/Cairo-Loto_PoC_backend_cairo-0

Primary LanguageCairo

CAIRO LOTO Backend Protocol - Proof of Concept


WORK IN PROGRESS!


Main Goals

  • Validating the technical feasibility of implementing a fully on-chain and automated zero-loss lottery dApp using Starknet and Cairo.
  • Showing that building on Starknet comes with all lot of awesome tools and that the network offers great performances.
  • Measure the interest of the community for such an application

Architecture

-> A "Tickets Handler" contract, to manage the issuance of tickets and keep track of each ticket's owner.

-> A "Lottery Engine" contract, in-progress,
to manage the execution of lottery draws.

-> A "Book Keeper contract", yet to be implemented,
to produce yield generation with the assets deposited on Cairo Loto and manage reward claim by the lottery winners.





Contracts currently Live on Testnet!

current Tickets Handler contract is deployed on testnet:
-> contract address: 0x074ba6bd39ac4ca2b388f63a48aa31f72e1c26a54dce6aaad9f86c76a4e41f37

Addresses will be updated as I progress (unless I forget!)



Step-by-step Project Development

This section provides an overview of the development process for building the CAIRO LOTO project.


Notes:

  1. The backend contracts are currently written in cairo-0 but will be upgraded to latest Cairo version and syntax in future iterations.
    (= an MVP version including more features and efforts on UI/UX, then the Production version to be deployed on mainnet).

  2. In order to kickstart this project and build a Proof of Concept ASAP, I am using OpenZeppelin's 'ERC721EnumerableMintableBurnable' preset contract as a base for the 'Tickets' contract.

  3. Also I'm adding the 'upgrade()' function from the 'ERC20Upgradable' preset library in each contract.
    It can be used to upgrade the contracts to the latest versions/syntax of Cairo, but is probably also going to be useful as I develop the project and implement new features (advantage = keeping the same contract address as I implement new features).



1 - Building the "Tickets" contract

[x] TokenURI

Note that your 'tokenURI' must be <= 31 characters long.
-> use https://uri.to/ to shorten an URI.
-> use the str_to_felt() function from /utils.py or just go on https://codebeautify.org/string-hex-converter to convert into a felt your shortened URI string (just add '0x' as prefix if using codebeautify).
😉



2 - Implementation of the "BookKeeper" contract



3 - Implementation of the "Lottery" contract







Cairo-0 contract Compilation, Declaration and Deployment

  1. Follow my Guide to setup your environment for Cairo-0.

  2. compile ozERC721MintBurnEnumUpgradable.cairo:

starknet-compile-deprecated contracts/OZ_Preset/ozERC721MintBurnEnumUpgradable.cairo --output compiled_contracts/ozERC721MintBurnEnumUpgradable_comp.json
  1. declare contract:
starknet declare --contract compiled_contracts/ozERC721MintBurnEnumUpgradable_comp.json --deprecated
  1. deploy contract:
starknet deploy --class_hash 0x590624cb14c82ec9cfa19124fe1a26e4b7b1132ba0e845925734975754b1327 --inputs 0x4c6f7474657279204d5650 0x544b54 0x044bdc0da3aebf62380588ebc75cd404a6bab6581bc01133554a873137a963bc

Note that with last versions of the compiler supporting cairo-0, converting every hex into felt/decimal representation for bash commands is not mandatory anymore.







Security Considerations

WARNING: This project is a work in progress.
Contracts may be deployed but haven't been audited.

USE AT YOUR OWN RISK

(although it's on testnet so...
WHO CARES? JUST HAVE FUN!)