Replace propagation chain + check-device with prompt=none OAuth handshake

Client apps now do a silent OAuth round-trip (prompt=none) to account on
first visit. If user is logged in on account, they get silently logged in.
If not, the result is cached (5 min) to avoid repeated handshakes.

Grant verification now uses direct DB query instead of aiohttp HTTP calls.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

infrastructure/factory.py

@@ -123,7 +123,7 @@ def create_base_app(
         for fn in before_request_fns:
             app.before_request(fn)
 
-    # Auth state check via device cookie + account internal endpoint
+    # Auth state check via grant verification + silent OAuth handshake
     if name != "account":
         @app.before_request
         async def _check_auth_state():
@@ -134,14 +134,11 @@ def create_base_app(
 
             uid = qs.get("uid")
             grant_token = qs.get("grant_token")
-            device_id = request.cookies.get(f"{name}_did")
 
-            import os, aiohttp
             from shared.browser.app.redis_cacher import get_redis
             redis = get_redis()
-            account_internal = (os.getenv("INTERNAL_URL_ACCOUNT") or "http://account:8000").rstrip("/")
 
-            # Case 1: logged in locally — verify grant still valid
+            # Case 1: logged in — verify grant still valid (direct DB, cached)
             if uid and grant_token:
                 cache_key = f"grant:{grant_token}"
                 if redis:
@@ -154,17 +151,17 @@ def create_base_app(
                         qs.pop("cart_sid", None)
                         return
 
+                from sqlalchemy import select
+                from shared.db.session import get_session
+                from shared.models.oauth_grant import OAuthGrant
                 try:
-                    async with aiohttp.ClientSession() as http:
-                        async with http.get(
-                            f"{account_internal}/auth/internal/verify-grant",
-                            params={"token": grant_token},
-                            timeout=aiohttp.ClientTimeout(total=3),
-                        ) as resp:
-                            data = await resp.json()
-                            valid = data.get("valid", False)
+                    async with get_session() as s:
+                        grant = await s.scalar(
+                            select(OAuthGrant).where(OAuthGrant.token == grant_token)
+                        )
+                        valid = grant is not None and grant.revoked_at is None
                 except Exception:
-                    return  # account unreachable — don't log user out
+                    return  # DB error — don't log user out
 
                 if redis:
                     await redis.set(cache_key, b"ok" if valid else b"revoked", ex=60)
@@ -174,33 +171,20 @@ def create_base_app(
                     qs.pop("cart_sid", None)
                 return
 
-            # Case 2: not logged in but device cookie exists — check for auth change
-            if not uid and device_id:
-                cache_key = f"device:{name}:{device_id}"
-                if redis:
-                    cached = await redis.get(cache_key)
+            # Case 2: not logged in — prompt=none OAuth (GET, non-HTMX only)
+            if not uid and request.method == "GET":
+                if request.headers.get("HX-Request"):
+                    return
+                import time as _time
+                pnone_at = qs.get("_pnone_at")
+                if pnone_at and (_time.time() - pnone_at) < 300:
+                    return
+                device_id = request.cookies.get(f"{name}_did")
+                if device_id and redis:
+                    cached = await redis.get(f"prompt:{name}:{device_id}")
                     if cached == b"none":
-                        return  # recently checked, no auth
-                    if cached == b"active":
-                        # Auth available — trigger OAuth
-                        return redirect(f"/auth/login/?next={_quote(request.url, safe='')}")
-
-                try:
-                    async with aiohttp.ClientSession() as http:
-                        async with http.get(
-                            f"{account_internal}/auth/internal/check-device",
-                            params={"device_id": device_id, "app": name},
-                            timeout=aiohttp.ClientTimeout(total=3),
-                        ) as resp:
-                            data = await resp.json()
-                            active = data.get("active", False)
-                except Exception:
-                    return  # account unreachable — stay anonymous
-
-                if redis:
-                    await redis.set(cache_key, b"active" if active else b"none", ex=60)
-                if active:
-                    return redirect(f"/auth/login/?next={_quote(request.url, safe='')}")
+                        return
+                return redirect(f"/auth/login?prompt=none&next={_quote(request.url, safe='')}")
 
     @app.before_request
     async def _csrf_protect():

infrastructure/oauth.py

@@ -63,23 +63,44 @@ def create_oauth_blueprint(app_name: str) -> Blueprint:
     @bp.get("/login/")
     async def login():
         next_url = request.args.get("next", "/")
+        prompt = request.args.get("prompt", "")
         state = secrets.token_urlsafe(32)
         qsession["oauth_state"] = state
         qsession["oauth_next"] = next_url
 
         device_id = request.cookies.get(cookie_name, "")
         redirect_uri = app_url(app_name, "/auth/callback")
-        authorize_url = account_url(
-            f"/auth/oauth/authorize?client_id={app_name}"
+        params = (
+            f"?client_id={app_name}"
             f"&redirect_uri={redirect_uri}"
             f"&device_id={device_id}"
             f"&state={state}"
         )
+        if prompt:
+            params += f"&prompt={prompt}"
+        authorize_url = account_url(f"/auth/oauth/authorize{params}")
         return redirect(authorize_url)
 
     @bp.get("/callback")
     @bp.get("/callback/")
     async def callback():
+        # Handle prompt=none error (user not logged in on account)
+        error = request.args.get("error")
+        if error == "login_required":
+            next_url = qsession.pop("oauth_next", "/")
+            qsession.pop("oauth_state", None)
+            import time as _time
+            qsession["_pnone_at"] = _time.time()
+            device_id = request.cookies.get(cookie_name, "")
+            if device_id:
+                from shared.browser.app.redis_cacher import get_redis
+                _redis = get_redis()
+                if _redis:
+                    await _redis.set(
+                        f"prompt:{app_name}:{device_id}", b"none", ex=300
+                    )
+            return redirect(next_url)
+
         code = request.args.get("code")
         state = request.args.get("state")
         expected_state = qsession.pop("oauth_state", None)
@@ -129,6 +150,7 @@ def create_oauth_blueprint(app_name: str) -> Blueprint:
         qsession[SESSION_USER_KEY] = user_id
         if grant_token:
             qsession[GRANT_TOKEN_KEY] = grant_token
+        qsession.pop("_pnone_at", None)
 
         # Emit login activity for cart adoption
         ident = current_cart_identity()
@@ -168,6 +190,7 @@ def create_oauth_blueprint(app_name: str) -> Blueprint:
         qsession.pop(SESSION_USER_KEY, None)
         qsession.pop(GRANT_TOKEN_KEY, None)
         qsession.pop("cart_sid", None)
+        qsession.pop("_pnone_at", None)
         # Redirect through account to revoke grants + clear account session
         return redirect(account_url("/auth/sso-logout/"))