diff --git a/messages/de.json b/messages/de.json
index d98ec822d..c25559632 100644
--- a/messages/de.json
+++ b/messages/de.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Mit WHOOP verbinden",
     "whoopNoCredentials": "Bitte gib oben deine API-Zugangsdaten ein, um WHOOP zu verbinden.",
     "whoopBackfillInProgress": "Dein WHOOP-Verlauf wird im Hintergrund importiert…",
+    "whoopOauthConnected": "WHOOP verbunden — die erste Synchronisierung startet im Hintergrund.",
+    "whoopOauthFailed": "WHOOP-Verbindung fehlgeschlagen",
+    "whoopOauthError": {
+      "csrf1": "Die Sicherheitsprüfung ist fehlgeschlagen, weil das Browser-Cookie fehlte. Bitte starte die Verbindung im selben Browser erneut.",
+      "state": "Die Antwort von WHOOP passte zu keiner offenen Verbindungsanfrage. Bitte starte die Verbindung erneut.",
+      "expired": "Die Verbindungsanfrage ist abgelaufen, bevor sie abgeschlossen wurde. Bitte starte die Verbindung erneut.",
+      "cross_user": "Die Antwort gehört zu einer Anfrage eines anderen Kontos. Bitte starte die Verbindung aus deinem eigenen Konto erneut.",
+      "nocode": "WHOOP hat keinen Autorisierungscode zurückgegeben. Versuche es erneut und erlaube den Zugriff im WHOOP-Dialog.",
+      "nocreds": "WHOOP ist nicht konfiguriert. Hinterlege oben deine WHOOP-OAuth-Zugangsdaten und versuche es erneut.",
+      "token": "Der Token-Austausch mit WHOOP ist fehlgeschlagen. Bitte starte die Verbindung erneut.",
+      "generic": "Unbekannter Fehler bei der Verbindung. Bitte starte die Verbindung erneut."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit & Pixel",
     "fitbitDescription": "Verbinde Google Health, um deine Fitbit- und Pixel-Watch-Werte zu synchronisieren — Gewicht, Körperfett, Ruhepuls, Sauerstoffsättigung, Herzfrequenzvariabilität und mehr.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Mit Google Health verbinden",
     "fitbitNoCredentials": "Bitte gib oben deine API-Zugangsdaten ein, um Google Health zu verbinden.",
     "fitbitBackfillInProgress": "Dein Google-Health-Verlauf wird im Hintergrund importiert…",
+    "fitbitOauthConnected": "Google Health verbunden — die erste Synchronisierung startet im Hintergrund.",
+    "fitbitOauthFailed": "Google-Health-Verbindung fehlgeschlagen",
+    "fitbitOauthError": {
+      "csrf1": "Die Sicherheitsprüfung ist fehlgeschlagen, weil das Browser-Cookie fehlte. Bitte starte die Verbindung im selben Browser erneut.",
+      "state": "Die Antwort von Google passte zu keiner offenen Verbindungsanfrage. Bitte starte die Verbindung erneut.",
+      "expired": "Die Verbindungsanfrage ist abgelaufen, bevor sie abgeschlossen wurde. Bitte starte die Verbindung erneut.",
+      "cross_user": "Die Antwort gehört zu einer Anfrage eines anderen Kontos. Bitte starte die Verbindung aus deinem eigenen Konto erneut.",
+      "nocode": "Google hat keinen Autorisierungscode zurückgegeben. Versuche es erneut und erlaube den Zugriff im Google-Dialog.",
+      "nocreds": "Google Health ist nicht konfiguriert. Hinterlege oben deine Google-OAuth-Zugangsdaten und versuche es erneut.",
+      "token": "Der Token-Austausch mit Google ist fehlgeschlagen. Bitte starte die Verbindung erneut.",
+      "generic": "Unbekannter Fehler bei der Verbindung. Bitte starte die Verbindung erneut."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/messages/en.json b/messages/en.json
index e8113d837..2d774166a 100644
--- a/messages/en.json
+++ b/messages/en.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Connect with WHOOP",
     "whoopNoCredentials": "Please enter your API credentials above to connect WHOOP.",
     "whoopBackfillInProgress": "Importing your WHOOP history in the background…",
+    "whoopOauthConnected": "WHOOP connected — the first sync starts in the background.",
+    "whoopOauthFailed": "WHOOP connection failed",
+    "whoopOauthError": {
+      "csrf1": "The security check failed because the browser cookie was missing. Please start the connection again in the same browser.",
+      "state": "The response from WHOOP did not match any open connection request. Please start the connection again.",
+      "expired": "The connection request expired before it completed. Please start the connection again.",
+      "cross_user": "The response belongs to a request from a different account. Please restart the connection from your own account.",
+      "nocode": "WHOOP did not return an authorization code. Try again and allow access in the WHOOP dialog.",
+      "nocreds": "WHOOP is not configured. Add your WHOOP OAuth credentials above and try again.",
+      "token": "The token exchange with WHOOP failed. Please start the connection again.",
+      "generic": "Unknown error while connecting. Please start the connection again."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit & Pixel",
     "fitbitDescription": "Connect Google Health to sync your Fitbit and Pixel Watch metrics — weight, body fat, resting heart rate, blood oxygen, heart-rate variability and more.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Connect with Google Health",
     "fitbitNoCredentials": "Please enter your API credentials above to connect Google Health.",
     "fitbitBackfillInProgress": "Importing your Google Health history in the background…",
+    "fitbitOauthConnected": "Google Health connected — the first sync starts in the background.",
+    "fitbitOauthFailed": "Google Health connection failed",
+    "fitbitOauthError": {
+      "csrf1": "The security check failed because the browser cookie was missing. Please start the connection again in the same browser.",
+      "state": "The response from Google did not match any open connection request. Please start the connection again.",
+      "expired": "The connection request expired before it completed. Please start the connection again.",
+      "cross_user": "The response belongs to a request from a different account. Please restart the connection from your own account.",
+      "nocode": "Google did not return an authorization code. Try again and allow access in the Google dialog.",
+      "nocreds": "Google Health is not configured. Add your Google OAuth credentials above and try again.",
+      "token": "The token exchange with Google failed. Please start the connection again.",
+      "generic": "Unknown error while connecting. Please start the connection again."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/messages/es.json b/messages/es.json
index 329cd2efe..21d3c6f22 100644
--- a/messages/es.json
+++ b/messages/es.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Conectar con WHOOP",
     "whoopNoCredentials": "Introduce tus credenciales de API arriba para conectar WHOOP.",
     "whoopBackfillInProgress": "Importando tu historial de WHOOP en segundo plano…",
+    "whoopOauthConnected": "WHOOP conectado: la primera sincronización empieza en segundo plano.",
+    "whoopOauthFailed": "Error al conectar con WHOOP",
+    "whoopOauthError": {
+      "csrf1": "La verificación de seguridad falló porque faltaba la cookie del navegador. Inicia la conexión de nuevo en el mismo navegador.",
+      "state": "La respuesta de WHOOP no coincidió con ninguna solicitud de conexión abierta. Inicia la conexión de nuevo.",
+      "expired": "La solicitud de conexión caducó antes de completarse. Inicia la conexión de nuevo.",
+      "cross_user": "La respuesta pertenece a una solicitud de otra cuenta. Reinicia la conexión desde tu propia cuenta.",
+      "nocode": "WHOOP no devolvió un código de autorización. Inténtalo de nuevo y permite el acceso en el diálogo de WHOOP.",
+      "nocreds": "WHOOP no está configurado. Añade tus credenciales OAuth de WHOOP arriba e inténtalo de nuevo.",
+      "token": "El intercambio de token con WHOOP falló. Inicia la conexión de nuevo.",
+      "generic": "Error desconocido al conectar. Inicia la conexión de nuevo."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit y Pixel",
     "fitbitDescription": "Conecta Google Health para sincronizar tus métricas de Fitbit y Pixel Watch: peso, grasa corporal, frecuencia cardíaca en reposo, saturación de oxígeno, variabilidad de la frecuencia cardíaca y más.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Conectar con Google Health",
     "fitbitNoCredentials": "Introduce tus credenciales de API arriba para conectar Google Health.",
     "fitbitBackfillInProgress": "Importando tu historial de Google Health en segundo plano…",
+    "fitbitOauthConnected": "Google Health conectado: la primera sincronización empieza en segundo plano.",
+    "fitbitOauthFailed": "Error al conectar con Google Health",
+    "fitbitOauthError": {
+      "csrf1": "La verificación de seguridad falló porque faltaba la cookie del navegador. Inicia la conexión de nuevo en el mismo navegador.",
+      "state": "La respuesta de Google no coincidió con ninguna solicitud de conexión abierta. Inicia la conexión de nuevo.",
+      "expired": "La solicitud de conexión caducó antes de completarse. Inicia la conexión de nuevo.",
+      "cross_user": "La respuesta pertenece a una solicitud de otra cuenta. Reinicia la conexión desde tu propia cuenta.",
+      "nocode": "Google no devolvió un código de autorización. Inténtalo de nuevo y permite el acceso en el diálogo de Google.",
+      "nocreds": "Google Health no está configurado. Añade tus credenciales OAuth de Google arriba e inténtalo de nuevo.",
+      "token": "El intercambio de token con Google falló. Inicia la conexión de nuevo.",
+      "generic": "Error desconocido al conectar. Inicia la conexión de nuevo."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/messages/fr.json b/messages/fr.json
index 6e8777654..e75419797 100644
--- a/messages/fr.json
+++ b/messages/fr.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Se connecter avec WHOOP",
     "whoopNoCredentials": "Veuillez saisir vos identifiants API ci-dessus pour connecter WHOOP.",
     "whoopBackfillInProgress": "Importation de votre historique WHOOP en arrière-plan…",
+    "whoopOauthConnected": "WHOOP connecté — la première synchronisation démarre en arrière-plan.",
+    "whoopOauthFailed": "Échec de la connexion à WHOOP",
+    "whoopOauthError": {
+      "csrf1": "La vérification de sécurité a échoué car le cookie du navigateur était absent. Veuillez relancer la connexion dans le même navigateur.",
+      "state": "La réponse de WHOOP ne correspondait à aucune demande de connexion en cours. Veuillez relancer la connexion.",
+      "expired": "La demande de connexion a expiré avant d'aboutir. Veuillez relancer la connexion.",
+      "cross_user": "La réponse appartient à une demande d'un autre compte. Veuillez relancer la connexion depuis votre propre compte.",
+      "nocode": "WHOOP n'a pas renvoyé de code d'autorisation. Réessayez et autorisez l'accès dans la fenêtre WHOOP.",
+      "nocreds": "WHOOP n'est pas configuré. Ajoutez vos identifiants OAuth WHOOP ci-dessus et réessayez.",
+      "token": "L'échange de jeton avec WHOOP a échoué. Veuillez relancer la connexion.",
+      "generic": "Erreur inconnue lors de la connexion. Veuillez relancer la connexion."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit et Pixel",
     "fitbitDescription": "Connectez Google Health pour synchroniser vos données Fitbit et Pixel Watch : poids, masse grasse, fréquence cardiaque au repos, saturation en oxygène, variabilité de la fréquence cardiaque et plus encore.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Se connecter à Google Health",
     "fitbitNoCredentials": "Veuillez saisir vos identifiants d'API ci-dessus pour connecter Google Health.",
     "fitbitBackfillInProgress": "Importation de votre historique Google Health en arrière-plan…",
+    "fitbitOauthConnected": "Google Health connecté — la première synchronisation démarre en arrière-plan.",
+    "fitbitOauthFailed": "Échec de la connexion à Google Health",
+    "fitbitOauthError": {
+      "csrf1": "La vérification de sécurité a échoué car le cookie du navigateur était absent. Veuillez relancer la connexion dans le même navigateur.",
+      "state": "La réponse de Google ne correspondait à aucune demande de connexion en cours. Veuillez relancer la connexion.",
+      "expired": "La demande de connexion a expiré avant d'aboutir. Veuillez relancer la connexion.",
+      "cross_user": "La réponse appartient à une demande d'un autre compte. Veuillez relancer la connexion depuis votre propre compte.",
+      "nocode": "Google n'a pas renvoyé de code d'autorisation. Réessayez et autorisez l'accès dans la fenêtre Google.",
+      "nocreds": "Google Health n'est pas configuré. Ajoutez vos identifiants OAuth Google ci-dessus et réessayez.",
+      "token": "L'échange de jeton avec Google a échoué. Veuillez relancer la connexion.",
+      "generic": "Erreur inconnue lors de la connexion. Veuillez relancer la connexion."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/messages/it.json b/messages/it.json
index bb9d81337..ca7636642 100644
--- a/messages/it.json
+++ b/messages/it.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Connetti con WHOOP",
     "whoopNoCredentials": "Inserisci le tue credenziali API qui sopra per connettere WHOOP.",
     "whoopBackfillInProgress": "Importazione dello storico WHOOP in background…",
+    "whoopOauthConnected": "WHOOP collegato — la prima sincronizzazione parte in background.",
+    "whoopOauthFailed": "Connessione a WHOOP non riuscita",
+    "whoopOauthError": {
+      "csrf1": "Il controllo di sicurezza è fallito perché il cookie del browser era assente. Riavvia la connessione nello stesso browser.",
+      "state": "La risposta di WHOOP non corrispondeva a nessuna richiesta di connessione aperta. Riavvia la connessione.",
+      "expired": "La richiesta di connessione è scaduta prima di completarsi. Riavvia la connessione.",
+      "cross_user": "La risposta appartiene a una richiesta di un altro account. Riavvia la connessione dal tuo account.",
+      "nocode": "WHOOP non ha restituito un codice di autorizzazione. Riprova e concedi l'accesso nella finestra di WHOOP.",
+      "nocreds": "WHOOP non è configurato. Aggiungi le tue credenziali OAuth di WHOOP qui sopra e riprova.",
+      "token": "Lo scambio del token con WHOOP è fallito. Riavvia la connessione.",
+      "generic": "Errore sconosciuto durante la connessione. Riavvia la connessione."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit e Pixel",
     "fitbitDescription": "Collega Google Health per sincronizzare i dati di Fitbit e Pixel Watch: peso, massa grassa, frequenza cardiaca a riposo, saturazione di ossigeno, variabilità della frequenza cardiaca e altro.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Connetti con Google Health",
     "fitbitNoCredentials": "Inserisci le tue credenziali API qui sopra per connettere Google Health.",
     "fitbitBackfillInProgress": "Importazione dello storico Google Health in background…",
+    "fitbitOauthConnected": "Google Health collegato — la prima sincronizzazione parte in background.",
+    "fitbitOauthFailed": "Connessione a Google Health non riuscita",
+    "fitbitOauthError": {
+      "csrf1": "Il controllo di sicurezza è fallito perché il cookie del browser era assente. Riavvia la connessione nello stesso browser.",
+      "state": "La risposta di Google non corrispondeva a nessuna richiesta di connessione aperta. Riavvia la connessione.",
+      "expired": "La richiesta di connessione è scaduta prima di completarsi. Riavvia la connessione.",
+      "cross_user": "La risposta appartiene a una richiesta di un altro account. Riavvia la connessione dal tuo account.",
+      "nocode": "Google non ha restituito un codice di autorizzazione. Riprova e concedi l'accesso nella finestra di Google.",
+      "nocreds": "Google Health non è configurato. Aggiungi le tue credenziali OAuth di Google qui sopra e riprova.",
+      "token": "Lo scambio del token con Google è fallito. Riavvia la connessione.",
+      "generic": "Errore sconosciuto durante la connessione. Riavvia la connessione."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/messages/pl.json b/messages/pl.json
index 09b493d64..e9c9ca571 100644
--- a/messages/pl.json
+++ b/messages/pl.json
@@ -4467,6 +4467,18 @@
     "whoopConnect": "Połącz z WHOOP",
     "whoopNoCredentials": "Wprowadź powyżej swoje dane API, aby połączyć WHOOP.",
     "whoopBackfillInProgress": "Importowanie historii WHOOP w tle…",
+    "whoopOauthConnected": "WHOOP połączony — pierwsza synchronizacja startuje w tle.",
+    "whoopOauthFailed": "Połączenie z WHOOP nie powiodło się",
+    "whoopOauthError": {
+      "csrf1": "Kontrola bezpieczeństwa nie powiodła się, ponieważ brakowało pliku cookie przeglądarki. Rozpocznij połączenie ponownie w tej samej przeglądarce.",
+      "state": "Odpowiedź z WHOOP nie pasowała do żadnego otwartego żądania połączenia. Rozpocznij połączenie ponownie.",
+      "expired": "Żądanie połączenia wygasło przed zakończeniem. Rozpocznij połączenie ponownie.",
+      "cross_user": "Odpowiedź należy do żądania z innego konta. Rozpocznij połączenie ponownie z własnego konta.",
+      "nocode": "WHOOP nie zwrócił kodu autoryzacji. Spróbuj ponownie i zezwól na dostęp w oknie WHOOP.",
+      "nocreds": "WHOOP nie jest skonfigurowany. Dodaj powyżej swoje dane OAuth WHOOP i spróbuj ponownie.",
+      "token": "Wymiana tokena z WHOOP nie powiodła się. Rozpocznij połączenie ponownie.",
+      "generic": "Nieznany błąd podczas łączenia. Rozpocznij połączenie ponownie."
+    },
     "fitbit": "Google Health",
     "fitbitTag": "Fitbit i Pixel",
     "fitbitDescription": "Połącz Google Health, aby synchronizować dane z Fitbita i Pixel Watch — wagę, tkankę tłuszczową, tętno spoczynkowe, saturację, zmienność rytmu serca i więcej.",
@@ -4494,6 +4506,18 @@
     "fitbitConnect": "Połącz z Google Health",
     "fitbitNoCredentials": "Wprowadź powyżej swoje dane uwierzytelniające API, aby połączyć Google Health.",
     "fitbitBackfillInProgress": "Importowanie historii Google Health w tle…",
+    "fitbitOauthConnected": "Google Health połączony — pierwsza synchronizacja startuje w tle.",
+    "fitbitOauthFailed": "Połączenie z Google Health nie powiodło się",
+    "fitbitOauthError": {
+      "csrf1": "Kontrola bezpieczeństwa nie powiodła się, ponieważ brakowało pliku cookie przeglądarki. Rozpocznij połączenie ponownie w tej samej przeglądarce.",
+      "state": "Odpowiedź z Google nie pasowała do żadnego otwartego żądania połączenia. Rozpocznij połączenie ponownie.",
+      "expired": "Żądanie połączenia wygasło przed zakończeniem. Rozpocznij połączenie ponownie.",
+      "cross_user": "Odpowiedź należy do żądania z innego konta. Rozpocznij połączenie ponownie z własnego konta.",
+      "nocode": "Google nie zwrócił kodu autoryzacji. Spróbuj ponownie i zezwól na dostęp w oknie Google.",
+      "nocreds": "Google Health nie jest skonfigurowany. Dodaj powyżej swoje dane OAuth Google i spróbuj ponownie.",
+      "token": "Wymiana tokena z Google nie powiodła się. Rozpocznij połączenie ponownie.",
+      "generic": "Nieznany błąd podczas łączenia. Rozpocznij połączenie ponownie."
+    },
     "integrations": {
       "withings": {
         "reconnect": {
diff --git a/src/app/api/fitbit/credentials/__tests__/route.test.ts b/src/app/api/fitbit/credentials/__tests__/route.test.ts
new file mode 100644
index 000000000..44160d2ec
--- /dev/null
+++ b/src/app/api/fitbit/credentials/__tests__/route.test.ts
@@ -0,0 +1,79 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { NextRequest } from "next/server";
+
+vi.mock("@/lib/api-handler", () => ({
+  apiHandler: <T extends (...args: unknown[]) => unknown>(fn: T) => fn,
+  requireAuth: vi.fn(async () => ({ user: { id: "u1" } })),
+}));
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    user: { findUnique: vi.fn(), update: vi.fn() },
+    fitbitConnection: { delete: vi.fn() },
+  },
+}));
+
+vi.mock("@/lib/logging/context", () => ({ annotate: vi.fn() }));
+vi.mock("@/lib/crypto", () => ({ encrypt: (s: string) => `enc:${s}` }));
+vi.mock("@/lib/auth/audit", () => ({ auditLog: vi.fn() }));
+vi.mock("@/lib/integrations/status", () => ({ markDisconnected: vi.fn() }));
+
+vi.mock("@/lib/api-response", () => ({
+  apiSuccess: (data: unknown) => ({ data, error: null, status: 200 }),
+  apiError: (error: string, status: number) => ({ data: null, error, status }),
+  safeJson: async (req: NextRequest) => {
+    try {
+      return { data: await req.json(), error: null };
+    } catch {
+      return { data: null, error: { status: 400 } };
+    }
+  },
+}));
+
+import { PUT, DELETE } from "../route";
+import { prisma } from "@/lib/db";
+import { auditLog } from "@/lib/auth/audit";
+import { markDisconnected } from "@/lib/integrations/status";
+
+const userUpdate = prisma.user.update as ReturnType<typeof vi.fn>;
+
+function req(body: unknown): NextRequest {
+  return new NextRequest("http://localhost/api/fitbit/credentials", {
+    method: "PUT",
+    body: JSON.stringify(body),
+    headers: { "Content-Type": "application/json" },
+  });
+}
+
+describe("/api/fitbit/credentials", () => {
+  beforeEach(() => vi.clearAllMocks());
+
+  it("PUT 422s on missing fields", async () => {
+    const res = (await (
+      PUT as unknown as (r: NextRequest) => Promise<{ status: number }>
+    )(req({ clientId: "" }))) as { status: number };
+    expect(res.status).toBe(422);
+    expect(userUpdate).not.toHaveBeenCalled();
+  });
+
+  it("DELETE clears credentials, audits the teardown, and parks the ledger (04-L1 parity)", async () => {
+    userUpdate.mockResolvedValue({});
+    (
+      prisma.fitbitConnection.delete as ReturnType<typeof vi.fn>
+    ).mockResolvedValue({});
+    const res = (await (DELETE as unknown as () => Promise<{ data: unknown }>)())
+      .data as { deleted: boolean };
+    expect(res.deleted).toBe(true);
+    expect(userUpdate).toHaveBeenCalledWith({
+      where: { id: "u1" },
+      data: {
+        fitbitClientIdEncrypted: null,
+        fitbitClientSecretEncrypted: null,
+      },
+    });
+    expect(auditLog).toHaveBeenCalledWith("fitbit.credentials.delete", {
+      userId: "u1",
+    });
+    expect(markDisconnected).toHaveBeenCalledWith("u1", "fitbit");
+  });
+});
diff --git a/src/app/api/fitbit/credentials/route.ts b/src/app/api/fitbit/credentials/route.ts
index 1a57ae5fe..9ecb39a6e 100644
--- a/src/app/api/fitbit/credentials/route.ts
+++ b/src/app/api/fitbit/credentials/route.ts
@@ -1,8 +1,10 @@
 import { prisma } from "@/lib/db";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { auditLog } from "@/lib/auth/audit";
 import { apiSuccess, apiError, safeJson } from "@/lib/api-response";
 import { annotate } from "@/lib/logging/context";
 import { encrypt } from "@/lib/crypto";
+import { markDisconnected } from "@/lib/integrations/status";
 import { fitbitCredentialsSchema } from "@/lib/validations/fitbit";
 import { NextRequest } from "next/server";
 import { z } from "zod/v4";
@@ -60,6 +62,10 @@ export const PUT = apiHandler(async (request: NextRequest) => {
 
 /**
  * Delete Fitbit credentials and the active connection.
+ *
+ * Audits the teardown and parks the integration ledger at `disconnected` for
+ * parity with the Polar / Oura credential-DELETE so a sensitive op leaves a
+ * uniform audit trail and the status snapshot does not linger at a stale state.
  */
 export const DELETE = apiHandler(async () => {
   const { user } = await requireAuth();
@@ -76,6 +82,8 @@ export const DELETE = apiHandler(async () => {
       fitbitClientSecretEncrypted: null,
     },
   });
+  await auditLog("fitbit.credentials.delete", { userId: user.id });
+  await markDisconnected(user.id, "fitbit");
 
   return apiSuccess({ deleted: true });
 });
diff --git a/src/app/api/integrations/status/__tests__/route.test.ts b/src/app/api/integrations/status/__tests__/route.test.ts
new file mode 100644
index 000000000..2f378f5d3
--- /dev/null
+++ b/src/app/api/integrations/status/__tests__/route.test.ts
@@ -0,0 +1,115 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+vi.mock("@/lib/api-handler", () => ({
+  apiHandler: <T extends (...args: unknown[]) => unknown>(fn: T) => fn,
+  requireAuth: vi.fn(async () => ({ user: { id: "u1" } })),
+}));
+
+vi.mock("@/lib/db", () => ({
+  prisma: {
+    user: { findUnique: vi.fn() },
+    withingsConnection: { findUnique: vi.fn(async () => null) },
+    whoopConnection: { findUnique: vi.fn(async () => null) },
+    fitbitConnection: { findUnique: vi.fn(async () => null) },
+    moodEntry: { count: vi.fn(async () => 0) },
+  },
+}));
+
+vi.mock("@/lib/logging/context", () => ({ annotate: vi.fn() }));
+
+vi.mock("@/lib/api-response", () => ({
+  apiSuccess: (data: unknown) => ({ data, error: null, status: 200 }),
+}));
+
+const ledger: Record<string, unknown> = {
+  state: "connected",
+  lastSuccessAt: null,
+  lastAttemptAt: null,
+  lastError: null,
+};
+vi.mock("@/lib/integrations/status", () => ({
+  getIntegrationStatus: vi.fn(async (_u: string, integration: string) => ({
+    integration,
+    ...ledger,
+  })),
+  getPersistentFailureThreshold: () => 5,
+}));
+
+vi.mock("@/lib/withings/client", () => ({ hasActivityScope: () => false }));
+vi.mock("@/lib/moodlog-secret", () => ({ readMoodLogSecret: () => null }));
+
+const polarAvailable = vi.fn(async () => true);
+const ouraAvailable = vi.fn(async () => false);
+vi.mock("@/lib/polar/credentials", () => ({
+  getPolarClientCredentials: () => polarAvailable(),
+}));
+vi.mock("@/lib/oura/credentials", () => ({
+  getOuraClientCredentials: () => ouraAvailable(),
+}));
+
+import { GET } from "../route";
+import { prisma } from "@/lib/db";
+
+const userFind = prisma.user.findUnique as ReturnType<typeof vi.fn>;
+
+type Entry = {
+  integration: string;
+  connected?: boolean;
+  configured?: boolean;
+  available?: boolean;
+  hasOwnCredentials?: boolean;
+};
+
+async function fetchEntries(): Promise<Entry[]> {
+  const res = (await (GET as unknown as () => Promise<{ data: unknown }>)())
+    .data as { integrations: Entry[] };
+  return res.integrations;
+}
+
+describe("/api/integrations/status — Polar/Oura fold (04-M2)", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    polarAvailable.mockResolvedValue(true);
+    ouraAvailable.mockResolvedValue(false);
+  });
+
+  it("includes polar + oura entries on the consolidated envelope", async () => {
+    userFind.mockResolvedValue({
+      polarAccessTokenEncrypted: "tok",
+      polarClientIdEncrypted: "id",
+      polarClientSecretEncrypted: "sec",
+      ouraAccessTokenEncrypted: null,
+      ouraClientIdEncrypted: null,
+      ouraClientSecretEncrypted: null,
+    });
+
+    const entries = await fetchEntries();
+    const keys = entries.map((e) => e.integration);
+    expect(keys).toEqual(
+      expect.arrayContaining(["polar", "oura"]),
+    );
+
+    const polar = entries.find((e) => e.integration === "polar")!;
+    expect(polar.connected).toBe(true);
+    expect(polar.configured).toBe(true);
+    expect(polar.available).toBe(true);
+    expect(polar.hasOwnCredentials).toBe(true);
+
+    const oura = entries.find((e) => e.integration === "oura")!;
+    expect(oura.connected).toBe(false);
+    expect(oura.available).toBe(false);
+    expect(oura.hasOwnCredentials).toBe(false);
+  });
+
+  it("reports polar disconnected when no access token is stored", async () => {
+    userFind.mockResolvedValue({
+      polarAccessTokenEncrypted: null,
+      polarClientIdEncrypted: null,
+      polarClientSecretEncrypted: null,
+    });
+    const entries = await fetchEntries();
+    const polar = entries.find((e) => e.integration === "polar")!;
+    expect(polar.connected).toBe(false);
+    expect(polar.configured).toBe(false);
+  });
+});
diff --git a/src/app/api/integrations/status/route.ts b/src/app/api/integrations/status/route.ts
index 9b3d768f8..8c3b5eec9 100644
--- a/src/app/api/integrations/status/route.ts
+++ b/src/app/api/integrations/status/route.ts
@@ -24,6 +24,8 @@ import {
   getPersistentFailureThreshold,
   type IntegrationKey,
 } from "@/lib/integrations/status";
+import { getOuraClientCredentials } from "@/lib/oura/credentials";
+import { getPolarClientCredentials } from "@/lib/polar/credentials";
 import { hasActivityScope } from "@/lib/withings/client";
 import { readMoodLogSecret } from "@/lib/moodlog-secret";
 
@@ -38,16 +40,25 @@ export const GET = apiHandler(async () => {
     moodLogStatus,
     whoopStatus,
     fitbitStatus,
+    polarStatus,
+    ouraStatus,
     dbUser,
     withingsConn,
     whoopConn,
     fitbitConn,
     moodLogEntryCount,
+    // v1.17.1 — `available` reports whether usable OAuth credentials resolve
+    // (per-user BYO first, then the shared env app), mirroring the per-card
+    // /api/<provider>/status the consolidated envelope now replaces.
+    polarAvailable,
+    ouraAvailable,
   ] = await Promise.all([
     getIntegrationStatus(user.id, "withings"),
     getIntegrationStatus(user.id, "moodlog"),
     getIntegrationStatus(user.id, "whoop"),
     getIntegrationStatus(user.id, "fitbit"),
+    getIntegrationStatus(user.id, "polar"),
+    getIntegrationStatus(user.id, "oura"),
     prisma.user.findUnique({
       where: { id: user.id },
       select: {
@@ -57,6 +68,12 @@ export const GET = apiHandler(async () => {
         whoopClientSecretEncrypted: true,
         fitbitClientIdEncrypted: true,
         fitbitClientSecretEncrypted: true,
+        polarAccessTokenEncrypted: true,
+        polarClientIdEncrypted: true,
+        polarClientSecretEncrypted: true,
+        ouraAccessTokenEncrypted: true,
+        ouraClientIdEncrypted: true,
+        ouraClientSecretEncrypted: true,
         moodLogUrlEncrypted: true,
         moodLogApiKeyEncrypted: true,
         moodLogEnabled: true,
@@ -95,6 +112,8 @@ export const GET = apiHandler(async () => {
     prisma.moodEntry.count({
       where: { userId: user.id, deletedAt: null },
     }),
+    getPolarClientCredentials(user.id).then((c) => !!c),
+    getOuraClientCredentials(user.id).then((c) => !!c),
   ]);
 
   const now = Date.now();
@@ -164,6 +183,28 @@ export const GET = apiHandler(async () => {
           : null,
         backfillCompleted: fitbitConn ? !!fitbitConn.backfillCompletedAt : null,
       } satisfies IntegrationViewModel & FitbitExtras,
+      {
+        ...polarStatus,
+        // `connected` = a stored access token; `configured` mirrors it (the
+        // OAuth card has no separate "credentials saved but disconnected" view
+        // beyond `hasOwnCredentials`). The card greys out the connect button
+        // when no usable credentials resolve (`available`).
+        connected: !!dbUser?.polarAccessTokenEncrypted,
+        configured: !!dbUser?.polarAccessTokenEncrypted,
+        available: polarAvailable,
+        hasOwnCredentials:
+          !!dbUser?.polarClientIdEncrypted &&
+          !!dbUser?.polarClientSecretEncrypted,
+      } satisfies IntegrationViewModel & OAuthProviderExtras,
+      {
+        ...ouraStatus,
+        connected: !!dbUser?.ouraAccessTokenEncrypted,
+        configured: !!dbUser?.ouraAccessTokenEncrypted,
+        available: ouraAvailable,
+        hasOwnCredentials:
+          !!dbUser?.ouraClientIdEncrypted &&
+          !!dbUser?.ouraClientSecretEncrypted,
+      } satisfies IntegrationViewModel & OAuthProviderExtras,
     ],
   });
 });
@@ -214,3 +255,13 @@ interface FitbitExtras {
   tokenExpired: boolean | null;
   backfillCompleted: boolean | null;
 }
+
+// v1.17.1 — Polar / Oura fold into the consolidated envelope. They carry the
+// per-user BYO-key flags the shared OAuth card reads instead of the dedicated
+// /api/<provider>/status round-trip the page used to fire per card.
+interface OAuthProviderExtras {
+  connected: boolean;
+  configured: boolean;
+  available: boolean;
+  hasOwnCredentials: boolean;
+}
diff --git a/src/app/api/whoop/credentials/__tests__/route.test.ts b/src/app/api/whoop/credentials/__tests__/route.test.ts
index 0816df18c..ec79e0cd1 100644
--- a/src/app/api/whoop/credentials/__tests__/route.test.ts
+++ b/src/app/api/whoop/credentials/__tests__/route.test.ts
@@ -15,6 +15,8 @@ vi.mock("@/lib/db", () => ({
 
 vi.mock("@/lib/logging/context", () => ({ annotate: vi.fn() }));
 vi.mock("@/lib/crypto", () => ({ encrypt: (s: string) => `enc:${s}` }));
+vi.mock("@/lib/auth/audit", () => ({ auditLog: vi.fn() }));
+vi.mock("@/lib/integrations/status", () => ({ markDisconnected: vi.fn() }));
 
 vi.mock("@/lib/api-response", () => ({
   apiSuccess: (data: unknown) => ({ data, error: null, status: 200 }),
@@ -30,6 +32,8 @@ vi.mock("@/lib/api-response", () => ({
 
 import { GET, PUT, DELETE } from "../route";
 import { prisma } from "@/lib/db";
+import { auditLog } from "@/lib/auth/audit";
+import { markDisconnected } from "@/lib/integrations/status";
 
 const userFind = prisma.user.findUnique as ReturnType<typeof vi.fn>;
 const userUpdate = prisma.user.update as ReturnType<typeof vi.fn>;
@@ -91,4 +95,16 @@ describe("/api/whoop/credentials", () => {
       },
     });
   });
+
+  it("DELETE audits the teardown and parks the ledger (04-L1 parity)", async () => {
+    userUpdate.mockResolvedValue({});
+    (prisma.whoopConnection.delete as ReturnType<typeof vi.fn>).mockResolvedValue(
+      {},
+    );
+    await (DELETE as unknown as () => Promise<unknown>)();
+    expect(auditLog).toHaveBeenCalledWith("whoop.credentials.delete", {
+      userId: "u1",
+    });
+    expect(markDisconnected).toHaveBeenCalledWith("u1", "whoop");
+  });
 });
diff --git a/src/app/api/whoop/credentials/route.ts b/src/app/api/whoop/credentials/route.ts
index 618d87405..6675fa11e 100644
--- a/src/app/api/whoop/credentials/route.ts
+++ b/src/app/api/whoop/credentials/route.ts
@@ -1,8 +1,10 @@
 import { prisma } from "@/lib/db";
 import { apiHandler, requireAuth } from "@/lib/api-handler";
+import { auditLog } from "@/lib/auth/audit";
 import { apiSuccess, apiError, safeJson } from "@/lib/api-response";
 import { annotate } from "@/lib/logging/context";
 import { encrypt } from "@/lib/crypto";
+import { markDisconnected } from "@/lib/integrations/status";
 import { whoopCredentialsSchema } from "@/lib/validations/whoop";
 import { NextRequest } from "next/server";
 import { z } from "zod/v4";
@@ -58,6 +60,10 @@ export const PUT = apiHandler(async (request: NextRequest) => {
 
 /**
  * Delete WHOOP credentials and the active connection.
+ *
+ * Audits the teardown and parks the integration ledger at `disconnected` for
+ * parity with the Polar / Oura credential-DELETE so a sensitive op leaves a
+ * uniform audit trail and the status snapshot does not linger at a stale state.
  */
 export const DELETE = apiHandler(async () => {
   const { user } = await requireAuth();
@@ -74,6 +80,8 @@ export const DELETE = apiHandler(async () => {
       whoopClientSecretEncrypted: null,
     },
   });
+  await auditLog("whoop.credentials.delete", { userId: user.id });
+  await markDisconnected(user.id, "whoop");
 
   return apiSuccess({ deleted: true });
 });
diff --git a/src/components/settings/__tests__/oauth-return-outcome.test.ts b/src/components/settings/__tests__/oauth-return-outcome.test.ts
new file mode 100644
index 000000000..a4c2f25ae
--- /dev/null
+++ b/src/components/settings/__tests__/oauth-return-outcome.test.ts
@@ -0,0 +1,67 @@
+/**
+ * v1.17.1 (04-M1) — the WHOOP / Fitbit OAuth callbacks redirect back with
+ * `?whoop=connected|error` / `?fitbit=connected|error&reason=<tag>`, but the
+ * settings page only read the param for Withings/Polar/Oura — so a user
+ * returning from a WHOOP or Fitbit round-trip landed on a silently unchanged
+ * page. These pin the four-provider outcome parsing + reason-key resolution.
+ */
+import { describe, it, expect } from "vitest";
+
+import {
+  parseOAuthOutcome,
+  oauthReasonKey,
+} from "../integrations-section";
+
+describe("parseOAuthOutcome", () => {
+  it("reads a connected outcome for every OAuth provider", () => {
+    for (const p of ["polar", "oura", "whoop", "fitbit"] as const) {
+      expect(parseOAuthOutcome(`?${p}=connected`)).toEqual({
+        provider: p,
+        kind: "connected",
+      });
+    }
+  });
+
+  it("reads WHOOP + Fitbit error outcomes with their reason tag (the gap fix)", () => {
+    expect(parseOAuthOutcome("?whoop=error&reason=token")).toEqual({
+      provider: "whoop",
+      kind: "error",
+      reason: "token",
+    });
+    expect(parseOAuthOutcome("?fitbit=error&reason=expired")).toEqual({
+      provider: "fitbit",
+      kind: "error",
+      reason: "expired",
+    });
+  });
+
+  it("defaults a missing reason to 'unknown'", () => {
+    expect(parseOAuthOutcome("?whoop=error")).toEqual({
+      provider: "whoop",
+      kind: "error",
+      reason: "unknown",
+    });
+  });
+
+  it("returns null when no provider param is present", () => {
+    expect(parseOAuthOutcome("?foo=bar")).toBeNull();
+    expect(parseOAuthOutcome("")).toBeNull();
+  });
+});
+
+describe("oauthReasonKey", () => {
+  it("maps a known tag to the provider-specific key", () => {
+    expect(oauthReasonKey("whoop", "token")).toBe(
+      "settings.whoopOauthError.token",
+    );
+    expect(oauthReasonKey("fitbit", "expired")).toBe(
+      "settings.fitbitOauthError.expired",
+    );
+  });
+
+  it("falls back to generic for an unknown tag", () => {
+    expect(oauthReasonKey("whoop", "totally_unknown")).toBe(
+      "settings.whoopOauthError.generic",
+    );
+  });
+});
diff --git a/src/components/settings/integrations-section.tsx b/src/components/settings/integrations-section.tsx
index 148a806ca..7484da40f 100644
--- a/src/components/settings/integrations-section.tsx
+++ b/src/components/settings/integrations-section.tsx
@@ -8,11 +8,13 @@ import { toast } from "sonner";
 
 import { FitbitCard } from "@/components/settings/integrations/fitbit-card";
 import { NightscoutCard } from "@/components/settings/integrations/nightscout-card";
+import type { OAuthProviderStatus } from "@/components/settings/integrations/oauth-provider-card";
 import { OuraCard } from "@/components/settings/integrations/oura-card";
 import { PolarCard } from "@/components/settings/integrations/polar-card";
 import {
   pickStatus,
   useIntegrationStatuses,
+  type IntegrationStatusViewModel,
 } from "@/components/settings/integrations/shared";
 import { WhoopCard } from "@/components/settings/integrations/whoop-card";
 import { WithingsCard } from "@/components/settings/integrations/withings-card";
@@ -43,6 +45,97 @@ type WithingsOauthOutcome =
   | { kind: "connected" }
   | { kind: "error"; reason: string };
 
+/**
+ * The OAuth providers whose callbacks redirect back to the settings page with a
+ * `?<provider>=connected|error&reason=<tag>` outcome param. Polar/Oura own a
+ * per-card status query; WHOOP/Fitbit read off the consolidated envelope — both
+ * are invalidated on a successful return so the card repaints either way.
+ */
+const OAUTH_OUTCOME_PROVIDERS = ["polar", "oura", "whoop", "fitbit"] as const;
+type OAuthOutcomeProvider = (typeof OAUTH_OUTCOME_PROVIDERS)[number];
+
+const OAUTH_OUTCOME_KEYS: Record<
+  OAuthOutcomeProvider,
+  () => readonly unknown[]
+> = {
+  polar: queryKeys.polar,
+  oura: queryKeys.oura,
+  whoop: queryKeys.whoop,
+  fitbit: queryKeys.fitbit,
+};
+
+/**
+ * Reason tags the four OAuth callbacks emit. Known tags resolve to a specific
+ * message; anything else falls back to the provider's `generic` copy. Union of
+ * the Polar/Oura set (`rate_limited`) and the WHOOP/Fitbit set (`expired`).
+ */
+const OAUTH_OUTCOME_REASONS = new Set([
+  "csrf1",
+  "state",
+  "cross_user",
+  "nocode",
+  "nocreds",
+  "token",
+  "rate_limited",
+  "expired",
+]);
+
+type OAuthOutcome =
+  | { provider: OAuthOutcomeProvider; kind: "connected" }
+  | { provider: OAuthOutcomeProvider; kind: "error"; reason: string };
+
+/**
+ * Parse the OAuth-return outcome from a URL query string. Reads the first
+ * provider whose `?<provider>=connected|error` param is present, in
+ * `OAUTH_OUTCOME_PROVIDERS` order. Pure + exported so the four-provider
+ * coverage is unit-testable without a browser.
+ */
+export function parseOAuthOutcome(search: string): OAuthOutcome | null {
+  const params = new URLSearchParams(search);
+  for (const provider of OAUTH_OUTCOME_PROVIDERS) {
+    const v = params.get(provider);
+    if (v === "connected") return { provider, kind: "connected" };
+    if (v === "error") {
+      return { provider, kind: "error", reason: params.get("reason") ?? "unknown" };
+    }
+  }
+  return null;
+}
+
+/**
+ * Resolve the i18n key for an error reason tag. Known tags map to the
+ * provider-specific message; anything else falls back to `generic`.
+ */
+export function oauthReasonKey(
+  provider: OAuthOutcomeProvider,
+  reason: string,
+): string {
+  return OAUTH_OUTCOME_REASONS.has(reason)
+    ? `settings.${provider}OauthError.${reason}`
+    : `settings.${provider}OauthError.generic`;
+}
+
+/**
+ * Adapt the consolidated-envelope view-model into the OAuth card's status
+ * shape. Returns `undefined` when the envelope hasn't loaded so the card
+ * renders its loading/disconnected default rather than a half-populated state.
+ */
+function toOAuthStatus(
+  vm: IntegrationStatusViewModel | undefined,
+): OAuthProviderStatus | undefined {
+  if (!vm) return undefined;
+  return {
+    connected: vm.connected ?? false,
+    configured: vm.configured ?? false,
+    available: vm.available ?? false,
+    hasOwnCredentials: vm.hasOwnCredentials,
+    state: vm.state,
+    lastSuccessAt: vm.lastSuccessAt,
+    lastAttemptAt: vm.lastAttemptAt,
+    lastError: vm.lastError,
+  };
+}
+
 export function IntegrationsSection() {
   const { t } = useTranslations();
   const { isAuthenticated } = useAuth();
@@ -92,23 +185,16 @@ export function IntegrationsSection() {
     }
   }, [withingsOauthOutcome, router, queryClient, t]);
 
-  // v1.17.0 (F4) — generic OAuth-callback toast for the env-based providers.
-  // The Polar / Oura callbacks redirect back with `?<provider>=connected` or
-  // `?<provider>=error&reason=<tag>`; surface the outcome as a toast and scrub
-  // the one-shot params so a reload doesn't replay it.
-  const [oauthOutcome] = useState<
-    { provider: "polar" | "oura"; kind: "connected" } | { provider: "polar" | "oura"; kind: "error"; reason: string } | null
-  >(() => {
+  // v1.17.0 (F4) — generic OAuth-callback toast for the OAuth providers.
+  // The Polar / Oura / WHOOP / Fitbit callbacks redirect back with
+  // `?<provider>=connected` or `?<provider>=error&reason=<tag>`; surface the
+  // outcome as a toast and scrub the one-shot params so a reload doesn't replay
+  // it. Pre-v1.17.1 only Polar/Oura were read here — a user returning from a
+  // WHOOP or Fitbit round-trip landed on a silently unchanged settings page,
+  // the same gap the Withings handler was written to close.
+  const [oauthOutcome] = useState<OAuthOutcome | null>(() => {
     if (typeof window === "undefined") return null;
-    const params = new URLSearchParams(window.location.search);
-    for (const provider of ["polar", "oura"] as const) {
-      const v = params.get(provider);
-      if (v === "connected") return { provider, kind: "connected" };
-      if (v === "error") {
-        return { provider, kind: "error", reason: params.get("reason") ?? "unknown" };
-      }
-    }
-    return null;
+    return parseOAuthOutcome(window.location.search);
   });
 
   useEffect(() => {
@@ -118,27 +204,19 @@ export function IntegrationsSection() {
     url.searchParams.delete(provider);
     url.searchParams.delete("reason");
     router.replace(`${url.pathname}${url.search}`, { scroll: false });
-    const key = provider === "polar" ? queryKeys.polar() : queryKeys.oura();
     if (oauthOutcome.kind === "connected") {
       toast.success(t(`settings.${provider}OauthConnected`));
-      queryClient.invalidateQueries({ queryKey: key });
+      // Polar/Oura own a per-card status query; WHOOP/Fitbit read off the
+      // consolidated envelope — invalidate both so the card repaints either way.
+      queryClient.invalidateQueries({ queryKey: OAUTH_OUTCOME_KEYS[provider]() });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
     } else {
       // Known reason tags resolve to a specific message; anything else falls
       // back to the generic copy (matching the Withings handler).
-      const knownReasons = new Set([
-        "csrf1",
-        "state",
-        "cross_user",
-        "nocode",
-        "nocreds",
-        "token",
-        "rate_limited",
-      ]);
-      const reasonKey = knownReasons.has(oauthOutcome.reason)
-        ? `settings.${provider}OauthError.${oauthOutcome.reason}`
-        : `settings.${provider}OauthError.generic`;
       toast.error(t(`settings.${provider}OauthFailed`), {
-        description: t(reasonKey),
+        description: t(oauthReasonKey(provider, oauthOutcome.reason)),
         duration: 10_000,
       });
     }
@@ -147,6 +225,10 @@ export function IntegrationsSection() {
   const withingsViewModel = pickStatus(integrationStatus, "withings");
   const whoopViewModel = pickStatus(integrationStatus, "whoop");
   const fitbitViewModel = pickStatus(integrationStatus, "fitbit");
+  // v1.17.1 — Polar/Oura now read off the same consolidated envelope; the cards
+  // no longer fire their own /api/<provider>/status round-trip.
+  const polarViewModel = toOAuthStatus(pickStatus(integrationStatus, "polar"));
+  const ouraViewModel = toOAuthStatus(pickStatus(integrationStatus, "oura"));
 
   return (
     <section
@@ -179,8 +261,8 @@ export function IntegrationsSection() {
       <WithingsCard viewModel={withingsViewModel} />
       <WhoopCard viewModel={whoopViewModel} />
       <FitbitCard viewModel={fitbitViewModel} />
-      <PolarCard enabled={isAuthenticated} />
-      <OuraCard enabled={isAuthenticated} />
+      <PolarCard enabled={isAuthenticated} viewModel={polarViewModel} />
+      <OuraCard enabled={isAuthenticated} viewModel={ouraViewModel} />
       <NightscoutCard enabled={isAuthenticated} />
     </section>
   );
diff --git a/src/components/settings/integrations/__tests__/oauth-provider-card.test.tsx b/src/components/settings/integrations/__tests__/oauth-provider-card.test.tsx
index 830904429..80672df84 100644
--- a/src/components/settings/integrations/__tests__/oauth-provider-card.test.tsx
+++ b/src/components/settings/integrations/__tests__/oauth-provider-card.test.tsx
@@ -23,7 +23,13 @@ vi.mock("@tanstack/react-query", () => ({
 import { I18nProvider } from "@/lib/i18n/context";
 import { OAuthProviderCard } from "../oauth-provider-card";
 
-function render({ credentials = false }: { credentials?: boolean } = {}) {
+function render({
+  credentials = false,
+  viewModel,
+}: {
+  credentials?: boolean;
+  viewModel?: Parameters<typeof OAuthProviderCard>[0]["viewModel"];
+} = {}) {
   return renderToStaticMarkup(
     <I18nProvider initialLocale="en">
       <OAuthProviderCard
@@ -33,6 +39,7 @@ function render({ credentials = false }: { credentials?: boolean } = {}) {
         icon={Watch}
         dataHref="/insights/sleep"
         credentials={credentials}
+        viewModel={viewModel}
       />
     </I18nProvider>,
   );
@@ -74,6 +81,25 @@ describe("OAuthProviderCard — parked + test + data-link parity", () => {
     expect(html).toContain('href="/insights/sleep"');
   });
 
+  it("reads off the passed view-model instead of the per-card fetch (04-M2)", () => {
+    // The per-card useQuery mock returns null; the card must render the
+    // connected state from the supplied envelope view-model alone, proving the
+    // /api/<provider>/status round-trip is no longer the source.
+    statusPayload = null;
+    const html = render({
+      viewModel: {
+        connected: true,
+        configured: true,
+        available: true,
+        state: "connected",
+        lastSuccessAt: "2026-06-01T00:00:00.000Z",
+        lastError: null,
+      },
+    });
+    expect(html).toContain('data-testid="polar-data-link"');
+    expect(html).toContain("Test connection");
+  });
+
   it("does not render the data link or test button when disconnected", () => {
     statusPayload = {
       connected: false,
diff --git a/src/components/settings/integrations/oauth-provider-card.tsx b/src/components/settings/integrations/oauth-provider-card.tsx
index d7642ecab..1b0e5aa41 100644
--- a/src/components/settings/integrations/oauth-provider-card.tsx
+++ b/src/components/settings/integrations/oauth-provider-card.tsx
@@ -36,7 +36,11 @@ import {
 import { TestConnectionButton } from "@/components/settings/test-connection-button";
 import { apiFetchRaw, apiGet, apiPost } from "@/lib/api/api-fetch";
 import { useTranslations } from "@/lib/i18n/context";
-import { invalidateKeys, measurementDependentKeys } from "@/lib/query-keys";
+import {
+  invalidateKeys,
+  measurementDependentKeys,
+  queryKeys,
+} from "@/lib/query-keys";
 import { IntegrationSetupGuideLink } from "./setup-guide-link";
 
 export interface OAuthProviderStatus {
@@ -85,6 +89,13 @@ export interface OAuthProviderCardProps {
    * button. The endpoint is the PUT target (e.g. `/api/polar/credentials`). */
   credentials?: boolean;
   enabled?: boolean;
+  /**
+   * When provided, the card reads its status from this view-model (sourced off
+   * the consolidated `/api/integrations/status` envelope) instead of firing its
+   * own `/api/<provider>/status` round-trip. v1.17.1 folds Polar/Oura onto the
+   * same envelope WHOOP/Fitbit already use, so the page reads from one source.
+   */
+  viewModel?: OAuthProviderStatus;
 }
 
 export function OAuthProviderCard({
@@ -95,6 +106,7 @@ export function OAuthProviderCard({
   dataHref,
   credentials = false,
   enabled = true,
+  viewModel,
 }: OAuthProviderCardProps) {
   const { t } = useTranslations();
   const queryClient = useQueryClient();
@@ -107,12 +119,17 @@ export function OAuthProviderCard({
     null,
   );
 
-  const { data: status } = useQuery({
+  // Read off the consolidated envelope when a view-model is passed; otherwise
+  // fall back to the per-card status fetch (still used by any caller that has
+  // not been migrated onto the envelope). The fetch is disabled once a
+  // view-model is supplied so the page makes one request, not one-per-card.
+  const { data: fetchedStatus } = useQuery({
     queryKey: statusQueryKey,
     queryFn: async () => apiGet<OAuthProviderStatus>(`/api/${provider}/status`),
-    enabled,
+    enabled: enabled && !viewModel,
     refetchOnWindowFocus: true,
   });
+  const status = viewModel ?? fetchedStatus;
 
   async function handleSaveCredentials(e: React.FormEvent) {
     e.preventDefault();
@@ -134,6 +151,11 @@ export function OAuthProviderCard({
         setClientId("");
         setClientSecret("");
         queryClient.invalidateQueries({ queryKey: statusQueryKey });
+        // The card may read off the consolidated envelope — invalidate it too
+        // so the saved-credentials state repaints regardless of the source.
+        queryClient.invalidateQueries({
+          queryKey: queryKeys.integrationsStatus(),
+        });
       } else {
         try {
           const json = await res.json();
@@ -156,6 +178,9 @@ export function OAuthProviderCard({
     },
     onSuccess: () => {
       queryClient.invalidateQueries({ queryKey: statusQueryKey });
+      queryClient.invalidateQueries({
+        queryKey: queryKeys.integrationsStatus(),
+      });
     },
   });
 
diff --git a/src/components/settings/integrations/oura-card.tsx b/src/components/settings/integrations/oura-card.tsx
index a3ce82e78..6d9243a8c 100644
--- a/src/components/settings/integrations/oura-card.tsx
+++ b/src/components/settings/integrations/oura-card.tsx
@@ -6,10 +6,19 @@
 
 import { CircleDot } from "lucide-react";
 
-import { OAuthProviderCard } from "@/components/settings/integrations/oauth-provider-card";
+import {
+  OAuthProviderCard,
+  type OAuthProviderStatus,
+} from "@/components/settings/integrations/oauth-provider-card";
 import { queryKeys } from "@/lib/query-keys";
 
-export function OuraCard({ enabled = true }: { enabled?: boolean }) {
+export function OuraCard({
+  enabled = true,
+  viewModel,
+}: {
+  enabled?: boolean;
+  viewModel?: OAuthProviderStatus;
+}) {
   return (
     <OAuthProviderCard
       provider="oura"
@@ -19,6 +28,7 @@ export function OuraCard({ enabled = true }: { enabled?: boolean }) {
       dataHref="/insights/sleep"
       credentials
       enabled={enabled}
+      viewModel={viewModel}
     />
   );
 }
diff --git a/src/components/settings/integrations/polar-card.tsx b/src/components/settings/integrations/polar-card.tsx
index 56a310212..3ee6ff5cd 100644
--- a/src/components/settings/integrations/polar-card.tsx
+++ b/src/components/settings/integrations/polar-card.tsx
@@ -6,10 +6,19 @@
 
 import { Watch } from "lucide-react";
 
-import { OAuthProviderCard } from "@/components/settings/integrations/oauth-provider-card";
+import {
+  OAuthProviderCard,
+  type OAuthProviderStatus,
+} from "@/components/settings/integrations/oauth-provider-card";
 import { queryKeys } from "@/lib/query-keys";
 
-export function PolarCard({ enabled = true }: { enabled?: boolean }) {
+export function PolarCard({
+  enabled = true,
+  viewModel,
+}: {
+  enabled?: boolean;
+  viewModel?: OAuthProviderStatus;
+}) {
   return (
     <OAuthProviderCard
       provider="polar"
@@ -19,6 +28,7 @@ export function PolarCard({ enabled = true }: { enabled?: boolean }) {
       dataHref="/insights/sleep"
       credentials
       enabled={enabled}
+      viewModel={viewModel}
     />
   );
 }
diff --git a/src/components/settings/integrations/shared.tsx b/src/components/settings/integrations/shared.tsx
index 8990d6652..3213a02bf 100644
--- a/src/components/settings/integrations/shared.tsx
+++ b/src/components/settings/integrations/shared.tsx
@@ -18,7 +18,13 @@ import { queryKeys } from "@/lib/query-keys";
 // v1.4.19 Phase A5: the redundant in-card status banner is gone — the
 // IntegrationStatusPill now owns state + last-sync presentation, and
 // the actionable error message is shown inline above the action row.
-export type IntegrationKey = "withings" | "whoop" | "fitbit" | "moodlog";
+export type IntegrationKey =
+  | "withings"
+  | "whoop"
+  | "fitbit"
+  | "moodlog"
+  | "polar"
+  | "oura";
 export type IntegrationState =
   | "connected"
   | "error_transient"
@@ -52,6 +58,11 @@ export interface IntegrationStatusViewModel {
   // moodLog webhook secret + entry count.
   webhookSecret?: string | null;
   entryCount?: number;
+  // Polar / Oura OAuth card: usable-credentials + BYO-key flags. `available`
+  // greys out the connect button when no credentials resolve; `hasOwnCredentials`
+  // drives the saved-placeholder UI.
+  available?: boolean;
+  hasOwnCredentials?: boolean;
 }
 
 export interface IntegrationStatusEnvelope {
diff --git a/src/lib/analytics/__tests__/sleep-night.test.ts b/src/lib/analytics/__tests__/sleep-night.test.ts
index 00221cea0..b10ce131c 100644
--- a/src/lib/analytics/__tests__/sleep-night.test.ts
+++ b/src/lib/analytics/__tests__/sleep-night.test.ts
@@ -399,6 +399,22 @@ describe("reconstructSleepSessions", () => {
     expect(new Set(ends).size).toBe(ends.length);
   });
 
+  it("flags a Polar-won night as reconstructed (synthetic stage order)", () => {
+    // Polar exposes only per-stage duration totals, so its mapper reconstructs
+    // a contiguous CORE→DEEP→REM order exactly like WHOOP. The reader must label
+    // such a night reconstructed so the UI never presents the synthetic order as
+    // measured timing.
+    const rows: SleepStageRow[] = [
+      srcRow("2026-06-04T01:00:00.000Z", "CORE", 240, "POLAR"),
+      srcRow("2026-06-04T03:00:00.000Z", "DEEP", 120, "POLAR"),
+      srcRow("2026-06-04T05:00:00.000Z", "REM", 120, "POLAR"),
+    ];
+    const sessions = reconstructSleepSessions(rows, "UTC");
+    expect(sessions).toHaveLength(1);
+    expect(sessions[0].source).toBe("POLAR");
+    expect(sessions[0].reconstructed).toBe(true);
+  });
+
   it("does NOT flag an Apple-Health night as reconstructed (measured timeline)", () => {
     const rows: SleepStageRow[] = [
       srcRow("2026-06-04T01:00:00.000Z", "CORE", 240, "APPLE_HEALTH"),
diff --git a/src/lib/analytics/sleep-night.ts b/src/lib/analytics/sleep-night.ts
index 88024e6c1..138d94e20 100644
--- a/src/lib/analytics/sleep-night.ts
+++ b/src/lib/analytics/sleep-night.ts
@@ -285,13 +285,15 @@ const NO_SOURCE = "__none__";
  * Sources whose per-segment stage ORDER is synthesised, not measured. WHOOP's
  * v2 API exposes only per-stage duration totals (no onset timestamps), so the
  * ingest mapper reconstructs a contiguous timeline in a fixed physiological
- * order (`whoop/client.ts` `mapSleep`). A session won by such a source carries
- * `reconstructed: true` so the UI labels it as an approximate layout. Apple
- * Health / Withings / Fitbit all store a real per-segment series and stay off
- * this set.
+ * order (`whoop/client.ts` + `polar/client.ts` `mapSleep`, both via the shared
+ * `reconstructContiguousSleepTimeline` builder). A session won by such a source
+ * carries `reconstructed: true` so the UI labels it as an approximate layout.
+ * Apple Health / Oura / Withings / Fitbit all store a real per-segment series
+ * and stay off this set.
  */
 const RECONSTRUCTED_TIMELINE_SOURCES: ReadonlySet<string> = new Set<string>([
   "WHOOP",
+  "POLAR",
 ]);
 
 /**
diff --git a/src/lib/polar/__tests__/client.test.ts b/src/lib/polar/__tests__/client.test.ts
index d68ae79f6..81ad2ff96 100644
--- a/src/lib/polar/__tests__/client.test.ts
+++ b/src/lib/polar/__tests__/client.test.ts
@@ -265,6 +265,53 @@ describe("mapSleep", () => {
     ).toBe(endMs);
   });
 
+  it("emits an AWAKE segment from total_interruption_duration", () => {
+    const start = "2026-06-09T23:00:00+02:00"; // 21:00 UTC
+    const s: PolarSleep = {
+      date: "2026-06-10",
+      sleep_start_time: start,
+      sleep_end_time: "2026-06-10T07:00:00+02:00",
+      total_interruption_duration: 900, // 15 min awake
+      light_sleep: 3600, // 60 min
+      deep_sleep: 1800, // 30 min
+      rem_sleep: 5400, // 90 min
+      sleep_score: 82,
+    };
+    const mapped = mapSleep(s);
+    const onset = Date.parse(start);
+
+    // AWAKE is laid first (leading settling-in block), so the asleep stages
+    // partition the rest of the window and the night reader can surface real
+    // awake time + efficiency rather than a fully consolidated night.
+    const awake = mapped.find((m) => m.sleepStage === "AWAKE")!;
+    expect(awake).toBeDefined();
+    expect(awake.value).toBe(15);
+    expect(awake.reconstructed).toBe(true);
+    expect(awake.externalId).toBe("sleep:2026-06-10:seg:sleep_awake:0");
+    // AWAKE ends at +15m; CORE then starts there and is index 1.
+    expect(awake.measuredAt.getTime()).toBe(onset + 15 * 60_000);
+
+    const core = mapped.find((m) => m.sleepStage === "CORE")!;
+    expect(core.externalId).toBe("sleep:2026-06-10:seg:sleep_core:1");
+    expect(core.measuredAt.getTime()).toBe(onset + (15 + 60) * 60_000);
+  });
+
+  it("omits AWAKE when no interruption time is reported", () => {
+    const mapped = mapSleep({
+      date: "2026-06-10",
+      sleep_start_time: "2026-06-09T23:00:00+02:00",
+      sleep_end_time: "2026-06-10T07:00:00+02:00",
+      light_sleep: 3600,
+      deep_sleep: 1800,
+      rem_sleep: 5400,
+    });
+    expect(mapped.find((m) => m.sleepStage === "AWAKE")).toBeUndefined();
+    // CORE stays index 0 when AWAKE is absent.
+    expect(mapped.find((m) => m.sleepStage === "CORE")!.externalId).toBe(
+      "sleep:2026-06-10:seg:sleep_core:0",
+    );
+  });
+
   it("falls back to a midnight-UTC anchor when the window is missing", () => {
     const mapped = mapSleep({
       date: "2026-06-10",
diff --git a/src/lib/polar/client.ts b/src/lib/polar/client.ts
index 1de24b073..7a8395d25 100644
--- a/src/lib/polar/client.ts
+++ b/src/lib/polar/client.ts
@@ -22,6 +22,7 @@
  */
 import { getEvent } from "@/lib/logging/context";
 import { safeFetch } from "@/lib/safe-fetch";
+import { reconstructContiguousSleepTimeline } from "@/lib/sleep/reconstruct-timeline";
 import { PolarApiError, classifyPolarResponse } from "./response-classifier";
 
 const POLAR_API_BASE = "https://www.polaraccesslink.com";
@@ -481,51 +482,47 @@ export function mapSleep(s: PolarSleep): MappedMeasurement[] {
     Number.isFinite(startMs) && Number.isFinite(endMs) && endMs > startMs;
 
   const stages: Array<
-    [number | null | undefined, NonNullable<MappedMeasurement["sleepStage"]>, string]
+    [number | null | undefined, "CORE" | "DEEP" | "REM" | "AWAKE", string]
   > = [
+    // AWAKE first — Polar reports the night's total interruption time, but no
+    // per-stage onset. Lay it as a leading settling-in/awake block so the asleep
+    // stages partition the remaining window and the night reader can surface a
+    // real awakeMinutes / efficiency rather than reading the night as fully
+    // consolidated. Matches WHOOP's leading-AWAKE ordering.
+    [s.total_interruption_duration, "AWAKE", "sleep_awake"],
     [s.light_sleep, "CORE", "sleep_core"],
     [s.deep_sleep, "DEEP", "sleep_deep"],
     [s.rem_sleep, "REM", "sleep_rem"],
   ];
 
   if (haveWindow) {
-    // Reconstructed timeline: lay each asleep stage contiguously from onset, one
-    // timed row per segment ending at the running cursor. The order is
-    // synthetic (Polar gives no per-stage onset), so flag every segment.
-    let cursor = startMs;
-    let segIndex = 0;
-    for (const [sec, stage, fieldTag] of stages) {
-      if (typeof sec !== "number" || sec <= 0) continue;
-      const segEnd = cursor + sec * 1000;
-      out.push({
-        type: "SLEEP_DURATION",
-        value: round2(sec * SEC_TO_MIN),
-        unit: "minutes",
-        measuredAt: new Date(segEnd),
-        fieldTag,
+    // Reconstructed timeline: lay each stage contiguously from onset, one timed
+    // row per segment ending at the running cursor. The order is synthetic
+    // (Polar gives no per-stage onset), so the shared builder flags every
+    // segment reconstructed; the same algorithm backs WHOOP's `mapSleep`.
+    out.push(
+      ...reconstructContiguousSleepTimeline({
+        startMs,
+        stages: stages.map(([sec, stage, fieldTag]) => ({
+          durationMs:
+            typeof sec === "number" && Number.isFinite(sec) ? sec * 1000 : sec,
+          stage,
+          fieldTag,
+        })),
+        // IN_BED — single envelope row over the whole sleep window, stamped at
+        // the sleep END so the in-bed reader resolves the span back to
+        // [start, end].
+        inBed: {
+          durationMs: endMs - startMs,
+          measuredAt: new Date(endMs),
+          fieldTag: "sleep_in_bed",
+        },
         // Indexed externalId keeps the several segment rows of one night
         // distinct under userId_type_source_externalId.
-        externalId: `sleep:${s.date}:seg:${fieldTag}:${segIndex}`,
-        sleepStage: stage,
-        reconstructed: true,
-      });
-      cursor = segEnd;
-      segIndex += 1;
-    }
-
-    // IN_BED — single envelope row over the whole sleep window, stamped at the
-    // sleep END so the in-bed reader resolves the span back to [start, end].
-    const inBedSec = (endMs - startMs) / 1000;
-    if (inBedSec > 0) {
-      out.push({
-        type: "SLEEP_DURATION",
-        value: round2(inBedSec * SEC_TO_MIN),
-        unit: "minutes",
-        measuredAt: new Date(endMs),
-        fieldTag: "sleep_in_bed",
-        sleepStage: "IN_BED",
-      });
-    }
+        externalIdFor: (fieldTag, index) =>
+          `sleep:${s.date}:seg:${fieldTag}:${index}`,
+      }),
+    );
 
     if (typeof s.sleep_score === "number") {
       out.push({
diff --git a/src/lib/sleep/__tests__/reconstruct-timeline.test.ts b/src/lib/sleep/__tests__/reconstruct-timeline.test.ts
new file mode 100644
index 000000000..121eb22a6
--- /dev/null
+++ b/src/lib/sleep/__tests__/reconstruct-timeline.test.ts
@@ -0,0 +1,90 @@
+import { describe, it, expect } from "vitest";
+
+import { reconstructContiguousSleepTimeline } from "../reconstruct-timeline";
+
+describe("reconstructContiguousSleepTimeline", () => {
+  const onset = Date.parse("2026-06-09T21:00:00.000Z");
+  const end = Date.parse("2026-06-10T05:00:00.000Z");
+
+  it("lays stages contiguously from onset, each ending at its own instant", () => {
+    const rows = reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [
+        { durationMs: 60 * 60_000, stage: "CORE", fieldTag: "sleep_core" },
+        { durationMs: 30 * 60_000, stage: "DEEP", fieldTag: "sleep_deep" },
+        { durationMs: 90 * 60_000, stage: "REM", fieldTag: "sleep_rem" },
+      ],
+      externalIdFor: (tag, i) => `night:seg:${tag}:${i}`,
+    });
+    const core = rows.find((r) => r.sleepStage === "CORE")!;
+    const deep = rows.find((r) => r.sleepStage === "DEEP")!;
+    const rem = rows.find((r) => r.sleepStage === "REM")!;
+    expect(core.value).toBe(60);
+    expect(core.measuredAt.getTime()).toBe(onset + 60 * 60_000);
+    expect(deep.measuredAt.getTime()).toBe(onset + 90 * 60_000);
+    expect(rem.measuredAt.getTime()).toBe(onset + 180 * 60_000);
+    // Distinct instants → ordered hypnogram, not a shared right edge.
+    expect(new Set(rows.map((r) => r.measuredAt.getTime())).size).toBe(3);
+  });
+
+  it("flags every laid segment reconstructed and keys an indexed externalId", () => {
+    const rows = reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [
+        { durationMs: 15 * 60_000, stage: "AWAKE", fieldTag: "sleep_awake" },
+        { durationMs: 60 * 60_000, stage: "CORE", fieldTag: "sleep_core" },
+      ],
+      externalIdFor: (tag, i) => `night:seg:${tag}:${i}`,
+    });
+    expect(rows.every((r) => r.reconstructed === true)).toBe(true);
+    expect(rows[0].externalId).toBe("night:seg:sleep_awake:0");
+    expect(rows[1].externalId).toBe("night:seg:sleep_core:1");
+  });
+
+  it("skips non-positive, null, undefined and non-finite durations", () => {
+    const rows = reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [
+        { durationMs: 0, stage: "AWAKE", fieldTag: "sleep_awake" },
+        { durationMs: null, stage: "CORE", fieldTag: "sleep_core" },
+        { durationMs: undefined, stage: "DEEP", fieldTag: "sleep_deep" },
+        { durationMs: Number.NaN, stage: "REM", fieldTag: "sleep_rem" },
+        { durationMs: 30 * 60_000, stage: "CORE", fieldTag: "sleep_core" },
+      ],
+      externalIdFor: (tag, i) => `night:seg:${tag}:${i}`,
+    });
+    expect(rows).toHaveLength(1);
+    // The only laid stage keeps index 0 (skipped stages do not consume indices).
+    expect(rows[0].externalId).toBe("night:seg:sleep_core:0");
+    expect(rows[0].measuredAt.getTime()).toBe(onset + 30 * 60_000);
+  });
+
+  it("appends a single IN_BED envelope at the given END instant", () => {
+    const rows = reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [{ durationMs: 60 * 60_000, stage: "CORE", fieldTag: "sleep_core" }],
+      inBed: {
+        durationMs: end - onset,
+        measuredAt: new Date(end),
+        fieldTag: "sleep_in_bed",
+      },
+      externalIdFor: (tag, i) => `night:seg:${tag}:${i}`,
+    });
+    const inBed = rows.find((r) => r.sleepStage === "IN_BED")!;
+    expect(inBed.measuredAt.getTime()).toBe(end);
+    expect(inBed.value).toBe(480); // 8 h
+    // IN_BED is an envelope, not a placed segment — no reconstructed flag / id.
+    expect(inBed.reconstructed).toBeUndefined();
+    expect(inBed.externalId).toBeUndefined();
+  });
+
+  it("omits IN_BED when its duration is missing or non-positive", () => {
+    const rows = reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [{ durationMs: 60 * 60_000, stage: "CORE", fieldTag: "sleep_core" }],
+      inBed: { durationMs: 0, measuredAt: new Date(end), fieldTag: "sleep_in_bed" },
+      externalIdFor: (tag, i) => `night:seg:${tag}:${i}`,
+    });
+    expect(rows.find((r) => r.sleepStage === "IN_BED")).toBeUndefined();
+  });
+});
diff --git a/src/lib/sleep/reconstruct-timeline.ts b/src/lib/sleep/reconstruct-timeline.ts
new file mode 100644
index 000000000..cc0bfa335
--- /dev/null
+++ b/src/lib/sleep/reconstruct-timeline.ts
@@ -0,0 +1,129 @@
+/**
+ * Shared reconstructed-sleep-timeline builder.
+ *
+ * Some wearables (WHOOP v2, Polar) expose only per-stage DURATION totals for a
+ * night — no per-stage onset timestamps and no hypnogram endpoint. Stamping
+ * every stage total on the one sleep-END instant collapses the hypnogram into
+ * overlapping spans that all touch the night's right edge. Since the API never
+ * carries an order, both vendors RECONSTRUCT an ordered, contiguous timeline:
+ * lay the stages back-to-back from sleep ONSET in a fixed physiological order,
+ * emitting one timed row per segment with `measuredAt = that segment's END`.
+ *
+ * The ORDER is synthetic, so every laid segment is flagged `reconstructed:
+ * true`; the night DTO advertises it and the UI labels such a night as an
+ * approximate layout, never as measured stage timing. The reader's honesty
+ * flag (`analytics/sleep-night.ts` `RECONSTRUCTED_TIMELINE_SOURCES`) carries
+ * the same contract on the read side.
+ *
+ * This helper is the single source of the algorithm; each vendor `mapSleep`
+ * keeps only its field-name → tuple normalisation (ms vs sec, source field
+ * names) so the segment shape and externalId scheme can never drift between the
+ * two synthetic-timeline vendors. Oura's measured 5-min hypnogram is a
+ * different algorithm and does NOT use this helper.
+ */
+
+/** The sleep-row shape both vendor mappers emit. Kept structurally identical to
+ * each vendor's local `MappedMeasurement`; the helper returns rows assignable to
+ * either. */
+export interface ReconstructedSleepRow {
+  type: "SLEEP_DURATION";
+  value: number;
+  unit: "minutes";
+  measuredAt: Date;
+  fieldTag: string;
+  externalId?: string;
+  sleepStage: "CORE" | "DEEP" | "REM" | "AWAKE" | "IN_BED";
+  reconstructed?: boolean;
+}
+
+/** One asleep/awake stage to lay onto the reconstructed timeline. `durationMs`
+ * is the stage total in milliseconds; non-positive or non-finite durations are
+ * skipped. */
+export interface ReconstructedStage {
+  durationMs: number | null | undefined;
+  stage: "CORE" | "DEEP" | "REM" | "AWAKE";
+  fieldTag: string;
+}
+
+/** Optional single IN_BED envelope row over the whole sleep window. The in-bed
+ * reader consumes the union envelope, so this stays one row stamped at the
+ * sleep END (`measuredAt`) — NOT a placed segment. */
+export interface ReconstructedInBed {
+  durationMs: number | null | undefined;
+  /** Sleep END instant; the in-bed reader resolves the span back to its window. */
+  measuredAt: Date;
+  fieldTag: string;
+}
+
+export interface ReconstructTimelineOptions {
+  /** Sleep ONSET instant; the contiguous walk starts here. */
+  startMs: number;
+  /** Stages in physiological lay-out order (e.g. AWAKE → CORE → DEEP → REM). */
+  stages: ReadonlyArray<ReconstructedStage>;
+  /** Optional IN_BED envelope row. */
+  inBed?: ReconstructedInBed;
+  /**
+   * Builds the indexed externalId for a laid segment so the several rows of one
+   * night stay distinct under `userId_type_source_externalId`. Called with the
+   * segment's fieldTag and its running index.
+   */
+  externalIdFor: (fieldTag: string, index: number) => string;
+}
+
+const MS_TO_MIN = 1 / 60_000;
+
+function round2(n: number): number {
+  return Math.round(n * 100) / 100;
+}
+
+/**
+ * Lay the asleep/awake stages contiguously from `startMs` in the given order,
+ * emitting one timed `SLEEP_DURATION` row per stage (`measuredAt` = that
+ * segment's END), each flagged `reconstructed: true` and keyed by an indexed
+ * externalId. Appends a single IN_BED envelope row when `inBed` is provided.
+ */
+export function reconstructContiguousSleepTimeline(
+  opts: ReconstructTimelineOptions,
+): ReconstructedSleepRow[] {
+  const { startMs, stages, inBed, externalIdFor } = opts;
+  const out: ReconstructedSleepRow[] = [];
+
+  let cursor = startMs;
+  let segIndex = 0;
+  for (const { durationMs, stage, fieldTag } of stages) {
+    if (typeof durationMs !== "number" || !Number.isFinite(durationMs) || durationMs <= 0) {
+      continue;
+    }
+    const segEnd = cursor + durationMs;
+    out.push({
+      type: "SLEEP_DURATION",
+      value: round2(durationMs * MS_TO_MIN),
+      unit: "minutes",
+      measuredAt: new Date(segEnd),
+      fieldTag,
+      externalId: externalIdFor(fieldTag, segIndex),
+      sleepStage: stage,
+      reconstructed: true,
+    });
+    cursor = segEnd;
+    segIndex += 1;
+  }
+
+  if (
+    inBed &&
+    typeof inBed.durationMs === "number" &&
+    Number.isFinite(inBed.durationMs) &&
+    inBed.durationMs > 0
+  ) {
+    out.push({
+      type: "SLEEP_DURATION",
+      value: round2(inBed.durationMs * MS_TO_MIN),
+      unit: "minutes",
+      measuredAt: inBed.measuredAt,
+      fieldTag: inBed.fieldTag,
+      sleepStage: "IN_BED",
+    });
+  }
+
+  return out;
+}
diff --git a/src/lib/whoop/client.ts b/src/lib/whoop/client.ts
index 19c30ddc7..84d0a01ad 100644
--- a/src/lib/whoop/client.ts
+++ b/src/lib/whoop/client.ts
@@ -17,6 +17,7 @@
  */
 import { getEvent } from "@/lib/logging/context";
 import { safeFetch } from "@/lib/safe-fetch";
+import { reconstructContiguousSleepTimeline } from "@/lib/sleep/reconstruct-timeline";
 import { WhoopApiError, classifyWhoopResponse } from "./response-classifier";
 
 const WHOOP_API_BASE = "https://api.prod.whoop.com/developer";
@@ -611,55 +612,38 @@ export function mapSleep(s: WhoopSleep): MappedMeasurement[] {
   // the remaining window.
   const onset = new Date(s.start).getTime();
   // Order the laid-out stages: a brief AWAKE settling-in block, then the asleep
-  // stages CORE → DEEP → REM. Each carries its own duration; the cursor walks
-  // forward so the spans are contiguous and non-overlapping.
-  const TIMELINE_ORDER: ReadonlyArray<{
-    key: keyof typeof stages;
-    stage: NonNullable<MappedMeasurement["sleepStage"]>;
-    tag: string;
-  }> = [
-    { key: "total_awake_time_milli", stage: "AWAKE", tag: "sleep_awake" },
-    { key: "total_light_sleep_time_milli", stage: "CORE", tag: "sleep_core" },
-    { key: "total_slow_wave_sleep_time_milli", stage: "DEEP", tag: "sleep_deep" },
-    { key: "total_rem_sleep_time_milli", stage: "REM", tag: "sleep_rem" },
-  ];
-  let cursor = onset;
-  let segIndex = 0;
-  for (const { key, stage, tag } of TIMELINE_ORDER) {
-    const ms = stages[key];
-    if (typeof ms !== "number" || ms <= 0) continue;
-    const segEnd = cursor + ms;
-    out.push({
-      type: "SLEEP_DURATION",
-      value: round2(ms * MS_TO_MIN),
-      unit: "minutes",
-      measuredAt: new Date(segEnd),
+  // stages CORE → DEEP → REM. Each carries its own duration; the shared builder
+  // walks the cursor forward so the spans are contiguous and non-overlapping,
+  // and lays the IN_BED envelope over the whole window. The order is synthetic
+  // (WHOOP gives no per-stage onset), so every laid segment is flagged
+  // reconstructed; the same algorithm backs Polar's `mapSleep`.
+  out.push(
+    ...reconstructContiguousSleepTimeline({
+      startMs: onset,
+      stages: [
+        { durationMs: stages.total_awake_time_milli, stage: "AWAKE", fieldTag: "sleep_awake" },
+        { durationMs: stages.total_light_sleep_time_milli, stage: "CORE", fieldTag: "sleep_core" },
+        {
+          durationMs: stages.total_slow_wave_sleep_time_milli,
+          stage: "DEEP",
+          fieldTag: "sleep_deep",
+        },
+        { durationMs: stages.total_rem_sleep_time_milli, stage: "REM", fieldTag: "sleep_rem" },
+      ],
+      // IN_BED — single envelope row over the whole sleep window. `measuredAt`
+      // is the sleep END so `segmentOf` resolves the span back to [start, end];
+      // the in-bed union-envelope reader consumes the full window.
+      inBed: {
+        durationMs: stages.total_in_bed_time_milli,
+        measuredAt,
+        fieldTag: "sleep_in_bed",
+      },
       // The sync layer keys reconstructed rows by this externalId verbatim; the
       // index keeps the several rows of one night distinct under
       // userId_type_source_externalId.
-      fieldTag: tag,
-      externalId: `${s.id}:seg:${tag}:${segIndex}`,
-      sleepStage: stage,
-      reconstructed: true,
-    });
-    cursor = segEnd;
-    segIndex += 1;
-  }
-
-  // IN_BED — single envelope row over the whole sleep window. `measuredAt` is
-  // the sleep END so `segmentOf` resolves the span back to [start, end]; the
-  // in-bed union-envelope reader consumes the full window.
-  const inBedMs = stages.total_in_bed_time_milli;
-  if (typeof inBedMs === "number" && inBedMs > 0) {
-    out.push({
-      type: "SLEEP_DURATION",
-      value: round2(inBedMs * MS_TO_MIN),
-      unit: "minutes",
-      measuredAt,
-      fieldTag: "sleep_in_bed",
-      sleepStage: "IN_BED",
-    });
-  }
+      externalIdFor: (tag, index) => `${s.id}:seg:${tag}:${index}`,
+    }),
+  );
 
   const need = s.score.sleep_needed;
   const totalNeedMilli =