The Solana India Fellowship Saga

This post is a part of a series of posts documenting my experience as a fellow in the Solana India Fellowship. You can find other posts in this series here.


We are done with all the exercises and quests for the fellowship! We are now in the 2nd phase, where all the fellows have to build out a complete project on Solana. Since week 2, I have been brainstorming and building out Aureus - a buy now, pay later style product on top of Solana pay. I have finalized a lot of details and also iterated on the code for a bit, here is my “one pager” for the project:

Aureus Pay

Aureus cover

Auerus allows you to get Instant loans while using Solana Pay.


Solana pay is a URL specification and does not have any on-chain footprint. If a merchant on Solana pay only accepts USDC, a customer with SOL in his wallet cannot make a payment even if he has enough funds. Aureus aims to fix this buy allowing users to lock up SOL/SPL tokens as collateral while the merchant gets instant payments in USDC. The user can then pay back his loan incrementally.


  • Instant payment to merchant in USDC/SOL/SPL tokens, while the on-chain program takes on any price/volatility risk.
  • The user gets to choose a fixed payment term (from 4 to 16 weeks), with variable interest rate.
  • Collateral is freed incrementally as the user repays his obligation.
  • If the payment term expires, any remaining locked collateral is liquidated.

Operating model

  • Liquidity will be provided by using one of the already available lending protocols on Solana. (Solend, Jet, Oxygen, etc)
  • Aureus will automatically select the cheapest protocol to borrow from, but advanced users will also have the option to choose a protocol they want.
  • Aureus itself earns revenue by charging a flat rate (typically less 0.2%) on top of the base borrowing rate.
Aureus workflow

The purchase flow


  • Given enough users, Aureus can create its own borrowing and lending platform, with anyone being able to contribute liquidity.
  • Add support for more complex products such as NFTs as collateral.