add concat endpoint

src/app/api/concat/route.ts

@@ -0,0 +1,64 @@
+import { NextResponse, NextRequest } from "next/server";
+import { sunoApi } from "@/lib/SunoApi";
+import { corsHeaders } from "@/lib/utils";
+
+export const dynamic = "force-dynamic";
+
+export async function POST(req: NextRequest) {
+  if (req.method === 'POST') {
+    try {
+      const body = await req.json();
+      const { clip_id } = body;
+      if (!clip_id) {
+        return new NextResponse(JSON.stringify({ error: 'Clip id is required' }), {
+          status: 400,
+          headers: {
+            'Content-Type': 'application/json',
+            ...corsHeaders
+          }
+        });
+      }
+      const audioInfo = await (await sunoApi).concatenate(clip_id);
+      return new NextResponse(JSON.stringify(audioInfo), {
+        status: 200,
+        headers: {
+          'Content-Type': 'application/json',
+          ...corsHeaders
+        }
+      });
+    } catch (error: any) {
+      console.error('Error generating concatenating audio:', error.response.data);
+      if (error.response.status === 402) {
+        return new NextResponse(JSON.stringify({ error: error.response.data.detail }), {
+          status: 402,
+          headers: {
+            'Content-Type': 'application/json',
+            ...corsHeaders
+          }
+        });
+      }
+      return new NextResponse(JSON.stringify({ error: 'Internal server error' }), {
+        status: 500,
+        headers: {
+          'Content-Type': 'application/json',
+          ...corsHeaders
+        }
+      });
+    }
+  } else {
+    return new NextResponse('Method Not Allowed', {
+      headers: {
+        Allow: 'POST',
+        ...corsHeaders
+      },
+      status: 405
+    });
+  }
+}
+
+export async function OPTIONS(request: Request) {
+  return new Response(null, {
+    status: 200,
+    headers: corsHeaders
+  });
+}

src/lib/SunoApi.ts

@@ -116,6 +116,29 @@ class SunoApi {
     return audios;
   }
 
+  /**
+   * Calls the concatenate endpoint for a clip to generate the whole song.
+   * @param clip_id The ID of the audio clip to concatenate.
+   * @returns A promise that resolves to an AudioInfo object representing the concatenated audio.
+   * @throws Error if the response status is not 200.
+   */
+  public async concatenate(clip_id: string): Promise<AudioInfo> {
+    await this.keepAlive(false);
+    const payload: any = { clip_id: clip_id };
+
+    const response = await this.client.post(
+      `${SunoApi.BASE_URL}/api/generate/concat/v2/`,
+      payload,
+      {
+        timeout: 10000, // 10 seconds timeout
+      },
+    );
+    if (response.status !== 200) {
+      throw new Error("Error response:" + response.statusText);
+    }
+    return response.data;
+  }
+
   /**
    * Generates custom audio based on provided parameters.
    *