SOL Swap with Jupiter Flash Fill

This borrows the concept of flash loan but instead of borrowing any amount the borrower wants. Borrower can only borrow the required amount for creating a wSOL account. This is to solve a problem when a borrower may not have enough SOL to do anything when swapping through Jupiter.

With this, the borrower can immediately swap any tokens on Jupiter to SOL even if they don't have enough to open a wSOL account. On top of that, if the user doesn't have any SOL, we can have another payer for the swap as well.

For an implementatin that uses Jupiter Swap as CPI, you can check out: https://github.com/jup-ag/sol-swap-cpi. The CPI implementation has one problem tho, it may run into CPI size limit.

How this works?

For a flash fill to work, the transaction will be composed of these instructions:

1. Borrow enough SOL for opening the wSOL account from this program.
2. Create the wSOL account for the borrower.
3. Swap X token to wSOL.
4. Close the wSOL account and send it to the borrower.
5. Repay the SOL for opening the wSOL account back to this program.

• Example: ./cli/flash-fill.ts
• Transaction: https://solscan.io/tx/4psWiUFGdRhKqi1UXSWrpoM3RCJWAXpz6CTpsd5fZwjr8nEpLiZVuiyaERj95hUNnm6dhfxircLgAqCbHV3wCVpT

References:

• https://github.com/moshthepitt/flash-loan-mastery
• https://github.com/2501babe/adobe