Deposit

Depositing tokens moves them from the public EVM world into the shielded pool.

Direct deposit

The standard deposit requires the user to have AVAX for gas.

import { deposit, waitForDeposit } from '@shroud/sdk';

const { tx, pendingNote } = await deposit({
  signer,
  provider,
  poolAddress: "0x91c912eac...",
  tokenAddress: "0xE4e328Fc6...",
  amount: 100n,  // 100 tokens (whole units)
  ownerPublicKey: keypair.publicKey,
});

const note = await waitForDeposit(tx, pendingNote, provider, poolAddress);

Flow

1. SDK generates random: secret, nullifier_preimage, blinding
2. Computes Pedersen commitment: C = amount * G + blinding * H
3. Computes note commitment: Poseidon(C.x, C.y, secret, nullifier_preimage, pk.x)
4. Approves ERC20 transfer to the pool contract
5. Calls pool.deposit(amount, noteCommitment)
6. Contract transfers tokens via transferFrom
7. Contract inserts commitment into Merkle tree
8. SDK stores full note data locally

Gasless deposit (relay)

No AVAX required (after one-time token approval).

import { relayDeposit, waitForRelayDeposit } from '@shroud/sdk';

const fee = amount / 1000n; // 0.1% fee

const { relay, pendingNote } = await relayDeposit({
  signer,
  provider,
  poolAddress: "0x91c912eac...",
  tokenAddress: "0xE4e328Fc6...",
  amount: 100n,
  ownerPublicKey: keypair.publicKey,
  fee,
  metaTxRelayerAddress: "0xF994781eC...",
});

const note = await waitForRelayDeposit(relay, pendingNote, provider, poolAddress);

Gasless flow

1. SDK checks token allowance for MetaTxRelayer, approves if needed (one-time gas cost)
2. SDK reads nonce from MetaTxRelayer contract
3. User signs EIP-712 typed data (wallet popup — no gas)
4. SDK POSTs signature + data to relay API
5. Relay wallet submits transaction and pays gas
6. Fee deducted from user's token balance

warning

Deposit amounts are visible on-chain because the ERC20 transferFrom is a public transaction. Privacy begins after the deposit is complete.