Messages TL-B schemes

In this section detailed explanation of TL-B schemes for messages.

Message TL-B

TL-B

Main message TL-B scheme declared as a combination of several nested structures

message$_ {X:Type} info:CommonMsgInfo
init:(Maybe (Either StateInit ^StateInit))
body:(Either X ^X) = Message X;

message$_ {X:Type} info:CommonMsgInfoRelaxed
init:(Maybe (Either StateInit ^StateInit))
body:(Either X ^X) = MessageRelaxed X;

_ (Message Any) = MessageAny;

Here Message X - is common message structure, MessageRelaxed X additional type with CommonMsgInfoRelaxed body and Message Any is a union of both. Message structure unified with X:Type, that in other words is a Cell. According to TL-B we can combine all data in one cell(if it will be fit to 1023 bits) or use references declared with caret ^.

Serialized Message X placed to action list with FunC method send_raw_message(), than smart contract execute this action and message send.

Definition of explicit serialization

For building valid binary data according TL-B structure we should do serialization, which defined for each type recurrently. It means, that for serialization of Message X we need to know how to serialize StateInit, CommonMsgInfo and so on.

Every nested structure we should get from another TL-B scheme according to link recurrently, until serialization for top structure will be explicit - every bit defined by Boolean or bit-like type(bits, uint, varuint).

Structures that currently does not use in regular development will mark with * in Type column, for example *Anycast usually skipped in serialization.

message$_

There is the top TL-B scheme whole messages Message X:

message$_ {X:Type} info:CommonMsgInfo
init:(Maybe (Either StateInit ^StateInit))
body:(Either X ^X) = Message X;

Structure	Type	Required	Description
message$_	Constructor		It defined according the constructor ruler. Empty tag $_ means we will not add any bits in the beginning
info	CommonMsgInfo	Required	Detailed Message properties define destination and its value. Always placed in message root cell.
init	StateInit	Optional	General structure using in TON for initilizing new contracts. Could be write in cell reference or root cell.
body	X	Required	Message Payload. Could be write in cell reference or root cell.

nothing$0 {X:Type} = Maybe X;
just$1 {X:Type} value:X = Maybe X;
left$0 {X:Type} {Y:Type} value:X = Either X Y;
right$1 {X:Type} {Y:Type} value:Y = Either X Y;

Recall how Maybe and Either works, we can serialize different cases:

• [CommonMsgInfo][10][StateInit][0][X] - Message X in the one cell

• [CommonMsgInfo][11][^StateInit][1][^X] - Message X with references

CommonMsgInfo TL-B

CommonMsgInfo

CommonMsgInfo is a list of parameters, that defines how message will be delivered in TON blockchain.

//internal message
int_msg_info$0 ihr_disabled:Bool bounce:Bool bounced:Bool
  src:MsgAddressInt dest:MsgAddressInt
  value:CurrencyCollection ihr_fee:Grams fwd_fee:Grams
  created_lt:uint64 created_at:uint32 = CommonMsgInfo;

//external incoming message
ext_in_msg_info$10 src:MsgAddressExt dest:MsgAddressInt
  import_fee:Grams = CommonMsgInfo;

//external outgoing message
ext_out_msg_info$11 src:MsgAddressInt dest:MsgAddressExt
  created_lt:uint64 created_at:uint32 = CommonMsgInfo;

int_msg_info$0

int_msg_info is a case of internal message. This means they could be sent between contracts, and only between contracts. Use case - ordinary cross contract messages.

nanograms$_ amount:(VarUInteger 16) = Grams;
//internal message
int_msg_info$0 ihr_disabled:Bool bounce:Bool bounced:Bool
  src:MsgAddressInt dest:MsgAddressInt
  value:CurrencyCollection ihr_fee:Grams fwd_fee:Grams
  created_lt:uint64 created_at:uint32 = CommonMsgInfo;

Structure	Type	Required	Description
int_msg_info$0	Constructor	Required	$0 tag means, that in serialization CommonMsgInfo started with 0 bit describes a internal message.
ihr_disabled	Bool	Required	Hyper cube routing flag.
bounce	Bool	Required	Message should be bounced if there are errors during processing. If message's flat bounce = 1, it calls bounceable.
bounced	Bool	Required	Flag that describes, that message itself is a result of bounce.
src	MsgAddressInt	Required	Address of smart contract sender of message.
dest	MsgAddressInt	Required	Address of smart contract destination of message.
value	CurrencyCollection	Required	Structure which describes currency information including total funds transferred in message.
ihr_fee	VarUInteger 16	Required	Fees for hyper routing delivery
fwd_fee	VarUInteger 16	Required	Fees for forwarding messages assigned by validators
created_lt	uint64	Required	Logic time of sending message assigned by validator. Using for odering actions in smart contract.
created_at	uint32	Required	Unix time

ext_in_msg_info$10

ext_in_msg_info$10 is a case of external incoming message. This means this type of messages sent from off-chain space to contracts. Use case - wallet application request to wallet contract.

nanograms$_ amount:(VarUInteger 16) = Grams;
//external incoming message
ext_in_msg_info$10 src:MsgAddressExt dest:MsgAddressInt
  import_fee:Grams = CommonMsgInfo;

Structure	Type	Required	Description
ext_in_msg_info$10	Constructor	Required	$10 tag means, that in serialization CommonMsgInfo started with 10 bits describes a external incoming message.
ihr_disabled	Bool	Required	Hyper routing flag. (currently always true)
src	MsgAddressExt	Required	Address of a external sender of the message.
dest	MsgAddressInt	Required	Address of smart contract destination of message.
import_fee	VarUInteger 16	Required	Fee for executing and delivering of message.

ext_out_msg_info$11

ext_out_msg_info$11 is a case of external outgoing message. This means they could be sent from contracts to off-chain space. Use case - logs.

//external outgoing message
ext_out_msg_info$11 src:MsgAddressInt dest:MsgAddressExt
  created_lt:uint64 created_at:uint32 = CommonMsgInfo;

Structure	Type	Required	Description
ext_out_msg_info$11	Constructor	Required	$11 tag means, that in serialization CommonMsgInfo started with 11 bit describes a external outgoing message.
src	MsgAddressInt	Required	Address of smart contract sender of message.
dest	MsgAddressExt	Required	Address of a external destination of the message.
created_lt	uint64	Required	Logic time of sending message assigned by validator. Using for odering actions in smart contract.
created_at	uint32	Required	Unix time

StateInit TL-B

StateInit serves to delivery inital data to contract and used in contract deployment.

_ split_depth:(Maybe (## 5)) special:(Maybe TickTock)
  code:(Maybe ^Cell) data:(Maybe ^Cell)
  library:(HashmapE 256 SimpleLib) = StateInit;

Structure	Type	Required	Description
split_depth	(## 5)	Optional	Parameter for the highload contracts, defines behaviour of splitting into multiple instances in different shards. Currently StateInit used without it.
special	TickTock*	Optional	Used for invoking smart contracts in every new block of the blockchain. Available only in the masterchain. Regular user's contracts used without it.
code	Cell	Optional	Contract's serialized code.
data	Cell	Optional	Contract initial data.
library	HashmapE 256 SimpleLib*	Optional	Currently used StateInit without libs

General detailed explanations for Hashmaps

MsgAddressExt TL-B

addr_none$00 = MsgAddressExt;
addr_extern$01 len:(## 9) external_address:(bits len)
= MsgAddressExt;

MsgAddress is a scheme of various serialization for addresses. Depends on which participant(off-chain or smartcontract) messages sent, different structures using.

addr_none$00

addr_none$00 - using for defining null address of off-chain participant. It means, that we can send external message to contract without unique sender's address.

addr_none$00 = MsgAddressExt;

Structure	Type	Required	Description
addr_none$00	Constructor	Required	$00 tag means, that in serialization MsgAddressExt started with 00 bits. This means whole external address is 00.

addr_extern$01

addr_extern$01 len:(## 9) external_address:(bits len)
= MsgAddressExt;

Structure	Type	Required	Description
addr_extern$01	Constructor	Required	$01 tag means, that in the serialization MsgAddressExt started with a 01 bits describes an external address.
len	## 9	Required	Same as uintN - means an unsigned N-bit number
external_address	(bits len)	Required	Address is a bitstring of the len equal to previous len

MsgAddressInt TL-B

addr_std$10 anycast:(Maybe Anycast)
workchain_id:int8 address:bits256  = MsgAddressInt;

addr_var$11 anycast:(Maybe Anycast) addr_len:(## 9)
workchain_id:int32 address:(bits addr_len) = MsgAddressInt;

addr_std$10

addr_std$10 anycast:(Maybe Anycast)
workchain_id:int8 address:bits256  = MsgAddressInt;

Structure	Type	Required	Description
addr_std$10	Constructor	Required	$10 tag means, that in the serialization MsgAddressInt started with a 10 bits describes an internal address.
anycast	Anycast*	Optional	Additional address data, currently do not used in ordinary internal messages
workchain_id	int8	Required	Workchain where smart contract of destination address placed. At moment always equals zero.
address	(bits256)	Required	Smart contract account ID number

addr_var$11

addr_var$11 anycast:(Maybe Anycast) addr_len:(## 9)
workchain_id:int32 address:(bits addr_len) = MsgAddressInt;

Structure	Type	Required	Description
addr_var$11	Constructor	Required	$11 tag means, that in the serialization MsgAddressInt started with a 11 bits describes an internal contract address.
anycast	Anycast*	Optional	Additional address data, currently do not used in ordinary internal messages
addr_len	## 9	Required	Same as uintN - means an unsigned N-bit number
workchain_id	int32	Required	Workchain where smart contract of destination address placed. At moment always equals zero.
address	(bits256)	Required	Payload address(could be account ID)

Basic used types

CurrencyCollection

nanograms$_ amount:(VarUInteger 16) = Grams;
currencies$_ grams:Grams other:ExtraCurrencyCollection
= CurrencyCollection;

Structure	Type	Required	Description
currencies$_	Constructor	Required	$_ empty tag means, that in the serialization CurrencyCollection we will not add any bits in the beginning
grams	(VarUInteger 16)	Required	Message value in nanoTons
other	ExtraCurrencyCollection	Optional	ExtraCurrencyCollection is a dict designed for additional currencies, that usually empty

• ExtraCurrencyCollection complex type, that usually wrote as empty dict in messages

VarUInteger n

var_uint$_ {n:#} len:(#< n) value:(uint (len * 8))
= VarUInteger n;
var_int$_ {n:#} len:(#< n) value:(int (len * 8))
= VarInteger n;

Structure	Type	Required	Description
var_uint$_	Constructor	Required	var_uint$_ empty tag means, that in the serialization CurrencyCollection we will not add any bits in the beginning
len	uintN	Required	bits len parameter for next value
value	(uint (len * 8))	Optional	uint value for integer number wrote in (len * 8) bits

Message example

Regular func internal message

  var msg = begin_cell()
    .store_uint(0, 1) ;; tag
    .store_uint(1, 1) ;; ihr_disabled
    .store_uint(1, 1) ;; allow bounces
    .store_uint(0, 1) ;; not bounced itself
    .store_slice(source)
    .store_slice(destination)
    ;; serialize CurrencyCollection (see below)
    .store_coins(amount)
    .store_dict(extra_currencies)
    .store_coins(0) ;; ihr_fee
    .store_coins(fwd_value) ;; fwd_fee
    .store_uint(cur_lt(), 64) ;; lt of transaction
    .store_uint(now(), 32) ;; unixtime of transaction
    .store_uint(0,  1) ;; no init-field flag (Maybe)
    .store_uint(0,  1) ;; inplace message body flag (Either)
    .store_slice(msg_body)
  .end_cell();

Regular func message in short form

Message parts that are always overwritten by validators could be skipped(fill with zero bits). Message's sender here skipped too, serialized as addr_none$00.

  cell msg = begin_cell()
        .store_uint(0x18, 6)
        .store_slice(addr)
        .store_coins(amount)
        .store_uint(0, 1 + 4 + 4 + 64 + 32 + 1 + 1)
        .store_slice(message_body)
.end_cell();