Here is a list of all documented files with brief descriptions:

asr_interface.hh
audio_player_interface.hh
battery_interface.hh
bluetooth_interface.hh
capability.hh
capability_factory.hh
capability_helper_interface.hh
capability_interface.hh
chips_interface.hh
dialog_ux_state_aggregator_interface.hh
directive_sequencer_interface.hh
display_interface.hh
extension_interface.hh
focus_manager_interface.hh
interaction_control_manager_interface.hh
location_interface.hh
media_player_interface.hh
media_player_mock.h
message_interface.hh
mic_interface.hh
network_manager_interface.hh
nudge_interface.hh
nugu_audio.h
nugu_auth.hh
nugu_buffer.h
nugu_client.hh
nugu_core_container_interface.hh
nugu_decoder.h
nugu_directive.h
nugu_encoder.h
nugu_equeue.h
nugu_event.h
nugu_http.h
nugu_http_rest.hh
nugu_log.h
nugu_media.h
nugu_network_manager.h
nugu_pcm.h
nugu_player.h
nugu_plugin.h
nugu_prof.h
nugu_recorder.h
nugu_ringbuffer.h
nugu_runner.hh
nugu_timer.h
nugu_timer_interface.hh
nugu_timer_mock.h
nugu_uuid.h
nugu_winsock.h
phone_call_interface.hh
playsync_manager_interface.hh
routine_interface.hh
routine_manager_interface.hh
session_interface.hh
session_manager_interface.hh
sound_interface.hh
speaker_interface.hh
speech_recognizer_aggregator_interface.hh
speech_recognizer_interface.hh
system_interface.hh
text_interface.hh
tts_interface.hh
utility_interface.hh
wakeup_interface.hh