WETH input identity and handling
WETH is classified as a wrapped asset for this route. WETH uses a wrapped contract asset on Arbitrum. The recorded Arbitrum 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.
Arbitrum to Scroll L2 handoff
This route crosses two L2 execution environments. Arbitrum settles to ethereum, while Scroll 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 Arbitrum. Its token balance, approvals, and contract transfer behavior are separate from the native coin used for network gas.
Scroll destination execution
Scroll is a L2 EVM network in the Ethereum ecosystem. ETH pays destination-side network gas on Scroll. EVM 0x account address A Scroll receipt is an L2 native or contract balance whose proof settlement to Ethereum is a separate milestone; later activity uses ETH on Scroll.
WBTC output identity and receiving
Wrapped Bitcoin is classified as a wrapped asset for this route. WBTC uses a wrapped contract asset on Scroll. The recorded Scroll 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.
Arbitrum source execution
Arbitrum is a L2 EVM network in the Ethereum ecosystem. ETH pays source-side network gas on Arbitrum. EVM 0x account address On an Arbitrum source, the Nitro sequencer records L2 execution before Ethereum settlement completes; ETH funds gas and ERC-20 inputs can need approval.
EVM-to-EVM execution boundary
Arbitrum and Scroll 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 Arbitrum to WBTC Scroll
Route-specific mistakes include sending on a network other than Arbitrum; using a destination that is not valid for Scroll; running out of ETH before the source transaction is submitted; treating a wrapped token as the native gas asset. On an Arbitrum source, the Nitro sequencer records L2 execution before Ethereum settlement completes; ETH funds gas and ERC-20 inputs can need approval. 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 Scroll receipt is an L2 native or contract balance whose proof settlement to Ethereum is a separate milestone; later activity uses ETH on Scroll. 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.