Youtube Vision MCP

Instructions

Implementation Reference

• src/index.ts:137-182 (handler)

  The main handler function for the 'summarize_youtube_video' tool. It validates input using the schema, constructs a prompt based on summary length, calls the Gemini API via callGeminiApi helper with the YouTube URL as video input, and returns the generated summary or handles errors.

  case "summarize_youtube_video": {
     try {
       // Parse and validate arguments
       const args = SummarizeYoutubeVideoInputSchema.parse(request.params.arguments);
       const { youtube_url, summary_length } = args;
       const length = summary_length || 'medium'; // Use default if not provided
  
       console.error(`[INFO] Received request to summarize YouTube URL: ${youtube_url} (Length: ${length})`);
  
       // Construct the prompt for Gemini API
       const finalPrompt = `Please summarize this video. Aim for a ${length} length summary.`;
  
       // Call Gemini API using the helper function
       const summary = await callGeminiApi(finalPrompt, {
         mimeType: "video/youtube",
         fileUri: youtube_url,
       });
  
       console.error(`[INFO] Successfully generated summary.`);
       // Return success response
       return {
         content: [{ type: "text", text: summary }],
       };
  
     } catch (error: any) {
       console.error(`[ERROR] Failed during summarize_youtube_video tool execution:`, error);
  
       // Handle Zod validation errors
       if (error instanceof z.ZodError) {
         return {
           content: [{ type: "text", text: `Invalid input: ${JSON.stringify(error.errors)}` }],
           isError: true,
         };
       }
  
       // Handle generic errors
       let errorMessage = `Failed to generate summary for the video.`;
       if (error.message) {
         errorMessage += ` Details: ${error.message}`;
       }
       return {
         content: [{ type: "text", text: errorMessage }],
         isError: true,
       };
     }
   }

• src/index.ts:45-49 (schema)

  Zod input schema for the tool, defining required YouTube URL and optional summary length enum.

  const SummaryLengthEnum = z.enum(['short', 'medium', 'long']).default('medium');
  const SummarizeYoutubeVideoInputSchema = z.object({
    youtube_url: z.string().url({ message: "Invalid YouTube URL provided." }),
    summary_length: SummaryLengthEnum.optional().describe("Desired summary length: 'short', 'medium', or 'long' (default: 'medium')."),
  });

• src/index.ts:70-74 (registration)

  Tool registration in the ListTools handler, providing name, description, and JSON schema derived from Zod schema.

  {
    name: "summarize_youtube_video",
    description: "Generates a summary of a given YouTube video URL using Gemini Vision API.",
    inputSchema: zodToJsonSchema(SummarizeYoutubeVideoInputSchema),
  },

• src/index.ts:96-127 (helper)

  Shared helper function used by the tool handler to call the Gemini API with a prompt and YouTube video file data, handling errors and returning the generated text.

  async function callGeminiApi(prompt: string, fileData: { mimeType: string; fileUri: string }): Promise<string> {
    try {
      const result = await geminiModel.generateContent([
        prompt,
        { fileData },
      ]);
      const response = result.response;
      return response.text();
    } catch (error: any) {
      console.error(`[ERROR] Gemini API call failed:`, error);
      // Attempt to provide more specific error info based on message content
      // (Since GoogleGenerativeAIError type seems unavailable for direct check)
      if (error instanceof Error) {
        // Check for common messages indicating client-side issues (API key, quota, etc.)
        // This part might need refinement based on actual observed error messages.
        if (error.message.includes('API key') || error.message.includes('permission denied')) {
           throw new Error(`Authentication/Authorization Error with Gemini API: ${error.message}`);
        } else if (error.message.includes('quota')) {
           throw new Error(`Gemini API quota likely exceeded: ${error.message}`);
        } else if (error.message.toLowerCase().includes('invalid')) { // Generic check for invalid inputs
           throw new Error(`Invalid input likely provided to Gemini API: ${error.message}`);
        } else if (error.message.includes('500') || error.message.includes('server error') || error.message.includes('network issue')) {
           // Guessing based on common error patterns for server/network issues
           throw new Error(`Gemini API server error or network issue: ${error.message}`);
        }
        // Re-throw generic error if specific checks don't match
        throw new Error(`Gemini API Error: ${error.message}`);
      }
      // Re-throw if it's not an Error instance for some reason
      throw error; // Keep original error if not an Error instance
    }
  }