> For the complete documentation index, see [llms.txt](https://docs.owlto.finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.owlto.finance/integration-guides/sdk.md).

# SDK

## Install

#### install with npm

{% code overflow="wrap" %}

```bash
npm install owlto-sdk
```

{% endcode %}

#### install with yarn

```bash
yarn add owlto-sdk
```

## Usage

{% embed url="<https://github.com/owlto-finance/owlto-sdk/blob/main/README.md>" %}

For example, to bridge USDC from Base to Scroll

```typescript
import * as owlto from "owlto-sdk";

const options: owlto.BridgeOptions = {}
let bridge = new owlto.Bridge(options);

const result = await bridge.getBuildTx(
    "USDC", //token name
    "BaseMainnet", //from chain name
    "ScrollMainnet",// to chain name
    "1", // value
    "0xa5E56D455BF247C475D752721Ba35A0c85Df81Dc", // from address
    "0xa5E56D455BF247C475D752721Ba35A0c85Df81Dc", // to address
);

//initialize your wallet
//...

if (result.txs.approveBody) {
    const tx = await wallet.sendTransaction(result.txs.approveBody as ethers.TransactionRequest);
    await tx.wait(); 
}

const tx = await wallet.sendTransaction(result.txs.transferBody as ethers.TransactionRequest);
await tx.wait(); 

const receipt = await bridge.waitReceipt(tx.hash)
console.log(receipt)
```

For more details, check the example/bridge\_usdc folder.

#### Bridge options

**1.chainNameMapping (Map\<string, string> | optional)**

Map your the chain names from your protocol with Owlto.

For example, if the chain name of Base Mainnet on your protocol is "Base", you can set `chainNameMapping["Base"] = "BaseMainnet"`.

Then you can run functions with chain name as "Base" in order to proceed with a bridge.

#### Get build tx

```typescript
const result = await bridge.getBuildTx(
    "USDC", //token name
    "BaseMainnet", //from chain name
    "ScrollMainnet",// to chain name
    "1", // value
    "0xa5E56D455BF247C475D752721Ba35A0c85Df81Dc", // from address
    "0xa5E56D455BF247C475D752721Ba35A0c85Df81Dc", // to address
);

//result:
{
 ...
  networkType: 1; //
  txs: any; //actual transactions need to be sent to from chain, see the following details
}
```

The txs contains the transactions user should send to `from chain` when bridging.

**1.Evm**

* **txs.approveBody**

  The approve transaction, if any, should be sent first.
* **txs.transferBody**

  The actual transfer transaction.

**2.Starknet**

Coming Soon

**3.Solana**

Coming Soon

#### Get receipt

1. `bridge.waitReceipt(fromChainHash: string)`
2. `bridge.getReceipt(fromChainHash: string)`

`fromChainHash` is the hash value of the transfer transaction.

`waitReceipt` refers to waiting for the bridge process to complete.

If the bridge process is not completed within 1 minute (usually due to not finding the hash value or failure), error message will be displayed.

`getReceipt` refers to get the status of a bridge process.

If `fromChainHash` is not found, bridge is in progress or failed, error message will be displayed.

#### Get pair info

1. `bridge.getPairInfo(tokenName: string, fromChainName: string, toChainName: string)`
2. `bridge.getAllPairInfos()`

A pair consists of three components: `token name`, `from chain name`, `to chain name`.

You can only bridge supported pairs

#### HTTP API Documentation

Please visit: <https://owlto.finance/bridge_api/v1/swagger/index.html> .