Struct TransactionBuilder

pub struct TransactionBuilder {
    pub fee: u32,
    pub source_account: Account,
    pub operations: Vec<Operation>,
    pub memo: Memo,
    pub preconditions: Preconditions,
    pub env: Env,
}

Builder for creating and configuring Stellar transactions.

TransactionBuilder provides an API for building Stellar transactions for Soroban operations. It handles sequence number retrieval, fee calculation, and transaction simulation to ensure transactions have the correct resources allocated for Soroban execution.

Fields

fee: u32

Transaction fee in stroops

source_account: Account

Account that will be the source of the transaction

operations: Vec<Operation>

List of operations to include in the transaction

memo: Memo

Optional memo to attach to the transaction

preconditions: Preconditions

Optional preconditions for transaction execution

env: Env

Environment for network interaction

Implementations

impl TransactionBuilder

pub fn new(source_account: &Account, env: &Env) -> Self

Creates a new transaction builder for the specified account and environment.

The builder is initialized with default values:

• Default transaction fee
• Empty operations list
• No memo
• No preconditions

Parameters

• source_account - The account that will be the source of the transaction
• env - The environment for network interaction

Returns

A new TransactionBuilder instance

pub fn set_env(self, env: Env) -> Self

Sets the environment for the transaction builder.

Parameters

• env - The new environment to use

Returns

The updated TransactionBuilder

pub fn add_operation(self, operation: Operation) -> Self

Adds an operation to the transaction.

https://developers.stellar.org/docs/learn/fundamentals/transactions/operations-and-transactions#operations

Parameters

• operation - The operation to add

Returns

The updated TransactionBuilder

pub fn set_memo(self, memo: Memo) -> Self

Sets the memo for the transaction.

Memos can be used to attach additional information to a transaction. They are not used by the protocol but can be used by applications. https://developers.stellar.org/docs/learn/encyclopedia/transactions-specialized/memos

Parameters

• memo - The memo to set

Returns

The updated TransactionBuilder

pub fn set_preconditions(self, preconditions: Preconditions) -> Self

Sets the preconditions for the transaction.

Preconditions specify requirements that must be met for a transaction to be valid, such as time bounds or ledger bounds. https://developers.stellar.org/docs/learn/fundamentals/transactions/operations-and-transactions#preconditions

Parameters

• preconditions - The preconditions to set

Returns

The updated TransactionBuilder

pub async fn build(self) -> Result<Transaction, SorobanHelperError>

Builds a transaction without simulation.

This method retrieves the source account’s current sequence number and constructs a transaction with the configured parameters.

Returns

A transaction ready to be signed, or an error if the build fails

Errors

Returns error if:

• Operations cannot be converted to XDR
• Sequence number cannot be retrieved

pub async fn simulate_and_build( self, env: &Env, source_account: &Account, ) -> Result<Transaction, SorobanHelperError>

Builds a transaction with simulation to determine proper fees and resources.

This method:

1. Builds a transaction with default fees
2. Simulates the transaction to determine required resources
3. Updates the transaction with the correct fees and resource data

This is the recommended way to build Soroban transactions, as it ensures they have sufficient fees and resources for execution.

Parameters

• env - The environment for transaction simulation
• account - The account to use for signing the simulation transaction

Returns

A transaction optimized for Soroban execution, or an error if the build fails

Errors

Returns error if:

• Transaction building fails
• Transaction signing fails
• Simulation fails
• Fee calculation results in a value too large for u32

Trait Implementations

impl Clone for TransactionBuilder

fn clone(&self) -> TransactionBuilder

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.