Using the TransactionBuilder
The
TransactionBuilder
is a network specific transaction builder configurable with .with_*
methods.
Common fields one can configure are:
- with_from
- with_to
- with_nonce
- with_chain_id
- with_value
- with_gas_limit
- with_max_priority_fee_per_gas
- with_max_fee_per_gas
It is generally recommended to use the builder pattern, as shown, rather than directly setting values (with_to
versus set_to
).
//! Example showing how to build a transaction using the `TransactionBuilder`
use alloy::{
network::TransactionBuilder,
primitives::U256,
providers::{Provider, ProviderBuilder},
rpc::types::TransactionRequest,
};
use eyre::Result;
#[tokio::main]
async fn main() -> Result<()> {
// Spin up a local Anvil node.
// Ensure `anvil` is available in $PATH.
let provider = ProviderBuilder::new().on_anvil();
// Create two users, Alice and Bob.
let accounts = provider.get_accounts().await?;
let alice = accounts[0];
let bob = accounts[1];
// Build a transaction to send 100 wei from Alice to Bob.
// The `from` field is automatically filled to the first signer's address (Alice).
let tx = TransactionRequest::default()
.with_to(bob)
.with_nonce(0)
.with_chain_id(provider.get_chain_id().await?)
.with_value(U256::from(100))
.with_gas_limit(21_000)
.with_max_priority_fee_per_gas(1_000_000_000)
.with_max_fee_per_gas(20_000_000_000);
// Send the transaction and wait for the broadcast.
let pending_tx = provider.send_transaction(tx).await?;
println!("Pending transaction... {}", pending_tx.tx_hash());
// Wait for the transaction to be included and get the receipt.
let receipt = pending_tx.get_receipt().await?;
println!(
"Transaction included in block {}",
receipt.block_number.expect("Failed to get block number")
);
assert_eq!(receipt.from, alice);
assert_eq!(receipt.to, Some(bob));
Ok(())
}
It is recommended to use the .with_recommended_fillers()
method on the ProviderBuilder to automatically fill fields for you.
Example: recommended_fillers
Example
To run this example:
- Clone the examples repository:
git clone git@github.com:alloy-rs/examples.git
- Run:
cargo run --example recommended_fillers
//! Example of using the `.with_recommended_fillers()` method in the provider.
use alloy::{
consensus::Transaction,
network::TransactionBuilder,
primitives::{address, U256},
providers::{Provider, ProviderBuilder},
rpc::types::request::TransactionRequest,
};
use eyre::Result;
#[tokio::main]
async fn main() -> Result<()> {
// Spin up a local Anvil node.
// Ensure `anvil` is available in $PATH.
let provider = ProviderBuilder::new()
// Adds the `ChainIdFiller`, `GasFiller` and the `NonceFiller` layers.
// This is the recommended way to set up the provider.
.with_recommended_fillers()
.on_anvil_with_wallet();
// Build an EIP-1559 type transaction to send 100 wei to Vitalik.
// Notice that the `nonce` field is set by the `NonceFiller`.
// Notice that the gas related fields are set by the `GasFiller`.
// Notice that the `chain_id` field is set by the `ChainIdFiller`.
let vitalik = address!("d8dA6BF26964aF9D7eEd9e03E53415D37aA96045");
let tx = TransactionRequest::default().with_to(vitalik).with_value(U256::from(100));
// Send the transaction, the nonce (0) is automatically managed by the provider.
let builder = provider.send_transaction(tx.clone()).await?;
let node_hash = *builder.tx_hash();
let pending_tx =
provider.get_transaction_by_hash(node_hash).await?.expect("Pending transaction not found");
assert_eq!(pending_tx.nonce(), 0);
println!("Transaction sent with nonce: {}", pending_tx.nonce());
// Send the transaction, the nonce (1) is automatically managed by the provider.
let builder = provider.send_transaction(tx).await?;
let node_hash = *builder.tx_hash();
let pending_tx =
provider.get_transaction_by_hash(node_hash).await?.expect("Pending transaction not found");
assert_eq!(pending_tx.nonce(), 1);
println!("Transaction sent with nonce: {}", pending_tx.nonce());
Ok(())
}
Find the source code on Github here.