In our saved endpoint case, we can also add pre/post operations to prepare data or test this endpoint.
Switch to **Post processors**.
Hover over **Add PostProcessor**, select **Assertion**.
In this case, I want to assert that if the response "id" is a positive integer.
So fill in the Assertion form:
**Name**: "id" is a positive integer
**Target Object**: Response JSON
**JSONPath expression**: `$.category.id`
**Assertion**: Greater than 0
</Step>
Click **Send**, and you will see the Assertion result in the bottom right corner.
Click "Save" to save the endpoint case.
:::tip[]
In Apidog, you can visually add assertions, extract variables, perform database operations, and more. Learn more about pre and post processors.
:::
:::tip[]
You can also write assertions or implement other operations using scripts by simply adding a "Custom script". Apidog is compatible with Postman scripts, which can run in Apidog without modification. Learn more about Scripts.
:::
Apidog Docs
