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Version: 2.0

Sell entire balance

When building applications that involve composable smart contract interactions, such as Collateralized Debt Positions and Portfolio Rebalancing, the precise amount to sell via the Swap API is often determined by the output of a preceding onchain transaction. As a result, the actual amount to swap may be unknown at the time of requesting the quote and generating calldata.

The 0x Swap API supports these kinds of transactions through the sellEntireBalance parameter. It enables developers to provide an estimate of the sell amount for the quote, and then determines the actual amount to sell based on the balance of the taker at the time of execution.

info

Not building with smart contracts? Look at our API Reference instead

How it works​

To enable this feature, set the sellEntireBalance parameter on the API to true . This is supported by both our allowance-holder and permit2 endpoints.

Example:

https://api.0x.org/swap/allowance-holder/quote?chainId=1&sellAmount=0xeeeeeeeeeeee&buyAmount=0x124363&taker=0xabcdef&sellEntireBalance=true

When set to true, the taker's balance during execution is used as the sellAmount. However, you must provide a sellAmount in the request so that we can determine the optimal route for the trade. The sellAmount provided should be the maximum estimated value, as close as possible to the actual taker's balance to ensure the best routing. We recommend that the taker's balance does not deviate by more than 1% from the set sellAmount. Attempting to sell more than the sellAmount may cause the trade to revert.

How using this feature impacts your swap:​

  • Slippage: Since the taker's balance will be lower than the sellAmount, ensure that the slippage tolerance is adjusted for the possible variation.
  • Routing: Routing will be optimized for the provided sellAmount. Ensure to keep the sellAmount as close to the taker balance as possible.
  • Fees: Trade surplus and swap fees will depend on the actual executed sell amount.

We recommend using the sellEntireBalance feature only for minor deviations in the intended sell amount. Larger deviations may lead to inefficient routing, inflated surplus fees, or trade reverts.