# Custom Source

Custom Source is responsible for validating the state of variables. It is useful in scenarios like validating the database state of your test application.

To use Custom Source Validation, simply set the assertion fields in this way:

  1. Source: In this field, specify Custom Source.
  2. Property: In this field, you may specify any variable or you may invoke any utility methods. Whatever is the value of this field will be treated as actual value.
  3. Operator: In this field, simply select any of the available operators.
  4. Expected Value: In this field, simply provide any value as per your expectations.

In the testcase shown in the above figure, we are creating a new user in our test application and then we are validating the database state whether the newly created user exists in the database or not. Here {{db_result}} variable is calculated by reading the database state.

For more information on you may read/validate the database state, please read our guide on Database Validation.