Instructions, Not Markup
The feeling from that first prototype has lingered all week. A "napkin sketch" is one thing; a fleeting moment of magic in a terminal window. But the potential it represented—the idea of a direct, near-instant connection between the server's state and the user's screen—was too compelling to let go. It felt like we had stumbled upon something important, and we spent our nights and weekends consumed by a single question: how do we make this _real_?
Our initial prototype, sending pre-rendered HTML fragments over the wire, worked surprisingly well. It was fast, simple, and proved our core thesis: the server could be the single source of truth for the UI. But as we started building more complex examples, we began to see the cracks in this simple approach.
Sending entire chunks of HTML felt inefficient. If we only needed to change a single word or toggle a CSS class on an element, why were we sending all the surrounding <div>s, <span>s, and attributes? It was better than sending a whole JSON object, but it still felt... clumsy. We were sending the _result_ of the change, not the change itself.
The breakthrough came during a late-night session, staring at the network tab in the browser's developer tools. The problem wasn't just the size of the HTML string; it was the philosophy. Sending markup is an act of replacement. The server says, "Throw out the old thing and put this new thing in its place." We realized we needed to be more surgical. The server shouldn't just replace; it should command.
What if, instead of sending _markup_, we sent _instructions_?
Instead of sending <li class="completed">Buy milk</li>, the server would send a tiny, precise, binary command that meant: UPDATE_TEXT_NODE(24, "Buy milk") and SET_ATTRIBUTE(23, "class", "completed").
The client's job would become radically simpler. It wouldn't need to parse HTML or have any complex logic for swapping DOM elements. It would just need to listen for a command and execute it, like a remote-controlled surgical tool. All the intelligence would remain on the server.
The last few days have been a blur of focused work, building out this binary protocol. We defined a handful of these core commands and built the engine to translate changes in the server's state object into a stream of these instructions.
Last night, we got the todo list working on this new engine. The feeling was electric. It was the same instantaneous update as the first prototype, but this time it felt solid. Engineered. We could see the stream of tiny, efficient instructions in the network log and watch the DOM obey them perfectly. It was no longer magic; it was a mechanism. A foundation we feel we can actually build on.
Of course, solving one problem immediately reveals the next. Our state still vanishes the moment the server restarts. To build anything useful, we need persistence. That's the next mountain to climb.