What Is HyperEVM?

HyperEVM is the EVM-compatible execution environment within the Hyperliquid layer 1 blockchain. HyperEVM runs as chain ID 999 on mainnet (998 on testnet) and enables general-purpose Solidity smart contracts and DeFi applications alongside Hyperliquid’s native HyperCore trading engine.

HyperEVM is not a separate layer 2 or sidechain — it is an integral part of the Hyperliquid L1, sharing the same validator set and consensus (HyperBFT) as HyperCore. This means HyperEVM inherits the security and finality guarantees of the underlying L1 while providing a familiar EVM environment for developers.

Interaction with HyperCore

Smart contracts on HyperEVM can interact with HyperCore through two mechanisms:

  • Precompiles — read-only system contracts at reserved addresses (e.g., 0x0802 for vault equity) that return HyperCore state. Precompile reads within the same block as a HyperCore Writer action return stale data from the start of the block.

  • HyperCore Writer (CoreWriter) — a system contract at 0x3333...3333 that queues write actions (vault deposits, token transfers, position management) for asynchronous execution on HyperCore. CoreWriter actions are not atomic — an action can succeed on HyperEVM but later fail on HyperCore with no revert propagation.

Dual-block architecture

HyperEVM produces two types of blocks under a unified block number sequence:

  • Small blocks (~2-3M gas limit, every ~1 second) — for normal transactions

  • Large blocks (30M gas limit, every ~1 minute) — for contract deployments and heavy computation

Addresses must opt into the large block mempool via HyperCore’s evmUserModify action to deploy contracts that exceed the small block gas limit.

Asset bridging

USDC can be bridged from HyperEVM to HyperCore spot accounts via the CoreDepositWallet system contract. The bridge is asynchronous — USDC is deducted from the EVM balance immediately, but the HyperCore balance updates in the next block. Smart contract addresses (such as Safe multisigs) must first be activated on HyperCore before bridge deposits will clear.

Vault integration

Lagoon ERC-4626 vaults can be deployed on HyperEVM and connected to HyperCore native vaults through the HyperCore Writer. A guarded Safe multisig executes a two-phase deposit flow: first bridging USDC from EVM to HyperCore spot, then moving it through spot-to-perp and into the target vault. Withdrawals reverse the process in a single multicall.

RPC endpoints

HyperEVM JSON-RPC endpoints can be unreliable. Multiple fallback RPC URLs should be used. HyperEVM extends standard JSON-RPC with custom methods: eth_bigBlockGasPrice, eth_usingBigBlocks, eth_getSystemTxsByBlockHash, and eth_getSystemTxsByBlockNumber.

See also