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

Type guard for a valid HL7 acknowledgment code (MSA-1).

**Signature:**

```typescript
export declare function isAckCode(value: string | undefined): value is AckCode;
```

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

| Parameter | Type | Description |
| --- | --- | --- |
| value | string \| undefined | The candidate code (already upper-cased, if applicable). |

**Returns:**

value is [AckCode](/content/docs/sdk/core.ackcode)

True if `value` is one of the recognized `AckCode` values.

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