protobuf.md

Protocol Documentation

The arrows indicate the direction the message goes.

• ← indicates the message is sent from the amp to the computer
• → indicates the message is sent from the computer to the amp

FenderMessageLT

(← →) Base message type used to communicate with the amp

All messages are of this type, and encapsulate the actual message

Field	Type	Label	Description	Direction
responseType	ResponseType	required	Response type. All messages from the host to the amp are UNSOLICITED Default: UNSOLICITED	← →
processorUtilizationRequest	ProcessorUtilizationRequest	optional		→
processorUtilization	ProcessorUtilization	optional
memoryUsageRequest	MemoryUsageRequest	optional		→
memoryUsageStatus	MemoryUsageStatus	optional		→
presetJSONMessageRequest_LT	PresetJSONMessageRequest_LT	optional
presetJSONMessage	PresetJSONMessage	optional
currentPresetStatus	CurrentPresetStatus	optional
loadPreset	LoadPreset	optional		→
setDspUnitParameter	SetDspUnitParameter	optional		→
setDspUnitParameterStatus	SetDspUnitParameterStatus	optional
dspUnitParameterStatus	DspUnitParameterStatus	optional
currentLoadedPresetIndexStatus	CurrentLoadedPresetIndexStatus	optional
presetEditedStatus	PresetEditedStatus	optional
replaceNode	ReplaceNode	optional		→
replaceNodeStatus	ReplaceNodeStatus	optional
shiftPreset	ShiftPreset	optional		→
shiftPresetStatus	ShiftPresetStatus	optional
swapPreset	SwapPreset	optional		→
swapPresetStatus	SwapPresetStatus	optional
currentPresetSet	CurrentPresetSet	optional
currentLoadedPresetIndexBypassStatus	CurrentLoadedPresetIndexBypassStatus	optional
currentDisplayedPresetIndexStatus	CurrentDisplayedPresetIndexStatus	optional
presetSavedStatus	PresetSavedStatus	optional
clearPreset	ClearPreset	optional		→
clearPresetStatus	ClearPresetStatus	optional
saveCurrentPreset	SaveCurrentPreset	optional		→
saveCurrentPresetTo	SaveCurrentPresetTo	optional		→
savePresetAs	SavePresetAs	optional		→
newPresetSavedStatus	NewPresetSavedStatus	optional
renamePresetAt	RenamePresetAt	optional		→
auditionPreset	AuditionPreset	optional		→
auditionPresetStatus	AuditionPresetStatus	optional
exitAuditionPreset	ExitAuditionPreset	optional		→
exitAuditionPresetStatus	ExitAuditionPresetStatus	optional
auditionStateRequest	AuditionStateRequest	optional		→
auditionStateStatus	AuditionStateStatus	optional
productIdentificationStatus	ProductIdentificationStatus	optional
productIdentificationRequest	ProductIdentificationRequest	optional		→
firmwareVersionRequest	FirmwareVersionRequest	optional		→
firmwareVersionStatus	FirmwareVersionStatus	optional
currentPresetRequest	CurrentPresetRequest	optional		→
retrievePreset	RetrievePreset	optional		→
usbGainRequest	UsbGainRequest	optional		→
usbGainStatus	UsbGainStatus	optional
qASlotsRequest	QASlotsRequest	optional		→
qASlotsStatus	QASlotsStatus	optional
lineOutGainRequest	LineOutGainRequest	optional		→
lineOutGainStatus	LineOutGainStatus	optional
modalStatusMessage	ModalStatusMessage	optional
usbGainSet	UsbGainSet	optional		→
lineOutGainSet	LineOutGainSet	optional		→
qASlotsSet	QASlotsSet	optional		→
unsupportedMessageStatus	UnsupportedMessageStatus	optional
heartbeat	Heartbeat	optional		→
connectionStatusRequest	ConnectionStatusRequest	optional		→
connectionStatus	ConnectionStatus	optional
indexPot	IndexPot	optional
indexButton	IndexButton	optional
indexEncoder	IndexEncoder	optional
activeDisplay	ActiveDisplay	optional
frameBufferMessageRequest	FrameBufferMessageRequest	optional		→
frameBufferMessage	FrameBufferMessage	optional
lt4FootswitchModeRequest	LT4FootswitchModeRequest	optional		→
lt4FootswitchModeStatus	LT4FootswitchModeStatus	optional
loadPreset_TestSuite	LoadPreset_TestSuite	optional
loopbackTest	LoopbackTest	optional

ResponseType

Message response type

Name	Number	Description
UNSOLICITED	0	Message sent not as the result of a command
NOT_LAST_ACK	1	Message sent as the result of a command, but NOT the last message in the batch
IS_LAST_ACK	2	Message sent as the last result of a command

Auditioning

AuditionPreset

(→) Sends a preset to the amp to be "auditioned"

response: AuditionPresetStatus message containing the preset data loaded to the amp

Field	Type	Label	Description
presetData	string	required	JSON string conaining the preset to be auditioned

AuditionPresetStatus

(←) Response to an AuditionPreset message

Field	Type	Label	Description
presetData	string	required	JSON data conatining preset data being auditioned

AuditionStateRequest

(→) Queries the amp for its audition state

response: AuditionStateStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

AuditionStateStatus

(←) The current audition state of the amp. Resposne to an AuditionStateRequest message

Field	Type	Label	Description
isAuditioning	bool	required	True if the amp is in audition mode

ExitAuditionPreset

(→) Leaves audition mode

response: ExitAuditionPresetStatus message

Field	Type	Label	Description
exit	bool	required	True to exit audition mode

ExitAuditionPresetStatus

(←) Result message for an ExitAuditionPreset message

Field	Type	Label	Description
isSuccess	bool	required	True if audition mode was exited successfully

Preset management

CurrentPresetRequest

(→) Requests the current preset from the amp

response: CurrentPresetStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

CurrentPresetSet

(→) Sets the current preset of the amp

response: CurrentPresetStatus message

Field	Type	Label	Description
currentPresetData	string	required	JSON data conatining preset data

CurrentPresetStatus

(←) Returns the state of the current preset

Field	Type	Label	Description
currentPresetData	string	required	JSON data conatining current preset data
currentSlotIndex	int32	required	Current preset bank number
currentPresetDirtyStatus	bool	required	True if current preset has been edited and not saved

LoadPreset

(→) Switches the amp to the specified preset number

response: CurrentLoadedPresetIndexStatus message

Field	Type	Label	Description
presetIndex	int32	required	Preset bank number currently loaded

CurrentDisplayedPresetIndexStatus

(←) The current preset displayed on the amp. Sent when the preset is changed at the amp

Field	Type	Label	Description
currentDisplayedPresetIndex	int32	required	The current preset bank number

CurrentLoadedPresetIndexStatus

(←) The current preset displayed on the amp. Sent when the preset is changed at the amp or via a LoadPreset message

Field	Type	Label	Description
currentLoadedPresetIndex	int32	required	The current preset bank number

RetrievePreset

(←) Queries the amp on the stored presets

response: PresetJsonMessage

Field	Type	Label	Description
slot	int32	required	Preset bank to retrieve

PresetJSONMessage

(←) Saved preset data

Field	Type	Label	Description
data	string	required	JSON data conatining preset data for requested preset bank
slotIndex	int32	required	Preset bank this preset is stored in

ShiftPreset

(→) Moves a preset to the specified point, shifting all other presets

response: ShiftPresetStatus message

Field	Type	Label	Description
indexToShiftFrom	int32	required	Preset to shift
indexToShiftTo	int32	required	Destination of preset to shift

ShiftPresetStatus

(←) Response to a ShiftPreset message with the status of the command

Field	Type	Label	Description
indexToShiftFrom	int32	required	Preset shifted
indexToShiftTo	int32	required	Destination

SwapPreset

(→) Swaps the presets in indexA and indexB

response: SwapPresetStatus message

Field	Type	Label	Description
indexA	int32	required
indexB	int32	required

SwapPresetStatus

(←) result of a SwapPreset message

Field	Type	Label	Description
indexA	int32	required
indexB	int32	required

SaveCurrentPreset

(→) saves the current preset

response: PresetSavedStatus

Field	Type	Label	Description
save	bool	required

SaveCurrentPresetTo

(→) response: PresetSavedStatus

Field	Type	Label	Description
presetName	string	required
presetSlot	int32	required

SavePresetAs

(→) response: PresetSavedStatus

Field	Type	Label	Description
presetData	string	required
isLoadPreset	bool	required
presetSlot	int32	required

PresetSavedStatus

(←) Result of a SaveCurrentPreset, SaveCurrentPresetTo, or SavePresetAs message. Also sent when the preset is saved on the amp.

Field	Type	Label	Description
name	string	required	Name of the preset saved
slot	int32	required	Preset bank of the saved preset

RenamePresetAt

(→) Renames a preset

Field	Type	Label	Description
presetName	string	required	new preset name
presetSlot	int32	required	slot index to rename

NewPresetSavedStatus

(←)

Field	Type	Label	Description
presetData	string	required
presetSlot	int32	required

ClearPreset

(→) Clears a preset in the amp

response: ClearPresetStatus message

Field	Type	Label	Description
slotIndex	int32	required	Preset bank to clear
isLoadPreset	bool	required	??? the Tone app sets this to true when clearing the preset

ClearPresetStatus

(←) Response to a ClearPreset message

Field	Type	Label	Description
slotIndex	int32	required	bank number cleared

ReplaceNode

(→) Swaps out a node (amp, stomp, mod, delay, or reverb)

response: ReplaceNodeStatus message

Field	Type	Label	Description
nodeIdToReplace	string	required	nodeid to replace (amp, stomp, mod, delay, or reverb)
fenderIdToReplaceWith	string	required	FenderId of node to set

ReplaceNodeStatus

(←) Status of a ReplaceNode message; also sent when the node is changed at the amp

Field	Type	Label	Description
nodeIdReplaced	string	required	node replaced (amp, stomp, mod, delay, or reverb)
fenderIdReplaced	string	required	FenderId of node set

SetDspUnitParameter

(→) Changes the parameters of the DSP units

response: SetDspUnitParameterStatus message

Field	Type	Label	Description
nodeId	string	required	string id of the node to change (one of amp, stomp, mod, delay, reverb)
parameterId	string	required	string id of the parameter to change
floatParameter	float	optional
stringParameter	string	optional
sint32Parameter	sint32	optional
boolParameter	bool	optional

SetDspUnitParameterStatus

(←) Status of the SetDspUnitParameter message. Also sent when parameters are adjusted on the amp

Field	Type	Label	Description
nodeId	string	required	string id of the node changed (one of amp, stomp, mod, delay, reverb)
parameterId	string	required	string id of the parameter to change
floatParameter	float	optional
stringParameter	string	optional
sint32Parameter	sint32	optional
boolParameter	bool	optional

PresetEditedStatus

(←)

Editing status of the current preset

Field	Type	Label	Description
presetEdited	bool	required	True if the preset is in editing state Default: false

System Messages

ModalStatusMessage (← →)

Changes the state of the amp

response: A ModalStatusMessage with the result of the request

Field	Type	Label	Description
context	ModalContext	required	Context to switch to
state	ModalState	required	The result of the request. Requests to the amp are sent with an OK state

ModalContext

Name	Number	Description
SYNC_BEGIN	0	Used during the initialization of the connection
SYNC_END	1	Used during the initialization of the connection
BACKUP_BEGIN	2
BACKUP_END	3
RESTORE_BEGIN	4
RESTORE_END	5
TUNER_ENABLE	6	Enables the tuner
TUNER_DISABLE	7	Disables the tuner
FACTORY_RESTORE_BEGIN	8
FACTORY_RESTORE_END	9
TONE_BUSY_BEGIN	10
TONE_BUSY_END	11

ModalState

Name	Number	Description
OK	0	Success; also the default when sending this message to the amp
FAIL	1	Failure

ConnectionStatusRequest

Queries the connection status of the amp

response: ConnectionStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

ConnectionStatus

(←) The current connection state of the amp. Response to a ConnectionStatusRequest message

Field	Type	Label	Description
isConnected	bool	required	True if the amp is connected

FirmwareVersionRequest

(→) Requests the current filrware version

response: FirmwareVersionStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

FirmwareVersionStatus

(←) The firmware version of the amp

Field	Type	Label	Description
version	string	required	Firmware Version

Heartbeat

(→) Heartbeat message sent every second to keep the connection alive

Field	Type	Label	Description
dummyField	bool	required

MemoryUsageRequest

(→) Requests memory usage statistics from the amp

response: MemoryUsageStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

MemoryUsageStatus

(←) Message conainting current memory usage statistics

Field	Type	Label	Description
stack	int32	required
heap	int32	required

ProcessorUtilizationRequest

(→) Requests processor statistics from the amp

response: ProcessorUtilization message

Field	Type	Label	Description
request	bool	required	Always true on requests

ProcessorUtilization

(←) Current processor utilization statistics

Field	Type	Label	Description
percent	float	required
minPercent	float	required
maxPercent	float	required

ProductIdentificationRequest

(→)

Identifies the amplifier

response: ProductIdentificationStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

ProductIdentificationStatus

(←)

Field	Type	Label	Description
id	string	required

Footswitch settings control

QASlotsRequest

(→) Requests the settings of the footswitch presets

response: QASlotsStatus message

Field	Type	Label	Description
request	bool	required	Always true on requests

QASlotsSet

(→) Assigns preset banks to the footswitch

response: QASlotsStatus message

Field	Type	Label	Description
slots	uint32	repeated	Preset banks to assign to the footswitch

QASlotsStatus

(←) The current settings of the footswitch presets

Field	Type	Label	Description
slots	uint32	repeated	The preset banks assigned to the footswitch

USB Gain Control

UsbGainRequest

(→) Gets the current USB Gain settings

response: UsbGainStatus message

Field	Type	Label	Description
request	bool	required

UsbGainSet

(→) Sets the gain for the USB audio device

response: UsbGainStatus message

Field	Type	Label	Description
valueDB	float	required	gain in dB

UsbGainStatus

(←) The current setting of the gain for the USB audio device

Field	Type	Label	Description
valueDB	float	required	gain in dB

UnsupportedMessageStatus (← →)

Sent when a message is invalid

Field	Type	Label	Description
status	ErrorType	required

ErrorType

Name	Number	Description
UNSUPPORTED	0
FAILED	1
INVALID_PARAM	2
INVALID_NODE_ID	3
PARAM_OUT_OF_BOUNDS	4
FACTORY_RESTORE_IN_PROGRESS	5

Scalar Value Types

.proto Type	Notes	C++	Java	Python	Go	C#	PHP	Ruby
double		double	double	float	float64	double	float	Float
float		float	float	float	float32	float	float	Float
int32	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
int64	Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead.	int64	long	int/long	int64	long	integer/string	Bignum
uint32	Uses variable-length encoding.	uint32	int	int/long	uint32	uint	integer	Bignum or Fixnum (as required)
uint64	Uses variable-length encoding.	uint64	long	int/long	uint64	ulong	integer/string	Bignum or Fixnum (as required)
sint32	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
sint64	Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s.	int64	long	int/long	int64	long	integer/string	Bignum
fixed32	Always four bytes. More efficient than uint32 if values are often greater than 2^28.	uint32	int	int	uint32	uint	integer	Bignum or Fixnum (as required)
fixed64	Always eight bytes. More efficient than uint64 if values are often greater than 2^56.	uint64	long	int/long	uint64	ulong	integer/string	Bignum
sfixed32	Always four bytes.	int32	int	int	int32	int	integer	Bignum or Fixnum (as required)
sfixed64	Always eight bytes.	int64	long	int/long	int64	long	integer/string	Bignum
bool		bool	boolean	boolean	bool	bool	boolean	TrueClass/FalseClass
string	A string must always contain UTF-8 encoded or 7-bit ASCII text.	string	String	str/unicode	string	string	string	String (UTF-8)
bytes	May contain any arbitrary sequence of bytes.	string	ByteString	str	[]byte	ByteString	string	String (ASCII-8BIT)

Unknown messages

ActiveDisplay

Field	Type	Label	Description
pageName	string	required

CurrentLoadedPresetIndexBypassStatus

The bypass status of the DSP units.

Field	Type	Label	Description
currentLoadedPresetIndex	int32	required
bypassStatus	bool	repeated	Indicates whether the DSP unit is bypassed or not

DspUnitParameterStatus

Field	Type	Label	Description
nodeId	string	required
parameterId	string	required
floatParameter	float	optional
stringParameter	string	optional
sint32Parameter	sint32	optional
boolParameter	bool	optional

FrameBufferMessage

Field	Type	Label	Description
data	bytes	required

FrameBufferMessageRequest

Field	Type	Label	Description
request	bool	required	Always true on requests

IndexButton

Field	Type	Label	Description
index	int32	required
event	IndexButton.Event	required
timestamp_ms	uint32	optional

IndexButton.Event

Name	Number	Description
EVENT_ERROR	0
BUTTON_DOWN	1
BUTTON_UP	2
BUTTON_HELD	3

IndexEncoder

Field	Type	Label	Description
index	int32	required
ticks	int32	required

IndexPot

Field	Type	Label	Description
index	int32	required
position	float	required

LT4FootswitchModeRequest

Field	Type	Label	Description
request	bool	required	Always true on requests

LT4FootswitchModeStatus

Field	Type	Label	Description
currentMode	LT4FtswModes	required	Default: LT4_FTSW_MODE_OFF

LT4FtswModes

Name	Number	Description
LT4_FTSW_MODE_OFF	0
LT4_FTSW_MODE_BANK1	1
LT4_FTSW_MODE_BANK2	2
LT4_FTSW_MODE_FX	3

LineOutGainRequest

Field	Type	Label	Description
request	bool	required	Always true on requests

LineOutGainSet

Field	Type	Label	Description
valueDB	float	required

LineOutGainStatus

Field	Type	Label	Description
valueDB	float	required

LoadPreset_TestSuite

Field	Type	Label	Description
presetIndex	int32	required

LoopbackTest

Field	Type	Label	Description
data	string	required

PresetJSONMessageRequest_LT

Field	Type	Label	Description
request	int32	required