diff --git a/src/vlibapi/api_format.c b/src/vlibapi/api_format.c
new file mode 100644
index 0000000..f7bb9d3
--- /dev/null
+++ b/src/vlibapi/api_format.c
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2022 Cisco Systems, Inc.
+ */
+
+#include <vppinfra/format.h>
+#include <vlibapi/api.h>
+
+u8 *
+format_vl_api_msg_text (u8 *s, va_list *args)
+{
+  api_main_t *am = va_arg (*args, api_main_t *);
+  u32 msg_id = va_arg (*args, u32);
+  void *msg = va_arg (*args, void *);
+  vl_api_msg_data_t *m = vl_api_get_msg_data (am, msg_id);
+
+  if (m->format_fn)
+    s = format (s, "%U", m->format_fn, msg);
+  else
+    s = format (s, "[format handler missing for `%s`]", m->name);
+  return s;
+}
+
+u8 *
+format_vl_api_msg_json (u8 *s, va_list *args)
+{
+  api_main_t *am = va_arg (*args, api_main_t *);
+  u32 msg_id = va_arg (*args, u32);
+  void *msg = va_arg (*args, void *);
+  vl_api_msg_data_t *m = vl_api_get_msg_data (am, msg_id);
+
+  cJSON *o = m->tojson_handler (msg);
+  char *out = cJSON_Print (o);
+
+  s = format (s, "%s", out);
+
+  cJSON_Delete (o);
+  cJSON_free (out);
+  return s;
+}