https://atproto.com/guides/applications

Find the source code for the example application on GitHub.

In this guide, we're going to build a simple multi-user app that publishes your current "status" as an emoji. Our application will look like this:

A screenshot of our example application

We will cover how to:

• Signin via OAuth
• Fetch information about users (profiles)
• Listen to the network firehose for new data
• Publish data on the user's account using a custom schema

We're going to keep this light so you can quickly wrap your head around ATProto. There will be links with more information about each step.

Introduction

Data in the Atmosphere is stored on users' personal repos. It's almost like each user has their own website. Our goal is to aggregate data from the users into our SQLite DB.

Think of our app like a Google. If Google's job was to say which emoji each website had under /status.json, then it would show something like:

• nytimes.com is feeling 📰 according to https://nytimes.com/status.json
• bsky.app is feeling 🦋 according to https://bsky.app/status.json
• reddit.com is feeling 🤓 according to https://reddit.com/status.json

The Atmosphere works the same way, except we're going to check at:// instead of https://. Each user has a data repo under an at:// URL. We'll crawl all the user data repos in the Atmosphere for all the "status.json" records and aggregate them into our SQLite database.

at:// is the URL scheme of the AT Protocol. Under the hood it uses common tech like HTTP and DNS, but it adds all of the features we'll be using in this tutorial.