The Complete Guide to ActivityPub Development in 2025
· 6 min read
ActivityPub has become the backbone of the decentralized social web. With over 13 million users across Mastodon, Lemmy, PeerTube, Pixelfed, and dozens of other platforms, understanding ActivityPub is essential for developers building the next generation of social applications.
This guide provides everything you need to start building with ActivityPub — from core concepts to production deployment.