From c8ee28d2b0d84135079a54f7f45131bba859dd20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Bombeck?= <mbombeck@gmail.com>
Date: Sat, 9 May 2026 01:27:07 +0200
Subject: [PATCH] fix(insights): map LLM-parse failure to 422 instead of 502
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Same Cloudflare-rewrites-5xx footgun the v1.4.5 ai/test fix solved. A
malformed JSON response from the upstream model returned HTTP 502, which
Cloudflare swapped for its own HTML error page; the client's
`await res.json()` then crashed with `Unexpected token '<', "<!DOCTYPE "`
and the user — already throttled by the 2/h rate limit — saw nothing
useful. 4xx passes through Cloudflare untouched, so the React Query
mutation can read the JSON envelope and show a real error.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 src/app/api/insights/generate/route.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/app/api/insights/generate/route.ts b/src/app/api/insights/generate/route.ts
index 8858bbfe7..64220042a 100644
--- a/src/app/api/insights/generate/route.ts
+++ b/src/app/api/insights/generate/route.ts
@@ -82,7 +82,11 @@ export const POST = apiHandler(async (request: NextRequest) => {
     const validated = insightResultSchema.safeParse(parsed);
     insights = validated.success ? validated.data : parsed;
   } catch {
-    return apiError("Failed to parse AI response", 502);
+    // Returning 502 here triggers Cloudflare's HTML error rewrite, which
+    // breaks `await res.json()` on the client side. 422 stays passthrough
+    // so the React Query mutation can read the JSON body and surface a
+    // readable message. Same fix pattern as v1.4.5 ai/test.
+    return apiError("AI response was not valid JSON", 422);
   }
 
   await prisma.user.update({