Devcon 8: Build Battle 1

Devcon 8 · Build Battle 1: Censorship-Free World

Build Battle 1 is a 24-hour build sprint around one problem. You build in your own public GitHub repo, and an AI judge reads your code against the brief and the rubric. It never runs the code. The checks and their point values are on the problem page, so you can see what counts as good before you write a line.

The challenge

Pick a real person whose work keeps getting taken down, like a small newsroom, a tenants' union, or a community archive. Build them something they can publish to tonight, with one link their readers can keep.

The test is simple: once your own server and domain are gone, that link still shows their latest work.

Build it on Swarm

Swarm is Ethereum's decentralised storage and communication network. Content is split into chunks and spread across many Bee nodes, so there is no single host to suspend and no single file to lock.

Free Swarm storage: get a gift card with 50 MB of free storage on Telegram: t.me/ethswarm_devcon

New to Swarm? Start with the presentation: katta-swarm.bzz.link

What's worth knowing for this battle:

• Postage stamps: you pay for storage with a postage stamp (bought with xBZZ), and the network keeps your data while the stamp lasts. The gift card covers your first 50 MB.
• Feeds: a stable address you can keep updating. This is how one link keeps showing the latest version.
• Sharing: open content through a bzz.link gateway URL, or point an ENS name at it.
• Live messaging with swarm-pubsub: swarm-pubsub gives your app live, signed, many-to-many messages from the browser or Node.js. It needs no local Bee node, no server of your own, and no database. It connects to a Swarm broker node over libp2p. Use it for anything live: breaking-news alerts, a live blog, reader chat, presence, or coordination between publishers.
• Tooling: Bee node, bee-js, create-swarm-app and swarm-cli, with TypeScript and Vite.

How swarm-pubsub fits

A channel is just an owner key plus a topic name. There are no accounts and nothing to register. The owner can publish, approve extra publishers ("seats"), or remove them. Anyone can subscribe without a key. Every message is signed, so a broker can drop messages but can't fake them.

Two things to plan around:

• Messages are not stored. A reader who isn't listening when you send misses that message. Keep the record in Swarm storage and feeds, and use pubsub only for the live layer on top. A good pattern is to publish the post to a feed, then announce its Swarm reference on a pubsub channel.
• One message holds 4 KB. For anything bigger, send a Swarm reference instead of the content itself.

Browsers need a broker with a wss:// endpoint. The package's chat example ships with a default broker you can start from. swarm-pubsub is brand new (v0.1.x), so expect rough edges and keep a fallback if it misbehaves.

You can update your entry until the deadline. Join the challenge now.