## Aurora SDK It's way too calm around @auroraecosystemnews.near's recent announcement about their SDK. If you're not yet freaking out about the possibilities this enables, you should better continue reading. ### How it works On April 21st Aurora [released their SDK](https://aurora.dev/blog/aurora-releases-its-engine-2-9-0-version). To give you a TLDR, it basically lets you interact between Near mainnet and Aurora EVM seamlessly. You might have heard that Aurora is in fact the EVM compiled to a smart contract, which runs on Near mainnet. This makes it different to Layer 2s on Ethereum. It's not really a L2, because if you call a smart contract that is deployed on Aurora you actually send a tx to Near mainnet. This also allows composability across Near and Aurora, because they're the same chain. However it used to be quite complicated to do so. @refsocial.near pioneered the cross chain contract calls with their own solution, which allows you to tap into the liquidity of Trisolaris and potentially other DEXes. In order to do so they create an EVM mapping account for you, which serves as a proxy. Now all this logic is abstracted away for you via Aurora's SDK and it works similarly in both directions, e.g. if you want to call a smart contract on Near from Aurora you first need to create a mapping account on Near mainnet. The SDK will deploy a specific smart contract on the newly created mapping address. The good thing about this is that this mapping account can be used by multiple dapps. If one dapp already created a mapping account for you, this account can be used by any other cross chain dapp. Afaik there does not yet exist a dapp on Aurora that interacts with Near mainnet. This will soon change due to the introduction of the SDK. However I'm not an EVM specialist and Idk what problems the asynchronous nature of Near might cause. ### Cross chain future Now I want to tell you why the introduction of this SDK makes me so excited. I've been developing an orderbook DEX for the last half year at @orderlylabs.near (views are my own in all social media posts). My vision has always been to create a fully on chain DEX that you can interact with seamlessly from any chain. It's deployed on Near testnet right now and we're currently internally figuring out the exact launch strategy. As you might know the current Orderly DEX has an off chain matching engine. The one I developed is fully on chain. Both concepts have their pros and cons. For the on chain version I want to highlight composability as the major point that makes it IMHO superior. Guess why @root.near is [excited about composability for the BOS](https://twitter.com/ilblackdragon/status/1645445420468846593)? With many widgets being developed on the BOS all this code can easily be reused by any other developer. On the smart contract level composability makes it possible to build seamless user experiences. Dapps building on top of other dapps like aggregators, liquidity managers, auto compounders, DAO tools. But if you have composability across chains you can build true cross chain dapps where all the settlement happens on Near mainnet. The user who uses his Metamask wallet on Aurora might not even notice. We can even go further and add protocols like [Axelar](https://twitter.com/axelarcore) which give you cross chain composability across the Cosmos and EVM. Hopefully they soon integrate Aurora. Imagine interacting with a dapp on Near mainnet from any Cosmos or EVM chain 🤯 Now let's compare [cross chain vs. multi chain](https://twitter.com/joespano_/status/1654843381640470534). You might have seen many DeFi products on EVM that go multi chain. What they do is deploy the same code on different EVM chains. But oh wait... The token is only native to one chain so staking is only available on one chain. Sorry! See this doesn't make a whole lot of sense. It's just driven by marketing. Products need users so they rush for deploying on as many chains as possible, but this hurts the UX. You can also read and share this thread on [Twitter](https://twitter.com/marior_dev/status/1654992797705945092)