Divergence from Ethereum

While SHE features full EVM compatibility, there are some distinctions between SHE’s EVM and Ethereum itself.

EVM Differences

Unlike Ethereum mainnet which is on Cancun for its execution layer, SHE uses the Shanghai version of EVM. This means that features like blob transactions are not supported on SHE.

Opcode Differences

PREVRANDAO

Since SHE doesn’t rely on the same pseudo-randomness way of determining the next validator like Proof of Stake (PoS) Ethereum does, it doesn’t really have the RANDOM artifact that can be set as PREVRANDO’s return value. In SHE PREVRANDAO is set to return the hash of the current block time. For strong randomness guarantee needs in contracts logic, it’s advised to use external verifiable oracles (as is advised on Ethereum itself).

COINBASE

Coinbase address on SHE is always set to (the EVM address of) the global fee collector.

State Root

Since SHE uses AVL-tree instead of Merkle Patricia Trie (MPT) for data storage, SHE doesn’t have per-account state root. The global state root is the AVL-tree root which is also not equivalent to Ethereum’s overall state root (which is a MPT root)

Block Hash

The block hash on SHE is computed based on the block header in Tendermint data format, and is different from Ethereum’s block Hash as a result.

Base Fee & Tips

SHE supports all transaction types. However for a legacy (non EIP1559) type transaction, you must specify a base fee of 1gwei. In addition to this, excess “gas wanted/gas limit” beyond the actual “gas used” may not be refunded in full or in part.

Current EIP1559 parameters can be fetched from the shed SDK tool:

shed q params subspace evm KeyTargetGasUsedPerBlock
 
key: KeyTargetGasUsedPerBlock
subspace: evm
value: '"850000"'
root@ip-172-31-4-247:/home/ubuntu# shed q params subspace evm KeyMaxDynamicBaseFeeUpwardAdjustment
key: KeyMaxDynamicBaseFeeUpwardAdjustment
subspace: evm
value: '"0.007500000000000000"'

Block Limit

SHE has a gas limit of 10M on pacific-1, compared to Ethereum’s 30M.

In addition, SHE also has a byte size limit of 21MB, whereas Ethereum doesn’t have byte-denominated limits.

Non-EVM Transactions

On SHE there exists non-EVM transactions which may update states accessible by EVM transactions. The simplest example would be bank balances, which may be updated by both native Cosmos bank send transactions and EVM send transactions. As a result, if certain offchain applications only parse EVM transactions, they may find certain state changes unattributable to any EVM transaction.

Finality

SHE has instant finality, meaning that commitment levels of “safe”, “latest”, “justified”, and “finalized” on Ethereum are all the same thing on SHE.

Pending State

On Ethereum the block proposer would execute its proposed block first (and update its local state) before broadcasting the proposal to others (the updated state would be marked “pending” until the node is accepted by other nodes).

However, on SHE, the block proposer would broadcast first and only execute the proposal if it’s accepted (i.e. every node would execute the block at roughly the same time), so SHE does not really have a window when “pending state” exists.