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Swap the Universal Router Balance (swapSource "UR")

Posted: September 28, 2026

The /quote and /swap endpoints now accept a new optional swapSource field which can be used to generate calldata that swaps the Universal Router's entire balance of the input token instead of pulling funds from a wallet. This enables bridge-and-swap in one atomic transaction.

What is changing?

swapSource is optional. Leaving it unset (or setting "WALLET") keeps the existing wallet-funded behavior. Setting "UR" returns calldata meant to be executed on the destination chain of a bridge, against the tokens the bridge deposited into the Universal Router, with no destination-chain signature or approval from the user.

Why is this changing?

Bridge providers asked for a way to swap on arrival without a second user transaction on the destination chain.

What do I need to do?

To use the feature, set swapSource: "UR" on your /quote or /swap request and follow the Universal Router balance swaps section of the integration guide. We highly recommend reading the guide before using this feature to avoid loss of funds.