# UpDownCounter

`import { UpDownCounter } from "destack:telemetry";`

Non-monotonic metric counter.

```ds title="UpDownCounter"
export class UpDownCounter {
    name: string;
    unit: string | undefined;
    constructor(name: string, unit?: string | undefined, sink?: readonly MetricSink | undefined);
    add(value: float64, fields?: Fields | undefined): void;
}
```

[language/library/src/telemetry/metric.ds:46:75](https://github.com/destack-sh/destack/blob/main/language/library/src/telemetry/metric.ds#L46-L75)

## Members

### `name: string`

Counter name.

### `unit: string | undefined`

Counter unit.

### `constructor(name: string, unit?: string | undefined, sink?: readonly MetricSink | undefined)`

Create an up-down counter.

### `add(value: float64, fields?: Fields | undefined): void`

Add to this counter.