### **1.** User enters a request to transfer funds on Brine.
User enters a request to transfer funds using Brine.
### **2.** Brine sends a `TransferRequest` transaction to Starkware.
Brine sends out a transfer request transaction to the Starkware gateway, using the `add_transaction` API with the `TransferRequest` transaction type.
The request includes the following information:
| `amount` | The quantized amount of the asset to transfer. |
| ---------------------- | ----------------------------------------------------------------------------------- |
| `sender_public_key` | The sender’s public Stark key. |
| `sender_vault_id` | The sender’s vault id. |
| `receiver_public_key` | The receiver’s public Stark key. |
| `receiver_vault_id` | The receiver’s vault id. |
| `token` | The token to be transferred. |
| `fee_info_user` | The maximum fee that the sender is willing to pay for the transaction. |
| `expiration_timestamp` | The time after which the request is no longer valid, in hours since the Unix epoch. |
| `nonce` | A nonce issued by Brine, to prevent replay attacks. |
| `signature` | The sender’s signature. |
### **3.** Starkware checks the validity of the request.
Starkware checks the following to validate the transfer request:
* The balance in the sender’s vault is sufficient to fulfill the transaction.
* The maximum fee that the party is willing to pay for the transaction is not less than the actual fee.
* The transaction request has not expired.
* According to the orders tree, the order has not already been fulfilled.
### **4.** Starkware includes the transfer in a batch.
If the transfer request is valid, the transfer is included in a batch to be submitted on-chain along with a validity proof.
