Spending Cross-Chain

Build a spend request, submit it to the attester for signing, then execute the attestation on the destination chain.

Example: Spend Cross-Chain

use alloy_primitives::{address, U256};
use trident_sdk::SpendRequestBuilder;

let request = SpendRequestBuilder::new(
    1,                          // source domain (Avalanche)
    address!("aaa..."),         // source token address
    2,                          // destination domain (Optimism)
    address!("bbb..."),         // destination token address
    address!("ccc..."),         // recipient on destination chain
    U256::from(500_000),        // amount
);

// Optional: pin execution to a specific caller address
// let request = request.with_caller(address!("ddd..."));

// Optional: set an explicit max fee (otherwise estimated automatically)
// let request = request.with_max_fee(U256::from(1000));

// Submit to attester - returns a signed attestation
let attestation = client.spend(request).await?;

// Execute the attestation on-chain (destination chain)
let receipt = attestation.execute().await?;
println!("Spend tx: {:?}", receipt.transaction_hash);

What Happens During spend()

1. The SDK generates a random anti-replay salt
2. If no max_fee is set, the SDK calls the attester’s GetSpendFees RPC to estimate fees
3. The spend intent is submitted to the attester’s delivery service
4. The attester validates the request, checks balances, and returns a signed AcceptedSpendAttestation
5. If rejected, a SpendRejected error is returned with the reason

What Happens During execute()

1. The SDK calls tridentSpend(attestation, signature) on the destination Trident contract
2. The contract verifies the signer, domain, expiry, and replay protection
3. If usdcMinted > 0: USDC is minted via Circle Gateway and supplied to Aave as collateral
4. The requested token is borrowed from Aave V3
5. The borrowed token is transferred to the recipient
6. If any step fails, the entire transaction reverts

Spend Request Options

Field	Required	Description
src_domain	Yes	Source chain domain ID
src_token	Yes	Token address on the source chain
dst_domain	Yes	Destination chain domain ID
dst_token	Yes	Token address on the destination chain
dst_recipient	Yes	Address that receives tokens on the destination chain
amount	Yes	Amount to transfer (in token’s smallest unit)
max_fee	No	Maximum fee you’re willing to pay. Auto-estimated if omitted
caller	No	If set, only this address can submit the attestation on-chain. Defaults to address(0) (any caller)