✨ feat: add extend api

- Added extend API
- Added documentation for extend API

src/app/api/extend_audio/route.ts

@@ -0,0 +1,70 @@
+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 { audio_id, prompt, continue_at, tags, title } = body;
+      console.log(body)
+
+      if (!audio_id) {
+        return new NextResponse(JSON.stringify({ error: 'Audio ID is required' }), {
+          status: 400,
+          headers: {
+            'Content-Type': 'application/json',
+            ...corsHeaders
+          }
+        });
+      }
+
+      const audioInfo = await (await sunoApi)
+        .extendAudio(audio_id, prompt, continue_at, tags, title);
+
+      return new NextResponse(JSON.stringify(audioInfo), {
+        status: 200,
+        headers: {
+          'Content-Type': 'application/json',
+          ...corsHeaders
+        }
+      });
+    } catch (error: any) {
+      console.error('Error extend audio:', JSON.stringify(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: ' + JSON.stringify(error.response.data.detail) }), {
+        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/app/docs/page.tsx

@@ -28,6 +28,7 @@ export default function Docs() {
 - \`/api/get\`: Get music information based on the id. Use “,” to separate multiple 
     ids.  If no IDs are provided, all music will be returned.
 - \`/api/get_limit\`: Get quota Info
+- \`/api/extend_audio\`: Extend audio length
 \`\`\`
 
 Feel free to explore the detailed API parameters and conduct tests on this page.

src/app/docs/swagger-suno-api.json

@@ -179,6 +179,50 @@
         }
       }
     },
+    "/api/extend_audio": {
+      "post": {
+        "summary": "Extend audio length.",
+        "description": "Extend audio length.",
+        "tags": ["default"],
+        "requestBody": {
+          "content": {
+            "application/json": {
+              "schema": {
+                "type": "object",
+                "required": ["audio_id"],
+                "properties": {
+                  "audio_id": {
+                    "type": "string",
+                    "description": "The ID of the audio clip to extend.",
+                    "example": "e76498dc-6ab4-4a10-a19f-8a095790e28d"
+                  },
+                  "prompt": {
+                    "type": "string",
+                    "description": "Detailed prompt, including information such as music lyrics.",
+                    "example": ""
+                  },
+                  "continue_at": {
+                    "type": "string",
+                    "description": "Extend a new clip from a song at mm:ss(e.g. 00:30). Default extends from the end of the song.",
+                    "example": "109.96"
+                  },
+                  "title": {
+                    "type": "string",
+                    "description": "Music title",
+                    "example": ""
+                  },
+                  "tags": {
+                    "type": "string",
+                    "description": "Music genre",
+                    "example": ""
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    },
     "/api/generate_lyrics": {
       "post": {
         "summary": "Generate lyrics based on Prompt.",

src/app/page.tsx

@@ -105,6 +105,7 @@ Suno API currently mainly implements the following APIs:
 - \`/api/get\`: Get music list
 - \`/api/get?ids=\`: Get music Info by id, separate multiple id with ",".
 - \`/api/get_limit\`: Get quota Info
+- \`/api/extend_audio\`: Extend audio length
 \`\`\`
 
 For more detailed documentation, please check out the demo site:

src/lib/SunoApi.ts

@@ -255,6 +255,34 @@ class SunoApi {
     return lyricsResponse.data;
   }
 
+  /**
+   * Extends an existing audio clip by generating additional content based on the provided prompt.
+   * 
+   * @param audioId The ID of the audio clip to extend.
+   * @param prompt The prompt for generating additional content.
+   * @param continueAt Extend a new clip from a song at mm:ss(e.g. 00:30). Default extends from the end of the song.
+   * @param tags Style of Music.
+   * @param title Title of the song.
+   * @returns A promise that resolves to an AudioInfo object representing the extended audio clip.
+   */
+  public async extendAudio(
+    audioId: string,
+    prompt: string = "",
+    continueAt: string = "0",
+    tags: string = "",
+    title: string = ""
+  ): Promise<AudioInfo> {
+    const response = await this.client.post(`${SunoApi.BASE_URL}/api/generate/v2/`, {
+      continue_clip_id: audioId,
+      continue_at: continueAt,
+      mv: "chirp-v3-0",
+      prompt: prompt,
+      tags: tags,
+      title: ""
+    });
+    return response.data;
+  }
+
   /**
    * Processes the lyrics (prompt) from the audio metadata into a more readable format.
    * @param prompt The original lyrics text.
@@ -327,7 +355,7 @@ const newSunoApi = async (cookie: string) => {
   return await sunoApi.init();
 }
 
-if (! process.env.SUNO_COOKIE) {
+if (!process.env.SUNO_COOKIE) {
   console.log("Environment does not contain SUNO_COOKIE.", process.env)
 }