Fitr

        pool.reserve = pool.reserve.checked_add(amount).ok_or(VaultError::MathOverflow)?;        emit!(ReserveFunded {            pool: pool.key(),            funder: ctx.accounts.funder.key(),            amount,            crew_id: pool.crew_id,            reserve: pool.reserve,            daily_sponsor_amount: pool.daily_sponsor_amount,        });        Ok(())    }     /// Authority can only ever withdraw accrued fees - never principal or the reserve directly.    pub fn withdraw_treasury(ctx: Context<WithdrawTreasury>, amount: u64) -> Result<()> {        require!(amount <= ctx.accounts.pool.treasury_accrued, VaultError::InsufficientFunds);        let mint_key = ctx.accounts.mint.key();        let crew = ctx.accounts.pool.crew_seed();        let bump = [ctx.accounts.pool.bump];        let signer_seeds: &[&[&[u8]]] = &[&[POOL_SEED, mint_key.as_ref(), &crew, &bump]];        token_interface::transfer_checked(            CpiContext::new_with_signer(                ctx.accounts.token_program.to_account_info(),                TransferChecked {                    from: ctx.accounts.vault.to_account_info(),

1. Line 733 pool.reserve = pool.reserve.checked_add(amount).ok_or(VaultError::MathOverflow)?;: Uses checked arithmetic so overflow fails instead of wrapping.
2. Line 734 emit!(ReserveFunded {: Emits an Anchor event that clients can parse from the logs.
3. Line 747 require!(amount <= ctx.accounts.pool.treasury_accrued, VaultError::InsufficientFunds);: An explicit validation that aborts the instruction with an error.
4. Line 750 let bump = [ctx.accounts.pool.bump];: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
5. Line 752 token_interface::transfer_checked(: A checked token transfer, which also verifies the mint and decimals.
6. Line 753 CpiContext::new_with_signer(: Makes a CPI signed by a PDA. The signer seeds prove the program controls that address.

    #[account(mut)]    pub creator: Signer<'info>,    /// The global pool (crew_id 0) of `mint`: the config source.    #[account(        seeds = [POOL_SEED, mint.key().as_ref(), &GLOBAL_CREW_SEED],        bump = global_pool.bump,        has_one = mint    )]    pub global_pool: Box<Account<'info, Pool>>,    #[account(mint::token_program = token_program)]    pub mint: Box<InterfaceAccount<'info, Mint>>,    /// The crew pool. `init` fails if this crew_id already exists.    #[account(        init,        payer = creator,        space = 8 + Pool::INIT_SPACE,        seeds = [POOL_SEED, mint.key().as_ref(), &crew_id.to_le_bytes()],        bump    )]    pub pool: Box<Account<'info, Pool>>,    #[account(        init,        payer = creator,        seeds = [VAULT_SEED, pool.key().as_ref()],

1. Line 98 pub creator: Signer<'info>,: Requires this account to have signed the transaction.
2. Line 101 seeds = [POOL_SEED, mint.key().as_ref(), &GLOBAL_CREW_SEED],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
3. Line 102 bump = global_pool.bump,: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
4. Line 103 has_one = mint: Checks that a stored pubkey field matches the passed account.
5. Line 110 init,: Creates and pays for a new account. Space and payer must be specified.

} /// Inclusive start of day `day`: day * len + offset.pub fn day_start(day: u32, offset: i64, len: i64) -> Result<i64> {    (day as i64)        .checked_mul(len)        .and_then(|v| v.checked_add(offset))        .ok_or(error!(VaultError::MathOverflow))} /// Exclusive end of the day window (== start of next day).pub fn day_end(day: u32, offset: i64, len: i64) -> Result<i64> {    day_start(day.checked_add(1).ok_or(VaultError::MathOverflow)?, offset, len)} /// Largest allowed commit cutoff: len - len/24 (23 h for a 24 h day), so at least/// 1/24 of the day always remains to do the workout after the last possible commit.pub fn max_commit_cutoff(len: i64) -> i64 {    len - len / 24} /// Hard stake ceiling in base units: MAX_STAKE_CEILING_TOKENS * 10^decimals.pub fn stake_ceiling(decimals: u8) -> Result<u64> {    require!(decimals <= MAX_MINT_DECIMALS, VaultError::UnsupportedMintDecimals);

1. Line 18 .checked_mul(len): Uses checked arithmetic so overflow fails instead of wrapping.
2. Line 34 /// Hard stake ceiling in base units: MAX_STAKE_CEILING_TOKENS * 10^decimals.: Touches staking state: the amount locked and when it was locked.
3. Line 36 require!(decimals <= MAX_MINT_DECIMALS, VaultError::UnsupportedMintDecimals);: An explicit validation that aborts the instruction with an error.

/** * Solana Actions (Blinks) wire format and HTTP helpers. Pure: no network, importable anywhere. * * Spec: https://solana.com/docs/advanced/actions (Actions spec v2.x). * - GET  → ActionGetResponse (metadata: icon, title, description, label, links.actions) * - POST {account} → ActionPostResponse {type: "transaction", transaction (base64, unsigned, *   fee payer = account), message} * - OPTIONS → CORS preflight. Every response (including errors) carries the CORS headers plus *   X-Action-Version / X-Blockchain-Ids so blink clients (dial.to, wallets) accept it. * - errors → 4xx/5xx with ActionError {message} (shown to the user verbatim). * - /actions.json at the domain root maps website paths to action API paths. */import type { SolanaCluster } from "@/lib/solana/config"; export const ACTION_VERSION = "2.4"; /** CAIP-2 ids: solana:<first 32 chars of the genesis hash>. */export const BLOCKCHAIN_IDS: Readonly<Record<SolanaCluster, string>> = Object.freeze({  mainnet: "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",  devnet: "solana:EtWTRABZaYq6iMfeYKouRu166VU2xqa1",}); export function actionsCorsHeaders(cluster: SolanaCluster): Record<string, string> {  return {

1. Line 5 * - GET → ActionGetResponse (metadata: icon, title, description, label, links.actions): The metadata a Blink client renders (title, icon, buttons).
2. Line 6 * - POST {account} → ActionPostResponse {type: "transaction", transaction (base64, unsigne: Returns the serialized transaction the wallet will sign.