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

# Lock the deposit widget to a fixed amount

> Use fixedFromAmount in routes.options to pre-set the Trustware deposit amount so users see a locked USD value and cannot change it at checkout.

For checkout flows where the amount is predetermined (subscription top-ups, fixed-price checkout, one-click refills), set `fixedFromAmount` to lock the widget's amount input to a single USD value.

## The fixedFromAmount option

`fixedFromAmount` lives inside `routes.options` in your `TrustwareConfigOptions`. When it is set, the amount input in the widget becomes read-only and displays the value you provide.

```ts theme={null}
import { type TrustwareConfigOptions } from "@trustware/sdk";

const fixedAmountConfig = {
  ...trustwareConfig,
  routes: {
    ...trustwareConfig.routes,
    options: {
      fixedFromAmount: "25",
    },
  },
} satisfies TrustwareConfigOptions;
```

Pass this config to `TrustwareProvider`:

```tsx theme={null}
<TrustwareProvider config={fixedAmountConfig}>
  <TrustwareWidget />
</TrustwareProvider>
```

## Value format

`fixedFromAmount` accepts a string or a number representing a USD amount:

```ts theme={null}
fixedFromAmount: "25"   // string: "25 USD"
fixedFromAmount: 25     // number: equivalent
```

The value is interpreted as a USD amount. Do not include a currency symbol or unit suffix.

<Note>
  When `fixedFromAmount` is set, the widget amount input is locked. Users can still select their source token, but they cannot modify the deposit amount.
</Note>