diff --git a/doc/audio-api.txt b/doc/audio-api.txt
index a73ba20..a3ff033 100644
--- a/doc/audio-api.txt
+++ b/doc/audio-api.txt
@@ -195,3 +195,116 @@ properties boolean Connected [readonly]
Indicates if a stream is active to a A2DP sink on
the remote device.
+
+
+Gateway 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
+
+
+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.
+