diff --git a/doc/audio-api.txt b/doc/audio-api.txt
index a73ba20..cdb6de9 100644
--- a/doc/audio-api.txt
+++ b/doc/audio-api.txt
@@ -195,3 +195,120 @@ properties	boolean Connected [readonly]
 
 			Indicates if a stream is active to a A2DP sink on
 			the remote device.
+
+
+AudioSink hierarchy
+===================
+
+Service		org.bluez
+Interface	org.bluez.Gateway
+Object path	[variable prefix]/{hci0,hci1,...}/dev_XX_XX_XX_XX_XX_XX
+
+This interface is available for remote devices which can function in the Audio
+Gateway role of the HFP profiles.
+
+Methods		void Connect()
+
+		     Connect to the AG service on the remote device.
+
+		void Disconnect()
+		boolean IsConnected()
+
+		void AnswerCall()
+		
+		      It has to called only after Ring signal received.
+    
+    		void CancelCurrentCall()
+
+		      Cancel call which is running now. This one does nothing with any 3-way
+		      situation incl. RaH. Just plain old PDH.
+         
+	 	void Call(string number)
+
+		      Dial a number 'number'. No number processing is done thus if AG would 
+		      reject to dial it don't blame me :)
+    
+    		string GetOperatorName()
+    
+    		void VoiceRecognitionActivate()
+		      in development
+		void VoiceRecognitionDeactivate()
+		      in development
+
+		string GetNumberForLastVoiceTag()
+
+		      Ask AG to provide a phone number. It looks like AG shell in turn 
+		      ask user to choose one. Idea behind this is VR on the HF side.
+
+    		void SendDTMF(string digits)
+
+		      Will send each digit in the 'digits' sequentially. Would send 
+		      nothing if there is non-dtmf digit.
+
+		void SendMicrophoneGain(uint8 gain)
+		void SendSpeakerGain(uint8 gain)
+
+		      Feel them useless but really easy to implement :)
+    
+    		string[] GetSubscriberNumbers()
+
+		      Get all the numbers of AG
+
+		void SendAudioData(uint8[] data)
+
+		      Would only be effective when call or VR is running
+		      (i.e. SCO link aka Audio Connection exists). Data should be 
+		      plain 16 bit LE PCM (e.g. directly from ALSA)
+
+Signals
+		void Connected(uint32 ag_features) 
+
+		      Connection successfully esteblished. 'ag_features' are
+		      ORed features:
+		                    0x001 Three-way calling
+				    0x002 Echo cancelling and/or noice reduction function
+				    0x004 Voice recognition function
+				    0x008 In-band ring tone capability
+              			    0x010 Attach a number to a voice tag
+              			    0x020 Ability to reject a call
+              			    0x040 Enhanced call status
+              			    0x080 Enhanced call control
+              			    0x100 Extended Error Result Cod
+
+    		void Disconnected()
+
+		void Ring(string number)
+
+		      Someone's calling from 'number'. 
+         	      Caller number is provided as received from AG.
+
+		void StatusUpdate(string indicator_name, uint32 indicator_value)
+
+		      Indicator 'indicator_name' changed its value to 'indicator_value'. 
+		      System (call, callsetup, etc.) statuses are not signalled.
+
+		void CallCancelled()
+		
+		      Call failed to set up. It means that we tried to call someone 
+		      or someone tried to call us but call was not accepted.
+
+		void CallStart()
+
+		      Call set up successfully.
+
+		void CallEnd()
+
+		      Call was started and now ended. In contrast with CallCancelled 
+		      where call didn't started
+
+		void VoiceRecognitionActive()
+		void VoiceRecognitionInactive()
+		      in development
+
+		void MicrophoneGain(uint8 gain) 
+		void SpeakerGain(uint8 gain)
+		      AG sent us new gain.
+
+		void AudioData(uint8[] data) 
+
+		      Array of audio data from AG. It is plain 16 bit PCM ready for ALSA.