OuroC

    #[account(        mut,        has_one = authority @ ErrorCode::UnauthorizedAccess    )]    pub config: Account<'info, Config>,     pub authority: Signer<'info>,} #[derive(Accounts)]#[instruction(subscription_id: String)]pub struct CreateSubscription<'info> {    #[account(        init,        payer = subscriber,        space = 8 + Subscription::LEN,        seeds = [b"subscription", subscription_id.as_bytes()],        bump    )]    pub subscription: Account<'info, Subscription>,     #[account(seeds = [b"config"], bump)]    pub config: Account<'info, Config>,

1. Line 75 has_one = authority @ ErrorCode::UnauthorizedAccess: Checks that a stored pubkey field matches the passed account.
2. Line 79 pub authority: Signer<'info>,: Requires this account to have signed the transaction.
3. Line 86 init,: Creates and pays for a new account. Space and payer must be specified.
4. Line 89 seeds = [b"subscription", subscription_id.as_bytes()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
5. Line 90 bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.

    #[account(        mut,        has_one = authority @ ErrorCode::UnauthorizedAccess    )]    pub config: Account<'info, Config>,     pub authority: Signer<'info>,} #[derive(Accounts)]#[instruction(subscription_id: String)]pub struct CreateSubscription<'info> {    #[account(        init,        payer = subscriber,        space = 8 + Subscription::LEN,        seeds = [b"subscription", subscription_id.as_bytes()],        bump    )]    pub subscription: Account<'info, Subscription>,     /// Subscription PDA (same as subscription account key, for delegation)    /// CHECK: PDA derived from subscription_id    #[account(

1. Line 75 has_one = authority @ ErrorCode::UnauthorizedAccess: Checks that a stored pubkey field matches the passed account.
2. Line 79 pub authority: Signer<'info>,: Requires this account to have signed the transaction.
3. Line 86 init,: Creates and pays for a new account. Space and payer must be specified.
4. Line 89 seeds = [b"subscription", subscription_id.as_bytes()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
5. Line 90 bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.

    let fee_config = &config.fee_config;    let platform_fee = subscription.amount        .checked_mul(fee_config.fee_percentage_basis_points as u64)        .ok_or(ErrorCode::MathOverflow)?        .checked_div(BASIS_POINTS_DIVISOR)        .ok_or(ErrorCode::MathOverflow)?;     let merchant_amount = subscription.amount        .checked_sub(platform_fee)        .ok_or(ErrorCode::InsufficientAmount)?;     // Use subscription PDA as authority (subscriber must delegate to this PDA)    // Derive PDA signer seeds for CPI - Clone ID to avoid borrow issues    let subscription_id = subscription.id.clone();    let subscription_key = subscription.key();     // Find the bump seed for this subscription PDA    let (subscription_pda, bump) = Pubkey::find_program_address(        &[b"subscription", subscription_id.as_bytes()],        program_id    );     // Verify the subscription account matches the derived PDA    require!(

1. Line 123 .checked_mul(fee_config.fee_percentage_basis_points as u64): Uses checked arithmetic so overflow fails instead of wrapping.
2. Line 137 // Find the bump seed for this subscription PDA: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
3. Line 138 let (subscription_pda, bump) = Pubkey::find_program_address(: Derives a PDA from seeds and the program ID and returns the address with its canonical bump.
4. Line 144 require!(: An explicit validation that aborts the instruction with an error.

 /// Pause a subscriptionpub fn pause_subscription(ctx: Context<UpdateSubscription>) -> Result<()> {    let subscription = &mut ctx.accounts.subscription;    require!(subscription.status == SubscriptionStatus::Active, ErrorCode::SubscriptionNotActive);     let clock = Clock::get()?;    let subscription_id = subscription.id.clone();     subscription.status = SubscriptionStatus::Paused;     msg!("Subscription {} paused", subscription_id);     emit!(SubscriptionPaused {        subscription_id,        paused_at: clock.unix_timestamp,    });     Ok(())} /// Resume a subscriptionpub fn resume_subscription(ctx: Context<UpdateSubscription>) -> Result<()> {    let subscription = &mut ctx.accounts.subscription;

1. Line 341 require!(subscription.status == SubscriptionStatus::Active, ErrorCode::SubscriptionNotActi: An explicit validation that aborts the instruction with an error.
2. Line 343 let clock = Clock::get()?;: Reads on-chain time from the Clock sysvar.
3. Line 348 msg!("Subscription {} paused", subscription_id);: Logs to the program log, which is visible in explorers and the test output.
4. Line 350 emit!(SubscriptionPaused {: Emits an Anchor event that clients can parse from the logs.