Fix: Use custom fetch to ensure correct OpenAI format

app/api/text-generation/route.ts

@@ -1,33 +1,29 @@
-import { OpenAIStream, StreamingTextResponse } from 'ai';
+import { streamText } from 'ai';
+import { createOpenAI } from '@ai-sdk/openai';
+
+const customOpenAI = createOpenAI({
+  apiKey: process.env.BLABLADOR_API_KEY || '',
+  baseURL: 'https://api.openai.com/v1', // Trick the SDK to use the OpenAI format
+  fetch: async (url, options) => {
+    const newUrl = url.toString().replace('https://api.openai.com/v1', 'https://api.helmholtz-blablador.fz-juelich.de/v1');
+    return fetch(newUrl, options);
+  },
+});
 
-// IMPORTANT! Set the runtime to edge
 export const runtime = 'edge';
 
 export async function POST(req: Request) {
   const { prompt, model } = await req.json();
 
-  const response = await fetch('https://api.helmholtz-blablador.fz-juelich.de/v1/chat/completions', {
-    method: 'POST',
-    headers: {
-      'Content-Type': 'application/json',
-      'Authorization': `Bearer ${process.env.BLABLADOR_API_KEY || ''}`,
-    },
-    body: JSON.stringify({
-      model: model || 'alias-code',
-      messages: [{ role: 'user', content: prompt }],
-      stream: true,
-    }),
+  const result = await streamText({
+    model: customOpenAI(model || 'alias-code'),
+    messages: [
+      {
+        role: 'user',
+        content: prompt,
+      },
+    ],
   });
 
-  // Check for errors
-  if (!response.ok) {
-    return new Response(await response.text(), {
-      status: response.status,
-      statusText: response.statusText,
-    });
-  }
-
-  // Convert the response into a friendly text-stream
-  const stream = OpenAIStream(response);
-  return new StreamingTextResponse(stream);
-}
+  return result.toTextStreamResponse();
+}