I am writing software which accesses a third-party library. Their API requires a key which is tied to my application. I do not want to put the key in application's code, because I do not want others to have access to it. So I want to put it on a server. The application talks to the server, which has the key, and the server talks to the third-party library.
I do not want to have to write this server. This seems like a common thing. Are there any existing products that server this purpose? What is a tool that I can tell my API key ahead of time, and then it will approve any of my API requests given a less-secret key?
I was thinking AWS may have a product like this, but I could not find the one I am looking for. AWS Gateway seemed promising, but that looks like it was more about building APIs than accessing them.
Some background: It is about an app that runs on the client, which runs on cross-platform mobile. It currently polls the third-party API directly, and includes the application-wide secret key on the client. So anyone can steal the key for my entire application. So as I understand, I need a server between the client and the third-party. I just did not want to have to build that server myself for something so simple. I was guessing that AWS had something that suits my need, but I do not know which it would be among their massive list of products.