Deposits - Paxos Labs

This guide demonstrates complete deposit flows using the unified deposit API, which automatically detects the optimal authorization method (permit vs approval).

Breaking change in v0.5.0: Transaction functions now use vaultName instead of yieldType. Discover account names with getVaultsByConfig() before making deposit calls. See the migration guide.

The unified deposit API handles three authorization paths automatically:

Method	Description
Permit	Gas-efficient off-chain signature (EIP-2612). Single transaction — no separate approval needed.
Approval	Standard ERC-20 `approve` transaction followed by the deposit transaction.
Already Approved	Direct deposit when sufficient allowance already exists.

Prerequisites

Node.js 22+
Amplify API key from Paxos Labs
SDK initialized with initAmplifySDK()

Installation

Privy
Wagmi
Viem

pnpm add @paxoslabs/amplify-sdk @privy-io/react-auth viem @tanstack/react-query

pnpm add @paxoslabs/amplify-sdk wagmi viem @tanstack/react-query

pnpm add @paxoslabs/amplify-sdk viem

Imports

Privy
Wagmi
Viem

// SDK imports
import {
  getVaultsByConfig,
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
  toEthSignTypedDataV4,
  YieldType,
} from "@paxoslabs/amplify-sdk";

// Privy imports
import { usePrivy, useWallets } from "@privy-io/react-auth";

// Viem imports
import { encodeFunctionData } from "viem";
import { mainnet } from "viem/chains";

// SDK imports
import {
  getVaultsByConfig,
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
  YieldType,
} from "@paxoslabs/amplify-sdk";

// Wagmi imports
import { useAccount, useWriteContract, useSignTypedData } from "wagmi";

// SDK imports
import {
  initAmplifySDK,
  getVaultsByConfig,
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
  YieldType,
} from "@paxoslabs/amplify-sdk";

// Viem imports
import { createWalletClient, createPublicClient, custom, http } from "viem";
import { mainnet } from "viem/chains";

Step 0: Fetch Available Accounts

Retrieve all accounts accessible with your API key. This is the data you need to build an account selector for your users.

import { getVaultsByConfig, YieldType } from '@paxoslabs/amplify-sdk'

const vaults = await getVaultsByConfig()

for (const vault of vaults) {
  console.log(`${vault.name} — ${vault.yieldType} on chain ${vault.chainId}`)
  for (const asset of vault.supportedAssets) {
    console.log(`  ${asset.symbol}: deposit=${asset.depositable}, withdraw=${asset.withdrawable}`)
  }
}

You can also narrow the list with filters:

const coreVaults = await getVaultsByConfig({ yieldType: YieldType.CORE })
const ethVaults = await getVaultsByConfig({ chainId: 1 })
const usdcVaults = await getVaultsByConfig({ depositAssetAddress: USDC_ADDRESS })

Step 1: Select an Account

Once the user picks an account from your UI, record its vault.name — all subsequent transaction calls require it.

const selectedVault = vaults[0] // or from user selection

const vaultName = selectedVault.name
const depositAsset = selectedVault.vault.baseTokenAddress
const chainId = selectedVault.chainId

Step 2: Check Authorization

Determine the optimal authorization method for this deposit. The SDK auto-detects permit support.

import {
  prepareDepositAuthorization,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
} from '@paxoslabs/amplify-sdk'

const auth = await prepareDepositAuthorization({
  vaultName,
  depositAsset,
  depositAmount: '1000',
  to: userAddress,
  chainId,
})

if (isPermitAuth(auth)) {
  // Sign EIP-712 typed data off-chain (gasless)
} else if (isApprovalAuth(auth)) {
  // Send an ERC-20 approve transaction first
} else if (isAlreadyApprovedAuth(auth)) {
  // Sufficient allowance exists — skip straight to deposit
}

Step 3: Execute Deposit

After authorization, prepare and submit the deposit transaction.

import { prepareDeposit } from '@paxoslabs/amplify-sdk'

const prepared = await prepareDeposit({
  vaultName,
  depositAsset,
  depositAmount: '1000',
  to: userAddress,
  chainId,
  // For permit path, also pass: signature, deadline
})

// Submit prepared.txData via your wallet provider

Complete Examples

Privy
Wagmi
Viem

useDeposit Hook

// src/hooks/useDeposit.ts
import { useState, useCallback } from "react";
import { encodeFunctionData } from "viem";
import { mainnet } from "viem/chains";
import {
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
  toEthSignTypedDataV4,
  YieldType,
} from "@paxoslabs/amplify-sdk";

declare const usePrivy: () => { sendTransaction: (tx: any) => Promise<string> };
declare const useWallets: () => { wallets: Array<{ address: string; getEthereumProvider: () => Promise<any> }> };

interface DepositParams {
  amount: string;
  depositAsset: `0x${string}`;
  vaultName: string;
}

export function useDeposit() {
  const { sendTransaction } = usePrivy();
  const { wallets } = useWallets();
  const [status, setStatus] = useState<string>("");
  const [isLoading, setIsLoading] = useState(false);

  const deposit = useCallback(
    async ({ amount, depositAsset, vaultName }: DepositParams) => {
      const wallet = wallets[0];
      if (!wallet) {
        throw new Error("Connect a wallet first");
      }

      setIsLoading(true);
      const to = wallet.address as `0x${string}`;

      try {
        const params = {
          vaultName,
          depositAsset,
          depositAmount: amount,
          to,
          chainId: mainnet.id,
        };

        // Step 1: Get authorization method
        setStatus("Checking authorization...");
        const auth = await prepareDepositAuthorization(params);

        // Step 2: Handle based on method using type guards
        if (isPermitAuth(auth)) {
          setStatus("Please sign permit in your wallet...");
          const provider = await wallet.getEthereumProvider();
          const signature = (await provider.request({
            method: "eth_signTypedData_v4",
            params: [to, toEthSignTypedDataV4(auth.permitData)],
          })) as `0x${string}`;

          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit({
            ...params,
            signature,
            deadline: auth.permitData.message.deadline,
          });

          await sendTransaction({
            chainId: prepared.txData.chainId,
            to: prepared.txData.address,
            data: encodeFunctionData({
              abi: prepared.txData.abi,
              functionName: prepared.txData.functionName,
              args: prepared.txData.args,
            }),
          });
        } else if (isApprovalAuth(auth)) {
          setStatus("Approving token spend...");
          await sendTransaction({
            chainId: mainnet.id,
            to: auth.txData.address,
            data: encodeFunctionData({
              abi: auth.txData.abi,
              functionName: auth.txData.functionName,
              args: auth.txData.args,
            }),
          });

          // Important: In production, wait for the approval transaction
          // to be confirmed before proceeding with the deposit.
          // See the Node.js example for the full pattern using
          // publicClient.waitForTransactionReceipt().

          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit(params);
          await sendTransaction({
            chainId: prepared.txData.chainId,
            to: prepared.txData.address,
            data: encodeFunctionData({
              abi: prepared.txData.abi,
              functionName: prepared.txData.functionName,
              args: prepared.txData.args,
            }),
          });
        } else if (isAlreadyApprovedAuth(auth)) {
          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit(params);
          await sendTransaction({
            chainId: prepared.txData.chainId,
            to: prepared.txData.address,
            data: encodeFunctionData({
              abi: prepared.txData.abi,
              functionName: prepared.txData.functionName,
              args: prepared.txData.args,
            }),
          });
        }

        setStatus("Deposit successful!");
      } catch (error) {
        setStatus(`Error: ${error instanceof Error ? error.message : "Unknown"}`);
        throw error;
      } finally {
        setIsLoading(false);
      }
    },
    [wallets, sendTransaction]
  );

  return { deposit, status, isLoading };
}

Deposit Component

// src/components/DepositForm.tsx
import { useState } from "react";
import { useQuery } from "@tanstack/react-query";
import { getVaultsByConfig, YieldType } from "@paxoslabs/amplify-sdk";
import { useDeposit } from "../hooks/useDeposit";
import { mainnet } from "viem/chains";

export function DepositForm() {
  const [amount, setAmount] = useState("100");
  const { deposit, status, isLoading } = useDeposit();

  const { data: vaults } = useQuery({
    queryKey: ["vaults", YieldType.CORE, mainnet.id],
    queryFn: () => getVaultsByConfig({ yieldType: YieldType.CORE, chainId: mainnet.id }),
  });

  const vault = vaults?.[0];

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!vault) return;
    await deposit({
      amount,
      depositAsset: vault.vault.baseTokenAddress as `0x${string}`,
      vaultName: vault.name,
    });
  };

  return (
    <form onSubmit={handleSubmit}>
      <label>
        Amount (USDC):
        <input
          type="number"
          value={amount}
          onChange={(e) => setAmount(e.target.value)}
          disabled={isLoading}
          min="0"
          step="0.01"
        />
      </label>
      <button type="submit" disabled={isLoading}>
        {isLoading ? "Processing..." : "Deposit"}
      </button>
      {status && <p>{status}</p>}
    </form>
  );
}

useDeposit Hook

// src/hooks/useDeposit.ts
import { useState, useCallback } from "react";
import { useAccount, useWriteContract, useSignTypedData } from "wagmi";
import {
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
} from "@paxoslabs/amplify-sdk";

interface DepositParams {
  amount: string;
  depositAsset: `0x${string}`;
  vaultName: string;
}

export function useDeposit() {
  const { address, chainId } = useAccount();
  const { writeContractAsync } = useWriteContract();
  const { signTypedDataAsync } = useSignTypedData();
  const [status, setStatus] = useState<string>("");
  const [isLoading, setIsLoading] = useState(false);

  const deposit = useCallback(
    async ({ amount, depositAsset, vaultName }: DepositParams) => {
      if (!address || !chainId) {
        throw new Error("Connect a wallet first");
      }

      setIsLoading(true);

      try {
        const params = {
          vaultName,
          depositAsset,
          depositAmount: amount,
          to: address,
          chainId,
        };

        // Step 1: Get authorization method
        setStatus("Checking authorization...");
        const auth = await prepareDepositAuthorization(params);

        // Step 2: Handle based on method using type guards
        if (isPermitAuth(auth)) {
          setStatus("Please sign permit in your wallet...");
          const signature = await signTypedDataAsync(auth.permitData);

          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit({
            ...params,
            signature,
            deadline: auth.permitData.message.deadline,
          });

          await writeContractAsync({
            ...prepared.txData,
            account: address,
          });
        } else if (isApprovalAuth(auth)) {
          setStatus("Approving token spend...");
          await writeContractAsync({
            ...auth.txData,
            account: address,
          });

          // Important: In production, wait for the approval transaction
          // to be confirmed before proceeding with the deposit.
          // See the Node.js example for the full pattern using
          // publicClient.waitForTransactionReceipt().

          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit(params);
          await writeContractAsync({
            address: prepared.txData.address,
            abi: prepared.txData.abi,
            functionName: prepared.txData.functionName,
            args: prepared.txData.args,
            account: address,
          });
        } else if (isAlreadyApprovedAuth(auth)) {
          setStatus("Submitting deposit...");
          const prepared = await prepareDeposit(params);
          await writeContractAsync({
            address: prepared.txData.address,
            abi: prepared.txData.abi,
            functionName: prepared.txData.functionName,
            args: prepared.txData.args,
            account: address,
          });
        }

        setStatus("Deposit successful!");
      } catch (error) {
        setStatus(`Error: ${error instanceof Error ? error.message : "Unknown"}`);
        throw error;
      } finally {
        setIsLoading(false);
      }
    },
    [address, chainId, writeContractAsync, signTypedDataAsync]
  );

  return { deposit, status, isLoading };
}

Deposit Component

// src/components/DepositForm.tsx
import { useState } from "react";
import { useAccount } from "wagmi";
import { getVaultsByConfig, YieldType } from "@paxoslabs/amplify-sdk";
import { useDeposit } from "../hooks/useDeposit";
import { useQuery } from "@tanstack/react-query";

const USDC_ADDRESS = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48" as const;

export function DepositForm() {
  const { isConnected, chainId } = useAccount();
  const [amount, setAmount] = useState("100");
  const { deposit, status, isLoading } = useDeposit();

  const { data: vault } = useQuery({
    queryKey: ["vault", chainId],
    queryFn: async () => {
      const [v] = await getVaultsByConfig({
        yieldType: YieldType.CORE,
        chainId,
        depositAssetAddress: USDC_ADDRESS,
      });
      return v;
    },
    enabled: !!chainId,
  });

  if (!isConnected) {
    return <p>Please connect your wallet</p>;
  }

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    if (!vault) return;
    await deposit({
      amount,
      depositAsset: USDC_ADDRESS,
      vaultName: vault.name,
    });
  };

  return (
    <form onSubmit={handleSubmit}>
      <label>
        Amount (USDC):
        <input
          type="number"
          value={amount}
          onChange={(e) => setAmount(e.target.value)}
          disabled={isLoading}
          min="0"
          step="0.01"
        />
      </label>
      <button type="submit" disabled={isLoading}>
        {isLoading ? "Processing..." : "Deposit"}
      </button>
      {status && <p>{status}</p>}
    </form>
  );
}

Complete Script

This example uses pure viem without React, suitable for Node.js scripts or vanilla TypeScript applications.

// deposit.ts
import { createWalletClient, createPublicClient, custom, http } from "viem";
import { mainnet } from "viem/chains";
import {
  initAmplifySDK,
  getVaultsByConfig,
  prepareDepositAuthorization,
  prepareDeposit,
  isPermitAuth,
  isApprovalAuth,
  isAlreadyApprovedAuth,
  YieldType,
} from "@paxoslabs/amplify-sdk";

declare const window: { ethereum: any };
declare const process: { env: { AMPLIFY_API_KEY: string } };

// Configuration
const CONFIG = {
  apiKey: process.env.AMPLIFY_API_KEY!,
  depositAsset: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48" as `0x${string}`, // USDC
  depositAmount: "1000",
};

async function main() {
  // Step 1: Initialize SDK
  console.log("Initializing SDK...");
  await initAmplifySDK(CONFIG.apiKey);

  // Step 2: Connect wallet
  console.log("Connecting wallet...");
  const ethereum = window.ethereum;
  if (!ethereum) {
    throw new Error("No wallet found");
  }

  const [account] = (await ethereum.request({
    method: "eth_requestAccounts",
  })) as `0x${string}`[];

  const walletClient = createWalletClient({
    account,
    chain: mainnet,
    transport: custom(ethereum),
  });

  const publicClient = createPublicClient({
    chain: mainnet,
    transport: http(),
  });

  // Step 3: Discover vault and prepare deposit parameters
  const [vault] = await getVaultsByConfig({
    yieldType: YieldType.CORE,
    chainId: mainnet.id,
    depositAssetAddress: CONFIG.depositAsset,
  });

  const params = {
    vaultName: vault.name,
    depositAsset: CONFIG.depositAsset,
    depositAmount: CONFIG.depositAmount,
    to: account,
    chainId: mainnet.id,
  };

  // Step 4: Get authorization method
  console.log("Checking authorization method...");
  const auth = await prepareDepositAuthorization(params);

  // Step 5: Handle based on method using type guards
  if (isPermitAuth(auth)) {
    console.log("Authorization method: permit");
    console.log("Signing permit...");
    const signature = await walletClient.signTypedData({
      account,
      domain: auth.permitData.domain,
      types: auth.permitData.types,
      primaryType: auth.permitData.primaryType,
      message: auth.permitData.message,
    });

    console.log("Submitting deposit with permit...");
    const prepared = await prepareDeposit({
      ...params,
      signature,
      deadline: auth.permitData.message.deadline,
    });

    const permitHash = await walletClient.writeContract({
      ...prepared.txData,
      account,
    });

    console.log(`Deposit submitted: ${permitHash}`);
    await publicClient.waitForTransactionReceipt({ hash: permitHash });
    console.log("Deposit confirmed!");
  } else if (isApprovalAuth(auth)) {
    console.log("Authorization method: approval");
    console.log("Sending approval transaction...");

    const approvalHash = await walletClient.writeContract({
      ...auth.txData,
      account,
    });

    console.log(`Approval submitted: ${approvalHash}`);
    await publicClient.waitForTransactionReceipt({ hash: approvalHash });
    console.log("Approval confirmed!");

    console.log("Submitting deposit...");
    const prepared = await prepareDeposit(params);

    const depositHash = await walletClient.writeContract({
      address: prepared.txData.address,
      abi: prepared.txData.abi,
      functionName: prepared.txData.functionName,
      args: prepared.txData.args,
      account,
    });

    console.log(`Deposit submitted: ${depositHash}`);
    await publicClient.waitForTransactionReceipt({ hash: depositHash });
    console.log("Deposit confirmed!");
  } else if (isAlreadyApprovedAuth(auth)) {
    console.log("Authorization method: already_approved");
    console.log(`Existing allowance: ${auth.allowance}`);
    console.log("Submitting deposit directly...");

    const prepared = await prepareDeposit(params);

    const directHash = await walletClient.writeContract({
      address: prepared.txData.address,
      abi: prepared.txData.abi,
      functionName: prepared.txData.functionName,
      args: prepared.txData.args,
      account,
    });

    console.log(`Deposit submitted: ${directHash}`);
    await publicClient.waitForTransactionReceipt({ hash: directHash });
    console.log("Deposit confirmed!");
  }
}

main().catch(console.error);

Running the Script

# Set environment variable
export AMPLIFY_API_KEY=pxl_your_api_key

# Run with tsx or ts-node
npx tsx deposit.ts

Expected Output

Initializing SDK...
Connecting wallet...
Checking authorization method...
Authorization method: permit
Signing permit...
Submitting deposit with permit...
Deposit submitted: 0x1234...
Deposit confirmed!

Customization

Custom Slippage

const prepared = await prepareDeposit({
  ...params,
  slippage: 100, // 1% instead of default 0.5%
})

Distributor Code

const prepared = await prepareDeposit({
  ...params,
  distributorCode: 'your_distributor_code',
})

Force Approval Flow

const auth = await prepareDepositAuthorization({
  ...params,
  forceMethod: 'approval', // Skip permit detection
})

Troubleshooting

Issue	Solution
”SDK not initialized”	Call `initAmplifySDK()` before using hooks
”Connect a wallet first”	Ensure user has connected wallet
Permit signature fails	Token may not support EIP-2612, falls back to approval
Transaction reverts	Check token balance and allowance

For more details on the deposit API, see Deposit Workflow.

​Prerequisites

​Installation

​Imports

​Step 0: Fetch Available Accounts

​Step 1: Select an Account

​Step 2: Check Authorization

​Step 3: Execute Deposit

​Complete Examples

​useDeposit Hook

​Deposit Component

​useDeposit Hook

​Deposit Component

​Complete Script

​Running the Script

​Expected Output

​Customization

​Custom Slippage

​Distributor Code

​Force Approval Flow

​Troubleshooting

Prerequisites

Installation

Imports

Step 0: Fetch Available Accounts

Step 1: Select an Account

Step 2: Check Authorization

Step 3: Execute Deposit

Complete Examples

useDeposit Hook

Deposit Component

useDeposit Hook

Deposit Component

Complete Script

Running the Script

Expected Output

Customization

Custom Slippage

Distributor Code

Force Approval Flow

Troubleshooting