Swap Calldata in the Quote Response

/quote responses can now include the ready-to-send swap transaction, so you can skip the second /swap call when no permit signature needs to be embedded in the calldata.

What is changing?

Eligible CLASSIC quotes carry two new response fields: swapTransaction, the same transaction /swap would return built with the default deadline and safetyMode, and swapGasFee. They are included whenever no permit signature has to be embedded in the calldata, which is the case when the request used x-permit2-disabled: true, the swapper already holds a valid permit (permitData is null), or the permit was requested as a transaction (generatePermitAsTransaction: true). They are left out when txFailureReasons is populated, in which case /swap still builds the calldata for you. /swap itself is unchanged.

Why is this changing?

Integrators comparing quotes across aggregators need the executable transaction at quote time. Returning it in /quote removes a full round trip and matches the single-call shape most aggregator APIs use.

What do I need to do?

No change is required, as these fields are added for optional use. If you want the single-call flow, read swapTransaction from the /quote response when present, and fall back to /swap when it is absent or when you need a custom deadline or safety mode. See the /quote reference.