kafka-ui/documentation/compose/proto/key-types.proto

syntax = "proto3";
package test;

import "google/protobuf/wrappers.proto";

message MyKey {
    string myKeyF1 = 1;
    google.protobuf.UInt64Value uint_64_wrapper = 2;
}

message MySpecificTopicKey {
    string special_field1 = 1;
    string special_field2 = 2;
    google.protobuf.FloatValue float_wrapper = 3;
}