WETH input identity and handling
WETH is classified as a wrapped asset for this route. WETH uses a wrapped contract asset on Base. The recorded Base 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.
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.
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 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.
WBTC output identity and receiving
Wrapped Bitcoin is classified as a wrapped asset for this route. WBTC uses a wrapped contract asset on Polygon. The recorded Polygon 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.
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 WETH Base to WBTC 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. 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 Polygon PoS receipt follows Polygon token contracts and checkpointed execution; later movement uses POL gas rather than Ethereum L1 gas. 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.