From 083b6e5d4129ab60cc14857cb283b5110a93b6fc Mon Sep 17 00:00:00 2001
From: Marco Sadjadi <marco@buildmymcpserver.local>
Date: Fri, 22 May 2026 00:03:12 +0200
Subject: [PATCH] fix(preview): switch spec generation to Haiku 4.5 to fit the
 proxy window
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Sonnet still overran Cloudflare's edge timeout — the 504 fired at 90s but
the proxy had already cut the connection, so the browser saw a headerless
524 reported as a CORS error.

Measured against the live API: Haiku 4.5 generates the spec at ~200 tok/s,
so a full 8k-token spec completes in ~40s. With a hard 60s timeout and no
retries the route is guaranteed to answer well inside the proxy window.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 apps/api/src/routes/servers.ts                | 13 ++++++++-----
 apps/web/app/(dashboard)/servers/new/page.tsx |  2 +-
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/apps/api/src/routes/servers.ts b/apps/api/src/routes/servers.ts
index 080ead7..355e6ca 100644
--- a/apps/api/src/routes/servers.ts
+++ b/apps/api/src/routes/servers.ts
@@ -53,11 +53,14 @@ export async function serverRoutes(app: FastifyInstance): Promise<void> {
     try {
       const { spec, source } = await generateSpec(parsed.data.prompt, {
         apiKey: config.ANTHROPIC_API_KEY,
-        // Sonnet 4.6 drafts the spec well inside Cloudflare's ~100s proxy cap;
-        // Opus routinely exceeded it, which reached the browser as a CORS error.
-        model: 'claude-sonnet-4-6',
-        timeoutMs: 45_000,
-        maxRetries: 1,
+        // Preview generates the spec synchronously inside an HTTP request that
+        // sits behind Cloudflare's edge timeout. Haiku 4.5 (~200 tok/s — a full
+        // 8k-token spec in ~40s) is the only model fast enough; Sonnet and Opus
+        // overran the proxy cap, which reached the browser as a CORS error. The
+        // hard 60s timeout guarantees a clean 504 before the proxy gives up.
+        model: 'claude-haiku-4-5-20251001',
+        timeoutMs: 60_000,
+        maxRetries: 0,
       });
       const previewId = await cacheSpec(spec);
       return reply.send({
diff --git a/apps/web/app/(dashboard)/servers/new/page.tsx b/apps/web/app/(dashboard)/servers/new/page.tsx
index df32567..bac0745 100644
--- a/apps/web/app/(dashboard)/servers/new/page.tsx
+++ b/apps/web/app/(dashboard)/servers/new/page.tsx
@@ -457,7 +457,7 @@ function NewServerPageInner() {
           <Loader2 className="mx-auto animate-spin text-[--color-accent]" size={22} />
           <p className="mt-4 text-[13px]">Analyzing your prompt…</p>
           <p className="mt-1 text-[12px] text-[--color-fg-subtle]">
-            Claude Sonnet 4.6 is drafting the tool spec. Usually 20–40 seconds.
+            Claude is drafting the tool spec. Usually 15–40 seconds.
           </p>
           <p className="mono mt-3 text-[11px] tabular-nums text-[--color-fg-muted]">
             {elapsedSec}s elapsed