cloudflare-browser-rendering-mcp

Instructions

Implementation Reference

• src/server.ts:327-383 (handler)

  The handler function for the extract_structured_content tool. Validates input arguments (url and selectors object), simulates content extraction using mock data for each selector, formats the results as Markdown sections, and returns a structured text content response. Includes error handling.

  /**
   * Handle the extract_structured_content tool
   */
  private async handleExtractStructuredContent(args: any) {
    // Validate arguments
    if (
      typeof args !== 'object' || 
      args === null || 
      typeof args.url !== 'string' ||
      typeof args.selectors !== 'object'
    ) {
      throw new McpError(ErrorCode.InvalidParams, 'Invalid arguments for extract_structured_content');
    }
  
    const { url, selectors } = args;
  
    try {
      // In a real implementation, you would:
      // 1. Use Cloudflare Browser Rendering to fetch the page
      // 2. Use the /scrape endpoint to extract content based on selectors
      
      // For this simulation, we'll return mock results
      const mockResults: Record<string, string> = {};
      
      for (const [key, selector] of Object.entries(selectors)) {
        if (typeof selector === 'string') {
          // Simulate extraction based on selector
          mockResults[key] = `Extracted content for selector "${selector}"`;
        }
      }
      
      // Format the results
      const formattedResults = Object.entries(mockResults)
        .map(([key, value]) => `## ${key}\n${value}`)
        .join('\n\n');
      
      return {
        content: [
          {
            type: 'text',
            text: `# Structured Content from ${url}\n\n${formattedResults}`,
          },
        ],
      };
    } catch (error) {
      console.error('[Error] Error extracting structured content:', error);
      return {
        content: [
          {
            type: 'text',
            text: `Error extracting structured content: ${error instanceof Error ? error.message : String(error)}`,
          },
        ],
        isError: true,
      };
    }
  }

• src/server.ts:108-128 (schema)

  Tool schema definition returned by listTools, specifying name, description, and inputSchema requiring 'url' string and 'selectors' object (CSS selectors as keys with string values).

  {
    name: 'extract_structured_content',
    description: 'Extracts structured content from a web page using CSS selectors',
    inputSchema: {
      type: 'object',
      properties: {
        url: {
          type: 'string',
          description: 'URL to extract content from',
        },
        selectors: {
          type: 'object',
          description: 'CSS selectors to extract content',
          additionalProperties: {
            type: 'string',
          },
        },
      },
      required: ['url', 'selectors'],
    },
  },

• src/server.ts:189-191 (registration)

  Registration in the CallToolRequest handler switch statement, logging the call and dispatching to the specific handleExtractStructuredContent method.

  case 'extract_structured_content':
    console.error(`[API] Extracting structured content from: ${args?.url}`);
    return await this.handleExtractStructuredContent(args);