How cross-chain swaps work

Blockchains do not talk to each other. A token on Arbitrum is an entry in Arbitrum's state; nothing on Solana can read it. Moving value between them means someone has to lock or burn it on one side and release or mint it on the other, and every design for doing that is a different answer to the question: who do you trust to do the second half?

Three answers dominate today. They feel similar from the front end but behave very differently when something goes wrong, and they price differently at different sizes.

The oldest design. You deposit into a contract on the source chain; a set of validators or a multisig observes the deposit and mints a wrapped representation on the destination. The wrapped token is an IOU against the locked funds.

Costs: the bridge fee, gas on both sides, and often a swap on the destination to turn the wrapped token into the native one. Risk: the validator set. Most of the largest losses in crypto have been bridge validator compromises, because the locked pool is a single target.

Instead of minting, a liquidity provider on the destination pays you out of a pool it already holds there, and is repaid later on the source side. You receive the native asset directly; no wrapped token.

Costs: a fee to the liquidity provider that rises when the pool is thin, plus gas. Behaviour under stress: when a pool empties, quotes get worse quickly or the route disappears. The size at which this happens is the useful thing to know, and it changes hour to hour.

You do not send a transaction that performs the swap. You sign a statement of the outcome you want: this much of asset A, at least this much of asset B on that chain, by this deadline. Independent solvers compete to fulfil it and are paid from the spread. If nobody can, the intent expires and your funds never moved.

Costs: the solver's margin, expressed as the gap between what you send and what arrives, plus gas on the source chain only. Behaviour under stress: binary. Solved or failed, never half-done. The limit is solver inventory: on a stablecoin corridor the cost is lowest between roughly $100 and $1,000 and above a few tens of thousands there may be no fill at all.

Each design has a fee that looks small on its own page. A bridge fee of 0.05% plus a destination swap at 0.3% plus two gas payments is a different total from an intent's 0.1% solver fee plus one gas payment, and neither headline tells you which is larger for your size today.

The only comparable number is the amount that lands in your wallet. That is what Everychain ranks on, with each provider's quote requested independently. When a bridge beats an intent at your size, it goes first.