upd

internal/proxy/server.go

@@ -40,7 +40,10 @@ func Run(cfg config.Config) error {
 			return resp
 		}
 
-		if !domain.IsMckoDomain(resp.Request.Host) {
+		contentType := strings.ToLower(resp.Header.Get("Content-Type"))
+		isImage := capture.IsImageResponse(contentType, resp.Request.URL.Path)
+		shouldRewrite := domain.IsMckoDomain(resp.Request.Host) && rewrite.IsHTMLResponse(contentType)
+		if !isImage && !shouldRewrite {
 			return resp
 		}
 
@@ -51,8 +54,7 @@ func Run(cfg config.Config) error {
 			return resp
 		}
 
-		contentType := strings.ToLower(resp.Header.Get("Content-Type"))
-		if capture.IsImageResponse(contentType, resp.Request.URL.Path) {
+		if isImage {
 			if err := imageSaver.Save(resp, original); err != nil {
 				log.Printf("save image failed for %s: %v", resp.Request.URL.String(), err)
 			}
@@ -60,7 +62,7 @@ func Run(cfg config.Config) error {
 			return resp
 		}
 
-		if !rewrite.IsHTMLResponse(contentType) {
+		if !shouldRewrite {
 			setResponseBody(resp, original)
 			return resp
 		}