"Okay so Facebook's bad. We know that. Why's Bluesky any different? It's a corporation too, right?"

Yup, you're right on the money there. Bluesky's also a corporation. They've got their own client and their own servers where they store your data. But Bluesky itself isn't what makes it different. When you want to use Instagram application, you need to access the Instagram servers with the Instagram client (reminder: the app on your phone). This isn't true for Bluesky and, because of that, a lot of really cool things are possible.

Tech Lesson: APIs and Protocols

We've discussed the client/server architecture, so we're going to continue on that conversation. The servers are called "Application Programming Interface" servers or 'API servers'. They are responsible for taking your request (your order) and giving you a response (your food). The server can then relay the request to the kitchen where the cooks (a different kind of computer server) prepare the food. The cooks know where the ingredients are (this is the database) and they can put the food together and give it to the server who then gives it to you.

Protocols are the way that you communicate with the server. In the real world you use spoken language, in the digital world you use 1s and 0s.

Now, the next part is confusing: the specific language you choose to speak between you, the client, and the server is also called an API. In the real world, you use the local language, in the digital world, it's code.

Putting it all together, the client (the app you use), uses a language (an API), over spoken word (the protocol), to communicate your order (the request) to the server (the API server). The server then responds by giving you what you asked for.

Proprietary vs Open APIs

Okay, so now imagine you're going to a restaurant where everyone talks to each other in a secret language. This is a proprietary API. Open APIs are like a typical language, there's documentation (dictionaries, thesauruses, grammar books, etc.) that anyone can read and use to learn to speak the language.

Facebook uses a proprietary API. The clients talk to the servers in a secret language and only Facebook knows how the language works. Bluesky uses an open API—anyone can learn the language and talk to the servers.

Open Protocols

Not only does Bluesky use a language anyone can learn, they use a protocol (a communication method like spoken word, writing, music, or dance) that anyone can use. The name for this one is the AT Protocol. Any application is able to use the AT protocol to communicate with other servers using the API that Bluesky helped create.

Tech Lesson: Schemas

The name for "the way stuff is organized" is called a schema. Say you make a spreadsheet with particular headers like 'name', 'date', etc.. That's a schema—you have created a set of rules for how the information is organized. Anything you put in the 'name' column you know is the name of something and anything you put in the 'date' column is some date in time.

Going back to our restaurant analogy, every restaurant organizes their pantry in a specific way so everyone who works there knows where things are. Facebook's database (the pantry) has a particular schema that all of the APIs (cooks) know, which allows them to find everything needed make the thing you ordered. TikTok's pantry, for example, is organized completely differently. None of the cooks in Facebook's kitchen know how TikTok's pantry is organized, so they cannot find the ingredients.

Open Schemas

Not only are the language and communication method that Bluesky uses open, the way they organize pantries is available for everyone to know as well. This means that, if a cook is allowed to access the pantry, they know how to find anything in there without learning a new organization method.

Instead of the restaurant owning and controlling the pantry, every Bluesky user has their own pantry that's organized the same way as everyone else's. This 'pantry' is called your Personal Data Store, or PDS for short. Every time you log into Bluesky, you are giving the Bluesky servers permission to access your pantry.

Other apps are allowed to ask for a permission slip to access your pantry as well. Any app that uses the AT Protocol can ask you for a permission slip to access your pantry (your username and password). They have to tell you what types of ingredients they can add, remove, and change before they can get this access as well. This means you know what every server you give your order to is only able to use the ingredients they said they would and this is enforced by your pantry's security system.

Lexicons

We've covered the wait staff (API servers), the kitchen staff ('other' servers), the pantry (your PDS), the language in which you order (APIs), and the communication method you use to relay your (protocols). The last thing we need to understand is the ingredients. Every app is able to bring their own types ingredients (like cheese or apples or flour) called lexicons, to put in the pantry, called the PDS. This is what they tell you when they ask for permission to use your pantry. In technical terms, ingredients are things like posts, follows, likes, blog posts, and really anything under the sun. The other part of the puzzle is a record. A record is a single piece of ingredient. "Apples" is the lexicon. "An apple" is the record. The concept of ingredients (things that are parts of foods) is data.