Transaction layout

info

To maximize your comprehension of this page, familiarizing yourself with the TL-B language is highly recommended.

The TON Blockchain operates using three key parts: accounts, messages, and transactions. This page describes the structure and layout of transactions.

A transaction is an operation that processes inbound and outbound messages related to a specific account, altering its state and potentially generating fees for validators.

Transaction

transaction$0111 account_addr:bits256 lt:uint64
    prev_trans_hash:bits256 prev_trans_lt:uint64 now:uint32
    outmsg_cnt:uint15
    orig_status:AccountStatus end_status:AccountStatus
    ^[ in_msg:(Maybe ^(Message Any)) out_msgs:(HashmapE 15 ^(Message Any)) ]
    total_fees:CurrencyCollection state_update:^(HASH_UPDATE Account)
    description:^TransactionDescr = Transaction;

Field	Type	Required	Description
`account_addr`	bits256	Yes	The hash part of the address on which the transaction was executed. More about addresses
`lt`	uint64	Yes	Represents Logical time. More about logical time
`prev_trans_hash`	bits256	Yes	The hash of the previous transaction on this account.
`prev_trans_lt`	uint64	Yes	The `lt` of the previous transaction on this account.
`now`	uint32	Yes	The `now` value that was set when executing this transaction. It's a Unix timestamp in seconds.
`outmsg_cnt`	uint15	Yes	The number of outgoing messages created while executing this transaction.
`orig_status`	AccountStatus	Yes	The status of this account before the transaction was executed.
`end_status`	AccountStatus	Yes	The status of this account after executing the transaction.
`in_msg`	(Message Any)	No	The incoming message that triggered the execution of the transaction. Stored in a reference.
`out_msgs`	HashmapE 15 ^(Message Any)	Yes	The dictionary that contains the list of outgoing messages that were created while executing this transaction.
`total_fees`	CurrencyCollection	Yes	The total amount of fees that were collected while executing this transaction. It consists of a Toncoin value and possibly some Extra-currencies.
`state_update`	HASH_UPDATE Account	Yes	The `HASH_UPDATE` structure. Stored in a reference.
`description`	TransactionDescr	Yes	A detailed description of the transaction execution process. Stored in a reference.

AccountStatus

acc_state_uninit$00 = AccountStatus;
acc_state_frozen$01 = AccountStatus;
acc_state_active$10 = AccountStatus;
acc_state_nonexist$11 = AccountStatus;

[00]: Account is not initialized
[01]: Account is frozen
[10]: Account is active
[11]: Account does not exist

HASH_UPDATE

update_hashes#72 {X:Type} old_hash:bits256 new_hash:bits256
    = HASH_UPDATE X;

Field	Type	Description
`old_hash`	bits256	The hash of the account state before executing the transaction.
`new_hash`	bits256	The hash of the account state after executing the transaction.

Ordinary

This is the most common type of transaction and it fulfills most developers' needs. Transactions of this type have exactly one incoming message and can create several outgoing messages.

trans_ord$0000 credit_first:Bool
    storage_ph:(Maybe TrStoragePhase)
    credit_ph:(Maybe TrCreditPhase)
    compute_ph:TrComputePhase action:(Maybe ^TrActionPhase)
    aborted:Bool bounce:(Maybe TrBouncePhase)
    destroyed:Bool
    = TransactionDescr;

Field	Type	Required	Description
`credit_first`	Bool	Yes	A flag that correlates with `bounce` flag of an incoming message. `credit_first = !bounce`
`storage_ph`	TrStoragePhase	No	Contains information about storage phase of a transaction execution. More Info
`credit_ph`	TrCreditPhase	No	Contains information about credit phase of a transaction execution. More Info
`compute_ph`	TrComputePhase	Yes	Contains information about compute phase of a transaction execution. More Info
`action`	TrActionPhase	No	Contains information about action phase of a transaction execution. More Info. Stored in a reference.
`aborted`	Bool	Yes	Indicates whether the transaction execution was aborted.
`bounce`	TrBouncePhase	No	Contains information about bounce phase of a transaction execution. More Info
`destroyed`	Bool	Yes	Indicates whether the account was destroyed during the execution.

Storage

Transactions of this type can be inserted by validators at their discretion. They do not process any inbound messages and do not invoke any code. Their only effect is to collect storage payments from an account, affecting its storage statistics and balance. If the resulting Toncoin balance of the account drops below a certain amount, the account may be frozen, and its code and data replaced by their combined hash.

trans_storage$0001 storage_ph:TrStoragePhase
    = TransactionDescr;

Field	Type	Description
`storage_ph`	TrStoragePhase	Contains information about storage phase of a transaction execution. More Info

Tick-tock

Tick and Tock transactions are reserved for special system smart contracts that are required to be automatically invoked in each block. Tick transactions are invoked at the beginning of each masterchain block, and Tock transactions are invoked at the end.

trans_tick_tock$001 is_tock:Bool storage_ph:TrStoragePhase
    compute_ph:TrComputePhase action:(Maybe ^TrActionPhase)
    aborted:Bool destroyed:Bool = TransactionDescr;

Field	Type	Required	Description
`is_tock`	Bool	Yes	A flag indicating the type of transaction. Used to separate `Tick` and `Tock` transactions
`storage_ph`	TrStoragePhase	Yes	Contains information about storage phase of a transaction execution. More Info
`compute_ph`	TrComputePhase	Yes	Contains information about compute phase of a transaction execution. More Info
`action`	TrActionPhase	No	Contains information about action phase of a transaction execution. More Info. Stored in a reference.
`aborted`	Bool	Yes	Indicates whether the transaction execution was aborted.
`destroyed`	Bool	Yes	Indicates whether the account was destroyed during the execution.

Split Prepare

note

This type of transaction is currently not in use. Information about this process is limited.

Split transactions are initiated on large smart contracts that need to be divided under high load. The contract should support this transaction type and manage the splitting process to balance the load.

Split Prepare transactions are initiated when a smart contract needs to be split. The smart contract should generate the state for a new instance of itself to be deployed.

trans_split_prepare$0100 split_info:SplitMergeInfo
    storage_ph:(Maybe TrStoragePhase)
    compute_ph:TrComputePhase action:(Maybe ^TrActionPhase)
    aborted:Bool destroyed:Bool
    = TransactionDescr;

Field	Type	Required	Description
`split_info`	SplitMergeInfo	Yes	Information about split process.
`storage_ph`	TrStoragePhase	No	Contains information about storage phase of a transaction execution. More Info
`compute_ph`	TrComputePhase	Yes	Contains information about compute phase of a transaction execution. More Info
`action`	TrActionPhase	No	Contains information about action phase of a transaction execution. More Info. Stored in a reference.
`aborted`	Bool	Yes	Indicates whether the transaction execution was aborted.
`destroyed`	Bool	Yes	Indicates whether the account was destroyed during the execution.

Split install

note

This type of transaction is currently not in use. Information about this process is limited.

Split Install transactions are used for creating new instances of large smart contracts. The state for the new smart contract is generated by a Split Prepare transaction.

trans_split_install$0101 split_info:SplitMergeInfo
    prepare_transaction:^Transaction
    installed:Bool = TransactionDescr;

Field	Type	Description
`split_info`	SplitMergeInfo	Information about split process.
`prepare_transaction`	Transaction	Information about the transaction prepared for the split operation. Stored in a reference.
`installed`	Bool	Indicates whether the transaction was installed.

Merge prepare

note

This type of transaction is currently not in use. Information about this process is limited.

Merge transactions are initiated on large smart contracts that need to recombine after being split due to high load. The contract should support this transaction type and manage the merging process to balance the load.

Merge Prepare transactions are initiated when two smart contracts need to be merged. The smart contract should generate a message for another instance of itself to facilitate the merge.

trans_merge_prepare$0110 split_info:SplitMergeInfo
    storage_ph:TrStoragePhase aborted:Bool
    = TransactionDescr;

Field	Type	Description
`split_info`	SplitMergeInfo	Information about merge process.
`storage_ph`	TrStoragePhase	Contains information about storage phase of a transaction execution. More Info
`aborted`	Bool	Indicates whether the transaction execution was aborted.

Merge install

note

This type of transaction is currently not in use. Information about this process is limited.

Merge Install transactions are used for merging instances of large smart contracts. The special message facilitating the merge is generated by a Merge Prepare transaction.

trans_merge_install$0111 split_info:SplitMergeInfo
    prepare_transaction:^Transaction
    storage_ph:(Maybe TrStoragePhase)
    credit_ph:(Maybe TrCreditPhase)
    compute_ph:TrComputePhase action:(Maybe ^TrActionPhase)
    aborted:Bool destroyed:Bool
    = TransactionDescr;

Field	Type	Required	Description
`split_info`	SplitMergeInfo	Yes	Information about merge process.
`prepare_transaction`	Transaction	Yes	Information about the transaction prepared for the merge operation. Stored in a reference.
`storage_ph`	TrStoragePhase	No	Contains information about storage phase of a transaction execution. More Info
`credit_ph`	TrCreditPhase	No	Contains information about credit phase of a transaction execution. More Info
`compute_ph`	TrComputePhase	Yes	Contains information about compute phase of a transaction execution. More Info
`action`	TrActionPhase	No	Contains information about action phase of a transaction execution. More Info. Stored in a reference.
`aborted`	Bool	Yes	Indicates whether the transaction execution was aborted.
`destroyed`	Bool	Yes	Indicates whether the account was destroyed during the execution.

Transaction layout

Transaction​

AccountStatus​

HASH_UPDATE​

TransactionDescr Types​

Ordinary​

Storage​

Tick-tock​

Split Prepare​

Split install​

Merge prepare​

Merge install​

See also​

Transaction

AccountStatus

HASH_UPDATE

TransactionDescr Types

Ordinary

Storage

Tick-tock

Split Prepare

Split install

Merge prepare

Merge install

See also