WETH input identity and handling
WETH is classified as a wrapped asset for this route. WETH uses a wrapped contract asset on Optimism. The recorded Optimism representation uses 18 decimal places. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer.
Optimism to zkSync Era L2 handoff
This route crosses two L2 execution environments. Optimism settles to ethereum, while zkSync Era settles to ethereum; each side keeps its own gas balance, token contracts, transaction hash, and settlement progress.
WETH unwrap or exchange input check
WETH is a contract wrapper for ETH. It can be transferred as a token but cannot replace the native gas balance required by the network. On this route WETH is the source token on Optimism. Its token balance, approvals, and contract transfer behavior are separate from the native coin used for network gas.
zkSync Era destination execution
zkSync Era is a L2 EVM network in the Ethereum ecosystem. ETH pays destination-side network gas on zkSync Era. EVM 0x account address A zkSync Era receipt belongs to EraVM account state and uses ETH for later fees; proof settlement to Ethereum remains distinct from L2 delivery.
WBTC output identity and receiving
Wrapped Bitcoin is classified as a wrapped asset for this route. WBTC uses a wrapped contract asset on zkSync Era. The recorded zkSync Era representation uses 8 decimal places. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path.
Optimism source execution
Optimism is a L2 EVM network in the Ethereum ecosystem. ETH pays source-side network gas on Optimism. EVM 0x account address An OP Mainnet source uses sequenced OP Stack execution and ETH gas; ordinary route processing is not the same as the canonical L2 withdrawal delay.
EVM-to-EVM execution boundary
Optimism and zkSync Era can use the same 0x address syntax, but they are separate networks with different chain identifiers, gas balances, token contracts, and transaction histories. The recorded settlement context includes ethereum, so L1 and L2 confirmation behavior should not be assumed identical.
Mistakes specific to WETH Optimism to WBTC zkSync Era
Route-specific mistakes include sending on a network other than Optimism; using a destination that is not valid for zkSync Era; running out of ETH before the source transaction is submitted; treating a wrapped token as the native gas asset. An OP Mainnet source uses sequenced OP Stack execution and ETH gas; ordinary route processing is not the same as the canonical L2 withdrawal delay. WETH leaves through a wrapper contract and needs native chain gas. A WETH token balance cannot pay the gas required to submit its own transfer. A zkSync Era receipt belongs to EraVM account state and uses ETH for later fees; proof settlement to Ethereum remains distinct from L2 delivery. WBTC arrives as a wrapper-contract token and must not be sent onward to a native Bitcoin address without an explicit unwrap or bridge path.