What can be the simplest, quick way to perfrom queries on the Public Content API 9.1 from local machine. Can we do it without installing any tool, exe on local machine. If not what are the different s/w tools that can be used. We know GraphiQL is mentioned in sdl online documentation, any other names. The pain point is the process, for any new s/w to get it approved in the business approved s/w database.
GraphiQL comes "out of the box" with Tridion. If you can locate your api endpoint, just add /graphiql and you should find that it works. So for example, on my local test setup, the API is at http://cd.local:8081/cd/api and graphiql is at http://cd.local:8081/cd/api/graphiql
You can use GraphiQL straight from the browser but you'll need to arrange for OAuth headers to be present. The documentation suggests using the Requestly browser plugin, but I found this irritating. My preferred technique is now to use Fiddler, as described here
I don't know how easy it is in your environment to get Fiddler installed, or for that matter browser plugins like Requestly. If you want a pure, native-Windows technique, then you might want to do it from Powershell. There is sample code for how to do this available on Tridion Practice. In my view this serves different use cases than GraphiQL, so its handy to have both in your toolbox.