Introduction

serve.build is a lightweight HTTP server framework for Java 25+. It sits directly on top of jdk.httpserver — the HTTP server that ships inside the JDK — and adds only what's missing: a routing DSL, middleware composition, virtual-thread dispatch, and a clean request/response abstraction.

Routes are code. Dependency injection is handled by codemodel.build. The result is a framework you can read top-to-bottom in an afternoon.

Design principles

Code over convention. Routes are registered with RouterBuilder, middleware is composed with .middleware(), and the application wires itself in a single configure() method.

JPMS-native. Every module has explicit requires and exports. You know exactly what depends on what.

Virtual threads throughout. Each request runs on its own virtual thread. No thread pools to tune, no reactive programming model to learn.

Null-free public API. Public methods return Optional<T> instead of null.

Module layers

serve.build is organized into four layers:

Layer	Modules
Core	serve-foundation, serve-transport-http, serve-transport-json, serve-application, serve-testing
Protocol	serve-websocket, serve-sse, serve-mcp, serve-lsp, serve-graphql
Middleware	serve-cors, serve-security, serve-compression, serve-logging, serve-health, serve-staticfiles
Template	serve-template, serve-jte, serve-htmx

Most applications only need core + a handful of middleware. Protocol and template modules are opt-in.

Key abstractions

Exchange is the pairing of a request and response for a single HTTP interaction. It carries a typed attribute bag, which is how middleware injects capabilities (JSON reading/writing, telemetry, etc.) into the request lifecycle without coupling modules together.

Handler is a @FunctionalInterface: void handle(Exchange) throws Exception. Everything that processes an HTTP request is a Handler — route callbacks, middleware-wrapped chains, and routers themselves.

Router extends Handler and dispatches by path and method. Build one with RouterBuilder.

Middleware is Handler apply(Handler next) — a function that wraps a handler. Compose middleware with .middleware() on RouterBuilder. The first-registered middleware is the outermost wrapper.

Next steps

• Quickstart — a working server in five minutes
• Installation — Maven setup and module selection
• Routing — path parameters, sub-routers, and Exchange