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

apps/remix/server/api/ai/detect-fields.client.ts

@@ -1,3 +1,4 @@
+import { formatPath } from '@documenso/lib/constants/app';
 import { z } from 'zod';
 
 import { type TDetectFieldsRequest, ZNormalizedFieldWithContextSchema } from './detect-fields.types';
@@ -69,7 +70,7 @@ export const detectFields = async ({
   onError,
   signal,
 }: DetectFieldsOptions): Promise<void> => {
-  const response = await fetch('/api/ai/detect-fields', {
+  const response = await fetch(formatPath('/api/ai/detect-fields'), {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',

apps/remix/server/api/ai/detect-recipients.client.ts

@@ -1,3 +1,4 @@
+import { formatPath } from '@documenso/lib/constants/app';
 import { ZDetectedRecipientSchema } from '@documenso/lib/server-only/ai/envelope/detect-recipients/schema';
 import { z } from 'zod';
 
@@ -70,7 +71,7 @@ export const detectRecipients = async ({
   onError,
   signal,
 }: DetectRecipientsOptions): Promise<void> => {
-  const response = await fetch('/api/ai/detect-recipients', {
+  const response = await fetch(formatPath('/api/ai/detect-recipients'), {
     method: 'POST',
     headers: {
       'Content-Type': 'application/json',

apps/remix/server/main.js

@@ -14,9 +14,22 @@ import { getLoadContext } from './hono/server/load-context.js';
 import server from './hono/server/router.js';
 import * as build from './index.js';
 
+// Sub-path the app is served under (e.g. "/ESign"). Empty = root.
+// Must match the basePath used by the Hono router and the Vite `base`/RR
+// `basename` so that hashed asset URLs like `/ESign/assets/app-xxx.css`
+// resolve to files on disk at `build/client/assets/app-xxx.css`.
+const basePath = (process.env.NEXT_PUBLIC_BASE_PATH ?? '').replace(/\/$/, '');
+
 server.use(
   serveStatic({
     root: 'build/client',
+    rewriteRequestPath: (path) => {
+      if (basePath && (path === basePath || path.startsWith(`${basePath}/`))) {
+        const stripped = path.slice(basePath.length);
+        return stripped === '' ? '/' : stripped;
+      }
+      return path;
+    },
     onFound: (path, c) => {
       if (path.startsWith('build/client/assets')) {
         // Hard cache assets with hashed file names.

apps/remix/server/router.ts

@@ -46,7 +46,9 @@ export interface HonoEnv {
   };
 }
 
-const app = new Hono<HonoEnv>();
+const basePath = (env('NEXT_PUBLIC_BASE_PATH') ?? '').replace(/\/$/, '');
+
+const app = new Hono<HonoEnv>().basePath(basePath || '/');
 
 /**
  * Database-backed rate limiting for API routes.

apps/remix/server/trpc/hono-trpc-open-api.ts

@@ -1,4 +1,4 @@
-import { API_V2_BETA_URL, API_V2_URL } from '@documenso/lib/constants/app';
+import { API_V2_BETA_URL, API_V2_URL, formatPath } from '@documenso/lib/constants/app';
 import { AppError, genericErrorCodeToTrpcErrorCodeMap } from '@documenso/lib/errors/app-error';
 import { createTrpcContext } from '@documenso/trpc/server/context';
 import { appRouter } from '@documenso/trpc/server/router';
@@ -11,8 +11,10 @@ type OpenApiTrpcServerHandlerOptions = {
 };
 
 export const openApiTrpcServerHandler = async (c: Context, { isBeta }: OpenApiTrpcServerHandlerOptions) => {
+  const endpoint = formatPath(isBeta ? API_V2_BETA_URL : API_V2_URL) as `/${string}`;
+
   return createOpenApiFetchHandler<typeof appRouter>({
-    endpoint: isBeta ? API_V2_BETA_URL : API_V2_URL,
+    endpoint,
     router: appRouter,
     createContext: async () => createTrpcContext({ c, requestSource: 'apiV2' }),
     req: c.req.raw,

apps/remix/server/trpc/hono-trpc-remix.ts

@@ -1,3 +1,4 @@
+import { formatPath } from '@documenso/lib/constants/app';
 import { createTrpcContext } from '@documenso/trpc/server/context';
 import { appRouter } from '@documenso/trpc/server/router';
 import { handleTrpcRouterError } from '@documenso/trpc/utils/trpc-error-handler';
@@ -5,10 +6,14 @@ import { trpcServer } from '@hono/trpc-server';
 
 /**
  * Trpc server for internal routes like /api/trpc/*
+ *
+ * `endpoint` must include the sub-path prefix (e.g. "/ESign") because the
+ * @hono/trpc-server adapter slices the prefix off the full URL pathname to
+ * compute the procedure name. Hono's `basePath` doesn't rewrite the URL.
  */
 export const reactRouterTrpcServer = trpcServer({
   router: appRouter,
-  endpoint: '/api/trpc',
+  endpoint: formatPath('/api/trpc'),
   createContext: async (_, c) => createTrpcContext({ c, requestSource: 'app' }),
   onError: (opts) => handleTrpcRouterError(opts, 'trpc'),
 });