Serverless Fediverse: Setting up a Minimal serverless Fediverse with Next.js and Vercel

Introduction

The Fediverse is a decentralized social network that allows users to interact across different platforms. Fediverse servers use protocols like ActivityPub to communicate seamlessly with each other.

Over the past few years, I’ve used many Fediverse servers, but I always wanted to set up my own minimal instance. Last year, I experimented with snac2, a minimal ActivityPub server, but it felt too complex for my needs. I wanted something simpler, lightweight, and easy to maintain.

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Understanding my Needs

For this project, I wanted a minimal server that could:

1. Handle basic ActivityPub interactions.
2. Be simple to set up and maintain.
3. Run on a serverless platform for cost-effectiveness.
4. Be fast and responsive.
5. Allow experimentation without worrying about server management.
6. Support a small number of users (just me, for now).

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Who is this for?

This project is ideal for anyone who wants to set up a minimal Fediverse server without managing a full-fledged instance. It’s especially useful for developers and hobbyists who want to experiment with Fediverse protocols and features.

Currently, this server is not intended for production use or for hosting multiple users. I mainly use it to integrate my blog posts with my Fediverse account so that whenever I publish a new post, it automatically shares on my Fediverse profile.

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What I Did

Steps I took to create the serverless Fediverse server

1. I chose Next.js route.ts for handling requests due to its simplicity and ease of use.
2. I set up basic functions to handle ActivityPub requests.
3. I implemented a simple ActivityPub endpoint capable of handling basic interactions like profiles, followers, following, and posts.

Sample Code Snippet

// src/app/.well-known/webfinger/route.ts

import { NextRequest, NextResponse } from 'next/server';

// Import a list of valid ActivityPub domains that you want to support (i.e., ['example.com', 'example.org', ...])
import { validActivitypubDomains } from '@/api-lib/fediverse';

export const runtime = 'edge';

export async function OPTIONS(req: NextRequest) {
  const origin = req.nextUrl.origin || '*';
  return new NextResponse(null, {
    status: 204,
    headers: {
      'Access-Control-Allow-Origin': origin,
      'Access-Control-Allow-Methods': 'GET, OPTIONS',
      'Access-Control-Allow-Headers': 'Content-Type'
    }
  });
}

export async function GET(req: NextRequest) {
  const resource = req.nextUrl.searchParams.get('resource');
  if (!resource) {
    return NextResponse.json(
      { error: 'Missing resource parameter' },
      {
        status: 400,
        headers: { 'Content-Type': 'application/jrd+json; charset=utf-8' }
      }
    );
  }
  // Change 'sivothajan' to your Fediverse username
  const match = /^acct:sivothajan@(.+)$/.exec(resource);
  const domain = match?.[1]?.toLowerCase();
  if (!domain || !validActivitypubDomains.includes(domain)) {
    return NextResponse.json(
      { error: 'Resource not found' },
      {
        status: 404,
        headers: { 'Content-Type': 'application/jrd+json; charset=utf-8' }
      }
    );
  }
  const jrd = {
    subject: `acct:sivothajan@${domain}`,
    aliases: [`https://${domain}`, `https://${domain}/fediverse`],
    links: [
      {
        rel: 'http://webfinger.net/rel/profile-page',
        type: 'text/html',
        href: `https://${domain}`
      },
      {
        rel: 'self',
        type: 'application/activity+json',
        href: `https://${domain}/fediverse`
      },
      {
        rel: 'http://webfinger.net/rel/avatar',
        type: 'image/png',
        href: `https://${domain}/images/pfp.png`
      }
    ]
  };
  return NextResponse.json(jrd, {
    headers: { 'Content-Type': 'application/jrd+json; charset=utf-8' }
  });
}

if you integrate the above code snippet into a Next.js project, it will create a WebFinger endpoint that responds to requests for the specified Fediverse username.

⚠️ Note 1: This is a simplified example. A complete Fediverse server would require handling many more aspects of the ActivityPub protocol.

⚠️ Note 2: TypeScript may not recognize files under the .well-known folder by default. To fix this, add the following to your tsconfig.json:

{
  "compilerOptions": {
    "include": ["**/.well-known/**/*.ts", "src"]
  }
}

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Deployment

Finally, I deployed the project on Vercel as a Next.js project.

You can check out my testing account here: @sivothajan@Sivothajan.me.

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Why I’m Not Open-Sourcing It Yet

The project is still a work in progress. I’m refining features, optimizing performance, and making it more stable before sharing it with the community. Once I’m satisfied with its functionality and scalability, I’ll consider open-sourcing it.

For now, the project’s name is Fediman.

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References

• ActivityPub Specification
• Next.js Documentation about route.ts
• Actor Verification Result
• Wikipedia: Fediverse
• Wikipedia: ActivityPub
• snac2: A Minimal ActivityPub Server
• Fediman GitHub Repository