## businessRule() function [​](/content/docs/sdk/core.businessrule#businessrule-function "Direct link to businessRule(/index.html) function")

**Signature:**

```typescript
export declare function businessRule(key: string, message: string): OperationOutcome;
```

## Parameters [​](/content/docs/sdk/core.businessrule#parameters "Direct link to Parameters"/index.html)

| Parameter | Type | Description |
| --- | --- | --- |
| key | string |  |
| message | string |  |

**Returns:**

OperationOutcome

- [businessRule() function](/content/docs/sdk/core.businessrule#businessrule-function/index.html)
- [Parameters](/content/docs/sdk/core.businessrule#parameters/index.html)