Fix : Add image compression utility for base64 screenshots

Author: tech-sushant

src/lib/utils.ts

@@ -1,3 +1,5 @@
+import sharp from "sharp";
+
 export function sanitizeUrlParam(param: string): string {
   // Remove any characters that could be used for command injection
   return param.replace(/[;&|`$(){}[\]<>]/g, "");
@@ -24,3 +26,24 @@ export interface HarEntry {
   serverIPAddress?: string;
   time?: number;
 }
+
+/**
+ * Compresses a base64 image intelligently to keep it under 1 MB if needed.
+ */
+export async function maybeCompressBase64(base64: string): Promise<string> {
+  const buffer = Buffer.from(base64, "base64");
+
+  if (buffer.length <= 1048576) {
+    return base64;
+  }
+
+  const sizeRatio = 1048576 / buffer.length;
+  const estimatedQuality = Math.floor(sizeRatio * 100);
+  const quality = Math.min(95, Math.max(30, estimatedQuality)); 
+
+  const compressedBuffer = await sharp(buffer)
+    .png({ quality })
+    .toBuffer();
+
+  return compressedBuffer.toString("base64");
+}

src/tools/appautomate.ts

@@ -4,6 +4,7 @@ import { CallToolResult } from "@modelcontextprotocol/sdk/types.js";
 import logger from "../logger";
 import config from "../config";
 import { trackMCP } from "../lib/instrumentation";
+import { maybeCompressBase64 } from "../lib/utils";
 
 import {
   getDevicesAndBrowsers,
@@ -122,13 +123,15 @@ async function takeAppScreenshot(args: {
     });
 
     const screenshotBase64 = await driver.takeScreenshot();
+    const compressed = await maybeCompressBase64(screenshotBase64);
 
     return {
       content: [
         {
           type: "image",
-          data: screenshotBase64,
+          data: compressed,
           mimeType: "image/png",
+          name: `screenshot-${selectedDevice.device}-${Date.now()}`,
         },
       ],
     };