---
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


---
Source attribution: BankrBot
Original project: https://github.com/BankrBot/claude-plugins/blob/67d33d4ee8e1680ce823eb9fe9ad371326c6b5ec/x402-sdk-dev/skills/sdk-transaction-builder/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Dave AI.

## Upstream license notice

MIT License

Copyright (c) 2024 Bankr

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Dave AI resource metadata

Creator / publisher: BankrBot
Original project: https://github.com/BankrBot/claude-plugins/blob/67d33d4ee8e1680ce823eb9fe9ad371326c6b5ec/x402-sdk-dev/skills/sdk-transaction-builder/SKILL.md
Attribution basis: Recovered original package and original project license at a pinned revision

Fields of work: Marketing, Sales
Roles: Business Development, Customer Success Manager, Growth Marketer, Product Marketer, Sales Engineer
Specialties: API
Tools: Bankr Sdk
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: 36c1e7eada671a4810e4dd1abcfc595882ab38562e4fa583650410d3d1849034
Metadata reviewed: 2026-10-27
This metadata supersedes earlier Dave AI catalog attribution. Original instruction and supporting files are preserved.