From 20311b41f5a3f4a0a907cb36a0c6ec7343cc523c Mon Sep 17 00:00:00 2001
From: Pamela Chia <pamelachiamayyee@gmail.com>
Date: Thu, 9 Jul 2026 17:33:38 +0800
Subject: [PATCH] fix: drop UA-based markdown switching, negotiate by Accept
 only

Signed-off-by: Pamela Chia <pamelachiamayyee@gmail.com>
---
 src/start.ts | 14 +-------------
 1 file changed, 1 insertion(+), 13 deletions(-)

diff --git a/src/start.ts b/src/start.ts
index 1a503db..6f0dfe0 100644
--- a/src/start.ts
+++ b/src/start.ts
@@ -5,23 +5,11 @@ import { getLLMText, markdownPathToSlugs, source } from '@/lib/source';
 import { getBlogLLMText, blogSource } from '@/lib/blog-source.server';
 import homepageMarkdown from './content/homepage.md?raw';
 
-const LIVE_FETCH_UA_RE =
-  /(?<![A-Za-z0-9])(?:Claude-User|Claude-Web|ChatGPT-User|PerplexityBot)(?![A-Za-z0-9-])/i;
-
-function isLiveFetchAgent(request: Request): boolean {
-  const ua = (request.headers.get('user-agent') ?? '').slice(0, 512);
-  return LIVE_FETCH_UA_RE.test(ua);
-}
-
 function prefersMarkdownByAccept(request: Request): boolean {
   const preferred = getNegotiator(request).mediaTypes(['text/html', 'text/markdown'])[0];
   return preferred === 'text/markdown';
 }
 
-function wantsMarkdown(request: Request): boolean {
-  return isLiveFetchAgent(request) || prefersMarkdownByAccept(request);
-}
-
 function markdownResponse(body: string): Response {
   return new Response(body, {
     headers: {
@@ -40,7 +28,7 @@ const llmMiddleware = createMiddleware().server(async ({ next, request }) => {
   const explicitMarkdown = pathname.endsWith(MARKDOWN_EXT);
 
   // Explicit `.md` URLs always serve markdown; bare URLs only when the client prefers it.
-  if (!explicitMarkdown && !wantsMarkdown(request)) {
+  if (!explicitMarkdown && !prefersMarkdownByAccept(request)) {
     return next();
   }