Even Guardians need to blow off steam every so often. Help a mage who maybe had one too many drinks get home…

Do you know how low-level calls work in Starknet? Or how calldata is encoded? This knowledge could be useful for on-chain sleuthing and some other advanced use cases. 

Learn about the inner workings of calls and calldata in this fun interface spoofing exercise!

Calldata Spoofing

Yamin seems determined to cast her portal spell rather than delegating the task to you. That could be for the better, since you aren’t sure how sober you are either. With some guidance from your end, she calls her portal one last time. 

Around you, your fellow drinkers look on in awe as Yasmin creates a shimmering golden portal before you. Mustering your remaining sobriety, you help Yasmin up onto her feet.

See… *hic* …I told you I could do it….

Shifting her weight, you step through the shimmering portal and into the halls of Denhkara. A few other Guardians look up at your sudden appearance. After a moment of concern, they laugh as they see that Yasmin is not hurt, only drunk.

Looks like someone is going to have some regrets come morning. Come, let me help you get her to bed.

With Raethis’ help, you carry Yasmin to her room and put her to bed. You’ve no doubt Raethis is right, she is not going to feel great come sunrise…

Under the awning of the caravanserai, you sit and watch the comings and goings of the local travelers. From merchants setting off across the desert to Guardians returning from their travels, there is nothing quite like a relaxed afternoon watching the world go by.

Look who it is. Would you mind me joining you? I could do with a good drink.

You pull up a chair. The company of a good friend is always welcome. Before long, she is several mugs of wine in as she fills you in on her research woes. Academic research can be fulfilling, but it can as easily be taxing when you hit a dead end.

As evening sets in, you realize it’s high time you got your friend to bed.

Don’t worry. *hic* A quick portal will get us back…

She raises her hands, but after drinking all evening she is in no state to cast even the most basic of spells, let alone a teleportation portal. But you have no desire to carry her back, so perhaps a portal would be the best option to get home with your drunk companion…

In this quest, we remedied a contract with a mismatched interface by diving into our understanding of low-level calldata.

For the uninitiated, this might have been your first time studying calldata at the lowest level. You might have asked yourself, why bother? Well, understanding how calldata is encoded and decoded is useful in Cairo contract development. For instance, knowing calldata encoding helps in:

In short, this knowledge will bound to prove itself useful if it has not already!

Do you know how low-level calls work in Starknet? Or how calldata is encoded? This knowledge could be useful for on-chain sleuthing and some other advanced use cases. 

Learn about the inner workings of calls and calldata in this fun interface spoofing exercise!

Starknet contracts support state variables, but how they live in contract storage is generally abstracted away from the typical developer. In this quest, we will take a peek under the hood and see how state variables are stored exactly.

Starknet Storage Layout

Starknet contract addresses, like in many other blockchains, can be precomputed too. This allows for the creation of vanity addresses.

In this quest, see if you can deploy your smart contract under a specified address pattern...

Vanity Addresses

Can we build an EVM inside of an EVM? That seems like a strange question, but the answer is yes we can! In this quest, we will build a self-hosted EVM (sEVM), squeezed into a single smart contract. By rebuilding the EVM, develop a deeper appreciation of the machine's inner workings and EVM bytecode.

Self-Hosted EVM

In some specific cases, assembly, and its full control over memory, is the most efficient way to optimize a snippet of code.

Practice using inline assembly in your Solidity smart contracts to further optimize them, to an extent vanilla Solidity does not offer!

Assembly Optimization

Equipped with the knowledge of Solidity's storage model, we can now execute some gas optimization tricks. Explore how the reordering of state variables and the use of memory caching can save some functions a considerable amount of gas.