Beats_input_codec_json_applied in tags

This is the same issue here (https://github.com/logstash-plugins/logstash-input-beats/issues/58 )
Every event will be add a tag beats_input_codec_json_applied if I specify the codec in input config file.

Is there any way to disable this tag in logstash? without using any plugin.

Thanks in advanced

See https://github.com/logstash-plugins/logstash-input-beats/issues/114, referenced in the issue you linked to. The change has been merged but has so far only ended up in the 3.1.0 beta releases.