AIX: request too large: broaden Vercel explanation

Author: enricoros

src/apps/chat/components/message/fragments-content/BlockPartError_RequestExceeded.tsx

@@ -4,6 +4,7 @@ import { Alert, Box, FormHelperText, Switch } from '@mui/joy';
 import WarningRoundedIcon from '@mui/icons-material/WarningRounded';
 
 import type { ContentScaling } from '~/common/app.theme';
+import { Is } from '~/common/util/pwaUtils';
 import { useLLM } from '~/common/stores/llms/llms.hooks';
 import { useModelServiceClientSideFetch } from '~/common/stores/llms/hooks/useModelServiceClientSideFetch';
 
@@ -36,9 +37,11 @@ export function BlockPartError_RequestExceeded(props: {
           Request Too Large
         </Box>
         <div>
-          Your message or attachments exceed the limit
-          of the Vercel edge network
-          {/*  Note: Assumption here - since explaing to any 413, it could be any network */}
+          {/* The 413 can come from any layer in front of the function: the hosted edge network, or a self-hosted
+              reverse proxy (nginx, etc.). Don't claim "Vercel" unless this is actually the hosted build. */}
+          {Is.Deployment.VercelFromFrontend
+            ? <>Your message or attachments exceed the ~4.5&nbsp;MB request limit of the Vercel edge network</>
+            : <>Your message or attachments exceed the request size limit of the server</>}
         </div>
 
         {/* Recovery options */}
@@ -100,6 +103,9 @@ export function BlockPartError_RequestExceeded(props: {
               <li>Use the cleanup button in the right pane to hide old messages</li>
               <li>Remove large attachments from the conversation</li>
               {/*<li>Reduce conversation length before sending</li>*/}
+              {!Is.Deployment.VercelFromFrontend && (
+                <li>If self-hosting, raise the request size limit on your server or proxy</li>
+              )}
             </Box>
           </Box>
         )}

src/common/util/pwaUtils.ts

@@ -30,7 +30,12 @@ export const Is = {
   Deployment: {
     Localhost: clientHostName().includes('localhost:300'),
     VercelFromBackendOrSSR: !!process.env.VERCEL_ENV,
-    VercelFromFrontend: !!process.env.NEXT_PUBLIC_VERCEL_URL,
+    // NOTE: Vercel auto-exposes NEXT_PUBLIC_VERCEL_URL on hosted prod/preview builds (framework env vars), so keying off
+    // it would also work - but we use our own NEXT_PUBLIC_DEPLOYMENT_TYPE (set in next.config.ts from VERCEL_ENV): it's
+    // explicit, self-controlled, and already the canonical deploy signal (see app.release buildInfo). Resolves to
+    // 'vercel-<env>' on the hosted build, 'local'/custom on self-host. Used to avoid showing Vercel-specific copy (e.g.
+    // the 413 "edge network" limit) on self-hosted deployments sitting behind nginx/other reverse proxies.
+    VercelFromFrontend: (process.env.NEXT_PUBLIC_DEPLOYMENT_TYPE ?? '').startsWith('vercel'),
   },
 } as const;
 

src/common/util/trpc.client.ts

@@ -33,11 +33,12 @@ const enableLoggerLink = (opts: any) => {
  * Detects transport-layer failures by HTTP status / content-type, BEFORE tRPC's JSONL parser turns them into
  * engine-specific `SyntaxError`s (which are only string-matchable on V8 - see aix.client.errors.ts). We tag a typed,
  * engine-independent marker (`error.cause.aixTransportCode`), read by [Error Channel 1] aixClassifyStreamingError - see the channel map in aix.client.errors.ts.
- * - 413 (Vercel rejects request bodies over the edge ~4.5MB limit, as `text/plain`, before the function runs)
+ * - 413 from whatever sits in front of the function: the hosted Vercel edge (~4.5MB, as `text/plain`), OR a
+ *   self-hosted reverse proxy (nginx `client_max_body_size`, etc.). The classifier emits host-appropriate copy.
  * - text/html where a JSON(L) stream is expected (captive portals / proxies / gateway error pages)
  *
  * NOTE: only the server-side tRPC path passes through here. CSF (client-side-fetch, direct browser->provider) has its
- * own error surface and structurally cannot hit a Vercel 413 (there is no edge hop), so it intentionally bypasses this.
+ * own error surface and structurally cannot hit a front-door 413 (there is no edge/proxy hop), so it bypasses this.
  */
 const streamingTransportFetch: typeof fetch = async (input, init) => {
   const res = await fetch(input, init);

src/modules/aix/client/aix.client.errors.ts

@@ -14,8 +14,11 @@ import { presentErrorToHumans } from '~/common/util/errorUtils';
 // configuration
 const AIX_CLIENT_DEV_ASSERTS = process.env.NODE_ENV === 'development';
 
-// user-facing messages reused by the typed transport-marker branch and the legacy string-match fallbacks
-const MSG_REQUEST_EXCEEDED = '**Request too large**: Your message or attachments exceed the 4.5MB limit of the Vercel edge network. Tip: use the cleanup button in the right pane to hide messages, remove large attachments or reduce conversation length.';
+// user-facing messages reused by the typed transport-marker branch and the legacy string-match fallbacks.
+// NOTE: this is the PORTABLE stored text (becomes the error fragment's `part.error` - used for plain rendering, edits,
+// exports, logs), so keep it host-neutral. The 413 case is additionally upgraded to the BlockPartError_RequestExceeded
+// component, which OVERRIDES this string in chat and owns the host-aware phrasing (Vercel 4.5MB vs generic self-host).
+const MSG_REQUEST_EXCEEDED = '**Request too large**: Your message or attachments exceed the request size limit of the server. Tip: use the cleanup button in the right pane to hide messages, remove large attachments or reduce conversation length.';
 const MSG_RESPONSE_CAPTIVE = '**Network issue**: The network returned an HTML page instead of expected data. This can be a Wi-Fi sign-in page, a proxy or browser extension, or a temporary gateway error. Please **refresh and try again**, or check your connection and disable blockers. Additional details may be available in the browser console.';
 
 
@@ -90,9 +93,9 @@ export function aixClassifyStreamingError(error: any, isUserAbort: boolean, hasF
   // Initial connection failures, HTTP errors, or text responses that blow up tRPC's JSON parser
   if (error instanceof TRPCClientError) {
 
-    // Server-side PAYLOAD_TOO_LARGE - HTTP 413
+    // Server-side PAYLOAD_TOO_LARGE - HTTP 413 (fallback; streamingTransportFetch normally tags this earlier)
     if (error.data?.httpStatus === 413)
-      return { errorType: 'request-exceeded', errorMessage: '**Request too large**: This request exceed the size limit of the servers' };
+      return { errorType: 'request-exceeded', errorMessage: MSG_REQUEST_EXCEEDED };
 
     switch (error.cause?.message) {
       /**