diff --git a/serve.go b/serve.go
index 235366c..3a8147c 100644
--- a/serve.go
+++ b/serve.go
@@ -43,6 +43,10 @@ var serve = &cli.Command{
 			Usage:       "file containing the initial batch of events that will be served by the relay as newline-separated JSON (jsonl)",
 			DefaultText: "the relay will start empty",
 		},
+		&cli.BoolFlag{
+			Name:  "negentropy",
+			Usage: "enable negentropy syncing",
+		},
 		&cli.BoolFlag{
 			Name:  "grasp",
 			Usage: "enable grasp server",
@@ -91,6 +95,10 @@ var serve = &cli.Command{
 
 		rl.UseEventstore(db, 500)
 
+		if c.Bool("negentropy") {
+			rl.Negentropy = true
+		}
+
 		started := make(chan bool)
 		exited := make(chan error)
 
@@ -152,7 +160,12 @@ var serve = &cli.Command{
 
 		// relay logging
 		rl.OnRequest = func(ctx context.Context, filter nostr.Filter) (reject bool, msg string) {
-			log("    got %s %v\n", color.HiYellowString("request"), colors.italic(filter))
+			negentropy := ""
+			if khatru.IsNegentropySession(ctx) {
+				negentropy = color.HiBlueString("negentropy ")
+			}
+
+			log("    got %s%s %v\n", negentropy, color.HiYellowString("request"), colors.italic(filter))
 			printStatus()
 			return false, ""
 		}