Minimum received sets the least you agree to get from a swap. It protects you from a worse exchange rate while your transaction waits to run.
- It is a floor for the tokens delivered, not a promised amount.
- A wider slippage tolerance lowers that floor and accepts more price movement.
- If the swap falls below the floor, it usually fails, but network gas may still be spent.
Minimum received is your swap’s output floor
A swap quote estimates how many tokens you will receive for the tokens you send. Minimum received is the smallest output the swap contract will accept when it runs.
The quote can change between the moment you review it and the moment the transaction runs. Other trades may move the pool price, or your trade may change it as it uses the pool’s available tokens. A pool is a set of tokens held for people to trade.
On Avalanche C-Chain, Blackhole swap is a decentralized exchange for swapping tokens and providing liquidity. If a quote involves AVAX, you may see WAVAX, the token form of AVAX used by apps and pools. Avalanche Builder Hub describes WAVAX as an ERC-20 token; EIP-20 is the standard that defines how such tokens can be transferred and approved for use.
Calculate the floor from the quote
Slippage tolerance is the percentage movement you are willing to accept from the quoted output. The swap uses it to calculate minimum received: quoted output multiplied by one minus the tolerance.
For example, suppose the quote is 10 WAVAX and the tolerance is 1%. The floor is 10 × 0.99, or 9.9 WAVAX. If the trade returns 9.95 WAVAX, it can complete; if it would return 9.8, the contract rejects it.
The quoted output usually reflects the trade’s expected effect on the pool price. That effect is called price impact. Network gas, the fee paid to process a transaction on Avalanche, is separate from the tokens shown as minimum received.
Check the number in the token you will receive, then compare it with the quote. A low floor may signal a loose tolerance; a floor close to the quote leaves less room for price movement and may make the swap fail more often.
A failed swap can still cost gas
If the price moves past your tolerance before the transaction runs, the contract checks the output against the floor and reverts the swap. Revert means the token exchange is undone, though the network may still charge gas for processing the failed attempt.
This is the useful edge case: a failed swap does not necessarily mean the quote was wrong. The quote may have been accurate when shown, but stale by the time the transaction ran. Raising tolerance can make a swap more likely to complete, but it also permits a worse rate.
Before acting, ask yourself: is the minimum acceptable output worth the tokens I’m sending? Blackhole swap can be one way to make an Avalanche C-Chain trade; for the full walkthrough, read how to use Blackhole swap on Avalanche.