> For the complete documentation index, see [llms.txt](https://docs.fly.trade/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fly.trade/developers/deprecated-magpie-contracts/magpieaggregator-diamond-proxy/bridge/libbridge.md).

# LibBridge

provides functions for bridging assets into and out of a decentralized exchange system using either the Wormhole bridge or the Stargate bridge.

### **bridgeIn()**

The purpose of this function is to provide a unified way to bridge assets into a decentralized exchange system using either the Wormhole or Stargate bridge, depending on the bridge type specified in the `BridgeArgs` struct. This allows the decentralized exchange system to support multiple bridge types and switch between them as needed.

The function first checks the type of bridge specified in the `BridgeArgs` struct. If it is `Wormhole`, it calls the `bridgeIn` function of the `LibWormhole` library, passing in the necessary parameters. If it is `Stargate`, it calls the `bridgeIn` function of the `LibStargate` library. If the specified bridge type is neither `Wormhole` nor `Stargate`, the function reverts and throws an `InvalidBridgeType` error.

**Input**

<table><thead><tr><th width="216.99999999999997">Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">recipientNetworkId
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint16
</code></pre></td><td>network identifier of the target chain</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">bridgeArgs
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">BridgeArgs
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">struct BridgeArgs {
    BridgeType bridgeType;
    bytes payload;
}
</code></pre></td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">amount
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint256
</code></pre></td><td>the amount that needs to be swapped</td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">toAssetAddress
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">address
</code></pre></td><td>the target asset</td></tr></tbody></table>

**Output**

<table><thead><tr><th width="216.99999999999997">Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">tokenSequence
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint64
</code></pre></td><td>the sequence received after a successful bridgIn</td></tr></tbody></table>

### bridgeOut()

Similar to the `bridgeIn` function but handles withdrawals of assets instead. It takes in a `BridgeArgs` struct that specifies the bridge type and the payload data for the bridge transaction. It also takes in a Transaction struct that contains information about the transaction being processed, such as the recipient address and the amount being withdrawn. Finally, it takes in a `TransferKey` struct that contains information needed to validate the withdrawal transaction. The `bridgeOut` function then delegates to the appropriate bridge implementation based on the bridge type specified in the `BridgeArgs` struct. If the bridge type is `BridgeType.Wormhole`, it calls the `bridgeOut` function in `LibWormhole`. If the bridge type is `BridgeType.Stargate`, it calls the `bridgeOut` function in `LibStargate`.

**Input**

<table><thead><tr><th width="216.99999999999997">Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">bridgeArgs
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">BridgeArgs
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">struct BridgeArgs {
    BridgeType bridgeType;
    bytes payload;
}
</code></pre></td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">transaction
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">Transaction
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">struct Transaction {
    DataTransferType dataTransferType;
    BridgeType bridgeType;
    uint16 recipientNetworkId;
    bytes32 fromAssetAddress;
    bytes32 toAssetAddress;
    bytes32 toAddress;
    bytes32 recipientAggregatorAddress;
    uint256 amountOutMin;
    uint256 swapOutGasFee;
}
</code></pre></td></tr><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">transferKey
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">TransferKey
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">struct TransferKey {
    uint16 networkId;
    bytes32 senderAddress;
    uint64 swapSequence;
}
</code></pre></td></tr></tbody></table>

**Output**

<table><thead><tr><th width="216.99999999999997">Field</th><th>Type</th><th>Description</th></tr></thead><tbody><tr><td><p></p><pre class="language-solidity"><code class="lang-solidity">amount
</code></pre></td><td><p></p><pre class="language-solidity"><code class="lang-solidity">uint256
</code></pre></td><td>The amount received after bridging out.</td></tr></tbody></table>