ActivityPub or AT Protocol?
We are forging ahead with a dual path strategy.
ActivityPub is an open, decentralized social networking protocol standardized by the World Wide Web Consortium (W3C). It enables interoperable communication between platforms, allowing different servers and applications to share content, messages, and activities seamlessly—without a central authority.
We are considering the AT Protocol (AT – authenticated transfer used by Bluesky) as a potential complement or alternative to ActivityPub—but with careful analysis of trade-offs.
🌐 What is ActivityPub?
ActivityPub is a protocol that lets different software applications exchange “activities” such as:
- Creating a post
- Commenting
- Liking
- Following someone
It enables a federated network (commonly called the Fediverse) where users can interact across different platforms as if they were on the same service.
🧩 Key Features
Feature | Description |
---|---|
Federated | Platforms can run independently and still communicate with each other. |
Interoperable | Connects diverse platforms like Mastodon, PeerTube, and others using a common language. |
Push-based | Supports real-time updates—followers receive content automatically. |
Extensible | Built on JSON-LD and ActivityStreams 2.0, it can be customized for different use cases. |
🔄 How It Works
- Actors: People, bots, groups—each is an “Actor” with an inbox and outbox.
- Activities: JSON-based messages (e.g., Create, Follow, Like, Announce).
- Federation: Servers exchange these messages, allowing cross-platform interaction.
For example:
A user on Mastodon (Twitter-like app) can follow and interact with someone on PeerTube (YouTube-like app)—because both speak ActivityPub.
🛠️ Example Activities
{
"@context": "https://www.w3.org/ns/activitystreams",
"type": "Follow",
"actor": "https://example.com/users/alice",
"object": "https://social.net/users/bob"
}
🤝 Why It Matters for CommunityAgents.AI
- Interoperability: Agents and community platforms can talk to each other across organizational boundaries.
- Decentralized Governance: Supports communication between autonomous communities without platform lock-in.
- Content Sharing: Community updates, event notices, or resource postings can be shared across tools built by different groups.
🔍 Overview: AT Protocol vs. ActivityPub
Feature | AT Protocol (Authenticated Transfer Protocol) | ActivityPub |
---|---|---|
Standards Body | Independently developed (Bluesky PBLLC) | W3C Standard |
Protocol Focus | Identity portability + composable data layers | Federated social networking |
Interoperability | In development; limited federation | Mature and widely adopted |
Data Model | Lexicons (schemas) + repositories (data DAGs) | JSON-LD + ActivityStreams 2.0 |
Account Portability | Built-in decentralized identity (DID-based) | Possible, but not native |
Governance & Extensibility | Modular and protocol-level governance | Message-centric, extensibility via vocab |
Real-world Adoption | Bluesky and its clients | Mastodon, PeerTube, Pixelfed, Friendica, etc. |
Open Source Status | Open spec, some key components still evolving | Fully open and implemented widely |
🧠 Strategic Fit for CommunityAgents.AI
✅ Reasons to Consider
AT Protocol
- Strong alignment with DIDs: Already based on decentralized identifiers, which you’re planning to use.
- Account & identity portability: Excellent fit if you envision agent or human identities being mobile across deployments.
- Composable architecture: Offers a modular framework ideal for building vertical agents that operate in evolving contexts.
- Future-proofing: Could become a major player in decentralized communication, especially with VC interest and developer adoption in Bluesky.
✅ Reasons to Stick with ActivityPub (or use both):
- Mature and widely adopted: ActivityPub is the standard of the Fediverse, already used by millions of users and dozens of platforms.
- Tooling and Libraries: More mature, more integrations, more stability right now.
- W3C-backed: Trusted and standardized, with more interoperability guarantees.
- Public Service Focus: Its architecture and philosophy align with nonprofit, public-interest work—like Community Internet and Commons-based Peer Production (CBPP).
🧭 Our Recommendations
CommunityAgents.AI is considering a dual-path strategy:
- Primary integration with ActivityPub in the near term to benefit from an existing network, tools, and standards.
- Monitor and experiment with AT Protocol via modular, opt-in identity or data-sharing layers—especially where account portability and DID-native use cases are required.
This approach allows us to:
- Participate in the present (ActivityPub/Fediverse)
- Prepare for the future (AT Protocol’s identity portability and modular data stack)