# FundingRequirement.assert

Validates a funding requirement's signed fields.

## Imports

:::code-group
```ts [Named]
import { FundingRequirement } from 'ox/tempo'
```

```ts [Entrypoint]
import * as FundingRequirement from 'ox/tempo/FundingRequirement'
```
:::

## Examples

```ts
import { FundingRequirement } from 'ox/tempo'

const token =
  '0x20c0000000000000000000000000000000000001' as const
FundingRequirement.assert({
  token,
  amount: 50n,
  sources: []
})
```

## Definition

```ts
function assert(
  value: FundingRequirement,
): void
```

**Source:** [src/tempo/FundingRequirement.ts](https://github.com/wevm/ox/blob/main/src/tempo/FundingRequirement.ts#L57)

## Parameters

### value

* **Type:** `FundingRequirement`

#### value.amount

* **Type:** `bigintType`

Target balance, including existing funds, in token base units.

#### value.policyRules

* **Type:** `0x${string}`
* **Optional**

Canonical policy rules for access key funding. Owners omit this field.

#### value.slippageBps

* **Type:** `numberType`
* **Optional**

Aggregate slippage in basis points. Omission uses the protocol default.

#### value.sources

* **Type:** `readonly Source[]`

Sources attempted in order.

#### value.token

* **Type:** `abitype_Address`

Requested output token.

## Return Type

`void`