Hello - I am trying to figure out the best way to grab JSON data from an http api -- the api requires url query parameters date_from and date_to Would I need to create a custom source connector, or is there another method I am missing?

Yes, you can create a simple connector using the CDK framework. Do you want to incremental sync your data or full refresh everytime?

incremental

So, using the CDK will help you building the connector because helps you implementing the incremental, fallback, error handling etc