicKey = process.env.VAPID_PUBLIC_KEY
-const vapidPrivateKey = process.env.VAPID_PRIVATE_KEY
+const vapidPublicKey = process.env.VAPID_PUBLIC_KEY;
+const vapidPrivateKey = process.env.VAPID_PRIVATE_KEY;
 
 // Configure web-push with your VAPID details
 webPush.setVapidDetails(
@@ -77,7 +82,37 @@ webPush.setVapidDetails(
   vapidPrivateKey,
 );
 
-async function saveFile(structureId, req, uploadedFile, asset=false) {
+// KaiOS's push service only understands the legacy draft `aesgcm` content
+// encoding; everyone else (iOS, Chrome, Firefox, modern Safari) uses the
+// RFC 8291 standard `aes128gcm`, which is web-push's default. The subscription
+// endpoint hostname tells us which is which, so we pick per-subscription and
+// keep the standard as the default for anything we don't recognize.
+const LEGACY_AESGCM_HOSTS = ["push.kaiostech.com", "kai.jiophone.net"];
+
+function pushEncodingFor(subscription) {
+  try {
+    const host = new URL(subscription.endpoint).hostname;
+    return LEGACY_AESGCM_HOSTS.some((h) => host === h || host.endsWith("." + h))
+      ? "aesgcm"
+      : "aes128gcm";
+  } catch {
+    return "aes128gcm";
+  }
+}
+
+// Transparent drop-in for the web-push module handed to structures via
+// require('push'): identical API (setVapidDetails, generateVAPIDKeys, …) via
+// the prototype chain, but sendNotification auto-selects the content encoding
+// from the subscription endpoint unless the caller passed one explicitly.
+const push = Object.create(webPush);
+push.sendNotification = function (subscription, payload, options = {}) {
+  return webPush.sendNotification(subscription, payload, {
+    ...options,
+    contentEncoding: options.contentEncoding || pushEncodingFor(subscription),
+  });
+};
+
+async function saveFile(structureId, req, uploadedFile, asset = false) {
   const name = uploadedFile.name;
   const [mime_type, mime_subtype] = uploadedFile.mimetype.split("/");
   // structureId may arrive as a number (route.structure_id is an INTEGER) when
@@ -103,7 +138,7 @@ async function saveFile(structureId, req, uploadedFile, asset=false) {
   let file = model.getFile(id);
   file.url = prefixUrlWithHost(req, file.path);
 
-  return file
+  return file;
 }
 
 // A console whose log() mirrors to stdout and to the structure's logs table.
@@ -120,7 +155,12 @@ function makeConsole(structureId, routeId) {
 // returning its exports. Each library runs in its own context so nothing
 // leaks between dbs.
 function runLibrary(sql, librarySource, console) {
-  const libContext = vm.createContext({ sql, console, fetch, module: { exports: null } });
+  const libContext = vm.createContext({
+    sql,
+    console,
+    fetch,
+    module: { exports: null },
+  });
   vm.runInContext(librarySource, libContext);
   return libContext.module.exports;
 }
@@ -130,12 +170,15 @@ function makeLibs(structureId, console) {
   const dbs = {};
   for (let appDb of model.getDbsForStructure(structureId)) {
     const sql = model.getDbInstance(appDb.id);
-    dbs[appDb.alias] = { library: runLibrary(sql, appDb.library, console), sql };
+    dbs[appDb.alias] = {
+      library: runLibrary(sql, appDb.library, console),
+      sql,
+    };
   }
   return {
     eta: model.getTemplater(structureId),
     db: (alias) => dbs[alias],
-    push: webPush,
+    push: push,
     files: { saveFile: (...args) => saveFile(structureId, ...args) },
   };
 }
@@ -180,7 +223,6 @@ function routeWithPrefix(route) {
   return withPrefix(route.route_prefix, route.path);
 }
 
-
 function compileWebsocketHandler(route) {
   try {
     // Keep the existing WS handler context for compatibility. Restricting the
@@ -482,8 +524,7 @@ function fragmentFromPage(html) {
 // carrying provenance becomes a decorated fragment; anything else passes through.
 function decorate(html, { headInjection, source, fragment } = {}) {
   const lower = html.toLowerCase();
-  const isFullDoc =
-    lower.startsWith("<html>") || lower.startsWith("<!doctype");
+  const isFullDoc = lower.startsWith("<html>") || lower.startsWith("<!doctype");
   if (!fragment) {
     return decoratePage(html, { headInjection, source });
   }
@@ -518,10 +559,13 @@ app.post("/_bliss/render-template", (req, res) => {
     req.body?.contextId,
     templateId,
   );
-  if (!savedContext) return res.status(410).send("Template context expired; refresh the page");
+  if (!savedContext)
+    return res.status(410).send("Template context expired; refresh the page");
   const context = { ...savedContext };
   context.route = makeRoute(structure);
-  return res.type("html").send(renderTemplate(structureId, template.name, context));
+  return res
+    .type("html")
+    .send(renderTemplate(structureId, template.name, context));
 });
 
 // Provenance for a rendered response: GET routes are re-embeddable, so they
@@ -578,7 +622,11 @@ function sidebarStuff(structId) {
 }
 
 app.get("/workshop/:structure_id", (req, res) => {
-  return renderWorkshop(res, "workshop/editor", sidebarStuff(req.params.structure_id));
+  return renderWorkshop(
+    res,
+    "workshop/editor",
+    sidebarStuff(req.params.structure_id),
+  );
 });
 
 app.post("/workshop/:structure_id/clone", (req, res) => {
@@ -663,8 +711,11 @@ app.put("/workshop/:structure_id/route/:route_id", (req, res) => {
   model.updateRoute({ ...route, ...req.body });
   if (req.body.scaffold_page) {
     // TODO: make this send over scaffold page id too someday
-    const latestPage = model.getLatestScaffoldPage(req.params.route_id)
-    model.updateScaffoldPage({ ...latestPage, content: req.body.scaffold_page })
+    const latestPage = model.getLatestScaffoldPage(req.params.route_id);
+    model.updateScaffoldPage({
+      ...latestPage,
+      content: req.body.scaffold_page,
+    });
   }
   buildRoutes();
   return res.send("good");
@@ -773,9 +824,12 @@ app.get("/workshop/:structure_id/template/:template_id/preview", (req, res) => {
   context.it.route = makeRoute(struct);
 
   return res.send(
-    decorate(renderTemplate(req.params.structure_id, template.name, context.it), {
-      headInjection: struct.head_injection,
-    }),
+    decorate(
+      renderTemplate(req.params.structure_id, template.name, context.it),
+      {
+        headInjection: struct.head_injection,
+      },
+    ),
   );
 });
 
@@ -784,16 +838,16 @@ app.get("/workshop/:structure_id/route/:id", (req, res) => {
   let routePrefix = model.getStructure(req.params.structure_id).route_prefix;
   let previewUrl = null;
 
-  if (route["verb"] == "GET" ) {
+  if (route["verb"] == "GET") {
     previewUrl = routePrefix
       ? path.join(routePrefix || "", route.path)
       : route.path;
-  }
-  else {
+  } else {
     previewUrl = `/workshop/${req.params.structure_id}/route/${req.params.id}/preview`;
   }
 
-  const template = route["verb"] == "GET" ? "workshop/route" : "workshop/cud_route";
+  const template =
+    route["verb"] == "GET" ? "workshop/route" : "workshop/cud_route";
 
   return renderWorkshop(res, template, {
     route: route,
@@ -844,15 +898,13 @@ app.post("/workshop/:structure_id/files", async (req, res) => {
   const targetFile = req.files.file;
 
   try {
-    const uploadedFile = await saveFile(structure_id, req, targetFile)
+    const uploadedFile = await saveFile(structure_id, req, targetFile);
     return res.send(eta.render("workshop/file_detail", { file: uploadedFile }));
+  } catch (e) {
+    console.log(e);
+    res.status(500);
+    return res.send(e);
   }
-  catch (e) {
-    console.log(e)
-      res.status(500);
-      return res.send(e);
-  }
-
 });
 
 function prefixUrlWithHost(req, path) {
@@ -973,9 +1025,13 @@ app.all("*", async (req, res) => {
             }),
           );
         };
-        const handlerScript = new vm.Script(route.handler, { filename: `handler_${route.id}.js` });
+        const handlerScript = new vm.Script(route.handler, {
+          filename: `handler_${route.id}.js`,
+        });
         // Prepare the execution code that invokes `handler(req, res)` and awaits it
-        const executionScript = new vm.Script(`handler(req, res); `, { filename: `execution_${route.id}.js` });
+        const executionScript = new vm.Script(`handler(req, res); `, {
+          filename: `execution_${route.id}.js`,
+        });
         await handlerScript.runInContext(context);
         const result = await executionScript.runInContext(context);
       } catch (e) {