Now that the on-chain pooling protocol has been released, pools are well underway and making payments, and the initial kinks have been ironed out through updates the attention is already turning to DeFi on Chia. Decentralized Finance, or DeFI, is a form of on-chain smart contract that allows for direct financial trades and automated markets on blockchain without intermediaries. Supposedly. You can tell this is the next big thing mostly because Bram has told us so in a blog post, and also because SpacePool’s Caleb Curry is shifting his focus to it.
And for the Chia Blockchain the tool of choice for creating on-chain DeFi applications is a programming language called ChiaLisp. Chialisp is a programming language built by the Chia Network team in order to enable smart contracts on the Chia Blockchain. In fact the first production chialisp application that you have interacted with is the on-chain pooling protocol, which uses chialisp to perform all the transactions involved with creating an NFT and joining a pool, as well as the pool handling claiming rewards. The actual first application were coloured coins according the the Chialisp.com documentation.
Chialisp is a version of LISP that is designed specifically to interact with coins on the blockchain. They chose LISP, not a popular choice, because it is an evaluated language that cannot be used to spawn processes or other malicious activity as well as it uses very controlled inputs and outputs in order to make the whole thing interoperable. Chialisp is Turing Complete, so in theory you should be able to program any interaction using the data available. That makes the platform relatively powerful when designing on-chain applications.

In practice chialisp is fairly complex, and the initial resources are not particularly user friendly. This has been acknowledged when they delayed the hackathon with Sirius Labs. You can tell by the example above that the structure will be familiar to most programmers and once the documentation is fleshed out I’m hoping a lot more applications begin to appear.
This is important, because the purpose of Chia is to operate a secure platform for these kinds of financial applications. Without any kind of utility offered by the Chia network there isn’t really any intrinsic purpose to the XCH coin, and the price will continue to drop until there are no buyers. That is why Chia Network is still hiring engineers and why they are working on making chialisp accessible to the community.
If you do want to get started with chialisp in preparation for the hackathon or because you have an idea you can get started here. But if you are like me and need a little more help I recommend starting with some YouTube videos linked to from here as well as reading everything available on the topic. Also, in his video on Chia DeFi Caleb suggested he might do a series on it. Go watch that video, comment on it and tell him you want that series. I will also be posting from time to time as I figure out what to do with it.