diff --git a/app/(main)/[locale]/layout.tsx b/app/(main)/[locale]/layout.tsx
index 7e87ba450..19886974f 100644
--- a/app/(main)/[locale]/layout.tsx
+++ b/app/(main)/[locale]/layout.tsx
@@ -10,6 +10,7 @@ import { ProInterfaceRedirect } from "@/components/pro/pro-interface-redirect";
 import { ImpersonationReconciler } from "@/components/impersonation/impersonation-reconciler";
 import { PluginDialogHost } from "@/components/plugins/plugin-dialog-host";
 import { PluginConsentDialog } from "@/components/plugins/plugin-consent-dialog";
+import { PluginOAuthCallbackListener } from "@/components/providers/plugin-oauth-callback-listener";
 import { PWAInstallPrompt } from "@/components/pwa-install-prompt";
 import { PushNotificationPrompt } from "@/components/push-notification-prompt";
 import { locales } from "@/i18n/routing";
@@ -45,6 +46,7 @@ export default async function LocaleLayout({
                   {children}
                   <PluginDialogHost />
                   <PluginConsentDialog />
+                  <PluginOAuthCallbackListener />
                   <PWAInstallPrompt />
                   <PushNotificationPrompt />
                 </ProtocolLaunchHandlerProvider>
diff --git a/app/(main)/[locale]/plugins/oauth/callback/page.tsx b/app/(main)/[locale]/plugins/oauth/callback/page.tsx
new file mode 100644
index 000000000..35872aa92
--- /dev/null
+++ b/app/(main)/[locale]/plugins/oauth/callback/page.tsx
@@ -0,0 +1,151 @@
+"use client";
+
+/**
+ * Generic OAuth callback landing page for plugins.
+ *
+ * Plugins that connect to third-party OAuth providers (Google, Nextcloud, …)
+ * cannot register their own routes. They send the user to the provider's
+ * authorize URL with a redirect_uri pointing here; this page parks the
+ * authorization code + state and notifies the plugin that initiated the flow.
+ * No tokens ever pass through this page - the plugin exchanges the code
+ * itself (via api.http.fetch, through its origin allowlist).
+ *
+ * Delivery chain:
+ *   1. The payload `{ code, state, receivedAt }` is written to sessionStorage
+ *      (`plugin-oauth-callback`) and mirrored into localStorage under the same
+ *      key, plus a same-tab CustomEvent `plugin-oauth-callback`.
+ *   2. The host listens via `PluginOAuthCallbackListener` (mounted in the
+ *      [locale] layout): the localStorage write raises a `storage` event in
+ *      every OTHER tab of this origin, including the tab that started the
+ *      flow. The listener forwards the payload to plugins through the
+ *      `authHooks.onOAuthCallback` hook bus.
+ *   3. Each plugin validates `state` against the verifier it stashed before
+ *      redirecting and ignores payloads that are not its own.
+ *
+ * The page then shows a status screen - the user closes the tab (or switches
+ * back) while the original tab completes the token exchange.
+ */
+
+import { OAuthStatusCard } from "@/components/auth/oauth-status-card";
+import {
+  PLUGIN_OAUTH_EVENT,
+  PLUGIN_OAUTH_STORAGE_KEY,
+  type OAuthCallbackPayload,
+} from "@/lib/plugin-oauth";
+import { CheckCircle2, XCircle } from "lucide-react";
+import { useTranslations } from "next-intl";
+import { useSearchParams } from "next/navigation";
+import { Suspense, useEffect, useState } from "react";
+
+function PluginOAuthCallbackInner() {
+  const searchParams = useSearchParams();
+  const t = useTranslations("plugins");
+  const [status, setStatus] = useState<"waiting" | "ok" | "error">("waiting");
+  const [errorMessage, setErrorMessage] = useState<string | null>(null);
+
+  useEffect(() => {
+    const code = searchParams.get("code");
+    const state = searchParams.get("state");
+    const errorParam = searchParams.get("error");
+    const errorDescription = searchParams.get("error_description");
+
+    // Build the payload to hand off. Error/denial responses still carry
+    // `state`, so the initiating plugin can match and terminate its pending
+    // flow instead of waiting forever.
+    let payload: OAuthCallbackPayload;
+    let errorMessageText: string;
+    if (errorParam) {
+      payload = {
+        state: state ?? undefined,
+        error: errorParam,
+        error_description: errorDescription ?? undefined,
+        receivedAt: Date.now(),
+      };
+      errorMessageText =
+        errorParam === "access_denied"
+          ? t("oauth_callback.denied")
+          : t("oauth_callback.failed_detail", { error: errorParam });
+    } else if (!code || !state) {
+      payload = { state: state ?? undefined, error: "invalid_request", receivedAt: Date.now() };
+      errorMessageText = t("oauth_callback.missing_params");
+    } else {
+      payload = { code, state, receivedAt: Date.now() };
+      errorMessageText = "";
+    }
+
+
+    let delivered = false;
+    try {
+      sessionStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+    } catch {
+      // sessionStorage unavailable - the event still fires for same-tab flows
+    }
+    try {
+      // localStorage (unlike sessionStorage) raises a `storage` event in the
+      // OTHER tabs of this origin - that is what carries the payload across
+      // to the tab where the plugin's background instance is running.
+      localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+      delivered = true;
+    } catch {
+      // localStorage unavailable - fall through to the same-tab CustomEvent
+    }
+    // Same-tab consumers can react immediately without waiting for storage.
+    window.dispatchEvent(
+      new CustomEvent(PLUGIN_OAUTH_EVENT, { detail: payload }),
+    );
+
+    if (errorMessageText) {
+      setErrorMessage(errorMessageText);
+      setStatus("error");
+    } else if (delivered) {
+      setStatus("ok");
+    } else {
+      // Storage write failed: the payload cannot reach the tab that started
+      // the flow (the listener is disabled on this route, so the same-tab
+      // event alone is not enough). Report failure instead of a false "ok".
+      setStatus("error");
+      setErrorMessage(t("oauth_callback.delivery_failed"));
+    }
+  }, [searchParams, t]);
+
+  return (
+    <OAuthStatusCard
+      icon={
+        status === "ok"
+          ? CheckCircle2
+          : status === "error"
+            ? XCircle
+            : undefined
+      }
+      iconClassName={
+        status === "ok"
+          ? "bg-green-500/10 text-green-600 dark:text-green-400"
+          : status === "error"
+            ? "bg-destructive/10 text-destructive"
+            : undefined
+      }
+      title={
+        status === "waiting"
+          ? t("oauth_callback.completing")
+          : status === "ok"
+            ? t("oauth_callback.received_title")
+            : t("oauth_callback.failed_title")
+      }
+      message={
+        status === "waiting"
+          ? t("oauth_callback.completing_message")
+          : status === "ok"
+            ? t("oauth_callback.received_message")
+            : (errorMessage ?? undefined)
+      }
+    />
+  );
+}
+
+export default function PluginOAuthCallbackPage() {
+  return (
+    <Suspense fallback={<OAuthStatusCard title="" />}>
+      <PluginOAuthCallbackInner />
+    </Suspense>
+  );
+}
diff --git a/components/__tests__/plugin-oauth-callback-listener.test.tsx b/components/__tests__/plugin-oauth-callback-listener.test.tsx
new file mode 100644
index 000000000..6b738810c
--- /dev/null
+++ b/components/__tests__/plugin-oauth-callback-listener.test.tsx
@@ -0,0 +1,173 @@
+import { authHooks } from "@/lib/plugin-hooks";
+import {
+    PLUGIN_OAUTH_EVENT,
+    PLUGIN_OAUTH_STORAGE_KEY,
+} from "@/lib/plugin-oauth";
+import { act, render } from "@testing-library/react";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { PluginOAuthCallbackListener } from "../providers/plugin-oauth-callback-listener";
+
+vi.mock("next/navigation", () => ({
+  usePathname: vi.fn(),
+}));
+
+import { usePathname } from "next/navigation";
+const mockUsePathname = vi.mocked(usePathname);
+
+function emitStorageEvent(newValue: string | null) {
+  act(() => {
+    window.dispatchEvent(
+      new StorageEvent("storage", {
+        key: PLUGIN_OAUTH_STORAGE_KEY,
+        newValue,
+      }),
+    );
+  });
+}
+
+describe("PluginOAuthCallbackListener", () => {
+  let handler: (payload: unknown) => Promise<void>;
+  let disposable: { dispose: () => void };
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    localStorage.clear();
+    mockUsePathname.mockReturnValue("/en/mail");
+    handler = vi.fn<(payload: unknown) => Promise<void>>().mockResolvedValue(undefined);
+    disposable = authHooks.onOAuthCallback.register("test-plugin", handler);
+  });
+
+  afterEach(() => {
+    disposable.dispose();
+  });
+
+  it("delivers a success payload via the storage event", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+    const payload = { code: "abc", state: "xyz", receivedAt: 1 };
+    localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+
+    emitStorageEvent(JSON.stringify(payload));
+
+    expect(handler).toHaveBeenCalledOnce();
+    expect(handler).toHaveBeenCalledWith(
+      expect.objectContaining({ code: "abc", state: "xyz" }),
+    );
+    // Best-effort cleanup after delivery
+    expect(localStorage.getItem(PLUGIN_OAUTH_STORAGE_KEY)).toBeNull();
+    unmount();
+  });
+
+  it("delivers an error payload (denial) with state", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+    const payload = { state: "xyz", error: "access_denied", receivedAt: 1 };
+    localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+
+    emitStorageEvent(JSON.stringify(payload));
+
+    expect(handler).toHaveBeenCalledOnce();
+    expect(handler).toHaveBeenCalledWith(
+      expect.objectContaining({ state: "xyz", error: "access_denied" }),
+    );
+    unmount();
+  });
+
+  it("does nothing on the callback route", () => {
+    mockUsePathname.mockReturnValue("/en/plugins/oauth/callback");
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+    const payload = { code: "abc", state: "xyz", receivedAt: 1 };
+    localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+
+    emitStorageEvent(JSON.stringify(payload));
+    act(() => {
+      window.dispatchEvent(
+        new CustomEvent(PLUGIN_OAUTH_EVENT, { detail: payload }),
+      );
+    });
+
+    expect(handler).not.toHaveBeenCalled();
+    // No cleanup either - the payload stays parked for the other tab
+    expect(localStorage.getItem(PLUGIN_OAUTH_STORAGE_KEY)).toBe(payload ? JSON.stringify(payload) : null);
+    unmount();
+  });
+
+  it("ignores malformed payloads", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+
+    emitStorageEvent("not json");
+    emitStorageEvent(JSON.stringify({ foo: "bar" }));
+    emitStorageEvent(JSON.stringify({ code: 123, state: "xyz" }));
+    emitStorageEvent(null);
+
+    expect(handler).not.toHaveBeenCalled();
+    unmount();
+  });
+
+  it("ignores payloads without state", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+
+    // A payload with no state at all cannot be matched to any pending flow,
+    // so the listener drops it rather than broadcasting an unmatchable event.
+    emitStorageEvent(JSON.stringify({ code: "abc", receivedAt: 1 }));
+    emitStorageEvent(JSON.stringify({ error: "server_error", receivedAt: 1 }));
+
+    expect(handler).not.toHaveBeenCalled();
+    unmount();
+  });
+
+  it("deduplicates identical payloads within the window", async () => {
+    vi.useFakeTimers();
+    try {
+      vi.setSystemTime(0);
+      const { unmount } = render(<PluginOAuthCallbackListener />);
+      const payload = { code: "abc", state: "xyz", receivedAt: 1 };
+      localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+
+      emitStorageEvent(JSON.stringify(payload));
+      emitStorageEvent(JSON.stringify(payload));
+
+      expect(handler).toHaveBeenCalledOnce();
+
+      // Outside the dedup window the same payload is delivered again
+      vi.setSystemTime(61_000);
+      emitStorageEvent(JSON.stringify(payload));
+      expect(handler).toHaveBeenCalledTimes(2);
+
+      unmount();
+    } finally {
+      vi.useRealTimers();
+    }
+  });
+
+  it("delivers same-tab custom events", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+    const payload = { code: "abc", state: "xyz", receivedAt: 1 };
+
+    act(() => {
+      window.dispatchEvent(
+        new CustomEvent(PLUGIN_OAUTH_EVENT, { detail: payload }),
+      );
+    });
+
+    expect(handler).toHaveBeenCalledOnce();
+    expect(handler).toHaveBeenCalledWith(
+      expect.objectContaining({ code: "abc", state: "xyz" }),
+    );
+    unmount();
+  });
+
+  it("stops listening after unmount", () => {
+    const { unmount } = render(<PluginOAuthCallbackListener />);
+    unmount();
+
+    const payload = { code: "abc", state: "xyz", receivedAt: 1 };
+    localStorage.setItem(PLUGIN_OAUTH_STORAGE_KEY, JSON.stringify(payload));
+    emitStorageEvent(JSON.stringify(payload));
+    act(() => {
+      window.dispatchEvent(
+        new CustomEvent(PLUGIN_OAUTH_EVENT, { detail: payload }),
+      );
+    });
+
+    expect(handler).not.toHaveBeenCalled();
+  });
+});
diff --git a/components/auth/oauth-status-card.tsx b/components/auth/oauth-status-card.tsx
new file mode 100644
index 000000000..d4b6348bf
--- /dev/null
+++ b/components/auth/oauth-status-card.tsx
@@ -0,0 +1,113 @@
+"use client";
+
+/**
+ * Branded full-screen status card for OAuth callback pages.
+ */
+
+import { Button } from "@/components/ui/button";
+import { useConfig } from "@/hooks/use-config";
+import { withBasePath } from "@/lib/browser-navigation";
+import { cn } from "@/lib/utils";
+import { useThemeStore } from "@/stores/theme-store";
+import type { LucideIcon } from "lucide-react";
+import { Loader2 } from "lucide-react";
+
+export interface OAuthStatusAction {
+  label: string;
+  onClick: () => void;
+}
+
+export interface OAuthStatusCardProps {
+  /** Icon badge shown below the logo (defaults to a spinner) */
+  icon?: LucideIcon;
+  /** Tailwind color classes for the icon badge, e.g. "bg-green-500/10 text-green-600" */
+  iconClassName?: string;
+  title: string;
+  message?: string;
+  action?: OAuthStatusAction;
+  /** Extra content rendered below the message (e.g. detail lines) */
+  children?: React.ReactNode;
+}
+
+export function OAuthStatusCard({
+  icon: Icon,
+  iconClassName,
+  title,
+  message,
+  action,
+  children,
+}: OAuthStatusCardProps) {
+  const {
+    appName,
+    appLogoLightUrl,
+    appLogoDarkUrl,
+    loginLogoLightUrl,
+    loginLogoDarkUrl,
+  } = useConfig();
+  const resolvedTheme = useThemeStore((s) => s.resolvedTheme);
+
+  // Same logo resolution order as the admin layout: app logo first, then the
+  // login logo (which has Bulwark defaults), so an unbranded instance still
+  // shows the Bulwark mark.
+  const logoUrl = withBasePath(
+    resolvedTheme === "dark"
+      ? appLogoDarkUrl || appLogoLightUrl || loginLogoDarkUrl
+      : appLogoLightUrl || appLogoDarkUrl || loginLogoLightUrl,
+  );
+
+  return (
+    <div className="min-h-dvh flex flex-col items-center justify-center bg-linear-to-br from-background via-background to-muted/20 px-4 py-10">
+      <div className="w-full max-w-100 mx-auto">
+        <div className="rounded-2xl border border-border/60 bg-background/80 backdrop-blur-sm shadow-xl shadow-black/5 dark:shadow-black/20 overflow-hidden">
+          {/* Header with instance branding */}
+          <div className="px-8 pt-10 pb-6 text-center">
+            <div className="inline-flex items-center justify-center w-16 h-16 mb-5">
+              <img
+                src={logoUrl}
+                alt={appName}
+                className="max-w-16 max-h-16 object-contain"
+              />
+            </div>
+            <h1 className="text-2xl font-semibold text-foreground tracking-tight">
+              {appName}
+            </h1>
+
+            {/* Status badge */}
+            <div
+              className={cn(
+                "mt-6 inline-flex items-center justify-center w-14 h-14 rounded-2xl",
+                iconClassName ?? "bg-primary/10 text-primary",
+              )}
+            >
+              {Icon ? (
+                <Icon className="w-7 h-7" />
+              ) : (
+                <Loader2 className="w-7 h-7 animate-spin" />
+              )}
+            </div>
+          </div>
+
+          {/* Status body */}
+          <div className="px-8 pb-10 pt-0 text-center">
+            <p className="text-base font-medium text-foreground">{title}</p>
+            {message && (
+              <p className="text-sm text-muted-foreground mt-1.5 leading-relaxed">
+                {message}
+              </p>
+            )}
+            {children}
+            {action && (
+              <Button
+                variant="outline"
+                className="mt-6"
+                onClick={action.onClick}
+              >
+                {action.label}
+              </Button>
+            )}
+          </div>
+        </div>
+      </div>
+    </div>
+  );
+}
diff --git a/components/providers/plugin-oauth-callback-listener.tsx b/components/providers/plugin-oauth-callback-listener.tsx
new file mode 100644
index 000000000..3b4299257
--- /dev/null
+++ b/components/providers/plugin-oauth-callback-listener.tsx
@@ -0,0 +1,109 @@
+'use client';
+
+/**
+ * Bridges third-party OAuth callbacks to plugins.
+ *
+ * The generic callback page (`/[locale]/plugins/oauth/callback`) parks the
+ * provider's `{ code, state }` payload in localStorage. A `storage` event
+ * fires in every OTHER same-origin tab - i.e. in the tab where the plugin's
+ * background sandbox instance is actually running. This listener forwards
+ * those payloads (and same-tab CustomEvents from the callback page) into the
+ * `authHooks.onOAuthCallback` hook bus so plugins can finish their PKCE
+ * exchange.
+ *
+ * This component intentionally does nothing when mounted ON the callback
+ * route: the callback tab must not process its own payload, otherwise two
+ * app instances would race to exchange the single-use authorization code.
+ */
+
+import { authHooks } from '@/lib/plugin-hooks';
+import {
+  PLUGIN_OAUTH_EVENT as EVENT_NAME,
+  PLUGIN_OAUTH_STORAGE_KEY as STORAGE_KEY,
+  type OAuthCallbackPayload,
+} from '@/lib/plugin-oauth';
+import { usePathname } from 'next/navigation';
+import { useEffect } from 'react';
+
+/** Window in which identical payloads are treated as duplicates. */
+const DEDUP_MS = 60_000;
+
+function parsePayload(raw: string | null | undefined): OAuthCallbackPayload | null {
+  if (!raw) return null;
+  try {
+    const parsed = JSON.parse(raw) as Record<string, unknown>;
+    if (typeof parsed !== 'object' || parsed === null) {
+      return null;
+    }
+    const state = typeof parsed.state === 'string' ? parsed.state : undefined;
+    // A payload without `state` cannot be matched to any pending flow, so
+    // drop it instead of broadcasting an unmatchable event.
+    if (state === undefined) {
+      return null;
+    }
+    const receivedAt = typeof parsed.receivedAt === 'number' ? parsed.receivedAt : Date.now();
+    // Success payloads carry { code, ... }; error/denial payloads carry
+    // { error, ... }. Exactly one must identify the kind.
+    if (typeof parsed.code === 'string') {
+      return { code: parsed.code, state, receivedAt };
+    }
+    if (typeof parsed.error === 'string') {
+      return {
+        error: parsed.error,
+        state,
+        error_description:
+          typeof parsed.error_description === 'string' ? parsed.error_description : undefined,
+        receivedAt,
+      };
+    }
+    return null;
+  } catch {
+    return null;
+  }
+}
+
+export function PluginOAuthCallbackListener() {
+  const pathname = usePathname();
+  // The callback route ends with /plugins/oauth/callback (locale is a
+  // preceding segment). On that route this component is a no-op.
+  const isCallbackRoute = !!pathname && pathname.endsWith('/plugins/oauth/callback');
+
+  useEffect(() => {
+    if (isCallbackRoute) return;
+
+    let lastCode: string | null = null;
+    let lastState: string | null = null;
+    let lastAt = 0;
+
+    const deliver = (payload: OAuthCallbackPayload | null) => {
+      if (!payload) return;
+      const now = Date.now();
+      const code = 'code' in payload ? payload.code : null;
+      if (code === lastCode && payload.state === lastState && now - lastAt < DEDUP_MS) return;
+      lastCode = code;
+      lastState = payload.state ?? null;
+      lastAt = now;
+      void authHooks.onOAuthCallback.emit(payload);
+      // Best-effort cleanup so a reload doesn't replay an old payload.
+      try { localStorage.removeItem(STORAGE_KEY); } catch { /* ignore */ }
+    };
+
+    const onStorage = (ev: StorageEvent) => {
+      if (ev.key !== STORAGE_KEY && ev.key !== null) return;
+      deliver(parsePayload(ev.newValue ?? (() => { try { return localStorage.getItem(STORAGE_KEY); } catch { return null; } })()));
+    };
+    const onCustomEvent = (ev: Event) => {
+      const detail = (ev as CustomEvent<OAuthCallbackPayload>).detail;
+      if (detail) deliver(detail);
+    };
+
+    window.addEventListener('storage', onStorage);
+    window.addEventListener(EVENT_NAME, onCustomEvent);
+    return () => {
+      window.removeEventListener('storage', onStorage);
+      window.removeEventListener(EVENT_NAME, onCustomEvent);
+    };
+  }, [isCallbackRoute]);
+
+  return null;
+}
diff --git a/lib/plugin-hooks.ts b/lib/plugin-hooks.ts
index 2b963fac9..fcb76f605 100644
--- a/lib/plugin-hooks.ts
+++ b/lib/plugin-hooks.ts
@@ -427,6 +427,15 @@ export const authHooks = {
   onAccountRemove: new HookBus(),
   onTokenRefresh: new HookBus(),
   onAuthReady: new HookBus(),
+  /**
+   * Fired when a third-party OAuth provider redirects back to the generic
+   * plugin OAuth callback page (`/[locale]/plugins/oauth/callback`). The
+   * payload is `{ code, state, receivedAt }` exactly as the provider sent it.
+   * Each plugin validates `state` against the verifier it stashed before
+   * redirecting, so plugins that did not initiate a flow simply ignore the
+   * event. See `components/providers/plugin-oauth-callback-listener.tsx`.
+   */
+  onOAuthCallback: new HookBus(),
 };
 
 // §7.6 Settings Hooks
diff --git a/lib/plugin-oauth.ts b/lib/plugin-oauth.ts
new file mode 100644
index 000000000..16149e104
--- /dev/null
+++ b/lib/plugin-oauth.ts
@@ -0,0 +1,32 @@
+/**
+ * Shared constants and types for the plugin OAuth callback handoff.
+ *
+ * The callback page (`/[locale]/plugins/oauth/callback`) parks the provider's
+ * payload in storage and dispatches events; the host relays it to plugins via
+ * the `authHooks.onOAuthCallback` hook bus. Both sides share the storage key,
+ * event name and payload contract from this module.
+ */
+
+export const PLUGIN_OAUTH_STORAGE_KEY = "plugin-oauth-callback";
+export const PLUGIN_OAUTH_EVENT = "plugin-oauth-callback";
+
+/**
+ * Payload delivered to plugins through `authHooks.onOAuthCallback`.
+ *
+ * Two shapes, discriminated by which field the provider returned:
+ * - Success: `{ code, state?, receivedAt? }`
+ * - Denial/failure: `{ error, state?, error_description?, receivedAt? }`
+ *
+ * `state` stays optional in both variants because a provider may omit it even
+ * on error; plugins match the flow against the verifier they stashed before
+ * redirecting and ignore payloads whose `state` does not match. Narrow with
+ * `'code' in payload` / `'error' in payload`.
+ */
+export type OAuthCallbackPayload =
+    | { code: string; state?: string; receivedAt?: number }
+    | {
+        error: string;
+        state?: string;
+        error_description?: string;
+        receivedAt?: number;
+    };
diff --git a/lib/plugin-sandbox/host-api.ts b/lib/plugin-sandbox/host-api.ts
index 161bdf36f..46511d708 100644
--- a/lib/plugin-sandbox/host-api.ts
+++ b/lib/plugin-sandbox/host-api.ts
@@ -27,7 +27,7 @@ import { KEYWORD_PREFIX } from '../thread-utils';
 import { awaitDialog, awaitPrompt, type PromptField } from './host-dialog';
 import { fileStorage } from '../plugin-storage';
 import { generateUUID } from '../utils';
-import { ContactCard, Identity } from '../jmap/types';
+import { AddressBook, ContactCard, Identity } from '../jmap/types';
 import { EncryptionAtRestConfig, PublicKeyInfo, PublicKeyInput, useAccountSecurityStore } from '@/stores/account-security-store';
 import { createHash } from 'crypto';
 
@@ -113,6 +113,11 @@ const PERM_PER_METHOD: Record<string, Permission | null> = {
   'contact.update': 'contacts:write',
   'contact.create': 'contacts:write',
   'contact.search': 'contacts:read',
+  'contact.list': 'contacts:read',
+  'contact.delete': 'contacts:write',
+  // addressbook
+  'addressbook.list': 'contacts:read',
+  'addressbook.create': 'contacts:write',
   // user
   'user.getAccounts': 'account:read',
   'user.getIdentities': 'identity:read',
@@ -648,6 +653,42 @@ async function doContactCreate(contact: ContactCard): Promise<ContactCard> {
   return await client.createContact(contact);
 }
 
+async function doContactList(addressBookId?: string): Promise<ContactCard[]> {
+  const { client } = useAuthStore.getState();
+  if (!client) {
+    throw new Error('contact.list: no active session');
+  }
+  // Propagate failures: a plugin must not mistake an outage for an empty
+  // address book.
+  return await client.getContacts(addressBookId, { throwOnError: true });
+}
+
+async function doContactDelete(contactId: string): Promise<void> {
+  const { client } = useAuthStore.getState();
+  if (!client) {
+    throw new Error('contact.delete: no active session');
+  }
+  await client.deleteContact(contactId);
+}
+
+async function doAddressBookList(): Promise<AddressBook[]> {
+  const { client } = useAuthStore.getState();
+  if (!client) {
+    throw new Error('addressbook.list: no active session');
+  }
+  // Propagate failures so plugins can tell "no books" from a failed fetch
+  // (see #730).
+  return await client.getAddressBooks({ throwOnError: true });
+}
+
+async function doAddressBookCreate(name: string): Promise<AddressBook> {
+  const { client } = useAuthStore.getState();
+  if (!client) {
+    throw new Error('addressbook.create: no active session');
+  }
+  return await client.createAddressBook(name);
+}
+
 // ─── Crypto (privileged tier) ─────────────────────────────────────────────
 
 type PRFResult = 
@@ -1406,6 +1447,11 @@ export async function dispatchApiCall(
     case 'contact.update': return doContactUpdate(args[0] as string, args[1] as Partial<ContactCard>);
     case 'contact.create': return doContactCreate(args[0] as ContactCard);
     case 'contact.search': return doContactSearch(args[0] as string);
+    case 'contact.list': return doContactList(args[0] as string | undefined);
+    case 'contact.delete': return doContactDelete(args[0] as string);
+    
+    case 'addressbook.list': return doAddressBookList();
+    case 'addressbook.create': return doAddressBookCreate(args[0] as string);
 
     case 'user.getAccounts':   return doUserGetAccounts();
     case 'user.getIdentities': return doUserGetIdentities();
diff --git a/lib/plugin-sandbox/runtime.tsx b/lib/plugin-sandbox/runtime.tsx
index 1307e1ea1..6e9a5f297 100644
--- a/lib/plugin-sandbox/runtime.tsx
+++ b/lib/plugin-sandbox/runtime.tsx
@@ -29,7 +29,7 @@ import type {
 } from './protocol';
 import { themeSnapshotToCSS, type ThemeSnapshot } from './host-theme';
 import type { SlotName } from '../plugin-types';
-import { ContactCard } from '../jmap/types';
+import { AddressBook, ContactCard } from '../jmap/types';
 import { EncryptionAtRestConfig, PublicKeyInput } from '@/stores/account-security-store';
 
 // ─── Module-scope state ──────────────────────────────────────
@@ -279,10 +279,16 @@ function buildPluginApi(manifest: PluginManifest) {
       ) => callApi('jmap.importRaw', [rawBytes, mailboxRoles, opts]),
     },
     contacts: {
-      get: (contactId: string) => callApi('contact.get', [contactId]) as Promise<ContactCard>,
-      update: (contactId: string, updates: Partial<ContactCard>) => callApi('contact.update', [contactId, updates]),
-      create: (contact: ContactCard) => callApi('contact.create', [contact]) as Promise<string>,
+      get: (contactId: string) => callApi('contact.get', [contactId]) as Promise<ContactCard | null>,
+      update: (contactId: string, updates: Partial<ContactCard>) => callApi('contact.update', [contactId, updates]) as Promise<void>,
+      create: (contact: ContactCard) => callApi('contact.create', [contact]) as Promise<ContactCard>,
       search: (query: string) => callApi('contact.search', [query]) as Promise<ContactCard[]>,
+      list: (addressBookId?: string) => callApi('contact.list', [addressBookId]) as Promise<ContactCard[]>,
+      remove: (contactId: string) => callApi('contact.delete', [contactId]) as Promise<void>,
+    },
+    addressBooks: {
+      list: () => callApi('addressbook.list', []) as Promise<AddressBook[]>,
+      create: (name: string) => callApi('addressbook.create', [name]) as Promise<AddressBook>,
     },
     /**
      * Used to alterate files before they are uploaded to server.
diff --git a/locales/ar/common.json b/locales/ar/common.json
index 1b2131aba..e1c8f45c4 100644
--- a/locales/ar/common.json
+++ b/locales/ar/common.json
@@ -303,9 +303,7 @@
     "move": "نقل",
     "print": "طباعة",
     "view_source": "عرض المصدر",
-
     "fullscreen": "ملء الشاشة",
-
     "exit_fullscreen": "الخروج من ملء الشاشة",
     "export_email": "تصدير كملف ‎.eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "نسخ رابط الحدث",
     "copied": "تم نسخ الرابط",
     "copy_failed": "تعذّر نسخ الرابط"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "جارٍ إكمال التفويض…",
+      "completing_message": "يرجى الانتظار بينما يتم إنشاء الاتصال.",
+      "received_title": "تم استلام التفويض",
+      "received_message": "يمكنك العودة إلى علامة التبويب التي بدأت فيها الاتصال.",
+      "failed_title": "فشل التفويض",
+      "denied": "تم رفض التفويض.",
+      "failed_detail": "فشل التفويض: {error}",
+      "missing_params": "رمز التفويض أو الحالة مفقود.",
+      "delivery_failed": "تعذّر إرسال نتيجة التفويض إلى تبويب التطبيق. يرجى إغلاق هذه النافذة والمحاولة مرة أخرى."
+    }
   }
 }
diff --git a/locales/ca/common.json b/locales/ca/common.json
index b6029b40d..bc41d46f7 100644
--- a/locales/ca/common.json
+++ b/locales/ca/common.json
@@ -303,9 +303,7 @@
     "move": "Mou",
     "print": "Imprimeix",
     "view_source": "Mostra el codi font",
-
     "fullscreen": "Pantalla completa",
-
     "exit_fullscreen": "Surt de la pantalla completa",
     "export_email": "Exporta com a .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copia l'enllaç de l'esdeveniment",
     "copied": "Enllaç copiat",
     "copy_failed": "No s'ha pogut copiar l'enllaç"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Completant l'autorització…",
+      "completing_message": "Espereu mentre s'estableix la connexió.",
+      "received_title": "S'ha rebut l'autorització",
+      "received_message": "Podeu tornar a la pestanya on heu iniciat la connexió.",
+      "failed_title": "Ha fallat l'autorització",
+      "denied": "Sha denegat lautorització.",
+      "failed_detail": "Ha fallat lautorització: {error}",
+      "missing_params": "Falta el codi dautorització o lestat.",
+      "delivery_failed": "No sha pogut lliurar el resultat de lautorització a la pestanya de laplicació. Tanqueu aquesta finestra i torneu-ho a provar."
+    }
   }
 }
diff --git a/locales/cs/common.json b/locales/cs/common.json
index b4fb5c477..5074f2199 100644
--- a/locales/cs/common.json
+++ b/locales/cs/common.json
@@ -303,9 +303,7 @@
     "move": "Přesunout",
     "print": "Tisk",
     "view_source": "Zobrazit zdrojový kód",
-
     "fullscreen": "Celá obrazovka",
-
     "exit_fullscreen": "Ukončit režim celé obrazovky",
     "export_email": "Exportovat jako .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Kopírovat odkaz na událost",
     "copied": "Odkaz zkopírován",
     "copy_failed": "Odkaz se nepodařilo zkopírovat"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Dokončování autorizace…",
+      "completing_message": "Počkejte prosím, než se naváže spojení.",
+      "received_title": "Autorizace přijata",
+      "received_message": "Můžete se vrátit na kartu, kde jste zahájili připojení.",
+      "failed_title": "Autorizace se nezdařila",
+      "denied": "Autorizace byla zamítnuta.",
+      "failed_detail": "Autorizace se nezdařila: {error}",
+      "missing_params": "Chybí autorizační kód nebo stav.",
+      "delivery_failed": "Výsledek autorizace se nepodařilo předat kartě aplikace. Zavřete toto okno a zkuste to znovu."
+    }
   }
 }
diff --git a/locales/da/common.json b/locales/da/common.json
index bfb8a80cf..648f88fc7 100644
--- a/locales/da/common.json
+++ b/locales/da/common.json
@@ -303,9 +303,7 @@
     "move": "Flyt",
     "print": "Udskriv",
     "view_source": "Vis kilde",
-
     "fullscreen": "Fuld skærm",
-
     "exit_fullscreen": "Afslut fuld skærm",
     "export_email": "Eksportér som .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Kopier link til begivenhed",
     "copied": "Link kopieret",
     "copy_failed": "Kunne ikke kopiere linket"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Fuldfører godkendelse…",
+      "completing_message": "Vent venligst, mens forbindelsen oprettes.",
+      "received_title": "Godkendelse modtaget",
+      "received_message": "Du kan vende tilbage til den fane, hvor du startede forbindelsen.",
+      "failed_title": "Godkendelse mislykkedes",
+      "denied": "Godkendelse blev nægtet.",
+      "failed_detail": "Godkendelse mislykkedes: {error}",
+      "missing_params": "Autorisationskode eller tilstand mangler.",
+      "delivery_failed": "Resultatet af godkendelsen kunne ikke leveres til app-fanen. Luk dette vindue og prøv igen."
+    }
   }
 }
diff --git a/locales/de/common.json b/locales/de/common.json
index bee259d61..3c0836cce 100644
--- a/locales/de/common.json
+++ b/locales/de/common.json
@@ -303,9 +303,7 @@
     "move": "Verschieben",
     "print": "Drucken",
     "view_source": "Quelltext anzeigen",
-
     "fullscreen": "Vollbild",
-
     "exit_fullscreen": "Vollbild beenden",
     "export_email": "Als .eml exportieren",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Link zum Termin kopieren",
     "copied": "Link kopiert",
     "copy_failed": "Link konnte nicht kopiert werden"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Autorisierung wird abgeschlossen…",
+      "completing_message": "Bitte warten, während die Verbindung hergestellt wird.",
+      "received_title": "Autorisierung empfangen",
+      "received_message": "Sie können zu dem Tab zurückkehren, in dem Sie die Verbindung gestartet haben.",
+      "failed_title": "Autorisierung fehlgeschlagen",
+      "denied": "Autorisierung wurde verweigert.",
+      "failed_detail": "Autorisierung fehlgeschlagen: {error}",
+      "missing_params": "Autorisierungscode oder State fehlt.",
+      "delivery_failed": "Das Autorisierungsergebnis konnte nicht an den App-Tab übermittelt werden. Bitte schließen Sie dieses Fenster und versuchen Sie es erneut."
+    }
   }
 }
diff --git a/locales/en/common.json b/locales/en/common.json
index 10ba19cba..6084976c7 100644
--- a/locales/en/common.json
+++ b/locales/en/common.json
@@ -303,9 +303,7 @@
     "move": "Move",
     "print": "Print",
     "view_source": "View source",
-
     "fullscreen": "Fullscreen",
-
     "exit_fullscreen": "Exit fullscreen",
     "export_email": "Export as .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -1670,7 +1668,7 @@
         "disable_tooltip": "Disable encryption",
         "enabled_success": "Encryption at rest enabled"
       },
-      "public_keys":{
+      "public_keys": {
         "name_label": "Public Key name",
         "name_placeholder": "e.g. My Key",
         "key_label": "Public Key (S/MIME or PGP ASCII-armored)",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copy link to event",
     "copied": "Link copied",
     "copy_failed": "Couldn't copy the link"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Completing authorization…",
+      "completing_message": "Please wait while the connection is established.",
+      "received_title": "Authorization received",
+      "received_message": "You can return to the tab where you started the connection.",
+      "failed_title": "Authorization failed",
+      "denied": "Authorization was denied.",
+      "failed_detail": "Authorization failed: {error}",
+      "missing_params": "Missing authorization code or state.",
+      "delivery_failed": "The authorization result could not be delivered to the app tab. Please close this window and try again."
+    }
   }
 }
diff --git a/locales/es/common.json b/locales/es/common.json
index 32aeffe4b..504aab1bc 100644
--- a/locales/es/common.json
+++ b/locales/es/common.json
@@ -303,9 +303,7 @@
     "move": "Mover",
     "print": "Imprimir",
     "view_source": "Ver código fuente",
-
     "fullscreen": "Pantalla completa",
-
     "exit_fullscreen": "Salir de pantalla completa",
     "export_email": "Exportar como .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copiar enlace del evento",
     "copied": "Enlace copiado",
     "copy_failed": "No se pudo copiar el enlace"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Completando la autorización…",
+      "completing_message": "Por favor, espera mientras se establece la conexión.",
+      "received_title": "Autorización recibida",
+      "received_message": "Puedes volver a la pestaña donde iniciaste la conexión.",
+      "failed_title": "Error de autorización",
+      "denied": "Se denegó la autorización.",
+      "failed_detail": "Error de autorización: {error}",
+      "missing_params": "Falta el código de autorización o el estado.",
+      "delivery_failed": "No se pudo entregar el resultado de la autorización a la pestaña de la aplicación. Cierre esta ventana e inténtelo de nuevo."
+    }
   }
 }
diff --git a/locales/fa/common.json b/locales/fa/common.json
index 4bba7084b..31b3bb449 100644
--- a/locales/fa/common.json
+++ b/locales/fa/common.json
@@ -303,9 +303,7 @@
     "move": "انتقال",
     "print": "چاپ",
     "view_source": "مشاهده منبع",
-
     "fullscreen": "تمام‌صفحه",
-
     "exit_fullscreen": "خروج از تمام‌صفحه",
     "export_email": "خروجی .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "کپی پیوند رویداد",
     "copied": "پیوند کپی شد",
     "copy_failed": "کپی پیوند ممکن نشد"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "در حال تکمیل احراز هویت…",
+      "completing_message": "لطفاً تا برقراری اتصال منتظر بمانید.",
+      "received_title": "احراز هویت دریافت شد",
+      "received_message": "می‌توانید به برگه‌ای که اتصال را در آن آغاز کردید بازگردید.",
+      "failed_title": "احراز هویت ناموفق بود",
+      "denied": "احراز هویت رد شد.",
+      "failed_detail": "احراز هویت ناموفق بود: {error}",
+      "missing_params": "کد احراز هویت یا حالت وجود ندارد.",
+      "delivery_failed": "نتیجه احراز هویت به برگه برنامه ارسال نشد. لطفاً این پنجره را ببندید و دوباره تلاش کنید."
+    }
   }
 }
diff --git a/locales/fr/common.json b/locales/fr/common.json
index b91e136c7..506dcc56b 100644
--- a/locales/fr/common.json
+++ b/locales/fr/common.json
@@ -303,9 +303,7 @@
     "move": "Déplacer",
     "print": "Imprimer",
     "view_source": "Voir la source",
-
     "fullscreen": "Plein écran",
-
     "exit_fullscreen": "Quitter le plein écran",
     "export_email": "Exporter en .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copier le lien de l'événement",
     "copied": "Lien copié",
     "copy_failed": "Impossible de copier le lien"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Finalisation de l'autorisation…",
+      "completing_message": "Veuillez patienter pendant l'établissement de la connexion.",
+      "received_title": "Autorisation reçue",
+      "received_message": "Vous pouvez revenir à l'onglet où vous avez commencé la connexion.",
+      "failed_title": "Échec de l'autorisation",
+      "denied": "Lautorisation a été refusée.",
+      "failed_detail": "Échec de lautorisation : {error}",
+      "missing_params": "Code dautorisation ou état manquant.",
+      "delivery_failed": "Le résultat de lautorisation na pas pu être transmis à longlet de lapplication. Fermez cette fenêtre et réessayez."
+    }
   }
 }
diff --git a/locales/he/common.json b/locales/he/common.json
index 33f67d331..c9d870c3d 100644
--- a/locales/he/common.json
+++ b/locales/he/common.json
@@ -250,9 +250,7 @@
     "mark_read": "סמן כנקרא",
     "print": "הדפס",
     "view_source": "צפה במקור",
-
     "fullscreen": "מסך מלא",
-
     "exit_fullscreen": "יציאה ממסך מלא",
     "export_email": "ייצא כ-.eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3542,5 +3540,18 @@
     "copy_event": "העתק קישור לאירוע",
     "copied": "הקישור הועתק",
     "copy_failed": "לא ניתן להעתיק את הקישור"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "משלים אימות…",
+      "completing_message": "אנא המתן בזמן יצירת החיבור.",
+      "received_title": "האימות התקבל",
+      "received_message": "באפשרותך לחזור לכרטיסייה שבה התחלת את החיבור.",
+      "failed_title": "האימות נכשל",
+      "denied": "האימות נדחה.",
+      "failed_detail": "האימות נכשל: {error}",
+      "missing_params": "חסר קוד אימות או מצב.",
+      "delivery_failed": "לא ניתן היה למסור את תוצאת האימות לכרטיסיית האפליקציה. סגרו חלון זה ונסו שוב."
+    }
   }
 }
diff --git a/locales/hu/common.json b/locales/hu/common.json
index b2caaae19..88595ee30 100644
--- a/locales/hu/common.json
+++ b/locales/hu/common.json
@@ -303,9 +303,7 @@
     "move": "Áthelyezés",
     "print": "Nyomtatás",
     "view_source": "Forrás megtekintése",
-
     "fullscreen": "Teljes képernyő",
-
     "exit_fullscreen": "Kilépés a teljes képernyőből",
     "export_email": "Exportálás .eml-ként",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Esemény linkjének másolása",
     "copied": "Link másolva",
     "copy_failed": "Nem sikerült másolni a linket"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Hitelesítés befejezése…",
+      "completing_message": "Kérjük, várjon, amíg a kapcsolat létrejön.",
+      "received_title": "Hitelesítés fogadva",
+      "received_message": "Visszatérhet arra a lapra, ahol elindította a kapcsolódást.",
+      "failed_title": "A hitelesítés sikertelen",
+      "denied": "A hitelesítés megtagadva.",
+      "failed_detail": "A hitelesítés sikertelen: {error}",
+      "missing_params": "Hiányzik a hitelesítési kód vagy az állapot.",
+      "delivery_failed": "A hitelesítés eredményét nem sikerült átadni az alkalmazás lapjának. Zárja be ezt az ablakot, és próbálja újra."
+    }
   }
 }
diff --git a/locales/it/common.json b/locales/it/common.json
index 885d03edf..30f0f94b4 100644
--- a/locales/it/common.json
+++ b/locales/it/common.json
@@ -303,9 +303,7 @@
     "move": "Sposta",
     "print": "Stampa",
     "view_source": "Visualizza sorgente",
-
     "fullscreen": "Schermo intero",
-
     "exit_fullscreen": "Esci da schermo intero",
     "export_email": "Esporta come .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copia link all'evento",
     "copied": "Link copiato",
     "copy_failed": "Impossibile copiare il link"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Completamento dell'autorizzazione…",
+      "completing_message": "Attendi mentre viene stabilita la connessione.",
+      "received_title": "Autorizzazione ricevuta",
+      "received_message": "Puoi tornare alla scheda in cui hai avviato la connessione.",
+      "failed_title": "Autorizzazione non riuscita",
+      "denied": "Lautorizzazione è stata negata.",
+      "failed_detail": "Autorizzazione non riuscita: {error}",
+      "missing_params": "Codice di autorizzazione o stato mancante.",
+      "delivery_failed": "Impossibile consegnare il risultato dellautorizzazione alla scheda dellapp. Chiudi questa finestra e riprova."
+    }
   }
 }
diff --git a/locales/ja/common.json b/locales/ja/common.json
index e015c2886..09a831bd2 100644
--- a/locales/ja/common.json
+++ b/locales/ja/common.json
@@ -303,9 +303,7 @@
     "move": "移動",
     "print": "印刷",
     "view_source": "ソースを表示",
-
     "fullscreen": "全画面表示",
-
     "exit_fullscreen": "全画面表示を終了",
     "export_email": ".emlとしてエクスポート",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "予定のリンクをコピー",
     "copied": "リンクをコピーしました",
     "copy_failed": "リンクをコピーできませんでした"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "認証を完了しています…",
+      "completing_message": "接続が確立されるまでお待ちください。",
+      "received_title": "認証を受信しました",
+      "received_message": "接続を開始したタブに戻ることができます。",
+      "failed_title": "認証に失敗しました",
+      "denied": "認証が拒否されました。",
+      "failed_detail": "認証に失敗しました: {error}",
+      "missing_params": "認証コードまたはステートがありません。",
+      "delivery_failed": "認証結果をアプリのタブに渡せませんでした。このウィンドウを閉じて、もう一度お試しください。"
+    }
   }
 }
diff --git a/locales/ko/common.json b/locales/ko/common.json
index 21c29b049..7d7707208 100644
--- a/locales/ko/common.json
+++ b/locales/ko/common.json
@@ -303,9 +303,7 @@
     "move": "이동",
     "print": "인쇄",
     "view_source": "원본 보기",
-
     "fullscreen": "전체 화면",
-
     "exit_fullscreen": "전체 화면 종료",
     "export_email": ".eml 파일로 내보내기",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "일정 링크 복사",
     "copied": "링크가 복사되었습니다",
     "copy_failed": "링크를 복사하지 못했습니다"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "인증 완료 중…",
+      "completing_message": "연결이 설정되는 동안 잠시 기다려 주세요.",
+      "received_title": "인증 수신됨",
+      "received_message": "연결을 시작했던 탭으로 돌아갈 수 있습니다.",
+      "failed_title": "인증 실패",
+      "denied": "인증이 거부되었습니다.",
+      "failed_detail": "인증 실패: {error}",
+      "missing_params": "인증 코드 또는 상태가 누락되었습니다.",
+      "delivery_failed": "인증 결과를 앱 탭에 전달하지 못했습니다. 이 창을 닫고 다시 시도해 주세요."
+    }
   }
 }
diff --git a/locales/lv/common.json b/locales/lv/common.json
index cf0272b4e..1656d7040 100644
--- a/locales/lv/common.json
+++ b/locales/lv/common.json
@@ -303,9 +303,7 @@
     "move": "Pārvietot",
     "print": "Drukāt",
     "view_source": "Skatīt avota kodu",
-
     "fullscreen": "Pilnekrāna režīms",
-
     "exit_fullscreen": "Iziet no pilnekrāna režīma",
     "export_email": "Eksportēt kā .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Kopēt saiti uz notikumu",
     "copied": "Saite nokopēta",
     "copy_failed": "Neizdevās nokopēt saiti"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Pabeidz autorizāciju…",
+      "completing_message": "Lūdzu, uzgaidiet, kamēr tiek izveidots savienojums.",
+      "received_title": "Autorizācija saņemta",
+      "received_message": "Varat atgriezties cilnē, kurā sākāt savienojumu.",
+      "failed_title": "Autorizācija neizdevās",
+      "denied": "Autorizācija tika atteikta.",
+      "failed_detail": "Autorizācija neizdevās: {error}",
+      "missing_params": "Trūkst autorizācijas kods vai stāvoklis.",
+      "delivery_failed": "Autorizācijas rezultātu neizdevās nodot lietotnes cilnei. Aizveriet šo logu un mēģiniet vēlreiz."
+    }
   }
 }
diff --git a/locales/mn/common.json b/locales/mn/common.json
index 10b08e758..1c3a8b0a1 100644
--- a/locales/mn/common.json
+++ b/locales/mn/common.json
@@ -303,9 +303,7 @@
     "move": "Хөдөлгөөн",
     "print": "Хэвлэх",
     "view_source": "Эх сурвалжийг харах",
-
     "fullscreen": "Бүтэн дэлгэц",
-
     "exit_fullscreen": "Бүтэн дэлгэцээс гарах",
     "export_email": ".eml",
     "forward_as_attachment": "Хавсралт болгон дамжуулах",
@@ -3541,5 +3539,18 @@
     "copy_event": "Арга хэмжээний холбоосыг хуулах",
     "copied": "Холбоос хуулагдлаа",
     "copy_failed": "Холбоосыг хуулж чадсангүй"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Зөвшөөрлийг дуусгаж байна…",
+      "completing_message": "Холболт үүсэх хүртэл түр хүлээнэ үү.",
+      "received_title": "Зөвшөөрөл хүлээн авсан",
+      "received_message": "Та холболт эхлүүлсэн таб руугаа буцаж болно.",
+      "failed_title": "Зөвшөөрөл амжилтгүй болсон",
+      "denied": "Зөвшөөрөл олгохыг татгалзсан.",
+      "failed_detail": "Зөвшөөрөл амжилтгүй болсон: {error}",
+      "missing_params": "Зөвшөөрлийн код эсвэл төлөв байхгүй байна.",
+      "delivery_failed": "Зөвшөөрлийн үр дүнг аппын таб руу дамжуулж чадсангүй. Энэ цонхыг хаагаад дахин оролдоно уу."
+    }
   }
 }
diff --git a/locales/nb/common.json b/locales/nb/common.json
index c7b9998fd..0f669ed47 100644
--- a/locales/nb/common.json
+++ b/locales/nb/common.json
@@ -3539,5 +3539,18 @@
     "copy_event": "Kopier lenken til hendelsen",
     "copied": "Lenken er kopiert",
     "copy_failed": "Kunne ikke kopiere lenken"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Fullfører autorisering…",
+      "completing_message": "Vennligst vent mens tilkoblingen opprettes.",
+      "received_title": "Autorisering mottatt",
+      "received_message": "Du kan gå tilbake til fanen der du startet tilkoblingen.",
+      "failed_title": "Autorisering mislyktes",
+      "denied": "Autorisering ble avslått.",
+      "failed_detail": "Autorisering mislyktes: {error}",
+      "missing_params": "Mangler autorisasjonskode eller tilstand.",
+      "delivery_failed": "Autoriseringsresultatet kunne ikke leveres til app-fanen. Lukk dette vinduet og prøv igjen."
+    }
   }
 }
diff --git a/locales/nl/common.json b/locales/nl/common.json
index 51f38ff9c..395427c4e 100644
--- a/locales/nl/common.json
+++ b/locales/nl/common.json
@@ -303,9 +303,7 @@
     "move": "Verplaatsen",
     "print": "Afdrukken",
     "view_source": "Bron bekijken",
-
     "fullscreen": "Volledig scherm",
-
     "exit_fullscreen": "Volledig scherm sluiten",
     "export_email": "Exporteren als .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Link naar afspraak kopiëren",
     "copied": "Link gekopieerd",
     "copy_failed": "Kon de link niet kopiëren"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Autorisatie voltooien…",
+      "completing_message": "Even geduld terwijl de verbinding tot stand wordt gebracht.",
+      "received_title": "Autorisatie ontvangen",
+      "received_message": "Je kunt terugkeren naar het tabblad waar je de verbinding bent gestart.",
+      "failed_title": "Autorisatie mislukt",
+      "denied": "Autorisatie geweigerd.",
+      "failed_detail": "Autorisatie mislukt: {error}",
+      "missing_params": "Autorisatiecode of status ontbreekt.",
+      "delivery_failed": "Het autorisatieresultaat kon niet worden afgeleverd bij het app-tabblad. Sluit dit venster en probeer het opnieuw."
+    }
   }
 }
diff --git a/locales/pl/common.json b/locales/pl/common.json
index 70de4d07c..0473d970d 100644
--- a/locales/pl/common.json
+++ b/locales/pl/common.json
@@ -303,9 +303,7 @@
     "move": "Przenieś",
     "print": "Drukuj",
     "view_source": "Pokaż źródło",
-
     "fullscreen": "Pełny ekran",
-
     "exit_fullscreen": "Zamknij pełny ekran",
     "export_email": "Eksportuj jako .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Kopiuj link do wydarzenia",
     "copied": "Link skopiowany",
     "copy_failed": "Nie udało się skopiować linku"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Kończenie autoryzacji…",
+      "completing_message": "Proszę czekać na nawiązanie połączenia.",
+      "received_title": "Otrzymano autoryzację",
+      "received_message": "Możesz wrócić do karty, w której rozpoczęto nawiązywanie połączenia.",
+      "failed_title": "Autoryzacja nie powiodła się",
+      "denied": "Autoryzacja została odrzucona.",
+      "failed_detail": "Autoryzacja nie powiodła się: {error}",
+      "missing_params": "Brak kodu autoryzacji lub stanu.",
+      "delivery_failed": "Nie udało się przekazać wyniku autoryzacji do karty aplikacji. Zamknij to okno i spróbuj ponownie."
+    }
   }
 }
diff --git a/locales/pt/common.json b/locales/pt/common.json
index aa13e3d4b..68b131064 100644
--- a/locales/pt/common.json
+++ b/locales/pt/common.json
@@ -303,9 +303,7 @@
     "move": "Mover",
     "print": "Imprimir",
     "view_source": "Ver código-fonte",
-
     "fullscreen": "Tela cheia",
-
     "exit_fullscreen": "Sair da tela cheia",
     "export_email": "Exportar como .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copiar link do evento",
     "copied": "Link copiado",
     "copy_failed": "Não foi possível copiar o link"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "A concluir a autorização…",
+      "completing_message": "Aguarde enquanto a ligação é estabelecida.",
+      "received_title": "Autorização recebida",
+      "received_message": "Pode voltar ao separador onde iniciou a ligação.",
+      "failed_title": "Falha na autorização",
+      "denied": "A autorização foi negada.",
+      "failed_detail": "Falha na autorização: {error}",
+      "missing_params": "Falta o código de autorização ou o estado.",
+      "delivery_failed": "Não foi possível entregar o resultado da autorização ao separador da aplicação. Feche esta janela e tente novamente."
+    }
   }
 }
diff --git a/locales/ro/common.json b/locales/ro/common.json
index ae3002660..5bea04169 100644
--- a/locales/ro/common.json
+++ b/locales/ro/common.json
@@ -303,9 +303,7 @@
     "move": "Mutare",
     "print": "Imprimare",
     "view_source": "Vizualizați sursa",
-
     "fullscreen": "Ecran complet",
-
     "exit_fullscreen": "Ieșire din ecran complet",
     "export_email": "Exportați ca fișier .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Copiați linkul evenimentului",
     "copied": "Link copiat",
     "copy_failed": "Linkul nu a putut fi copiat"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Se finalizează autorizarea…",
+      "completing_message": "Vă rugăm să așteptați stabilirea conexiunii.",
+      "received_title": "Autorizare primită",
+      "received_message": "Vă puteți întoarce la fila în care ați inițiat conexiunea.",
+      "failed_title": "Autorizarea a eșuat",
+      "denied": "Autorizarea a fost refuzată.",
+      "failed_detail": "Autorizarea a eșuat: {error}",
+      "missing_params": "Lipsește codul de autorizare sau starea.",
+      "delivery_failed": "Rezultatul autorizării nu a putut fi transmis filei aplicației. Închideți această fereastră și încercați din nou."
+    }
   }
 }
diff --git a/locales/ru/common.json b/locales/ru/common.json
index e59452e39..2a3210e5f 100644
--- a/locales/ru/common.json
+++ b/locales/ru/common.json
@@ -303,9 +303,7 @@
     "move": "Переместить",
     "print": "Распечатать",
     "view_source": "Просмотреть исходный код",
-
     "fullscreen": "Во весь экран",
-
     "exit_fullscreen": "Выйти из полноэкранного режима",
     "export_email": "Экспортировать как .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Скопировать ссылку на событие",
     "copied": "Ссылка скопирована",
     "copy_failed": "Не удалось скопировать ссылку"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Завершение авторизации…",
+      "completing_message": "Пожалуйста, подождите, пока устанавливается соединение.",
+      "received_title": "Авторизация получена",
+      "received_message": "Вы можете вернуться на вкладку, где начали подключение.",
+      "failed_title": "Ошибка авторизации",
+      "denied": "В авторизации отказано.",
+      "failed_detail": "Ошибка авторизации: {error}",
+      "missing_params": "Отсутствует код авторизации или состояние.",
+      "delivery_failed": "Не удалось передать результат авторизации на вкладку приложения. Закройте это окно и попробуйте снова."
+    }
   }
 }
diff --git a/locales/sk/common.json b/locales/sk/common.json
index 18cb177ab..f9c70c57b 100644
--- a/locales/sk/common.json
+++ b/locales/sk/common.json
@@ -303,9 +303,7 @@
     "move": "Presunúť",
     "print": "Tlačiť",
     "view_source": "Zobraziť zdrojový kód",
-
     "fullscreen": "Celá obrazovka",
-
     "exit_fullscreen": "Ukončiť režim celej obrazovky",
     "export_email": "Exportovať ako .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Kopírovať odkaz na udalosť",
     "copied": "Odkaz skopírovaný",
     "copy_failed": "Odkaz sa nepodarilo skopírovať"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Dokončovanie autorizácie…",
+      "completing_message": "Počkajte, kým sa vytvorí spojenie.",
+      "received_title": "Autorizácia prijatá",
+      "received_message": "Môžete sa vrátiť na kartu, kde ste začali pripájanie.",
+      "failed_title": "Autorizácia zlyhala",
+      "denied": "Autorizácia bola zamietnutá.",
+      "failed_detail": "Autorizácia zlyhala: {error}",
+      "missing_params": "Chýba autorizačný kód alebo stav.",
+      "delivery_failed": "Výsledok autorizácie sa nepodarilo odovzdať karte aplikácie. Zavrite toto okno a skúste to znova."
+    }
   }
 }
diff --git a/locales/tr/common.json b/locales/tr/common.json
index bd371c36a..6d98cf1c4 100644
--- a/locales/tr/common.json
+++ b/locales/tr/common.json
@@ -303,9 +303,7 @@
     "move": "Taşı",
     "print": "Yazdır",
     "view_source": "Kaynağı görüntüle",
-
     "fullscreen": "Tam ekran",
-
     "exit_fullscreen": "Tam ekrandan çık",
     "export_email": ".eml olarak dışa aktar",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Etkinlik bağlantısını kopyala",
     "copied": "Bağlantı kopyalandı",
     "copy_failed": "Bağlantı kopyalanamadı"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Yetkilendirme tamamlanıyor…",
+      "completing_message": "Bağlantı kurulurken lütfen bekleyin.",
+      "received_title": "Yetkilendirme alındı",
+      "received_message": "Bağlantıyı başlattığınız sekmeye dönebilirsiniz.",
+      "failed_title": "Yetkilendirme başarısız oldu",
+      "denied": "Yetkilendirme reddedildi.",
+      "failed_detail": "Yetkilendirme başarısız oldu: {error}",
+      "missing_params": "Yetkilendirme kodu veya durum eksik.",
+      "delivery_failed": "Yetkilendirme sonucu uygulama sekmesine iletilemedi. Lütfen bu pencereyi kapatıp tekrar deneyin."
+    }
   }
 }
diff --git a/locales/uk/common.json b/locales/uk/common.json
index 37866f534..fb8cfebfa 100644
--- a/locales/uk/common.json
+++ b/locales/uk/common.json
@@ -303,9 +303,7 @@
     "move": "Перенести",
     "print": "Роздрукувати",
     "view_source": "Переглянути джерело",
-
     "fullscreen": "На весь екран",
-
     "exit_fullscreen": "Вийти з повноекранного режиму",
     "export_email": "Експортувати як .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "Скопіювати посилання на подію",
     "copied": "Посилання скопійовано",
     "copy_failed": "Не вдалося скопіювати посилання"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "Завершення авторизації…",
+      "completing_message": "Зачекайте, поки встановлюється з'єднання.",
+      "received_title": "Авторизацію отримано",
+      "received_message": "Ви можете повернутися на вкладку, де розпочали підключення.",
+      "failed_title": "Не вдалося виконати авторизацію",
+      "denied": "В авторизації відмовлено.",
+      "failed_detail": "Не вдалося виконати авторизацію: {error}",
+      "missing_params": "Відсутній код авторизації або стан.",
+      "delivery_failed": "Не вдалося передати результат авторизації на вкладку програми. Закрийте це вікно та спробуйте ще раз."
+    }
   }
 }
diff --git a/locales/zh-TW/common.json b/locales/zh-TW/common.json
index ac0516542..36d8ce6d5 100644
--- a/locales/zh-TW/common.json
+++ b/locales/zh-TW/common.json
@@ -3534,5 +3534,18 @@
     "copy_event": "複製活動連結",
     "copied": "連結已複製",
     "copy_failed": "無法複製連結"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "正在完成授權…",
+      "completing_message": "請稍候，正在建立連線。",
+      "received_title": "已收到授權",
+      "received_message": "您可以返回開始連線的分頁。",
+      "failed_title": "授權失敗",
+      "denied": "授權被拒絕。",
+      "failed_detail": "授權失敗：{error}",
+      "missing_params": "缺少授權碼或狀態。",
+      "delivery_failed": "無法將授權結果傳遞至應用程式分頁。請關閉此視窗並再試一次。"
+    }
   }
 }
diff --git a/locales/zh/common.json b/locales/zh/common.json
index cc88bbb11..c08f8b377 100644
--- a/locales/zh/common.json
+++ b/locales/zh/common.json
@@ -303,9 +303,7 @@
     "move": "移动",
     "print": "打印",
     "view_source": "查看源码",
-
     "fullscreen": "全屏",
-
     "exit_fullscreen": "退出全屏",
     "export_email": "导出为 .eml",
     "forward_as_attachment": "Forward as attachment",
@@ -3541,5 +3539,18 @@
     "copy_event": "复制日程链接",
     "copied": "链接已复制",
     "copy_failed": "无法复制链接"
+  },
+  "plugins": {
+    "oauth_callback": {
+      "completing": "正在完成授权…",
+      "completing_message": "正在建立连接，请稍候。",
+      "received_title": "已收到授权",
+      "received_message": "您可以返回发起连接的标签页。",
+      "failed_title": "授权失败",
+      "denied": "授权被拒绝。",
+      "failed_detail": "授权失败：{error}",
+      "missing_params": "缺少授权码或状态。",
+      "delivery_failed": "无法将授权结果传递到应用标签页。请关闭此窗口并重试。"
+    }
   }
 }