Smoke Signal Blog

Introducing Acudo: Bridging ATProtocol and Event Ticketing with Signed RSVPs

Published by @smokesignal.events on 2025-08-20 20:00 UTC.

We're excited to announce the first release candidate of Acudo, a specialized ATProtocol application that brings cryptographically signed RSVPs and badge awards to your ticketed events. By integrating with Ti.to's ticketing infrastructure, Acudo creates a trust layer for event attendance that lives on the decentralized AT Protocol network.

What is Acudo?

Think of Acudo as a single-purpose tool in the ATProtocol event ecosystem. While Smoke Signal handles event discovery and management across the network, Acudo focuses on one thing really well: creating verifiable attendance records for individual events.

Each Acudo instance serves as a microsite for a single conference, workshop, or gathering. When attendees purchase tickets through Ti.to, Acudo automatically generates signed RSVPs and awards badges based on configurable rules. It's the missing link between traditional ticketing systems and the decentralized social web.

The Technical Stack

Acudo builds on several foundational technologies from the ATProtocol ecosystem:

This combination allows event organizers to spin up instances quickly while retaining everything that makes ATProtocol special.

Use Cases: From Simple to Advanced

The Simple Case

At its core, Acudo does one thing: when someone has a valid ticket, it signs an RSVP that attests to their legitimate registration for the event. This creates a verifiable chain of trust from ticket purchase to event attendance. It sounds simple, but this is essential to trust in a truly decentralized event ecosystem.

Advanced Scenarios

But that's just the beginning. With datalogic-rs powering the rules engine, you can:

How It Works

  1. Event Setup: Configure your Acudo instance with your event details and Ti.to integration
  2. Ticket Purchase: Attendees buy tickets through your existing Ti.to flow
  3. Webhook Magic: Ti.to webhooks notify Acudo of ticket assignments in real-time
  4. Rule Processing: The datalogic-rs engine evaluates your configured rules
  5. Record Creation: Signed RSVPs and badges are created on the ATProtocol network
  6. Verification: Anyone can verify the authenticity of RSVPs and badges through the protocol

Understanding Signed RSVPs

What makes Acudo's RSVPs special? They're cryptographically signed following the ATProtocol Attestation and Signatures Lexicon proposal currently being discussed over at Lexicon Community. This isn't just a database entry saying someone RSVP'd - it's a verifiable attestation from the event organizer or recognized issuer.

Here's what a live signed RSVP looks like (you can explore this record in the ATProto browser):

{
    "$type": "community.lexicon.calendar.rsvp",
    "createdAt": "2025-08-20T20:50:14.152Z",
    "signatures": [
        {
            "$type": "community.lexicon.attestation.signature",
            "issuedAt": "2025-08-20T20:50:14.152Z",
            "issuer": "did:web:oauth-masterclass.atproto.camp",
            "signature": {
                "$bytes": "+0fdzowikSCT1QK9rYnG/9NH/nV2pBU7deuyjCZ8oJzl+3rcC1SWLCXSgpTvGyRQ9g+4+OLlptOSicEfAyru7g"
            }
        }
    ],
    "status": "community.lexicon.calendar.rsvp#going",
    "subject": {
        "cid": "bafyreiad2w4nabfqf6hs2vjsju64qhjjtr7yyfqig6szkij2cyfnuzkoi4",
        "uri": "at://did:plc:cbkjy5n7bk3ax2wplmtjofq2/community.lexicon.calendar.event/3luzkrwivzm2a"
    }
}

The key here is the signatures array. The event organizer's DID (did:web:oauth-masterclass.atproto.camp) cryptographically signs the RSVP, creating an immutable attestation that this person has a valid ticket. This signature can be verified by anyone, anywhere, without needing to trust a centralized database. It's the difference between "the database says you're registered" and "here's mathematical proof you're registered."

See It in Action

We're already dogfooding Acudo for the ATProtocol OAuth Masterclass. Check it out to see how seamlessly it integrates with the ticketing flow while adding that extra layer of verifiable attendance.

What's Next?

This is just the first release candidate, and we've got an ambitious roadmap ahead:

We recently published a guide to creating did:web identities as a foundational piece for this ecosystem. If you're planning to run an Acudo instance, that's essential reading.

Get Involved

Acudo represents another step toward a more open, verifiable, and interconnected event ecosystem built on ATProtocol. Whether you're running a small workshop or a major conference, Acudo can add that cryptographic layer of trust to your attendance records.

Want to try it for your next event? Check out the source code and keep an eye out for our upcoming deployment guide. Have questions or ideas? We'd love to hear from you in the Smoke Signal Discourse.

Open Source and Credible Exit

Acudo is open source under the MIT license, joining our family of open source libraries and event platform applications. This isn't just about transparency - it's about our commitment to the principle of "credible exit."

With Smoke Signal, we believe you should truly own and operate your events and communities. You don't have to use Smoke Signal's infrastructure to benefit from these tools. With Acudo and our other open source projects, you can operate events at any scale, on your own terms, with your own infrastructure. If you ever want to leave, you can take the code with you. That's not a bug - it's the entire point.

This commitment to credible exit ensures that the event ecosystem we're building together remains genuinely decentralized and resistant to platform lock-in. Your events, your data, your choice.

Let's build the future of verifiable event attendance together! 🎫🔐

Acudo is part of the growing ecosystem of ATProtocol applications being developed by the Smoke Signal team. Follow our journey @smokesignal.events as we build tools for decentralized event management and community building.

This post has had 1 interaction.