diff --git a/main.go b/main.go
index b5431b6..0f0ee1a 100644
--- a/main.go
+++ b/main.go
@@ -125,10 +125,20 @@ func clone() {
 			badExit(err)
 		}
 
-		// update go.sum and go.mod
-		// todo: only do this if they don't exist?
-		// todo: make these git commit metadata
-		pb.RedoGoMod()
+		if err := pb.ValidGoSum(); err != nil {
+			// update go.sum and go.mod
+			if err := pb.RunStrict([]string{"go-mod-clean"}); err != nil {
+				log.Info("")
+				log.Info("Do you have go-mod-clean? Otherwise:")
+				log.Info("  go install go.wit.com/apps/go-mod-clean@latest")
+				log.Info("")
+				badExit(err)
+			}
+		}
+		if err := pb.ValidGoSum(); err != nil {
+			log.Info("could not generate valid go.sum file")
+			badExit(err)
+		}
 
 		// double check it actually downloaded
 		fullgitdir := filepath.Join(forge.GetGoSrc(), argv.Repo, ".git")
diff --git a/stdin.go b/stdin.go
new file mode 100644
index 0000000..370bc27
--- /dev/null
+++ b/stdin.go
@@ -0,0 +1,57 @@
+package main
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"go.wit.com/log"
+)
+
+func showOptions(b bool, s []string) {
+	fmt.Println("")
+	for _, line := range s {
+		fmt.Println(line)
+	}
+	fmt.Println("")
+	if b {
+		fmt.Println("Enter (Y/n)")
+	} else {
+		fmt.Println("Enter (y/N)")
+	}
+}
+
+// if b == true, default is to continue with 'Y'
+func simpleStdin(b bool, s []string) {
+	/*
+		if argv.Auto {
+			return
+		}
+	*/
+	err := errors.New("user cancelled via stdin")
+	showOptions(b, s)
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		s := scanner.Text()
+		s = strings.TrimSpace(s)
+		s = strings.ToLower(s)
+		switch s {
+		case "y":
+			log.Info("got y")
+			return
+		case "n":
+			log.Info("got n")
+			badExit(err)
+		case "":
+			if b {
+				return
+			} else {
+				badExit(err)
+			}
+		default:
+			badExit(err)
+		}
+	}
+}