diff --git a/public/sw.js b/public/sw.js
index 510aecf..0da426d 100644
--- a/public/sw.js
+++ b/public/sw.js
@@ -1,66 +1,349 @@
-// defensive IDB write that matches localforage shape and falls back to alternate put form.
-// Assumes openLFDB() returns an open IDB database and STORE_NAME constant exists.
+// /sw.js
+// Service worker that uses localforage inside the worker to read/write 'threads_v1'.
+// It tees streaming responses and continuously overwrites the last thread with accumulated assistant text.
 
-async function writeThreadsToLF(threadsArr) {
-  const key = THREADS_KEY; // 'threads_v1'
-  // 1) sanitize to ensure structured-cloneable data
-  let safeValue;
+try {
+  importScripts('https://cdn.jsdelivr.net/npm/localforage@1.10.0/dist/localforage.min.js');
+} catch (e) {
+  // importScripts may throw if blocked by CSP — we'll detect later and broadcast error
+}
+
+// Config / constants
+const TARGET_SUBSTRING = 'openrouter.ai/api/v1/chat/completions';
+const THREADS_KEY = 'threads_v1';
+const SAVE_BYTES_THRESHOLD = 6 * 1024;
+const SAVE_TIME_THRESHOLD = 800;
+const BROADCAST_THROTTLE_MS = 600;
+
+const gid = () => Math.random().toString(36).slice(2,9) + '-' + Date.now().toString(36);
+const now = () => Date.now();
+
+let lfAvailable = (typeof localforage !== 'undefined');
+let lfLoadError = lfAvailable ? null : 'localforage not loaded (importScripts failed or blocked)';
+
+async function broadcast(msg) {
   try {
-    safeValue = JSON.parse(JSON.stringify(threadsArr || []));
-  } catch (err) {
-    // fallback: attempt to shallow-clone minimal info
-    safeValue = (threadsArr || []).map(t => ({
-      id: t && t.id,
-      title: t && t.title,
-      updatedAt: t && t.updatedAt,
-      messages: Array.isArray(t && t.messages) ? t.messages.map(m => ({ id: m.id, role: m.role, content: String(m.content || '') })) : []
-    }));
-  }
+    const clients = await self.clients.matchAll({ includeUncontrolled: true, type: 'window' });
+    for (const c of clients) {
+      try { c.postMessage(msg); } catch (_) {}
+    }
+  } catch (_) {}
+}
 
-  const db = await openLFDB(); // your existing helper
-  const tx = db.transaction(STORE_NAME, 'readwrite');
-  const store = tx.objectStore(STORE_NAME);
+function logDebug(text) {
+  // console and broadcast
+  try { console.log('[sw] ' + text); } catch {}
+  broadcast({ type: 'sw-debug-log', ts: now(), text: String(text) });
+}
 
-  // Try the localforage-native format first: object with `key` and `value`
+/** sanitize to structured-cloneable value */
+function sanitizeForIDB(v) {
   try {
-    await new Promise((resolve, reject) => {
-      const req = store.put({ key, value: safeValue });
-      req.onsuccess = () => resolve(true);
-      req.onerror = (e) => reject(e.target?.error || new Error('put(key,value) failed'));
-    });
-    // success
-    await tx.complete?.catch(()=>{}).catch(()=>{}); // noop if not present
-    return { ok: true, method: 'put({key,value})' };
-  } catch (err1) {
-    // fallback: try objectStore.put(value, key)
+    return JSON.parse(JSON.stringify(v));
+  } catch (e) {
+    // shallow fallback - keep minimal properties
     try {
-      // create a fresh transaction (previous tx is probably aborted)
-      const tx2 = db.transaction(STORE_NAME, 'readwrite');
-      const store2 = tx2.objectStore(STORE_NAME);
-      await new Promise((resolve, reject) => {
-        const req = store2.put(safeValue, key);
-        req.onsuccess = () => resolve(true);
-        req.onerror = (e) => reject(e.target?.error || new Error('put(value, key) failed'));
-      });
-      await tx2.complete?.catch(()=>{}).catch(()=>{});
-      return { ok: true, method: 'put(value, key)' };
-    } catch (err2) {
-      // final fallback: store stringified JSON (always cloneable)
-      try {
-        const tx3 = db.transaction(STORE_NAME, 'readwrite');
-        const store3 = tx3.objectStore(STORE_NAME);
-        await new Promise((resolve, reject) => {
-          const req = store3.put({ key, value: JSON.stringify(safeValue) });
-          req.onsuccess = () => resolve(true);
-          req.onerror = (e) => reject(e.target?.error || new Error('put string fallback failed'));
-        });
-        await tx3.complete?.catch(()=>{}).catch(()=>{});
-        return { ok: true, method: 'put({key, value: JSON.stringify(...)})', note: 'value stored as JSON string' };
-      } catch (err3) {
-        // give up and return the most informative error
-        const msg = 'writeThreadsToLF failed: ' + (err3?.message || err2?.message || err1?.message || String(err1));
-        throw new Error(msg);
-      }
+      if (!Array.isArray(v)) return [];
+      return v.map(t => ({
+        id: t && t.id,
+        title: t && t.title,
+        updatedAt: t && t.updatedAt,
+        messages: Array.isArray(t && t.messages) ? t.messages.map(m => ({ id: m && m.id, role: m && m.role, content: String((m && m.content) || '') })) : []
+      }));
+    } catch (_) {
+      return [];
     }
   }
 }
+
+/** write threads with localforage.setItem and fallback to string if needed */
+async function writeThreadsViaLocalForage(threadsArr) {
+  if (!lfAvailable) throw new Error('localforage unavailable: ' + lfLoadError);
+  const safeVal = sanitizeForIDB(threadsArr || []);
+  try {
+    await localforage.setItem(THREADS_KEY, safeVal);
+    return { ok: true, method: 'localforage.setItem', storedAs: 'object' };
+  } catch (err1) {
+    // fallback: store as JSON string (always cloneable)
+    try {
+      await localforage.setItem(THREADS_KEY, JSON.stringify(safeVal));
+      return { ok: true, method: 'localforage.setItem(stringified)', storedAs: 'string' };
+    } catch (err2) {
+      // both failed
+      throw new Error('setItem failed: ' + (err2 && err2.message ? err2.message : String(err1)));
+    }
+  }
+}
+
+async function readThreadsViaLocalForage() {
+  if (!lfAvailable) throw new Error('localforage unavailable: ' + lfLoadError);
+  try {
+    const v = await localforage.getItem(THREADS_KEY);
+    // if value is a JSON string (fallback), try parse
+    if (typeof v === 'string') {
+      try { const parsed = JSON.parse(v); return Array.isArray(parsed) ? parsed : []; } catch { return []; }
+    }
+    return Array.isArray(v) ? v : [];
+  } catch (err) {
+    throw err;
+  }
+}
+
+/* pick last thread heuristic (newest updatedAt) */
+function pickLastThread(threads) {
+  if (!threads || threads.length === 0) return null;
+  const sorted = [...threads].sort((a,b) => (b.updatedAt||0) - (a.updatedAt||0));
+  return sorted[0];
+}
+
+/* upsert assistant message with sw_streamId into thread object */
+function upsertAssistantInThreadObj(threadObj, streamId, text) {
+  threadObj.updatedAt = now();
+  threadObj.messages = threadObj.messages || [];
+  for (let i = threadObj.messages.length - 1; i >= 0; i--) {
+    const m = threadObj.messages[i];
+    if (m && m.sw_streamId === streamId) {
+      m.content = text;
+      m.contentParts = [{ type:'text', text }];
+      m.updatedAt = now();
+      m._sw_savedAt = now();
+      return threadObj;
+    }
+  }
+  // append
+  const msg = {
+    id: 'swmsg-' + gid(),
+    role: 'assistant',
+    content: text,
+    contentParts: [{ type:'text', text }],
+    kind: 'assistant',
+    sw_saved: true,
+    sw_streamId: streamId,
+    createdAt: now(),
+    updatedAt: now(),
+    _sw_savedAt: now()
+  };
+  threadObj.messages.push(msg);
+  return threadObj;
+}
+
+/* write helper used while streaming */
+async function flushToLastThreadUsingLF(streamId, accumulated, meta) {
+  // read threads via localforage, update last thread, write back via localforage
+  try {
+    const threads = await readThreadsViaLocalForage();
+    let thread = pickLastThread(threads);
+    const createdAt = now();
+    if (!thread) {
+      thread = { id: 'sw-thread-' + gid(), title: 'Missed while backgrounded', pinned:false, updatedAt: createdAt, messages: [] };
+      threads.unshift(thread);
+    }
+    upsertAssistantInThreadObj(thread, streamId, accumulated);
+    const writeRes = await writeThreadsViaLocalForage(threads);
+    return { ok: true, threadId: thread.id, writeRes };
+  } catch (err) {
+    // propagate error
+    return { ok: false, error: String(err && err.message ? err.message : err) };
+  }
+}
+
+/* lifecycle */
+self.addEventListener('install', ev => { self.skipWaiting(); });
+self.addEventListener('activate', ev => { ev.waitUntil(self.clients.claim()); });
+
+/* in-memory state */
+const state = { totalIntercepted: 0, activeStreams: {}, lastStream: null };
+
+/* fetch handler */
+self.addEventListener('fetch', event => {
+  try {
+    const url = String(event.request.url || '');
+    if (!url.includes(TARGET_SUBSTRING)) return; // not relevant
+    event.respondWith((async () => {
+      const upstream = await fetch(event.request);
+      if (!upstream || !upstream.body) return upstream;
+
+      const streamId = 'sw-' + gid();
+      const meta = { url, startedAt: now(), bytes: 0, status: 'started' };
+      state.totalIntercepted = (state.totalIntercepted || 0) + 1;
+      state.activeStreams[streamId] = meta;
+      broadcast({ type: 'sw-intercept-start', streamId, meta });
+
+      const [clientStream, swStream] = upstream.body.tee();
+
+      const saveTask = (async () => {
+        const reader = swStream.getReader();
+        const decoder = new TextDecoder('utf-8');
+        let acc = '';
+        let sinceBytes = 0;
+        let lastSaveAt = 0;
+        let lastBroadcastAt = 0;
+
+        async function maybeFlush(force = false) {
+          const nowMs = now();
+          if (!force && sinceBytes < SAVE_BYTES_THRESHOLD && (nowMs - lastSaveAt) < SAVE_TIME_THRESHOLD) return;
+          // attempt localforage write
+          const res = await flushToLastThreadUsingLF(streamId, acc, { bytes: meta.bytes });
+          lastSaveAt = nowMs;
+          sinceBytes = 0;
+          if (res.ok) {
+            const now2 = Date.now();
+            if (now2 - lastBroadcastAt > BROADCAST_THROTTLE_MS) {
+              lastBroadcastAt = now2;
+              broadcast({ type:'sw-intercept-progress', streamId, meta: { bytes: meta.bytes, savedAt: lastSaveAt, snippet: acc.slice(-1024), threadId: res.threadId, writeRes: res.writeRes } });
+            }
+          } else {
+            broadcast({ type:'sw-intercept-error', streamId, meta: { error: res.error } });
+          }
+        }
+
+        try {
+          while (true) {
+            const { value, done } = await reader.read();
+            if (done) break;
+            let chunk = '';
+            try { chunk = decoder.decode(value, { stream: true }); } catch (e) { chunk = ''; }
+            acc += chunk;
+            const bytes = value ? (value.byteLength || 0) : chunk.length;
+            meta.bytes += bytes;
+            sinceBytes += bytes;
+            // flush according to thresholds
+            await maybeFlush(false);
+          }
+          // final flush
+          await maybeFlush(true);
+          meta.status = 'finished';
+          meta.endedAt = now();
+          state.lastStream = { streamId, url: meta.url, startedAt: meta.startedAt, endedAt: meta.endedAt, totalBytes: meta.bytes };
+          delete state.activeStreams[streamId];
+          broadcast({ type:'sw-intercept-end', streamId, meta: { totalBytes: meta.bytes, endedAt: meta.endedAt } });
+        } catch (err) {
+          meta.status = 'error';
+          meta.error = String(err && err.message ? err.message : err);
+          delete state.activeStreams[streamId];
+          broadcast({ type:'sw-intercept-error', streamId, meta: { error: meta.error } });
+        }
+      })();
+
+      // keep alive while saving
+      event.waitUntil(saveTask);
+
+      return new Response(clientStream, {
+        status: upstream.status,
+        statusText: upstream.statusText,
+        headers: upstream.headers
+      });
+    })());
+  } catch (err) {
+    logDebug('fetch handler top-level error: ' + (err && err.message ? err.message : String(err)));
+  }
+});
+
+/* message handler for debug commands */
+self.addEventListener('message', event => {
+  const data = event.data || {};
+  (async () => {
+    try {
+      if (data && data.type === 'PING') {
+        if (event.ports && event.ports[0]) event.ports[0].postMessage({ type:'PONG', ts: now(), ok:true });
+        else broadcast({ type:'PONG', ts: now(), ok:true });
+        return;
+      }
+      if (data && data.type === 'PING_STATUS') {
+        const reply = { type:'PONG_STATUS', ts: now(), lfAvailable, lfLoadError, totalIntercepted: state.totalIntercepted||0, lastStream: state.lastStream || null };
+        if (event.ports && event.ports[0]) event.ports[0].postMessage(reply);
+        else broadcast(reply);
+        return;
+      }
+
+      if (data && data.type === 'TEST_WRITE') {
+        if (!lfAvailable) {
+          const res = { type:'TEST_WRITE_RESULT', ok:false, error: 'localforage unavailable: ' + lfLoadError };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(res); else broadcast(res);
+          return;
+        }
+        try {
+          const threads = await readThreadsViaLocalForage();
+          const tid = 'sw-test-' + gid();
+          const nowMs = now();
+          const t = { id: tid, title: 'SW test ' + new Date(nowMs).toISOString(), pinned:false, updatedAt: nowMs, messages: [ { id:'swtest-'+gid(), role:'assistant', content:'sw test write @ ' + new Date(nowMs).toISOString(), contentParts:[{type:'text',text:'sw test write'}], createdAt: nowMs, updatedAt: nowMs } ] };
+          threads.unshift(t);
+          const writeRes = await writeThreadsViaLocalForage(threads);
+          const out = { type:'TEST_WRITE_RESULT', ok:true, tid, writeRes };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        } catch (err) {
+          const out = { type:'TEST_WRITE_RESULT', ok:false, error: String(err && err.message ? err.message : err) };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        }
+        return;
+      }
+
+      if (data && data.type === 'READ_KEY') {
+        const key = data.key || THREADS_KEY;
+        if (!lfAvailable) {
+          const res = { type:'READ_KEY_RESULT', ok:false, key, error: 'localforage unavailable: ' + lfLoadError };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(res); else broadcast(res);
+          return;
+        }
+        try {
+          const val = await localforage.getItem(key);
+          const parsed = (typeof val === 'string') ? ( (() => { try { return JSON.parse(val); } catch { return val; } })() ) : val;
+          const out = { type:'READ_KEY_RESULT', ok:true, key, value: parsed };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        } catch (err) {
+          const out = { type:'READ_KEY_RESULT', ok:false, key, error: String(err && err.message ? err.message : err) };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        }
+        return;
+      }
+
+      if (data && data.type === 'LIST_SW_SAVED') {
+        if (!lfAvailable) {
+          const res = { type:'LIST_SW_SAVED_RESULT', ok:false, error: 'localforage unavailable: ' + lfLoadError };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(res); else broadcast(res);
+          return;
+        }
+        try {
+          const threads = await readThreadsViaLocalForage();
+          const found = [];
+          for (const t of (threads||[])) {
+            for (const m of (t.messages||[])) {
+              if (m && m.sw_streamId) found.push({ threadId: t.id, threadTitle: t.title, messageId: m.id, sw_streamId: m.sw_streamId, snippet: (m.content||'').slice(0,200), updatedAt: m.updatedAt });
+            }
+          }
+          const out = { type:'LIST_SW_SAVED_RESULT', ok:true, found };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        } catch (err) {
+          const out = { type:'LIST_SW_SAVED_RESULT', ok:false, error: String(err && err.message ? err.message : err) };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        }
+        return;
+      }
+
+      if (data && data.type === 'CLEAR_TESTS') {
+        if (!lfAvailable) {
+          const res = { type:'CLEAR_TESTS_RESULT', ok:false, error: 'localforage unavailable: ' + lfLoadError };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(res); else broadcast(res);
+          return;
+        }
+        try {
+          const threads = await readThreadsViaLocalForage();
+          const before = threads.length;
+          const cleaned = threads.filter(t => !(t.id && String(t.id).startsWith('sw-test-')));
+          await writeThreadsViaLocalForage(cleaned);
+          const removed = before - cleaned.length;
+          const out = { type:'CLEAR_TESTS_RESULT', ok:true, removed };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        } catch (err) {
+          const out = { type:'CLEAR_TESTS_RESULT', ok:false, error: String(err && err.message ? err.message : err) };
+          if (event.ports && event.ports[0]) event.ports[0].postMessage(out); else broadcast(out);
+        }
+        return;
+      }
+
+    } catch (err) {
+      const r = { type:'SW_ERROR', error: String(err && err.message ? err.message : err) };
+      if (event.ports && event.ports[0]) event.ports[0].postMessage(r); else broadcast(r);
+    }
+  })();
+});