feat(remix): support serving app under a sub-path via NEXT_PUBLIC_BASE_PATH (#2824)

packages/auth/client/index.ts

@@ -1,4 +1,4 @@
-import { NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
+import { formatPath, NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
 import { AppError } from '@documenso/lib/errors/app-error';
 import type { ClientResponse, InferRequestType } from 'hono/client';
 import { hc } from 'hono/client';
@@ -36,8 +36,6 @@ type TPasskeySignin = InferRequestType<AuthClientType['passkey']['authorize']['$
 export class AuthClient {
   public client: AuthClientType;
 
-  private signOutredirectPath: string = '/signin';
-
   constructor(options: { baseUrl: string }) {
     this.client = hc<AuthAppType>(options.baseUrl);
   }
@@ -45,7 +43,7 @@ export class AuthClient {
   public async signOut({ redirectPath }: { redirectPath?: string } = {}) {
     await this.client.signout.$post();
 
-    window.location.href = redirectPath ?? this.signOutredirectPath;
+    window.location.href = redirectPath ?? formatPath('/signin');
   }
 
   public async signOutAllSessions() {

packages/auth/server/lib/utils/handle-oauth-callback-url.ts

@@ -1,4 +1,4 @@
-import { NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
+import { formatPath, NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
 import {
   isDisposableEmail,
   isEmailDomainAllowedForSignup,
@@ -121,7 +121,7 @@ export const handleOAuthCallbackUrl = async (options: HandleOAuthCallbackUrlOpti
 
   // Check if signups are disabled for this provider.
   if (!isSignupEnabledForProvider(clientOptions.id as 'google' | 'microsoft' | 'oidc')) {
-    const errorUrl = new URL('/signin', NEXT_PUBLIC_WEBAPP_URL());
+    const errorUrl = new URL(formatPath('/signin'), NEXT_PUBLIC_WEBAPP_URL());
 
     errorUrl.searchParams.set('error', AuthenticationErrorCode.SignupDisabled);
 
@@ -130,7 +130,7 @@ export const handleOAuthCallbackUrl = async (options: HandleOAuthCallbackUrlOpti
 
   // Check domain restriction for new SSO users.
   if (!isEmailDomainAllowedForSignup(email)) {
-    const errorUrl = new URL('/signin', NEXT_PUBLIC_WEBAPP_URL());
+    const errorUrl = new URL(formatPath('/signin'), NEXT_PUBLIC_WEBAPP_URL());
 
     errorUrl.searchParams.set('error', AuthenticationErrorCode.SignupDisabled);
 
@@ -141,7 +141,7 @@ export const handleOAuthCallbackUrl = async (options: HandleOAuthCallbackUrlOpti
   const additionalBlockedDomains = await getEmailBlocklistDomains();
 
   if (isDisposableEmail(email, additionalBlockedDomains)) {
-    const errorUrl = new URL('/signin', NEXT_PUBLIC_WEBAPP_URL());
+    const errorUrl = new URL(formatPath('/signin'), NEXT_PUBLIC_WEBAPP_URL());
 
     errorUrl.searchParams.set('error', AuthenticationErrorCode.SignupDisposableEmail);
 
@@ -213,15 +213,18 @@ export const validateOauth = async (options: HandleOAuthCallbackUrlOptions) => {
   // eslint-disable-next-line prefer-const
   let [redirectState, redirectPath] = storedRedirectPath.split(' ');
 
+  // The sub-path aware root, e.g. "/" or "/ESign/".
+  const defaultRedirectPath = formatPath('/');
+
   if (redirectState !== storedState || !redirectPath) {
-    redirectPath = '/';
+    redirectPath = defaultRedirectPath;
   }
 
   if (!isValidReturnTo(redirectPath)) {
-    redirectPath = '/';
+    redirectPath = defaultRedirectPath;
   }
 
-  redirectPath = normalizeReturnTo(redirectPath) || '/';
+  redirectPath = normalizeReturnTo(redirectPath) || defaultRedirectPath;
 
   const tokens = await oAuthClient.validateAuthorizationCode(token_endpoint, code, storedCodeVerifier);
 

packages/auth/server/lib/utils/handle-oauth-organisation-callback-url.ts

@@ -1,4 +1,5 @@
 import { sendOrganisationAccountLinkConfirmationEmail } from '@documenso/ee/server-only/lib/send-organisation-account-link-confirmation-email';
+import { formatPath } from '@documenso/lib/constants/app';
 import { isDisposableEmail, isSignupEnabledForProvider } from '@documenso/lib/constants/auth';
 import { AppError } from '@documenso/lib/errors/app-error';
 import { getEmailBlocklistDomains } from '@documenso/lib/server-only/site-settings/get-email-blocklist-domains';
@@ -56,7 +57,7 @@ export const handleOAuthOrganisationCallbackUrl = async (options: HandleOAuthOrg
   if (existingAccount) {
     await onAuthorize({ userId: existingAccount.user.id }, c);
 
-    return c.redirect(`/o/${orgUrl}`, 302);
+    return c.redirect(formatPath(`/o/${orgUrl}`), 302);
   }
 
   let userToLink = await prisma.user.findFirst({

packages/auth/server/lib/utils/redirect.ts

@@ -1,5 +1,25 @@
 import { NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
 
+/**
+ * Derive the default redirect target ("/" at the root, "/ESign/" when served under a sub-path).
+ */
+const getDefaultRedirect = () => {
+  try {
+    const pathname = new URL(NEXT_PUBLIC_WEBAPP_URL()).pathname.replace(/\/$/, '');
+    return `${pathname}/`;
+  } catch {
+    return '/';
+  }
+};
+
+const getWebAppOrigin = () => {
+  try {
+    return new URL(NEXT_PUBLIC_WEBAPP_URL()).origin;
+  } catch {
+    return NEXT_PUBLIC_WEBAPP_URL();
+  }
+};
+
 /**
  * Handle an optional redirect path.
  */
@@ -10,19 +30,20 @@ export const handleRequestRedirect = (redirectUrl?: string) => {
 
   const url = new URL(redirectUrl, NEXT_PUBLIC_WEBAPP_URL());
 
-  if (url.origin !== NEXT_PUBLIC_WEBAPP_URL()) {
-    window.location.href = '/';
+  if (url.origin !== getWebAppOrigin()) {
+    window.location.href = getDefaultRedirect();
   } else {
     window.location.href = redirectUrl;
   }
 };
 
-export const handleSignInRedirect = (redirectUrl: string = '/') => {
-  const url = new URL(redirectUrl, NEXT_PUBLIC_WEBAPP_URL());
+export const handleSignInRedirect = (redirectUrl?: string) => {
+  const target = redirectUrl ?? getDefaultRedirect();
+  const url = new URL(target, NEXT_PUBLIC_WEBAPP_URL());
 
-  if (url.origin !== NEXT_PUBLIC_WEBAPP_URL()) {
-    window.location.href = '/';
+  if (url.origin !== getWebAppOrigin()) {
+    window.location.href = getDefaultRedirect();
   } else {
-    window.location.href = redirectUrl;
+    window.location.href = target;
   }
 };

packages/ee/server-only/limits/client.ts

@@ -12,7 +12,10 @@ export type GetLimitsOptions = {
 export const getLimits = async ({ headers, teamId }: GetLimitsOptions) => {
   const requestHeaders = headers ?? {};
 
-  const url = new URL('/api/limits', NEXT_PUBLIC_WEBAPP_URL());
+  // Note: the path must be appended rather than passed as the `new URL()` path
+  // argument, since a leading-slash path replaces the sub-path that
+  // NEXT_PUBLIC_WEBAPP_URL may carry (e.g. https://host/ESign).
+  const url = new URL(`${NEXT_PUBLIC_WEBAPP_URL()}/api/limits`);
 
   if (teamId) {
     requestHeaders['team-id'] = teamId.toString();

packages/lib/constants/app.ts

@@ -6,6 +6,42 @@ export const APP_DOCUMENT_UPLOAD_SIZE_LIMIT = Number(env('NEXT_PUBLIC_DOCUMENT_S
 
 export const NEXT_PUBLIC_WEBAPP_URL = () => env('NEXT_PUBLIC_WEBAPP_URL') ?? 'http://localhost:3000';
 
+/**
+ * The sub-path the app is served under (no trailing slash), e.g. "/ESign".
+ * Returns an empty string when served at root.
+ *
+ * Prefers the explicit NEXT_PUBLIC_BASE_PATH (which is the same value baked
+ * into the Vite/React Router build). Falls back to the pathname of
+ * NEXT_PUBLIC_WEBAPP_URL so the function still works in dev when the env
+ * variable is unset.
+ *
+ * Avoid using this to build URLs, use {@link formatPath} instead. Reserve this
+ * for cases where the raw prefix itself is needed, such as path comparisons.
+ */
+export const getBasePath = (): string => {
+  const explicit = env('NEXT_PUBLIC_BASE_PATH');
+
+  if (explicit) {
+    return explicit.replace(/\/$/, '');
+  }
+
+  try {
+    return new URL(NEXT_PUBLIC_WEBAPP_URL()).pathname.replace(/\/$/, '');
+  } catch {
+    return '';
+  }
+};
+
+/**
+ * Prefix a root-relative path with the app's base path.
+ *
+ * `formatPath('/api/trpc')` -> `/ESign/api/trpc` under sub-path hosting,
+ * `/api/trpc` otherwise.
+ */
+export const formatPath = (path: string): string => {
+  return `${getBasePath()}${path}`;
+};
+
 export const NEXT_PUBLIC_SIGNING_CONTACT_INFO = () =>
   env('NEXT_PUBLIC_SIGNING_CONTACT_INFO') ?? NEXT_PUBLIC_WEBAPP_URL();
 

packages/lib/universal/get-base-url.ts

@@ -1,10 +1,10 @@
 /* eslint-disable turbo/no-undeclared-env-vars */
-import { NEXT_PUBLIC_WEBAPP_URL } from '../constants/app';
+import { NEXT_PUBLIC_WEBAPP_URL, getBasePath } from '../constants/app';
 import { env } from '../utils/env';
 
 export const getBaseUrl = () => {
   if (typeof window !== 'undefined') {
-    return '';
+    return getBasePath();
   }
 
   const webAppUrl = NEXT_PUBLIC_WEBAPP_URL();

packages/lib/universal/upload/get-file.ts

@@ -2,6 +2,8 @@ import { DocumentDataType } from '@prisma/client';
 import { base64 } from '@scure/base';
 import { match } from 'ts-pattern';
 
+import { formatPath } from '../../constants/app';
+
 export type GetFileOptions = {
   type: DocumentDataType;
   data: string;
@@ -36,7 +38,7 @@ const getFileFromBytes64 = (data: string) => {
 };
 
 const getFileFromS3 = async (key: string) => {
-  const getPresignedUrlResponse = await fetch(`/api/files/presigned-get-url`, {
+  const getPresignedUrlResponse = await fetch(formatPath('/api/files/presigned-get-url'), {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',

packages/lib/universal/upload/put-file.ts

@@ -1,5 +1,6 @@
 import type { TUploadPdfResponse } from '@documenso/remix/server/api/files/files.types';
 
+import { formatPath } from '../../constants/app';
 import { AppError } from '../../errors/app-error';
 
 type File = {
@@ -38,7 +39,7 @@ export const putPdfFile = async (file: File, options?: PutFileOptions) => {
 
   formData.append('file', properFile);
 
-  const response = await fetch('/api/files/upload-pdf', {
+  const response = await fetch(formatPath('/api/files/upload-pdf'), {
     method: 'POST',
     headers: buildUploadAuthHeaders(options),
     body: formData,

packages/lib/utils/is-valid-return-to.ts

@@ -1,4 +1,15 @@
-import { NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
+import { getBasePath, NEXT_PUBLIC_WEBAPP_URL } from '@documenso/lib/constants/app';
+
+/**
+ * The origin of the web app, ignoring any sub-path NEXT_PUBLIC_WEBAPP_URL carries.
+ */
+const getWebAppOrigin = () => {
+  try {
+    return new URL(NEXT_PUBLIC_WEBAPP_URL()).origin;
+  } catch {
+    return NEXT_PUBLIC_WEBAPP_URL();
+  }
+};
 
 export const isValidReturnTo = (returnTo?: string) => {
   if (!returnTo) {
@@ -10,7 +21,10 @@ export const isValidReturnTo = (returnTo?: string) => {
     const decodedReturnTo = decodeURIComponent(returnTo);
     const returnToUrl = new URL(decodedReturnTo, NEXT_PUBLIC_WEBAPP_URL());
 
-    if (returnToUrl.origin !== NEXT_PUBLIC_WEBAPP_URL()) {
+    // Compare against the origin, not the raw env value: when the app is served
+    // under a sub-path NEXT_PUBLIC_WEBAPP_URL is e.g. "https://host/ESign", which
+    // never equals a URL's origin ("https://host").
+    if (returnToUrl.origin !== getWebAppOrigin()) {
       return false;
     }
 
@@ -30,7 +44,17 @@ export const normalizeReturnTo = (returnTo?: string) => {
     const decodedReturnTo = decodeURIComponent(returnTo);
     const returnToUrl = new URL(decodedReturnTo, NEXT_PUBLIC_WEBAPP_URL());
 
-    return `${returnToUrl.pathname}${returnToUrl.search}${returnToUrl.hash}`;
+    const basePath = getBasePath();
+
+    let pathname = returnToUrl.pathname;
+
+    // A root-relative returnTo ("/inbox") resolves to a pathname without the
+    // sub-path, so re-apply it when it is missing.
+    if (basePath && pathname !== basePath && !pathname.startsWith(`${basePath}/`)) {
+      pathname = `${basePath}${pathname}`;
+    }
+
+    return `${pathname}${returnToUrl.search}${returnToUrl.hash}`;
   } catch {
     return undefined;
   }

packages/ui/components/common/language-switcher-dialog.tsx

@@ -1,3 +1,4 @@
+import { formatPath } from '@documenso/lib/constants/app';
 import { SUPPORTED_LANGUAGES } from '@documenso/lib/constants/i18n';
 import { dynamicActivate } from '@documenso/lib/utils/i18n';
 import { cn } from '@documenso/ui/lib/utils';
@@ -23,7 +24,7 @@ export const LanguageSwitcherDialog = ({ open, setOpen }: LanguageSwitcherDialog
 
     formData.append('lang', lang);
 
-    await fetch('/api/locale', {
+    await fetch(formatPath('/api/locale'), {
       method: 'post',
       body: formData,
     });