What exactly leaves Base as ETH?
ETH is listed as the native representation on Base; ETH is used for network gas. A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger. Native ETH can fund both transfer value and gas on its selected network. If the source is WETH or another tokenized form, approval and unwrap or exchange logic differ.
What exactly arrives on Optimism as OP?
OP is a contract representation on Optimism at 0x4200000000000000000000000000000000000042. ETH, not OP, pays gas unless both symbols are the same. An OP Mainnet receipt belongs to the OP Stack L2 and needs ETH on that network for later activity; it is not an Ethereum L1 balance. OP receipt is a governance-token balance, not destination gas. Verify the destination contract and keep ETH available for OP Mainnet activity.
Why does the ETH to OP direction matter?
Native ETH can fund both transfer value and gas on its selected network. If the source is WETH or another tokenized form, approval and unwrap or exchange logic differ. On receipt, OP receipt is a governance-token balance, not destination gas. Verify the destination contract and keep ETH available for OP Mainnet activity.
What changes between the source and destination asset roles?
ETH is the deposited native-asset input; OP is the quoted token output. Source allowance or native-spend rules and destination wallet/representation checks are evaluated separately.
What should be matched before sending ETH?
Native ETH can fund both transfer value and gas on its selected network. If the source is WETH or another tokenized form, approval and unwrap or exchange logic differ. A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger. An OP Mainnet receipt belongs to the OP Stack L2 and needs ETH on that network for later activity; it is not an Ethereum L1 balance. OP receipt is a governance-token balance, not destination gas. Verify the destination contract and keep ETH available for OP Mainnet activity.
What funds the Base source transaction?
ETH is the native gas asset for Base. A Base source transaction is sequenced on the OP Stack rollup and later settles to Ethereum; Base ETH and Base token approvals remain on the L2 ledger. ETH is recorded as native on this source.
What is the most dangerous wrong-network mistake here?
Sending ETH on a network other than Base, or using an address that is not valid for Optimism, can prevent detection or delivery. Match both network labels and representations to the active route.
Can I swap ETH on Base to OP on OP Mainnet without KYC?
Requirements are checked for the live ETH Base to OP OP Mainnet quote. Verification requirements can depend on the provider, amount, jurisdiction, and current route. Sasquatch does not verify this route as universally no-KYC; check the live flow before continuing.