Hey folks! We're excited to share a preview of a new API coming in #Fedify 1.6 that should make structuring larger federated apps much cleaner: FederationBuilder.

As your Fedify applications grow, you might encounter circular dependency issues when registering dispatchers and listeners across multiple files. The new FederationBuilder pattern helps solve this by separating the configuration phase from instantiation.

Instead of this:

// federation.ts
import { createFederation } from "@fedify/fedify";

export const federation = createFederation<AppContext>({
  kv: new DbKvStore(), 
  queue: new RedisMessageQueue(),
  // Other options...
});

// Now we need to import this federation instance in other files
// to register dispatchers and listeners...

You can now do this:

// builder.ts
import { createFederationBuilder } from "@fedify/fedify";

export const builder = createFederationBuilder<AppContext>();

// other files can import and configure this builder...

// actors.ts
import { builder } from "./builder.ts";
import { Person } from "@fedify/fedify";

builder.setActorDispatcher("/users/{handle}", async (ctx, handle) => {
  // Actor implementation
});

// inbox.ts
import { builder } from "./builder.ts";
import { Follow } from "@fedify/fedify";

builder.setInboxListeners("/users/{handle}/inbox", "/inbox")
  .on(Follow, async (ctx, follow) => {
    // Follow handling
  });

// main.ts — Only create the Federation instance at startup
import { builder } from "./builder.ts";

// Build the Federation object with actual dependencies
export const federation = await builder.build({
  kv: new DbKvStore(),
  queue: new RedisMessageQueue(),
  // Other options...
});

This pattern helps avoid circular dependencies and makes your code more modular. Each part of your app can configure the builder without needing the actual Federation instance.

The full documentation will be available when 1.6 is released, but we wanted to share this early with our community. Looking forward to your feedback when it lands!

Want to try it right now? You can install the development version from JSR or npm:

# Deno
deno add jsr:@fedify/fedify@1.6.0-dev.777+1206cb01

# Node.js
npm add @fedify/fedify@1.6.0-dev.777

# Bun
bun add @fedify/fedify@1.6.0-dev.777

As we consider ways to implement #ActivityPub into our FOSS Community Calendar Ecosystem platform Koalagator, I've been looking over the differing specs for how to specify the event object schema.

Have any other folk wrestled with this?Asking before I get arms deep in this stuff.

For those playing at home...

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Schema.org - Event

Schema.org is a collaborative, community activity with a mission to create, maintain, and promote schemas for structured data on the Internet.

https://schema.org/Event

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W3C Activity Vocabulary - Event

This specification describes the Activity vocabulary. It is intended to be used in the context of the ActivityStreams 2.0 format and provides a foundational vocabulary for activity structures, and specific activity types.

https://www.w3.org/TR/activitystreams-vocabulary/#dfn-event

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Fediverse Enhancement Proposal
FEP-8a8e: A common approach to using the Event object type

ActivityStreams defines the Object Type Event. In real-world applications, the event object immediately showed the need for extension. Applications featuring Event objects have often chosen to add additional attributes and clarifications (i.e., interpretations) in order to implement their particular use case. This proposal clarifies and extends the ActivityPub standard to address the needs that have arisen in real-world implementations.

https://codeberg.org/linos/fep/src/branch/fep-8a8e/fep/8a8e/fep-8a8e.md

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[HTML] Microformats - h-event

People are using microformats to mark up profiles, posts, events and other data on their personal sites, enabling developers to build applications which use this data in useful and interesting ways.

https://microformats.org/wiki/h-event

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iCalendar Standard (RFC 5545)

iCalendar was first defined as a standard as RFC 2445 in 1998 by the Internet Engineering Task Force (IETF). Today, iCalendar is used to import and synchronize events on various platforms, including smart phones, computer and web applications.

https://icalendar.org/the-icalendar-standard-2.html