feat: add WALLET_OPERATIONS feature flag for the sunset

apps/web-wallet/app/features/homepage/components/join-beta-button.tsx

@@ -1,5 +1,6 @@
 import { useQuery } from '@tanstack/react-query';
-import { Link, useLocation } from 'react-router';
+import { Link, type Location, type To, useLocation } from 'react-router';
+import { useFeatureFlagOrDefault } from '~/features/shared/feature-flags';
 import { authQueryOptions } from '~/features/user/auth';
 import { cn } from '~/lib/utils';
 
@@ -8,27 +9,43 @@ type JoinBetaButtonProps = {
   className?: string;
 };
 
+function getCallToAction(
+  isLoggedIn: boolean,
+  signupEnabled: boolean,
+  location: Location,
+): { to: To; label: string } {
+  if (isLoggedIn) {
+    return { to: '/', label: 'Go to Wallet' };
+  }
+  if (signupEnabled) {
+    return { to: { ...location, pathname: '/signup' }, label: 'Get Started' };
+  }
+  return { to: { ...location, pathname: '/login' }, label: 'Log in' };
+}
+
 export function JoinBetaButton({
   size = 'default',
   className,
 }: JoinBetaButtonProps) {
   const location = useLocation();
   const { data: authState } = useQuery(authQueryOptions());
   const isLoggedIn = authState?.isLoggedIn ?? false;
+  const signupEnabled = useFeatureFlagOrDefault('WALLET_OPERATIONS');
+  const { to, label } = getCallToAction(isLoggedIn, signupEnabled, location);
 
   const sizeClasses =
     size === 'lg' ? 'h-12 px-7 text-base' : 'h-10 px-5 text-sm';
 
   return (
     <Link
-      to={isLoggedIn ? '/' : { ...location, pathname: '/signup' }}
+      to={to}
       className={cn(
         'inline-flex items-center justify-center rounded-md border border-[color:var(--mk-brand)] bg-[color:var(--mk-brand)] font-medium font-mono text-[#04080f] tracking-wide transition-[background-color,color] duration-200 hover:bg-transparent hover:text-[color:var(--mk-brand)] focus-visible:outline-2 focus-visible:outline-[color:var(--mk-brand)] focus-visible:outline-offset-2',
         sizeClasses,
         className,
       )}
     >
-      {isLoggedIn ? 'Go to Wallet' : 'Get Started'}
+      {label}
     </Link>
   );
 }

apps/web-wallet/app/features/homepage/components/marketing-nav.tsx

@@ -1,6 +1,7 @@
 import { useQuery } from '@tanstack/react-query';
 import { Link, useLocation } from 'react-router';
 import logoUrl from '~/assets/full_logo.png';
+import { useFeatureFlagOrDefault } from '~/features/shared/feature-flags';
 import { authQueryOptions } from '~/features/user/auth';
 
 const navBtnBase =
@@ -16,6 +17,7 @@ export function MarketingNav() {
   const location = useLocation();
   const { data: authState } = useQuery(authQueryOptions());
   const isLoggedIn = authState?.isLoggedIn ?? false;
+  const signupEnabled = useFeatureFlagOrDefault('WALLET_OPERATIONS');
 
   return (
     <header className="sticky top-0 z-50 w-full border-[color:var(--mk-border)] border-b bg-[rgba(4,8,15,0.78)] backdrop-blur-[14px] backdrop-saturate-[140%]">
@@ -50,12 +52,14 @@ export function MarketingNav() {
               >
                 Log in
               </Link>
-              <Link
-                to={{ ...location, pathname: '/signup' }}
-                className={`${navBtnBase} ${signupBtn}`}
-              >
-                Sign up
-              </Link>
+              {signupEnabled && (
+                <Link
+                  to={{ ...location, pathname: '/signup' }}
+                  className={`${navBtnBase} ${signupBtn}`}
+                >
+                  Sign up
+                </Link>
+              )}
             </>
           )}
         </nav>

apps/web-wallet/app/features/login/login-form.tsx

@@ -10,6 +10,7 @@ import {
 } from '~/components/ui/card';
 import { Input } from '~/components/ui/input';
 import { Label } from '~/components/ui/label';
+import { useFeatureFlag } from '~/features/shared/feature-flags';
 import { useAuthActions } from '~/features/user/auth';
 import { useToast } from '~/hooks/use-toast';
 import { buildEmailValidator } from '~/lib/validation';
@@ -24,6 +25,7 @@ export function LoginForm({ onBack }: Props) {
   const { signIn } = useAuthActions();
   const { toast } = useToast();
   const location = useLocation();
+  const signupEnabled = useFeatureFlag('WALLET_OPERATIONS');
   const {
     register,
     handleSubmit,
@@ -112,12 +114,17 @@ export function LoginForm({ onBack }: Props) {
             Back
           </Button>
         </form>
-        <div className="mt-4 text-center text-sm">
-          Don&apos;t have a wallet?{' '}
-          <Link to={{ ...location, pathname: '/signup' }} className="underline">
-            Sign up
-          </Link>
-        </div>
+        {signupEnabled && (
+          <div className="mt-4 text-center text-sm">
+            Don&apos;t have a wallet?{' '}
+            <Link
+              to={{ ...location, pathname: '/signup' }}
+              className="underline"
+            >
+              Sign up
+            </Link>
+          </div>
+        )}
       </CardContent>
     </Card>
   );

apps/web-wallet/app/features/login/login-options.tsx

@@ -8,13 +8,15 @@ import {
   CardHeader,
   CardTitle,
 } from '~/components/ui/card';
+import { useFeatureFlag } from '~/features/shared/feature-flags';
 
 type Option = 'email' | 'google';
 type Props = { onSelect: (option: Option) => Promise<void> };
 
 export function LoginOptions({ onSelect }: Props) {
   const [submitting, setSubmitting] = useState<Option | null>(null);
   const location = useLocation();
+  const signupEnabled = useFeatureFlag('WALLET_OPERATIONS');
   const handeSelect = async (option: Option) => {
     if (submitting) return;
 
@@ -47,12 +49,17 @@ export function LoginOptions({ onSelect }: Props) {
             Log in with Google
           </Button>
         </div>
-        <div className="mt-4 text-center text-sm">
-          Don&apos;t have an account?{' '}
-          <Link to={{ ...location, pathname: '/signup' }} className="underline">
-            Sign up
-          </Link>
-        </div>
+        {signupEnabled && (
+          <div className="mt-4 text-center text-sm">
+            Don&apos;t have an account?{' '}
+            <Link
+              to={{ ...location, pathname: '/signup' }}
+              className="underline"
+            >
+              Sign up
+            </Link>
+          </div>
+        )}
       </CardContent>
     </Card>
   );

apps/web-wallet/app/features/receive/lightning-address-service.ts

@@ -19,6 +19,7 @@ import {
 } from '~/lib/xchacha20poly1305';
 import type { AgicashDb } from '../agicash-db/database';
 import { NotFoundError } from '../shared/error';
+import type { FeatureFlag } from '../shared/feature-flags';
 import { sparkWalletQueryOptions } from '../shared/spark';
 import {
   ReadUserDefaultAccountRepository,
@@ -45,6 +46,11 @@ if (!encryptionKey) {
 }
 const encryptionKeyBytes = hexToBytes(encryptionKey);
 
+const SUNSET_ERROR: LNURLError = {
+  status: 'ERROR',
+  reason: 'Agicash is shutting down and no longer accepts payments.',
+};
+
 /**
  * This data needed to verify the status of lnurl-pay request is encrypted
  * to improve user privacy by obfuscating the quote data from the LNURL client
@@ -109,6 +115,10 @@ export class LightningAddressService {
     username: string,
   ): Promise<LNURLPayParams | LNURLError> {
     try {
+      if (!(await this.isWalletOperationsEnabled())) {
+        return SUNSET_ERROR;
+      }
+
       const user = await this.userRepository.getByUsername(username);
 
       if (!user) {
@@ -156,6 +166,10 @@ export class LightningAddressService {
     }
 
     try {
+      if (!(await this.isWalletOperationsEnabled())) {
+        return SUNSET_ERROR;
+      }
+
       const user = await this.userRepository.get(userId);
 
       if (!user) {
@@ -351,6 +365,19 @@ export class LightningAddressService {
     };
   }
 
+  /**
+   * The WALLET_OPERATIONS flag gates Lightning Address receives. Its row is missing until the
+   * migration runs, so a missing key counts as enabled.
+   */
+  private async isWalletOperationsEnabled(): Promise<boolean> {
+    const { data, error } = await this.db.rpc('evaluate_feature_flags');
+    if (error) {
+      throw new Error('Failed to evaluate feature flags', { cause: error });
+    }
+    const flags = data as Partial<Record<FeatureFlag, boolean>>;
+    return flags.WALLET_OPERATIONS ?? true;
+  }
+
   private buildLnurlpMetadata(username: string): string {
     const address = `${username}@${new URL(this.baseUrl).host}`;
     return JSON.stringify([

apps/web-wallet/app/features/receive/receive-cashu-token.tsx

@@ -19,6 +19,7 @@ import {
 } from '~/components/page';
 import { Button } from '~/components/ui/button';
 import { useFeatureFlag } from '~/features/shared/feature-flags';
+import { TOKEN_CLAIM_DISABLED_MESSAGE } from '~/features/shared/wallet-operations';
 import { useBuildLinkWithSearchParams } from '~/hooks/use-search-params-link';
 import { useToast } from '~/hooks/use-toast';
 import { encodeToken } from '~/lib/cashu/token';
@@ -372,6 +373,7 @@ export function PublicReceiveCashuToken({ token }: { token: Token }) {
   const { signUpGuest } = useAuthActions();
   const { toast } = useToast();
   const guestSignupEnabled = useFeatureFlag('GUEST_SIGNUP');
+  const walletOperationsEnabled = useFeatureFlag('WALLET_OPERATIONS');
   const {
     selectableAccounts,
     receiveAccount,
@@ -382,6 +384,12 @@ export function PublicReceiveCashuToken({ token }: { token: Token }) {
     useCashuTokenWithClaimableProofs({
       token,
     });
+  const canClaim =
+    !!claimableToken && sourceAccount.canReceive && walletOperationsEnabled;
+  const cannotClaimMessage = !claimableToken
+    ? cannotClaimReason
+    : (sourceAccount.cannotReceiveReason ??
+      'Token from this mint cannot be claimed');
 
   const giftCard = getGiftCardByUrl(sourceAccount.mintUrl);
   const mintRequiresTerms =
@@ -456,7 +464,7 @@ export function PublicReceiveCashuToken({ token }: { token: Token }) {
         />
 
         <div className="absolute top-0 right-0 bottom-0 left-0 mx-auto flex max-w-sm items-center justify-center">
-          {claimableToken && sourceAccount.canReceive ? (
+          {canClaim ? (
             <div className="w-full max-w-sm px-4">
               {giftCard ? (
                 <div className="flex flex-col items-center gap-3">
@@ -487,17 +495,16 @@ export function PublicReceiveCashuToken({ token }: { token: Token }) {
           ) : (
             <TokenErrorDisplay
               message={
-                !claimableToken
-                  ? cannotClaimReason
-                  : (sourceAccount.cannotReceiveReason ??
-                    'Token from this mint cannot be claimed')
+                walletOperationsEnabled
+                  ? cannotClaimMessage
+                  : TOKEN_CLAIM_DISABLED_MESSAGE
               }
             />
           )}
         </div>
       </PageContent>
 
-      {claimableToken && sourceAccount.canReceive && (
+      {canClaim && (
         <PageFooter className="pb-14">
           <div className="flex flex-col gap-4">
             {guestSignupEnabled && (

apps/web-wallet/app/features/shared/error.ts

@@ -15,6 +15,13 @@ export const getErrorMessage = (
 
 export class UniqueConstraintError extends Error {}
 
+export class PermissionDeniedError extends Error {
+  constructor(message: string) {
+    super(message);
+    this.name = 'PermissionDeniedError';
+  }
+}
+
 export class NotFoundError extends Error {
   constructor(message: string) {
     super(message);

apps/web-wallet/app/features/shared/feature-flags.ts

@@ -1,15 +1,24 @@
 import * as Sentry from '@sentry/react-router';
-import { queryOptions, useSuspenseQuery } from '@tanstack/react-query';
+import {
+  queryOptions,
+  useQuery,
+  useSuspenseQuery,
+} from '@tanstack/react-query';
 import { agicashDbClient } from '~/features/agicash-db/database.client';
 import { getQueryClient } from '~/features/shared/query-client';
 
-export type FeatureFlag = 'GUEST_SIGNUP' | 'DEBUG_LOGGING_SPARK';
+export type FeatureFlag =
+  | 'GUEST_SIGNUP'
+  | 'DEBUG_LOGGING_SPARK'
+  | 'WALLET_OPERATIONS';
 
 type FeatureFlags = Record<FeatureFlag, boolean>;
 
 const FEATURE_FLAG_DEFAULTS: FeatureFlags = {
   GUEST_SIGNUP: false,
   DEBUG_LOGGING_SPARK: false,
+  // Gates the core wallet, so a failed fetch must not lock users out.
+  WALLET_OPERATIONS: true,
 };
 
 const MAX_RETRIES = 3;
@@ -19,7 +28,8 @@ async function fetchFeatureFlags(): Promise<FeatureFlags> {
   if (error) {
     throw new Error('Failed to fetch feature flags', { cause: error });
   }
-  return data as FeatureFlags;
+  // A flag row is missing until its migration runs, so defaults fill the gaps.
+  return { ...FEATURE_FLAG_DEFAULTS, ...(data as Partial<FeatureFlags>) };
 }
 
 export const featureFlagsQueryOptions = queryOptions({
@@ -48,6 +58,15 @@ export function useFeatureFlag(flag: FeatureFlag): boolean {
   return data[flag];
 }
 
+/**
+ * Like {@link useFeatureFlag} but never suspends, so it is safe in server-rendered trees.
+ * Returns the default value until the flags are fetched.
+ */
+export function useFeatureFlagOrDefault(flag: FeatureFlag): boolean {
+  const { data } = useQuery(featureFlagsQueryOptions);
+  return data?.[flag] ?? FEATURE_FLAG_DEFAULTS[flag];
+}
+
 /**
  * Reads a feature flag from the query cache.
  * Returns the default value if flags haven't been fetched yet.