Bankr x402 SDK - Token Swaps

SDK Token Swaps

Build and execute token swaps with AI-powered 0x routing.

Prompt Patterns

Pattern	Example
Amount-based	"Swap 0.1 ETH to USDC"
Value-based	"Buy $100 worth of DEGEN"
Percentage	"Swap 50% of my ETH to USDC"
Sell all	"Sell all my DEGEN"
Chain-specific	"Swap ETH to USDC on Polygon"

# Amount Swaps
"Swap 0.1 ETH to USDC"
"Exchange 100 USDC for WETH"
"Swap 1000 DEGEN to ETH"

Value Swaps

"Buy $100 worth of DEGEN" "Purchase $50 of ETH"

Percentage Swaps

"Swap 50% of my ETH to USDC" "Sell 25% of my DEGEN"

Chain-Specific

"Swap 0.1 ETH to USDC on Base" "Exchange 100 USDC for WETH on Ethereum"

## ERC20 Approval Handling

For ERC20 swaps (selling tokens other than ETH), approval is required before the swap.

```typescript
const result = await client.promptAndWait({
  prompt: "Swap 100 USDC to WETH",
});

const swapTx = result.transactions?.find(tx => tx.type === "swap");

// Check if approval is needed
if (swapTx?.metadata.approvalRequired) {
  // Execute pre-built approval transaction first
  await wallet.sendTransaction(swapTx.metadata.approvalTx);
}

// Then execute the swap
await wallet.sendTransaction(swapTx.metadata.transaction);

Approval Fields

Field	Description
approvalRequired	Whether approval needed before swap
approvalTx	Pre-built approval transaction (ready to send)
allowanceTarget	0x AllowanceHolder address (for manual approval)

Usage

import { BankrClient } from "@bankr/sdk";

const client = new BankrClient({
  privateKey: process.env.BANKR_PRIVATE_KEY as `0x${string}`,
});

const result = await client.promptAndWait({
  prompt: "Swap 0.1 ETH to USDC on Base",
});

if (result.status === "completed" && result.transactions?.length) {
  const tx = result.transactions[0].metadata.transaction;
  await wallet.sendTransaction(tx);
}

Supported Chains

Chain	Native Token	Default
Base	ETH	Yes
Ethereum	ETH	No
Polygon	MATIC	No
Solana	SOL	No

Related Skills

• sdk-capabilities: Full list of supported operations
• sdk-transaction-builder: Other transaction types (transfers, NFTs)
• sdk-wallet-operations: Client setup and configuration