Question 1

How do you build a Chrome extension that recommends your YouTube videos?

Accepted Answer

I kept it simple: you basically need an index.html for the popup UI and a manifest file for the extension settings. Then you load the folder via chrome://extensions as an unpacked extension. From there, I add the logic that fetches videos and injects an overlay into the YouTube player near the end of playback.

Question 2

Which YouTube API did you use to fetch channel videos and current video details?

Accepted Answer

I used the YouTube Data API v3. One endpoint fetches videos from my channel using my channel ID (I grab 20, then randomly select 6), and another endpoint fetches details about the currently watched video (title/description/keywords). That data becomes the input for the Gemini prompt.

Question 3

How do you enable YouTube Data API v3 and get an API key?

Accepted Answer

You go into Google Cloud Console, open “APIs & Services,” then “Enable APIs and services,” and enable YouTube Data API v3. After that, in “Credentials,” you create an API key. Once you’ve got that, you’re ready to call the endpoints from your extension.

Question 4

How did you use Google Gemini to generate a call to action for recommendations?

Accepted Answer

I used the Gemini API with the Gemini Pro model (text in, text out). I prompt it with the current video’s title and ask for a one-line CTA that creatively combines that video’s genre with web development and fun programming. I also nudge the structure with something like “you watched this video because… so you’ll want to watch these videos because…” and let Gemini connect the dots.

Question 5

What model did you use in Gemini for this project?

Accepted Answer

For this build I used Gemini Pro because I only needed text input and text output. There are other models like Gemini Pro Vision, but that’s a different use case. Here the whole point was: analyze the title and spit out a punchy one-liner.

Question 6

How do you inject an overlay into the YouTube video player from an extension?

Accepted Answer

The final step is basically an HTML injection into the YouTube player so the CTA and recommended videos actually show up on top of the video. I coded the UI in JavaScript (yes, styling via JS declarations is pain), but it works. Then I trigger it at the crucial ending moments of a video so it feels like a natural next click.

Question 7

Is it safe to put API keys in a Chrome extension?

Accepted Answer

You should never hardcode keys directly in your code—especially not in something users can inspect. In the video I literally call it out: use environment variables and don’t expose secrets. If you’re shipping an extension publicly, you need a proper backend/proxy strategy or restricted keys, otherwise you’re asking for trouble.

I used AI to recommend my YouTube videos to people ft. Google Gemini

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