Astra DB MCP Server

Instructions

Implementation Reference

• tools/OpenBrowser.ts:5-54 (handler)

  The core handler function for the OpenBrowser tool. Validates the URL (only http/https allowed), determines platform-specific command to open the browser, and executes it safely using execFile to prevent injection.

  export async function OpenBrowser(params: { url: string }) {
    const { url } = params;
    
    // Validate URL to prevent command injection
    let validatedUrl: string;
    try {
      // Validate URL format
      const parsedUrl = new URL(url);
      // Only allow http and https protocols
      if (!['http:', 'https:'].includes(parsedUrl.protocol)) {
        return {
          success: false,
          message: "Invalid URL protocol. Only http and https are supported.",
        };
      }
      validatedUrl = parsedUrl.toString();
    } catch (e) {
      return {
        success: false,
        message: `Invalid URL format: ${e instanceof Error ? e.message : String(e)}`,
      };
    }
    
    // Determine the command based on platform
    const command =
      platform() === "darwin"
        ? "open"
        : platform() === "win32"
        ? "start"
        : "xdg-open";
  
    return new Promise<{ success: boolean; message: string }>(
      (resolve) => {
        // Use execFile instead of exec to prevent command injection
        execFile(command, [validatedUrl], (error) => {
          if (error) {
            resolve({
              success: false,
              message: `Failed to open browser: ${error.message}`,
            });
          } else {
            resolve({
              success: true,
              message: `Successfully opened ${validatedUrl} in default browser`,
            });
          }
        });
      }
    );
  }

• tools.ts:428-437 (schema)

  JSON schema for OpenBrowser tool input, requiring a 'url' string parameter.

  inputSchema: {
    type: "object",
    properties: {
      url: {
        type: "string",
        description: "The URL to open in the browser",
      },
    },
    required: ["url"],
  },

• tools.ts:425-438 (registration)

  Registration of the OpenBrowser tool in the exported tools array used for MCP listTools capability.

  {
    name: "OpenBrowser",
    description: "Open a web browser to a specific URL",
    inputSchema: {
      type: "object",
      properties: {
        url: {
          type: "string",
          description: "The URL to open in the browser",
        },
      },
      required: ["url"],
    },
  },

• index.ts:348-359 (registration)

  MCP server request handler dispatches calls to the OpenBrowser tool function.

  case "OpenBrowser":
    const openBrowserResult = await OpenBrowser({
      url: args.url as string,
    });
    return {
      content: [
        {
          type: "text",
          text: openBrowserResult.message,
        },
      ],
    };