From HTTP/0.9’s minimalist request/response to early servers, browsers, and the first dynamic gateways, 1990–1994 created the web’s core interface patterns—patterns modern AI model APIs still rely on.
In the Web’s first years (1990–1994), HTTP was tiny, servers were simple, and “APIs” mostly meant speaking basic request/response over the network. Those constraints later produced AJAX—and eventually the Fetch API, which modernized the same fundamental idea.
In the Web’s first years, HTTP’s simple request/response model made “real-time” feel out of reach. This chapter traces the early interface patterns—HTTP/0.9, evolving headers, and CGI scripts—that set the stage for later solutions like the WebSocket API.