Solana Anchor Flash Loan Protocol

A production-grade, secure Flash Loan smart contract built on Solana using the Anchor Framework and Instruction Introspection (solana_program::sysvar::instructions).

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💡 Architecture & Security Highlights

1. Atomic Flash Loans via Sysvar Introspection:
   • Verifies within borrow_flash_loan that a corresponding repay_flash_loan instruction targeting the same program exists in the same atomic transaction.
2. Deterministic PDA Vaults:
   • Vault PDA seeds: [b"flash_loan_vault", mint.key()]
   • Pool PDA seeds: [b"flash_loan_pool", mint.key()]
3. Protocol Fees:
   • 0.09% (9 basis points) fee per flash loan, accumulating autonomously into pool fees.
4. Safety & Overflow Protection:
   • checked_add, checked_mul, checked_div arithmetic across all fee and balance calculations.
   • SPL Token CPI transfers with PDA signer seeds.

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🛠️ Instructions Included

• initialize_pool: Creates pool & vault for an SPL token mint.
• deposit_liquidity: Allows LPs to supply liquidity.
• borrow_flash_loan: Issues flash loan and asserts repayment index.
• repay_flash_loan: Repays borrowed capital + 0.09% fee.
• withdraw_admin: Enables pool admin to claim collected fees.

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🧪 Testing

anchor test