stellar-sdk/com.soneso.stellar.sdk/TransactionBuilder

TransactionBuilder

class TransactionBuilder(val sourceAccount: TransactionBuilderAccount, val network: Network)

Builds a new Transaction following the builder pattern.

TransactionBuilder provides a fluent API for constructing Stellar transactions with all necessary parameters and validations.

Usage

val sourceAccount = Account("GABC...", 1234567890)

val transaction = TransactionBuilder(sourceAccount, Network.TESTNET)
    .setBaseFee(100)
    .addOperation(
        PaymentOperation(
            destination = "GDEF...",
            asset = AssetTypeNative,
            amount = "10.0"
        )
    )
    .addMemo(MemoText("Payment"))
    .setTimeout(300) // 5 minutes from now
    .build()

transaction.sign(keypair)

Fee Calculation

The transaction fee is calculated as: baseFee * operations.size

You must set the base fee explicitly using setBaseFee before building.

Sequence Number Management

The builder automatically increments the source account's sequence number when build is called. This ensures the transaction has the correct sequence number (account.sequence + 1).

See also

Constructors

TransactionBuilder

constructor(sourceAccount: TransactionBuilderAccount, network: Network)

Types

object Companion

Properties

val network: Network

The network this transaction is for (TESTNET, PUBLIC, etc.)

val sourceAccount: TransactionBuilderAccount

The source account for this transaction

Functions

fun addMemo(memo: Memo): TransactionBuilder

Adds a memo to this transaction.

fun addOperation(operation: Operation): TransactionBuilder

Adds an operation to this transaction.

fun addOperations(operations: List<Operation>): TransactionBuilder

Adds multiple operations to this transaction.

addPreconditions

fun addPreconditions(preconditions: TransactionPreconditions): TransactionBuilder

Adds preconditions to this transaction.

fun addTimeBounds(timeBounds: TimeBounds): TransactionBuilder

Adds time bounds to this transaction.

fun build(): Transaction

Builds the transaction and increments the source account's sequence number.

getOperationsCount

fun getOperationsCount(): Int

Returns the number of operations currently added to this transaction.

fun setBaseFee(baseFee: Long): TransactionBuilder

Sets the base fee per operation for this transaction.

fun setSorobanData(sorobanData: SorobanTransactionDataXdr): TransactionBuilder

Sets Soroban transaction data for smart contract operations.

fun setTimeout(timeout: Long): TransactionBuilder

Sets the transaction timeout in seconds from now.

fun setTimeout(timeout: Duration): TransactionBuilder

Sets the transaction timeout using Kotlin Duration from now.