txData = 0x quote for held token → vault asset, taker = strategy address.txData = 0x quote for intermediate token → vault asset.minIntermediateOut = quote's sellAmount.sellToken, buyToken, sellAmount, and taker = strategy contract address. The API returns encoded calldata to pass directly as txData. Quotes are time-sensitive — fetch and submit in the same session. The strategy approves the 0x AllowanceHolder internally. The Alchemix Admin UI should be used to construct txData when available.