> For the complete documentation index, see [llms.txt](https://ion-finance.gitbook.io/ion-finance/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ion-finance.gitbook.io/ion-finance/developer/messages/exchange.md).

# Exchange

<figure><img src="https://4024631951-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FdmYjEWNzJL1PXSRz7hgr%2Fuploads%2FAJizFqx09ZRC3Vl3MFil%2Fexchange.png?alt=media&amp;token=9fba7e15-76a5-4f43-9a20-b2d06e26ad80" alt=""><figcaption></figcaption></figure>

Alice wants to swap WTON for USDT in the USDT/WTON pool. Alice sends USDT to the Router, and in return, the Router sends WTON to Alice.

1. Alice's Wallet sends a transfer message to Alice's USDT Wallet.
   1. The Router is the recipient, and the message contains swap details such as the pool used and minimum amount.
2. An `internal_transfer` message is sent from Alice's USDT Wallet to the Router's USDT Wallet.
3. A `transfer_notification` message is sent from the Router's USDT Wallet to the Router.
4. An `exchange` message is sent from the Router to the Pool.
5. The Pool contract sends a `pay_to` message to the Router.
   1. This message includes the type and amount of coins that should be sent to Alice.
   2. If Alice's WTON amount is less than the minimum, a message is generated to send USDT back to her.
6. The Router contract sends a `transfer` message to the Router's WTON Wallet.
7. A `transfer` message is sent from the Router's Wallet to Alice's Wallet.
   1. Alice receives WTON.