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Swap and deposit

Swap-and-deposit is the inbound sibling of reshield. You hold token X in a wallet and want a shielded note in token Y. Rather than swapping in one transaction and depositing in another, the SDK fetches an aggregator contractCalls quote whose post-swap step is the deposit itself, and you submit that single transaction from your wallet.

This path does not touch PoolVault.transact or a relayer. It is a wallet-funded swap whose final call is Entrypoint.deposit (or PPRouter.depositExactShares when the target is a yield share), so your wallet is the public depositor exactly as it is for a plain deposit.

How it works​

  1. Prove the deposit. The SDK builds a standard deposit proof for depositToken and depositAmount; the note it describes is the one you will hold.
  2. Quote. The aggregator returns calldata that swaps inputToken into enough depositToken to cover the deposit value plus the on-chain vetting fee, then calls the deposit with your proof and note data. The SDK verifies the deposit calldata and target it finds in that quote match what it built (LiFiDepositCalldataNotFound / LiFiDepositTargetNotFound otherwise).
  3. Approve and submit. You approve the aggregator for the input token if needed, then send the aggregator transaction. Swap and deposit land together; the pool inserts your commitment.

How to swap in​

// At session build time:
//   builder.withSwapAndDepositQuoteProvider(new LiFiSwapQuoteProvider({ integrator, apiKey }))

const prepared = await session.prepareSwapAndDeposit({
    fromChainId: 42161,               // where the input token lives
    inputToken: arbUsdcAddress,       // what your wallet holds
    depositToken: poolUsdtAddress,    // the shielded asset you end up with
    depositAmount: depositValue,      // Hex, in depositToken
});

console.log("will spend about", prepared.estimatedInputAmount, "of the input token");
console.log("estimated duration (s):", prepared.estimatedDuration);

// Submits prepared.approvalTxs in order, then the aggregator transaction,
// and persists prepared.pendingNote once mined.
const receipt = await session.executeSwapAndDeposit(prepared);
console.log("tx:", receipt.txHash);

swapAndDeposit(params) runs both steps in one call. The prepared result exposes the raw pieces (transactionTo, transactionData, msgValue, depositCallData, depositTarget) for integrators who broadcast themselves.

When fromChainId differs from the pool's chain the aggregator bridges first; configure the session's sourceChain (a wallet and RPC for the source chain) so the approval and the aggregator transaction are sent there, and set fallbackAddress for a failed bridge leg.

Constraints​

  • Your wallet is public. This is a deposit. The depositor address and the swapped-in value are visible on-chain like any deposit's; privacy begins once the note is attested, not at entry.
  • Sizing is approximate on the input side. The deposit value is exact (it is in the proof); the input amount is the aggregator's estimate plus slippage, and any surplus output beyond the deposit and its vetting fee is handled by the aggregator's route.
  • Vetting fee is included automatically. The SDK reads Entrypoint.assets(depositToken).vettingFeeBPS and sizes the swap so the deposit call receives value plus fee.
  • Yield targets need a configured deployment. Landing as ppUSDC embeds a PPRouter call, so the session must know the router (withYieldDeployments, or derived from the relayer's /v1/details).
  • The note is PENDING. Awaiting ASP attestation, as any deposit.

Behind the scenes​

SDK call session.prepareSwapAndDeposit(...) then session.executeSwapAndDeposit(...), or session.swapAndDeposit(...). Requires withSwapAndDepositQuoteProvider(...).
Contract method The aggregator's entry point, whose route ends in Entrypoint.deposit(proof, noteData, aspCiphertext) or PPRouter.depositExactShares(...). No pool transact and no RelaySwaps execution is involved.
Circuit deposit only.

What's next​

  • Manage notes: discovery promotes the attested note into your spendable set.
  • Reshield: change asset again later without leaving the pool.