Pollinations MCP Server

Instructions

Implementation Reference

• src/index.ts:436-529 (handler)

  The main handler function for the 'download_image' tool. Downloads image from provided URL using axios, ensures output directory exists, writes to file, verifies success, and returns JSON response with file info or error.

  private async handleDownloadImage(args: any) {
    try {
      if (!this.isValidDownloadImageArgs(args)) {
        throw this.handleValidationError('无效的图像下载参数');
      }
  
      // 获取参数
      let { url, output_path = 'image.jpg' } = args;
      
      // 使用相对路径保存图像到当前工作目录
      output_path = path.resolve(process.cwd(), output_path);
      console.error(`图像将保存到: ${output_path}`);
  
      try {
        // 确保输出目录存在
        const dirname = path.dirname(output_path);
        if (!fs.existsSync(dirname)) {
          console.error(`创建目录: ${dirname}`);
          fs.mkdirSync(dirname, { recursive: true });
        }
      } catch (fsError) {
        throw this.handleFileSystemError(fsError, '创建目录');
      }
  
      // 下载图像
      console.error(`开始下载图像: ${url}`);
      let response;
      try {
        response = await axios.get(url, { responseType: 'arraybuffer' });
      } catch (downloadError) {
        throw this.handleApiError(downloadError);
      }
      
      // 写入文件
      try {
        console.error(`写入文件: ${output_path}`);
        fs.writeFileSync(output_path, Buffer.from(response.data, 'binary'));
      } catch (writeError) {
        throw this.handleFileSystemError(writeError, '写入文件');
      }
      
      // 验证文件是否写入成功
      try {
        if (fs.existsSync(output_path)) {
          const fileSize = fs.statSync(output_path).size;
          console.error(`文件成功写入: ${output_path}, 大小: ${fileSize} 字节`);
          
          return {
            content: [
              {
                type: 'text',
                text: JSON.stringify({
                  success: true,
                  message: `图像已下载到 ${output_path}`,
                  size: fileSize,
                  path: output_path
                }, null, 2),
              },
            ],
          };
        } else {
          throw new PollinationsError(
            `文件写入失败: ${output_path}`,
            PollinationsErrorType.FILE_SYSTEM_ERROR
          );
        }
      } catch (verifyError) {
        if (verifyError instanceof PollinationsError) {
          throw verifyError;
        } else {
          throw this.handleFileSystemError(verifyError, '验证文件');
        }
      }
    } catch (error) {
      // 处理所有错误
      let pollinationsError: PollinationsError;
      
      if (error instanceof PollinationsError) {
        pollinationsError = error;
      } else {
        pollinationsError = this.handleApiError(error);
      }
      
      return {
        content: [
          {
            type: 'text',
            text: pollinationsError.toUserFriendlyMessage(),
          },
        ],
        isError: true,
      };
    }
  }

• src/index.ts:559-569 (schema)

  Type guard function that validates the input arguments for the download_image tool, ensuring 'url' is string and 'output_path' is optional string.

  private isValidDownloadImageArgs(args: any): args is {
    url: string;
    output_path?: string;
  } {
    return (
      typeof args === 'object' &&
      args !== null &&
      typeof args.url === 'string' &&
      (args.output_path === undefined || typeof args.output_path === 'string')
    );
  }

• src/index.ts:208-226 (registration)

  Tool registration in the ListTools response, including name, description, and input schema definition.

  {
    name: 'download_image',
    description: '下载Pollinations.ai生成的图像到本地文件',
    inputSchema: {
      type: 'object',
      properties: {
        url: {
          type: 'string',
          description: '要下载的图像URL',
        },
        output_path: {
          type: 'string',
          description: '保存图像的路径（包括文件名）',
          default: 'image.jpg',
        },
      },
      required: ['url'],
    },
  },

• src/index.ts:272-273 (registration)

  Dispatcher switch case that routes 'download_image' tool calls to the handleDownloadImage method.

  case 'download_image':
    return this.handleDownloadImage(request.params.arguments);