> ## Documentation Index
> Fetch the complete documentation index at: https://docs.snek.fun/llms.txt
> Use this file to discover all available pages before exploring further.

# UTxO input modes

> How to use "splash-wallet" and string[] in Transaction Builder requests

# UTxO input modes

Many Transaction Builder endpoints accept a `utxos` field with this shape:

```ts theme={null}
"splash-wallet" | string[]
```

## `"splash-wallet"`

Use `"splash-wallet"` when the request is running in a Turbo Wallet session and you want the builder to resolve the wallet's current unspent outputs for you.

The builder derives the payment key hash from `changeAddress` and fetches unspent UTxOs from the UTXO Monitor automatically.

Use this mode when:

* you are building inside the Snekfun app flow
* the user is connected with Turbo Wallet
* you do not want to gather and serialize UTxOs on the client

## `string[]`

Use `string[]` when you already have the exact UTxOs you want the builder to use and want to send them explicitly.

Each array item is a serialized UTxO string. In this mode, the builder uses the provided UTxOs as-is instead of resolving them from the wallet.

Use this mode when:

* you are integrating an external wallet flow
* you want explicit control over the inputs used for transaction building
* you are not relying on the builder to fetch wallet state

## Difference

The difference is who provides the UTxOs:

* `"splash-wallet"` means the builder fetches them for you from the wallet identified by `changeAddress`
* `string[]` means your client provides them directly

<Note>
  `collaterals`, when supported by an endpoint, is an optional field separate from `utxos`. It contains only collateral inputs, not the main spendable inputs.
</Note>