prepareWithdrawalAuthorization

Determine whether vault share approval is needed for a withdrawal operation and prepare the appropriate authorization. This is the recommended entry point for the withdrawal flow. It automatically:

Checks existing vault share allowance
Detects smart contract wallets (Safe, EIP-4337, EIP-7702)
Returns the appropriate authorization result

Import

import {
  prepareWithdrawalAuthorization,
  isWithdrawApprovalAuth,
  isWithdrawAlreadyApprovedAuth,
  WithdrawAuthMethod,
} from "@paxoslabs/amplify-sdk";

Usage

const auth = await prepareWithdrawalAuthorization({
  yieldType: "CORE",
  wantAsset: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC
  withdrawAmount: "1.0",
  userAddress: "0x1234...",
  chainId: 1,
});

if (isWithdrawApprovalAuth(auth)) {
  // Execute approval transaction
  await walletClient.writeContract(auth.txData);
} else {
  // Already approved, proceed to withdrawal
  console.log(`Allowance: ${auth.allowance}`);
}

Parameters

Parameter	Type	Required	Description
`yieldType`	`YieldType`	Yes	Yield strategy (CORE, TREASURY, FRONTIER)
`wantAsset`	`Address`	Yes	Token address to receive upon withdrawal
`withdrawAmount`	`string`	Yes	Vault shares to withdraw (decimal string)
`userAddress`	`Address`	Yes	Owner of vault shares
`chainId`	`ChainId`	Yes	Blockchain network ID
`forceMethod`	`"approval" \| "allowance_check"`	No	Override auto routing behavior

Return Type

Returns a discriminated union WithdrawAuthorizationResult:

WithdrawAuthMethod.APPROVAL

Returned when approval is needed (insufficient allowance, smart wallet detected in auto mode, or forceMethod: "approval").

interface WithdrawApprovalAuthorizationResult {
  method: "approval";
  txData: ApproveWithdrawOrderTxData; // Ready-to-use approval tx
}

WithdrawAuthMethod.ALREADY_APPROVED

Returned when existing allowance is sufficient.

interface WithdrawAlreadyApprovedAuthorizationResult {
  method: "already_approved";
  allowance: string;
  allowanceAsBigInt: string;
}

Type Guards

Use type guards for type-safe handling:

import {
  isWithdrawApprovalAuth,
  isWithdrawAlreadyApprovedAuth,
} from "@paxoslabs/amplify-sdk";

const auth = await prepareWithdrawalAuthorization({ ... });

if (isWithdrawApprovalAuth(auth)) {
  // TypeScript knows auth.txData exists
  await walletClient.writeContract(auth.txData);
}

if (isWithdrawAlreadyApprovedAuth(auth)) {
  // TypeScript knows auth.allowance exists
  console.log(auth.allowance);
}

Or use a switch statement:

switch (auth.method) {
  case WithdrawAuthMethod.APPROVAL:
    await walletClient.writeContract(auth.txData);
    break;
  case WithdrawAuthMethod.ALREADY_APPROVED:
    console.log(`Approved: ${auth.allowance}`);
    break;
}

Smart Wallet Behavior

In auto mode, smart contract wallets (Safe, EIP-4337, EIP-7702) are routed to APPROVAL with approve tx data so they can batch approve + withdraw atomically.

// Smart wallet detected automatically
const auth = await prepareWithdrawalAuthorization({
  yieldType: "CORE",
  wantAsset: USDC_ADDRESS,
  withdrawAmount: "1.0",
  userAddress: safeAddress, // Smart contract wallet
  chainId: 1,
});

// Returns APPROVAL in auto mode for smart wallets
// auth.method === WithdrawAuthMethod.APPROVAL

The SDK detects smart wallets by checking for deployed bytecode at the address using getCode. This covers:

Safe (Gnosis Safe) multi-sig wallets
EIP-4337 smart accounts (e.g., Biconomy, ZeroDev, Alchemy)
EIP-7702 delegated EOAs
Privy embedded wallets (when using smart wallets)

Force Method Overrides

Use forceMethod for deterministic behavior:

// Always return approval tx data (skip checks)
const forceApproval = await prepareWithdrawalAuthorization({
  yieldType: "CORE",
  wantAsset: USDC_ADDRESS,
  withdrawAmount: "1.0",
  userAddress,
  chainId: 1,
  forceMethod: "approval",
});

// Always run allowance check (skip smart-wallet heuristic)
const forceAllowanceCheck = await prepareWithdrawalAuthorization({
  yieldType: "CORE",
  wantAsset: USDC_ADDRESS,
  withdrawAmount: "1.0",
  userAddress,
  chainId: 1,
  forceMethod: "allowance_check",
});

Examples

Complete Viem Flow
Smart Wallet Batching

import {
  prepareWithdrawalAuthorization,
  isWithdrawApprovalAuth,
  prepareWithdrawal,
} from "@paxoslabs/amplify-sdk";

async function withdraw(
  walletClient: WalletClient,
  publicClient: PublicClient,
  userAddress: `0x${string}`,
) {
  const USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
  const withdrawAmount = "1.0";

  // Step 1: Authorize
  const auth = await prepareWithdrawalAuthorization({
    yieldType: "CORE",
    wantAsset: USDC,
    withdrawAmount,
    userAddress,
    chainId: 1,
  });

  if (isWithdrawApprovalAuth(auth)) {
    const approveHash = await walletClient.writeContract(auth.txData);
    await publicClient.waitForTransactionReceipt({ hash: approveHash });
  }

  // Step 2: Submit withdrawal order
  const withdrawTx = await prepareWithdrawal({
    yieldType: "CORE",
    wantAsset: USDC,
    userAddress,
    chainId: 1,
    withdrawAmount,
  });

  const hash = await walletClient.writeContract(withdrawTx);
  return hash;
}

import {
  prepareWithdrawalAuthorization,
  isWithdrawApprovalAuth,
  prepareWithdrawal,
} from "@paxoslabs/amplify-sdk";
import { encodeFunctionData } from "viem";

async function batchedWithdraw(safeAddress: `0x${string}`) {
  const USDC = "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
  const withdrawAmount = "1.0";

  // Get authorization (default: APPROVAL for smart wallets)
  const auth = await prepareWithdrawalAuthorization({
    yieldType: "CORE",
    wantAsset: USDC,
    withdrawAmount,
    userAddress: safeAddress,
    chainId: 1,
  });

  const calls = [];

  // Add approval call
  if (isWithdrawApprovalAuth(auth)) {
    calls.push({
      to: auth.txData.address,
      data: encodeFunctionData({
        abi: auth.txData.abi,
        functionName: auth.txData.functionName,
        args: auth.txData.args,
      }),
      value: 0n,
    });
  }

  // Add withdrawal call
  const withdrawTx = await prepareWithdrawal({
    yieldType: "CORE",
    wantAsset: USDC,
    userAddress: safeAddress,
    chainId: 1,
    withdrawAmount,
  });

  calls.push({
    to: withdrawTx.address,
    data: encodeFunctionData({
      abi: withdrawTx.abi,
      functionName: withdrawTx.functionName,
      args: withdrawTx.args,
    }),
    value: 0n,
  });

  // Execute both atomically via smart wallet
  return calls;
}

Comparison with Deposit Authorization

prepareWithdrawalAuthorization() mirrors the deposit flow’s prepareDepositAuthorization():

Feature	Deposit Auth	Withdrawal Auth
Methods	PERMIT, APPROVAL, ALREADY_APPROVED	APPROVAL, ALREADY_APPROVED
Permit Support	Yes (EIP-2612)	No
Smart Wallet Auto-Detect	Yes	Yes
Force Method	`forceMethod: "permit" \| "approval"`	`forceMethod: "approval" \| "allowance_check"`

Withdrawals don’t support EIP-2612 permits since the approval is on vault shares (BoringVault ERC20), not the deposit token.

Error Handling

Error	Description	Resolution
`No vault found for asset`	Invalid yield type, chain, or asset combination	Verify parameters match an existing vault
`Failed to check withdrawal approval`	On-chain multicall failed	Check RPC connectivity and retry

import { prepareWithdrawalAuthorization, APIError } from "@paxoslabs/amplify-sdk";

try {
  const auth = await prepareWithdrawalAuthorization({
    yieldType: "CORE",
    wantAsset: USDC_ADDRESS,
    withdrawAmount: "1.0",
    userAddress: "0x...",
    chainId: 1,
  });
} catch (error) {
  if (error instanceof APIError) {
    console.error("SDK Error:", error.message);
  }
}

prepareDepositAuthorization - Deposit authorization (equivalent for deposits)
prepareWithdrawal - Unified withdrawal wrapper
prepareWithdrawOrderTxData - Low-level withdrawal tx builder
prepareApproveWithdrawOrderTxData - Manual approval
Withdrawals Guide - Complete withdrawal integration guide
Smart Wallets Guide - Smart wallet integration patterns

Getting started

Origin - Branded Stablecoins

Amplify - Stablecoin Earn

Access - Borrow

USDG0

prepareWithdrawalAuthorization

Import

Usage

Parameters

Return Type

WithdrawAuthMethod.APPROVAL

WithdrawAuthMethod.ALREADY_APPROVED

Type Guards

Smart Wallet Behavior

Force Method Overrides

Examples

Comparison with Deposit Authorization

Error Handling

​Import

​Usage

​Parameters

​Return Type

​WithdrawAuthMethod.APPROVAL

​WithdrawAuthMethod.ALREADY_APPROVED

​Type Guards

​Smart Wallet Behavior

​Force Method Overrides

​Examples

​Comparison with Deposit Authorization

​Error Handling

​Related

Import

Usage

Parameters

Return Type

WithdrawAuthMethod.APPROVAL

WithdrawAuthMethod.ALREADY_APPROVED

Type Guards

Smart Wallet Behavior

Force Method Overrides

Examples

Comparison with Deposit Authorization

Error Handling

Related