Tool Auth Question

[sandorvasas]

I'd like to use a server-side tool in Node.js/Bun, with authentication. The docs are not clear on this.

https://docs.ultravox.ai/essentials/tools#creating-your-first-custom-tool

First the doc says let's create our first tool at call creation.
Later on on how to auth that tool, there's a section showing "let's create your tool" and then "pass that tool with your API key" when you create the call.
Yes, that I guess works with the client-sdk, but how about on the server?

How can I define a server-side tool with my own API endpoint that is protected by an API key?

(temporary tool)

...or.. Do I need to create a durable tool in this case?

Thanks!