I built an all-in-one Social Media Toolkit API — 8 tools in one endpoint set

TL;DR: I bundled 8 commonly-needed social media utilities into a single API — username availability, hashtag generation, engagement rate, best time to post, competitor analysis, bio generation, profile validation and link shortening. It's live on RapidAPI with a free tier. Here's how I built it and how you can use it.

The problem

Every time I worked on a social-media-related side project, I needed the same small utilities:

Is this username taken on Instagram / GitHub / TikTok?

What hashtags should I suggest for this topic?