# Smart Trigger an online Evaluator

{% hint style="info" %}
Note that only evaluators with **input** and **output** variables can be triggered for online evaluation in production
{% endhint %}

### Add Trigger Logic

To automatically evaluate an inference, you can add **Triggers** on the Evaluator detail page.

* Select the evaluator you just created.

<figure><img src="https://2399115798-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FWsdxCCToJ5K2nk2ZZvqc%2Fuploads%2FmWuQuj1O7HVybP6l8bAr%2FScreenshot%202024-09-26%20at%201.35.12%E2%80%AFPM.png?alt=media&#x26;token=8bd14bdc-4a0d-404b-a4cc-d1e2bbc8c207" alt="" width="563"><figcaption></figcaption></figure>

* Navigate to the 'Triggers' section within the evaluator's detail page, and click on '**Add tag**'

<figure><img src="https://2399115798-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FWsdxCCToJ5K2nk2ZZvqc%2Fuploads%2FxZlH7QpIQo50yq1DqAyb%2FScreenshot%202024-09-26%20at%201.36.57%E2%80%AFPM.png?alt=media&#x26;token=6860af0f-a1f1-4ca8-a726-ec4ba4ea1858" alt="" width="375"><figcaption></figcaption></figure>

### Implement Trigger in Inference Stream

* Ensure that the tags specified in the evaluators' triggers are included when you stream your inference data.
* Follow the full [API documentation](https://app.ownlayer.com/docs#tag/inferences) for detailed instructions on how to implement triggers in your inference stream.