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What's an Atmosphere account?

One account for the entire AT Protocol ecosystem. Sign up once and use it across Arabica, Bluesky, Leaflet, and more. Your data is portable — you own it.

Portable identity, portable coffee records

The AT Protocol

Arabica stores your coffee data where your account lives. The app is a client, your PDS is the notebook.

What is the AT Protocol?

Arabica uses the AT Protocol (Authenticated Transfer Protocol) to power many of its social features, allowing you to own your data and use one account across all compatible applications.

Once you create an account, you can use other apps like Bluesky and Tangled with the same account.

Key Concepts

Personal Data Server (PDS)

Your PDS is where all your data lives. It can be hosted by a large provider like Bluesky, an independent host like selfhosted.social or Eurosky, or self-hosted on your own server. You choose where your PDS lives and can migrate between providers at any time. When you create brew logs in Arabica, they're stored in your PDS, not on Arabica's servers.

Decentralized Identity (DID)

Your identity is represented by a DID (Decentralized Identifier) that you own. This identity is portable across applications and PDS providers. Your handle (e.g. yourname.arabica.systems) is just a human-friendly alias for your DID.

Lexicons

Lexicons define the structure of data in the AT Protocol. Arabica uses custom lexicons for coffee data: beans, roasters, grinders, brewers, and brew sessions. These schemas ensure data consistency and enable interoperability with other coffee apps.

AT-URIs

Records reference each other using AT-URIs, which look like: at://did:plc:xxx/collection/recordkey. When a brew references a bean, it uses an AT-URI to point to that bean record in your PDS.

How Arabica Uses AT Protocol

When you use Arabica, here's what happens behind the scenes:

  1. Authentication: You log in via OAuth with your PDS (not with Arabica). Arabica never sees your password.
  2. Data storage: Your brew logs, beans, and equipment are stored as records in your PDS using Arabica's lexicons.
  3. Data retrieval: When you view your brews, Arabica fetches them from your PDS using your authentication token.
  4. Community feed: Public brews are aggregated from users' PDSes via the AT Protocol firehose.

Why This Matters

Data Ownership

Your coffee data is yours. If Arabica shuts down, your data remains safe in your PDS.

Portability

Switch PDS providers without losing anything. Your identity and data move with you.

Interoperability

Other apps can build on the same data. Future coffee apps could read your Arabica brews.

Transparency

Open protocol means no hidden algorithms. You can see exactly how your data is handled.

Learn More

The AT Protocol is an open standard with comprehensive documentation. To dive deeper:

  • atproto.com, Official AT Protocol website and documentation
  • Protocol Overview, Technical introduction to the protocol
  • Bluesky, A microblogging social network built on AT Protocol
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