CYNIC

        vault.total_burned_units += amount;        vault.last_burn_timestamp = Clock::get()?.unix_timestamp;         Ok(())    }} #[derive(Accounts)]#[instruction(epoch: u64)]pub struct RecordPohCheckpoint<'info> {    #[account(        init,        payer = node_authority,        space = 8 + std::mem::size_of::<PohRecordAccount>(),        seeds = [b"cynic_poh", node_authority.key().as_ref(), &epoch.to_le_bytes()],        bump    )]    pub poh_record: AccountLoader<'info, PohRecordAccount>,    #[account(mut)]    pub node_authority: Signer<'info>,    pub system_program: Program<'info, System>,} #[derive(Accounts)]

1. Line 134 vault.last_burn_timestamp = Clock::get()?.unix_timestamp;: Reads on-chain time from the Clock sysvar.
2. Line 144 init,: Creates and pays for a new account. Space and payer must be specified.
3. Line 147 seeds = [b"cynic_poh", node_authority.key().as_ref(), &epoch.to_le_bytes()],: Declares the PDA seeds. Anchor re-derives the address and rejects the account if it doesn't match.
4. Line 148 bump: Uses the bump seed, the extra byte that pushes the derived address off the ed25519 curve.
5. Line 152 pub node_authority: Signer<'info>,: Requires this account to have signed the transaction.

/// Capability-aware egress route for external API calls.#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]pub struct CapabilityEgressRoute {    pub schema: String,    /// Allowed RPC methods (e.g., "getLatestBlockhash", "simulateTransaction").    pub allowed_methods: Vec<String>,    /// Max requests per second.    pub rate_limit_rps: u32,    /// Total bytes allowed per session.    pub max_bytes_per_session: u64,} impl CapabilityEgressRoute {    pub fn solana_rpc() -> Self {        Self {            schema: CAPABILITY_EGRESS_ROUTE_SCHEMA.to_string(),            allowed_methods: vec![                "getLatestBlockhash".to_string(),                "simulateTransaction".to_string(),                "sendTransaction".to_string(),            ],            rate_limit_rps: 10,            max_bytes_per_session: 10 * 1024 * 1024, // 10 MB        }

1. Line 77 /// Allowed RPC methods (e.g., "getLatestBlockhash", "simulateTransaction").: Fetches a recent blockhash. Transactions expire if it gets too old.
2. Line 92 "sendTransaction".to_string(),: Submits the signed transaction to the cluster.