WBTC input identity and handling
Wrapped Bitcoin is classified as a wrapped asset for this route. WBTC uses a wrapped contract asset on Base. The Base side is contract-tracked rather than a native gas balance. WBTC leaves through a custodial wrapper contract with token approval and source-chain gas; no native Bitcoin UTXO is spent by that transfer.
Leaving Base L2 for Polygon L1
Base inclusion and its ethereum settlement are distinct from final receipt on Polygon. The live route, rather than a generic rollup withdrawal assumption, determines the provider path and timing for this direction.
WBTC unwrap or exchange input check
WBTC is a custodial tokenized Bitcoin representation on smart-contract networks. Its transfers use token contracts and approvals rather than native Bitcoin inputs and outputs. On this route WBTC is the source token on Base. Its token balance, approvals, and contract transfer behavior are separate from the native coin used for network gas.
Polygon destination execution
Polygon is a L1 EVM network in the Polygon ecosystem. POL pays destination-side network gas on Polygon. EVM 0x account address A Polygon PoS receipt follows Polygon token contracts and checkpointed execution; later movement uses POL gas rather than Ethereum L1 gas.
WETH output identity and receiving
WETH is classified as a wrapped asset for this route. WETH uses a wrapped contract asset on Polygon. The recorded Polygon representation uses 18 decimal places. WETH arrives as a token contract balance. It may need an explicit unwrap before becoming native ETH and cannot itself pay transaction gas.
Base source execution
Base is a L2 EVM network in the Ethereum ecosystem. ETH pays source-side network gas on Base. EVM 0x account address 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.
EVM-to-EVM execution boundary
Base and Polygon 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 WBTC Base to WETH Polygon
Route-specific mistakes include sending on a network other than Base; using a destination that is not valid for Polygon; running out of ETH before the source transaction is submitted; treating a wrapped token as the native gas asset. 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. WBTC leaves through a custodial wrapper contract with token approval and source-chain gas; no native Bitcoin UTXO is spent by that transfer. A Polygon PoS receipt follows Polygon token contracts and checkpointed execution; later movement uses POL gas rather than Ethereum L1 gas. WETH arrives as a token contract balance. It may need an explicit unwrap before becoming native ETH and cannot itself pay transaction gas.