Developer Reference

Complete API reference for the vaea-flash-ctx crate — function signatures, error types, constants, and protocol use cases.

verify()

rust

pub fn verify(
    flash_state: &AccountInfo,
    sysvar_instructions: &AccountInfo,
) -> Result<FlashContext, ProgramError>

Validates the flash loan context. Returns FlashContext on success, or a ProgramError if any check fails.

Parameter	Type	Description
flash_state	`&AccountInfo`	The VAEA FlashState PDA — must be owned by the VAEA program
sysvar_instructions	`&AccountInfo`	The instructions sysvar (Sysvar1nstructions...)

FlashContext

rust

pub struct FlashContext {
    pub amount: u64,           // Borrowed amount (native units)
    pub token_mint: Pubkey,    // Token mint address
    pub fee: u64,              // VAEA fee (native units)
    pub payer: Pubkey,         // Borrower's public key
    pub source_tier: u8,       // 0=SDK, 1=UI, 2=Protocol
    pub slot_created: u64,     // Slot when loan began
}

Field	Type	Notes
amount	u64	In native token units (e.g. lamports for SOL, 1e6 for USDC)
token_mint	Pubkey	Use this to confirm which token was borrowed
fee	u64	The VAEA fee, already calculated. 2 bps of borrowed amount
payer	Pubkey	The user who initiated the flash loan
source_tier	u8	0 = SDK bot, 1 = web UI, 2 = protocol-level CPI
slot_created	u64	Should match the current slot — used for freshness check

Error Types

Error	Code	Cause	Fix
InvalidOwner	6000	flash_state.owner is not the VAEA program	Pass the correct FlashState PDA
InvalidPDA	6001	PDA seeds don't match the expected derivation	Derive PDA correctly from payer + token_mint
NoBeginFlash	6002	begin_flash instruction not found before current IX	Ensure VAEA.begin_flash is in the TX before your IX
NoEndFlash	6003	end_flash instruction not found after current IX	Ensure VAEA.end_flash is in the TX after your IX
InvalidSysvar	6004	sysvar_instructions account is wrong	Pass Sysvar1nstructions... as the sysvar account
StaleSlot	6005	slot_created doesn't match current slot	The PDA is from a different transaction — invalid

Constants

rust

// VAEA Program ID
pub const VAEA_PROGRAM_ID: Pubkey = pubkey!("HoYiwkNB7a3gmZXEkTqLkborNDc976vKEUAzBm8YpK5E");

// FlashState PDA seeds prefix
pub const FLASH_SEED: &[u8] = b"flash";

// Account size
pub const FLASH_STATE_SIZE: usize = 99;

// Source tiers
pub const SOURCE_SDK: u8 = 0;
pub const SOURCE_UI: u8 = 1;
pub const SOURCE_PROTOCOL: u8 = 2;

Cost Breakdown

Metric	Value	Notes
CPI consumed	0	PDA read — not a cross-program call
Compute Units	~2,000 CU	Owner check + deserialization + sysvar scan
Account rent	~0.001 SOL	Reclaimed at end_flash
VAEA fee	2 bps (0.02%)	Flat rate for all tiers

Protocol Use Cases

Use Case	How Your Program Uses CTX
Self-liquidation	Verify flash loan before releasing collateral — prevent unauthorized withdrawals
Leverage vaults	Confirm initial deposit is flash-loaned — enforce atomic rollback on failure
Risk gating	Read flash.amount to apply different risk parameters during flash loans
Atomic rebalancing	Compose with Jupiter + AMMs at full CPI depth — impossible with CPI verification
Flash mint	Verify collateral backing before minting synthetic tokens

FAQ

Does this work without Anchor?

Yes. The crate depends only on solana-program. Pass two AccountInfo references and call verify().

What happens if the user doesn't use VAEA?

If the user borrows directly from Kamino or Marginfi without VAEA, no FlashState PDA is created. verify() will fail with InvalidOwner or NoBeginFlash. Your program decides how to handle that — reject the TX, or proceed without flash loan verification.

Can I make verification optional?

Yes. You can make the flash_state account optional in your Accounts struct and only call verify() if it's present. This lets your instruction work both inside and outside flash loans.

What if VAEA goes offline?

The VAEA on-chain program is immutable (no upgrade authority post-mainnet). verify() only reads on-chain data. It has zero dependency on VAEA's backend servers, API, or Smart Router. The verification is fully decentralized.

💡 Tip

Need help integrating? Join the Discord and ask in #protocol-integrations.