0ktopus

        product.active = true;        product.bump = ctx.bumps.product;        msg!("Product registered: {}", product.name);        Ok(())    }     pub fn purchase_access<'info>(        ctx: Context<'_, '_, '_, 'info, PurchaseAccess<'info>>,        purchase_nonce: u64,    ) -> Result<()> {        let product = &ctx.accounts.product;        let config = &ctx.accounts.config;        let total_price = product.price_lamports;         let platform_fee = (total_price as u128)            .checked_mul(config.fee_bps as u128)            .and_then(|v| v.checked_div(10000))            .and_then(|v| u64::try_from(v).ok())            .ok_or(CapabilityError::ArithmeticOverflow)?;         // Transfer platform fee using CPI        let cpi_context = anchor_lang::context::CpiContext::new(            ctx.accounts.system_program.to_account_info(),            anchor_lang::system_program::Transfer {

1. Line 74 product.bump = ctx.bumps.product;: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
2. Line 75 msg!("Product registered: {}", product.name);: Logs to the program log, which is visible in explorers and the test output.
3. Line 88 .checked_mul(config.fee_bps as u128): Uses checked arithmetic so overflow fails instead of wrapping.
4. Line 94 let cpi_context = anchor_lang::context::CpiContext::new(: Makes a cross-program invocation into another program.

      const toAta = getAssociatedTokenAddressSync(nftMint, recipient);       const transaction = new Transaction();       // Check if recipient ATA exists      const toAccountInfo = await connection.getAccountInfo(toAta);      if (!toAccountInfo) {        transaction.add(          createAssociatedTokenAccountInstruction(            wallet.publicKey,            toAta,            recipient,            nftMint          )        );      }       transaction.add(        createTransferInstruction(fromAta, toAta, wallet.publicKey, 1)      );       transaction.feePayer = wallet.publicKey;      transaction.recentBlockhash = (await connection.getLatestBlockhash()).blockhash;

1. Line 67 createTransferInstruction(fromAta, toAta, wallet.publicKey, 1): An SPL token transfer through the Token Program.
2. Line 71 transaction.recentBlockhash = (await connection.getLatestBlockhash()).blockhash;: Fetches a recent blockhash. Transactions expire if it gets too old.

 impl AccessState {    pub const LEN: usize = 8 + // discriminator        32 + // nft_mint        32 + // buyer        32 + // product        1 + 4 + // remaining_uses (Option<u32>)        1 + 8 + // expires_at (Option<i64>)        8 + // purchase_nonce        1; // bump     pub fn is_valid(&self, clock: &Clock) -> bool {        // Check if expired        if let Some(expires_at) = self.expires_at {            if clock.unix_timestamp > expires_at {                return false;            }        }         // Check if uses remaining        if let Some(remaining) = self.remaining_uses {            if remaining == 0 {                return false;            }

1. Line 22 1; // bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
2. Line 27 if clock.unix_timestamp > expires_at {: Reads on-chain time from the Clock sysvar.