Apple Health upload flow in the new app (parser in a worker, preview, save)

CLAUDE.md

@@ -177,6 +177,8 @@ Returns `{ url, anonKey }` for frontend initialization.
 - The Settings page is where users manage their BYOK key. A provider dropdown lets them choose Vertex AI or Claude for their own key.
 - BYOK localStorage keys: `userByokApiKey` (the key), `userByokProvider` (`vertex` or `claude`). The legacy key `userVertexApiKey` is still read for migration but new saves go to `userByokApiKey`.
 - `syncChatMode()` no longer gates Vertex/Claude on server key availability — both are always selectable. Only BYOK requires a saved key.
+- The new app's upload flow (`web/src/features/upload/`, parser in `web/src/lib/health/`): `parseExport` streams XML chunks into per-day running totals (O(days) memory) inside a Web Worker; `fileToChunks` reads `.xml` or streams the health XML entry out of `.zip` with `fflate`; `repository.ts` saves under RLS and keeps the user's existing `events`. `parity.test.ts` extracts the classic `parseHealthXML` from `index.html` and asserts identical output, so the two parsers must stay in step until the classic one is removed.
+- `/api/health` and `/api/chat` answer `503` (not "No health data found") when Supabase cannot be queried.
 
 ---
 

README.md

@@ -127,6 +127,10 @@ Open it with the trailing slash (`/app/`).
 
 If the classic page is missing at `http://localhost:3000/` under `vercel dev`, build it first with `npm --prefix web run build && node scripts/build-site.mjs`.
 
+### Uploading Apple Health data in the new app
+
+Open `/app/upload`, drop Apple's `export.zip` (or `export.xml`) and review the preview, then press **Save**. The file is parsed in your browser by a Web Worker (see `web/src/lib/health/`), and only aggregated daily numbers are saved to your account. Re-uploading replaces your data and keeps your life events. The classic upload at `/` still works.
+
 ---
 
 ## Features

api/chat.py

@@ -4,6 +4,7 @@
 
 from api.auth import AuthError, authenticate
 from api.chat_core import (
+    HealthDataUnavailable,
     chat_with_claude,
     chat_with_vertex,
     get_claude_model,
@@ -35,7 +36,13 @@ def do_POST(self):
         length = int(self.headers.get("Content-Length", 0))
         body = json.loads(self.rfile.read(length))
 
-        health_data = load_health_data(auth=auth)
+        try:
+            health_data = load_health_data(auth=auth)
+        except HealthDataUnavailable:
+            self._send_json(
+                {"error": "Health data is temporarily unavailable. Please try again."}, 503
+            )
+            return
         if not health_data:
             self._send_json({"reply": "No health data available."})
             return

api/chat_core.py

@@ -46,6 +46,10 @@ def get_claude_model():
     return (os.environ.get("CLAUDE_MODEL") or "").strip() or DEFAULT_CLAUDE_MODEL
 
 
+class HealthDataUnavailable(Exception):
+    """Supabase could not be queried, so we cannot say whether the user has data."""
+
+
 def fetch_supabase_health_data(auth):
     """Return the caller's own health data, else the shared demo data, else None.
 
@@ -62,14 +66,16 @@ def fetch_supabase_health_data(auth):
         f"{base}&user_id=eq.{urllib.parse.quote(auth.user_id, safe='')}", headers
     )
     if status != 200:
-        # Never mask an outage as the user's data by serving the demo row.
-        return None
+        # An outage must never look like "no data" and must never serve the demo row.
+        raise HealthDataUnavailable(f"health_data query failed with status {status}")
     if rows:
         return rows[0].get("data")
 
     # Signed in, query succeeded, no row yet: fall back to the shared demo data.
     status, rows = supabase_http.http_get_json(f"{base}&is_demo=eq.true", headers)
-    if status == 200 and rows:
+    if status != 200:
+        raise HealthDataUnavailable(f"demo data query failed with status {status}")
+    if rows:
         data = rows[0].get("data")
         if isinstance(data, dict):
             return {**data, "is_demo": True}

api/health.py

@@ -2,7 +2,7 @@
 import json
 
 from api.auth import AuthError, authenticate
-from api.chat_core import load_health_data
+from api.chat_core import HealthDataUnavailable, load_health_data
 
 
 class handler(BaseHTTPRequestHandler):
@@ -13,7 +13,13 @@ def do_GET(self):
             self._send_json({"error": str(e)}, 401)
             return
 
-        data = load_health_data(auth=auth)
+        try:
+            data = load_health_data(auth=auth)
+        except HealthDataUnavailable:
+            self._send_json(
+                {"error": "Health data is temporarily unavailable. Please try again."}, 503
+            )
+            return
         if data is None:
             data = {"error": "No health data found."}
         self._send_json(data)