Morley Hackathon (ZuriHac 2019)

Are you interested in smart contracts? If you want to learn about this topic and get hands-on experience, developers from Serokell and the Tocqueville Group are happy to offer some real-world tasks to you and help you to solve them.

Morley is a set of developer tools for the Michelson language which is the smart contract language of the Tezos blockchain. Tezos is a new platform for smart contracts and decentralized applications. It’s based on the Proof of Stake consensus algorithm and can evolve by upgrading itself. Its smart contract language – Michelson – is a low-level stack-based language. Unlike many other smart contract languages, Michelson is statically typed, which prevents many errors in contracts before they are deployed.


For this hackathon, we have selected the most suitable issues and copied them to GitLab.

We expect that different people will want to spend a different amount of time on Morley, so we picked various issues:

  1. Some of them are relatively big (but can be done within the time frame of this hackathon) and imply you will have to add new functionality.
  2. Other issues are smaller and can be resolved faster. They mostly imply you will need to improve existing functionality or add something small.


Here is an overview of all issues selected for Zurihac. We start with the most interesting issues which require the biggest effort.

  1. #5 Interactive debugger. You need to develop a simplified version of gdb for Michelson.
  2. #6 REPL. Similar to the previous one, but here you need to develop a REPL to be able to execute standalone instructions.
  3. #7 Optimizer. The goal here is to come up with a set of rules for optimizing the Michelson contract and implement them.

These three issues are more substantial than others and will probably take more time.

  1. #11 Benchmarks. Morley lacks benchmarks and we would like to add some.
  2. #9 The goal is to update the typechecker to print a stack type after processing each instruction.
  3. #10 Pretty printer. The goal is to update the Michelson printer to print a human-readable contract as opposed to printing everything on one line.
  4. #8 There is a custom STACKTYPE instruction which allows us to assert that the stack has a given type signature. Currently, one can only write specific types (e. g. int) or type variables there – not type constructors applied to type variables (e. g. pair a b). The goal is to modify the parser and the typechecker to make it possible.

These issues are about improving existing functionality and should be easier to do.

If you have chosen an issue, please leave a comment stating that you are working on this issue, even if you are not sure that you’ll complete it.