ActivityPub MCP

ActivityPub MCP gives Claude direct access to the Fediverse through the ActivityPub protocol. It handles WebFinger discovery, fetches public timelines, and works across Mastodon, Pleroma, and Misskey instances. No API keys, no OAuth dance, just point it at a server and start reading. I'd reach for this when I'm researching how a conversation spreads across federated instances or when I want Claude to summarise what's happening on a specific Mastodon server without opening a browser. The WebFinger lookup is particularly handy for turning @[email protected] into a proper ActivityPub actor ID, which then lets you pull their public posts. One workflow I've used: ask Claude to fetch the timeline from a niche instance, summarise the top topics, then cross-reference with another instance to see how communities differ. The tool is read-only, which is both a strength and a limitation. You can't post, boost, or reply, so this isn't for building bots that interact. It's for observation and analysis. The lack of authentication means you're limited to public data, but that's usually enough for research or content discovery. Performance depends entirely on the target instance's responsiveness, and some smaller servers can be slow or flaky. Quirks: error messages can be cryptic if an instance doesn't fully implement ActivityPub, and there's no rate limiting built in, so you'll need to be thoughtful about how many requests you fire off. The documentation is light but the codebase is small enough to read if you need to understand what's happening under the hood. Skip this if you're after a full-featured Mastodon client or need write access. It's for developers who want to integrate Fediverse data into workflows, not for casual browsing. If you're building tools that analyse federated social networks or need Claude to pull context from Mastodon without leaving the conversation, this does the job cleanly.