diff --git a/codeagent-wrapper/parser.go b/codeagent-wrapper/parser.go
index 0718d21..1d37563 100644
--- a/codeagent-wrapper/parser.go
+++ b/codeagent-wrapper/parser.go
@@ -271,8 +271,8 @@ func parseJSONStreamInternal(r io.Reader, warnFn func(string), infoFn func(strin
 			continue
 		}
 
-		// Unknown event format
-		warnFn(fmt.Sprintf("Unknown event format: %s", truncateBytes(line, 100)))
+		// Unknown event format from other backends (turn.started/assistant/user); ignore.
+		continue
 	}
 
 	switch {
diff --git a/codeagent-wrapper/parser_unknown_event_test.go b/codeagent-wrapper/parser_unknown_event_test.go
new file mode 100644
index 0000000..386d921
--- /dev/null
+++ b/codeagent-wrapper/parser_unknown_event_test.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestBackendParseJSONStream_UnknownEventsAreSilent(t *testing.T) {
+	input := strings.Join([]string{
+		`{"type":"turn.started"}`,
+		`{"type":"assistant","text":"hi"}`,
+		`{"type":"user","text":"yo"}`,
+		`{"type":"item.completed","item":{"type":"agent_message","text":"ok"}}`,
+	}, "\n")
+
+	var infos []string
+	infoFn := func(msg string) { infos = append(infos, msg) }
+
+	message, threadID := parseJSONStreamInternal(strings.NewReader(input), nil, infoFn, nil, nil)
+	if message != "ok" {
+		t.Fatalf("message=%q, want %q (infos=%v)", message, "ok", infos)
+	}
+	if threadID != "" {
+		t.Fatalf("threadID=%q, want empty (infos=%v)", threadID, infos)
+	}
+
+	for _, msg := range infos {
+		if strings.Contains(msg, "Agent event:") {
+			t.Fatalf("unexpected log for unknown event: %q", msg)
+		}
+	}
+}
+