I particularly enjoyed the attention to detail in the docs and examples. Great work, well done.

A couple things that came up in my review:

1. Running the Dockers gave me errors, I had to modify your dockerfiles to make it run smoothly
2. The tutorial is nice but it doesn't help me as a newbie to the library to get started easily. Could you update it so that we follow concrete steps and provide boilerplate project structure if necessary?
3. I don't see any address transforming from Ethereum to Substrate in the library. I was expecting this to be part of the basic SDK? I would think that working with public key addresses directly would be a lot easier (EVM addresses right-padded to 32 bytes to fit Substrate's AccountId32 address type) than using the SS58 as your public key starting point.

If you can address 2 and update it so I can finish my review this is approved on my end!

Hey @sacha-l!
I have updated the deliverable template (and the deliverable) to address the comments.

For 1, I am not sure which exact issues you run into when running docker. It all works for me when I run it from a clean state but I would love to know what went wrong for you so I can fix it.

For 2, I included more straightforward instructions and a couple boilerplate apps so you can see how it is intended to work even if the tutorials aren’t helpful enough. Please, let me know if anything is still unclear. I have also recorded a demo showing the boilerplate and authentication in action.

For the third point, I actually considered using right-padded EVM addresses for Substrate, but I went with native SS58 addresses instead for a few practical reasons:

1. Wallet Compatibility: I found that most Substrate wallets (like Polkadot.js and Talisman) work with SS58 addresses, and I wanted to make sure the SDK works smoothly with existing wallet infrastructure.
2. Security: SS58's built-in checksum validation is really helpful for catching address typos, which I'm using in the validation functions.
3. Chain Flexibility: I noticed that not all Substrate chains use AccountId32, so I went with SS58 to keep things more flexible.
   I ended up implementing a DID-based approach for cross-chain identity instead of direct address transformation. But I'm totally open to adding address transformation utilities if you think that would be more useful!

Let me know if there are any other questions or adjustments needed!

Hey @uliana1one, the payout was made 3 days ago: https://polkadot.subsquare.io/treasury/child-bounties/63_3. Thanks for your patience.