Show HN: Community Ninja – Discover and Engage with Communities Using AI Agents (opens in new tab)

Hey everyone! I’m excited to share Community Ninja -- a tool I built to make finding and engaging with online communities way easier. If you’ve ever struggled to keep up with communities on Reddit, Facebook, or X to promote a project or connect with users, this might be for you.

Here’s what it does:

Community Discovery: Scans Reddit, Facebook, and X using agents to find active groups talking about your niche or product. No more manual hunting.

Smart Engagement: AI analyzes conversations and suggests posts or replies that fit the group’s vibe, so you’re not just spamming links.

Multi-Platform Posting: Write a post once, and the AI tweaks it for each platform’s style, letting you share to multiple groups in one go.

I started this project after burning hours trying to promote my tennis app across Facebook groups. It was a mess—too many communities, too little time. Community Ninja now pulls in hundreds of users a week for me with way less effort.

I’d love to hear your thoughts! What’s your biggest pain point with community engagement? Any features you’d want to see? Let me know what you think or if you run into any bugs.