How to use Youtube api v3 on client computer without API-key?

Question

I am planning to make a browser extension which uses Youtube data API v3. Since the code is public to the user, I am unable to use my API-key in the code. What is the correct way to use API in such a scenario? Also, since the API call will be made from user's browser, is there any other way to fetch data without using API-key at all?

Answer 1

TL;DR

On the API screen of Google Cloud Console, create a new key or edit an existing one to have no restriction. This will enable anyone to use this key to make requests the moment you publish it. There is no way to use the YouTube API without a key (or token respectively, when using OAuth). Your clients are allowed to consume up to 50.000.000 quota units per day, after which your app will essentially break for the rest of the day unless you buy more quota.

However, I have to disagree with the statement that you cannot (or "shouldn't") publish your API key; in certain scenarios, this may very well be desired.

Detailed Explanation

Web application keys used to be organized in two groups: Server keys and browser keys, the former of which where to be kept secret on the server of the web application, while the latter was sent to the client for use in JavaScript. Server keys could be configured to only be accepted from certain IP addresses. That way, even if someone got hold of your key, they wouldn't be able to use it. Browser keys could be restricted to a specified referrer, i.e. the domain (as in DNS) of your web application, so it wouldn't work on other sites beside your own either.

Nowadays, there is no distinction between server and browser keys anymore, they are simply called "API keys". This union makes perfect sense to me, since the only difference between the two types was how they were restricted. With the new API keys, one can still choose how to restrict its usage - or choose to not restrict the key at all.

This is where we get back to your case: It is, of course, possible to publish a key and at the same time not restrict it. Depending on how many users are using your app (and will be using it in the future) and how many are using your key for their own app (which you have no control over), the 50 million quota limit will work out for you or it will not.

An then there's responsibility as well. You are responsible for the queries that are made with your API key. This is probably one of the reasons why YouTube doesn't allow for requests without a valid key: They need to stay in control of their service and, naturally, want to protect it from DOS attacks. If someone does mischief with your key, you are the one who gets punished for it, usually by deactivation of the key.