sdk-transaction-builder skill

---
name: Bankr x402 SDK - Transaction Builder
description: This skill should be used when the user asks to "send tokens", "transfer ETH", "send USDC to", "transfer NFT", "wrap ETH", "unwrap WETH", "bridge tokens", "mint NFT", "buy NFT", "approve token", "build transaction", "DeFi transaction", or needs to build transactions for transfers, approvals, NFT operations, cross-chain bridges, ETH/WETH conversions, or DeFi interactions beyond simple swaps using the Bankr SDK.
version: 1.1.0
---

# SDK Transaction Builder

Build blockchain transactions for transfers, NFTs, bridges, and DeFi operations.

## Transaction Types

| Type | Description | Example Prompt |
|------|-------------|----------------|
| `transfer_erc20` | Send ERC20 tokens | "Send 100 USDC to 0x..." |
| `transfer_eth` | Send native ETH | "Send 0.1 ETH to 0x..." |
| `convert_eth_to_weth` | Wrap ETH | "Wrap 0.5 ETH" |
| `convert_weth_to_eth` | Unwrap WETH | "Unwrap 1 WETH" |
| `transfer_nft` | Send NFT | "Transfer my NFT #123 to 0x..." |
| `buy_nft` | Purchase NFT | "Buy the cheapest Pudgy Penguin" |
| `mint_manifold_nft` | Mint from Manifold | "Mint from Manifold at 0x..." |
| `mint_seadrop_nft` | Mint from SeaDrop | "Mint from SeaDrop at 0x..." |
| `swapCrossChain` | Bridge tokens | "Bridge 100 USDC from Ethereum to Base" |

## Prompt Patterns

```
# Transfers
"Send 100 USDC to 0x742d35..."
"Transfer 0.5 ETH to vitalik.eth"
"Send 50 USDC to 0x123... on Base"

# ETH/WETH
"Wrap 0.5 ETH to WETH"
"Unwrap 1 WETH to ETH"

# NFTs
"Transfer my Pudgy Penguin #1234 to 0x..."
"Buy the cheapest Pudgy Penguin on OpenSea"
"Mint NFT from Manifold contract 0x..."

# Cross-Chain
"Bridge 100 USDC from Ethereum to Base"
"Move 0.5 ETH from Base to Ethereum"
```

## Usage

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

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

// Transfer tokens
const result = await client.promptAndWait({
  prompt: "Send 100 USDC to 0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0",
});

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

## Transaction Metadata

All transactions include metadata for verification:

```typescript
const tx = result.transactions[0];
const meta = tx.metadata.__ORIGINAL_TX_DATA__;

console.log(`Chain: ${meta.chain}`);
console.log(`Amount: ${meta.inputTokenAmount} ${meta.inputTokenTicker}`);
console.log(`To: ${meta.receiver}`);
console.log(`Message: ${meta.humanReadableMessage}`);
```

## Timing Guidelines

| Operation | Typical Time |
|-----------|--------------|
| ERC20/ETH transfer | 2-5s |
| Wrap/Unwrap | 2-5s |
| NFT transfer | 3-5s |
| NFT purchase | 5-10s |
| Cross-chain bridge | 10-30s |

## Related Skills

- **sdk-token-swaps**: Token swap patterns and approval handling
- **sdk-capabilities**: Full list of supported operations
- **sdk-wallet-operations**: Client setup and configuration