Set Cross-Chain Slippage Per Swap Leg

Integrators should set cross-chain swap slippage for each on-chain swap step, then show users the minimum output those limits protect. Slippage tolerance is the amount a swap may fall below its quote before it fails. A cross-chain route can include a bridge and one or more swaps, and those steps do not always share one limit.

That distinction matters when a route crosses chains. Uniswap’s Chained Actions documentation says its slippage tolerance applies to each AMM swap step, not to the bridge or the whole route. For a route with two swaps, a 0.5% limit on each does not promise an end-to-end result within 0.5%. The manta bridge guide offers more detail on a bridge flow and what users receive.

What does slippage tolerance protect?

It sets a floor for what a swap may deliver. If a quote expects 100 tokens and the tolerance is 1%, the swap’s minimum output is 99 tokens. If the market moves past that floor before the transaction runs, the swap can revert instead of accepting a worse price.

That floor covers price movement and available liquidity during the swap. It does not guarantee that the full cross-chain route will deliver a particular amount. A bridge may quote its own fee, rate, or delivery amount. Those terms need to be shown separately from the swap’s minimum output.

How should integrators choose a limit?

Use the narrowest tolerance that lets the quoted swap execute reliably. A wide limit can reduce failed transactions, but it also lets a swap complete at a worse price. A very tight limit protects the quoted amount more closely, but ordinary market movement can make the transaction fail.

There is no single percentage that fits every route. Base the setting on the swap’s quote, liquidity, market movement, and the time users may wait before signing. If a route has several swaps, assess each leg on its own. Avoid silently widening a limit after a quote: users should see and accept the terms that will govern execution.

• Request a fresh quote close to the time the user signs.
• Show the minimum output for each swap and the bridge’s quoted delivery terms.
• Keep the tolerance used to build the transaction consistent with the quote.
• If execution fails, explain which step failed and request a new quote before retrying.

What should the interface tell users?

Say which parts of the route have a slippage limit and which use separate bridge terms. Uniswap’s developer documentation says its chained plan fixes slippage at quote time and applies it independently to swap steps; the bridge step is quoted separately. That is one provider’s design, so integrators should check how their chosen route handles each step.

The practical rule is simple: treat a cross-chain swap as a sequence of actions, not one trade with one universal slippage setting. Set and explain each swap’s floor, surface the bridge’s quoted delivery, and refresh the route when conditions change.