8. Fee Market
Kortana implements the EIP-1559 dynamic fee market mechanism adopted from the Ethereum Cancun hard fork revision. The fee market dynamically balances block space supply and demand while introducing a powerful disinflationary token burning mechanism.
8.1 EIP-1559 Base Fee Mechanism
The cost of transaction execution is split into two components: the Base Fee and the Priority Tip:
- Base Fee Burn (50%): Every transaction must pay at least the current block's base fee per unit of gas. Exactly
50%of this base fee is permanently destroyed (burned) from the world state during block settlement. This token destruction directly reduces the circulating supply of DNR, enforcing the protocol's disinflationary monetary policy. - Base Fee to Proposer (50%) + Priority Tip: The remaining
50%of the base fee, along with100%of the priority tip (max_priority_fee_per_gas), is credited directly to the validator that proposed and finalized the block. - Dynamic Base Fee Adjustment: The base fee adjusts automatically from block to block based on target block fullness. The target gas per block is 50% of the block gas limit (15,000,000 gas). If a block exceeds this target, the base fee increases for the next block; if it is below target, the base fee decreases. The maximum base fee change between consecutive blocks is bounded by
12.5%(1250 basis points).
8.2 Block Gas Limit
The maximum cumulative gas that can be consumed by all transactions in a single block is configured at 30,000,000 gas. This high capacity ceiling ensures that Kortana can process hundreds of complex DeFi swaps, ERC-20 transfers, and KVM module calls per 1.5-second block without hitting congestion walls prematurely.
Gas limits are strictly enforced during block construction: the block builder halts transaction inclusion the moment adding another transaction would push total gas consumption past the 30,000,000 threshold. Validating nodes instantly reject any proposed block header declaring a gas_used greater than the block gas_limit.
8.3 Minimum Gas Price
To prevent distributed denial-of-service (DDoS) attacks, zero-fee transaction flooding, and state trie bloat, Kortana enforces a hard protocol floor:
Minimum Gas Price = 1 gwei (1,000,000,000 wei)
Any transaction submitted with a max_fee_per_gas or gasPrice below this 1 gwei threshold is rejected at the RPC layer and mempool admission stage before consuming any network resources. This hard economic floor ensures that spam attacks incur non-trivial financial costs to the attacker while keeping fees negligibly small for everyday users.
8.4 Intrinsic Gas Costs
Before transaction execution begins, an intrinsic gas cost is deducted based on payload complexity:
- Base Transfer Cost:
21,000 gasfor standard account-to-account value transfers. - Contract Creation Cost:
53,000 gaswhen deploying new smart contracts (CREATE/CREATE2). - Calldata Costs:
4 gasper zero byte of transaction calldata;16 gasper non-zero byte of calldata.
In accordance with Kortana's architectural rules (§4 Rule 1), intrinsic gas parameters are not hardcoded as constants in the C++ binaries; they are dynamically loaded from the on-chain governance ParamStore.
8.5 Max Transaction Size
To prevent memory exhaustion attacks against peer-to-peer transport layers and RPC deserializers, individual transaction payloads are strictly capped at 128 KiB (131,072 bytes). Any transaction exceeding this size is immediately dropped upon reception.
This limit applies to both raw transaction bytes and compiled bytecode payloads submitted during contract deployment. Developers deploying large contract systems are encouraged to modularize their architecture using libraries or delegate proxies to remain comfortably within the 128 KiB boundary.
Part III — Execution Engines
Kortana runs two execution engines over one state trie. By combining the Ethereum Virtual Machine (EVM) for ecosystem compatibility and the custom Kortana Virtual Machine (KVM) for capability-secure smart contracts, developers can choose the right tool for their protocol without sacrificing interoperability.