HTTP

js/net/http.md

fino's HTTP subsystem is built around the global Fetch-compatible Request, Response, and Headers objects. All server and client logic lives in fino: modules. WebSocket, EventSource, and WebTransport are globals; no import is needed to use them in application code.

The subsystem has several focused surfaces that cover different concerns. Pick based on what you're building.

Which guide to read

Starting an HTTP server — use fino:net/http/server. It provides serveHttp() (simple request/response handler), serve() (accept-based handler that also handles WebSocket and WebTransport upgrades), and server lifecycle management. See the server guide.

Routing and middleware — use fino:net/http/app. It provides App, Router, Koa-style middleware, URLPattern route builders, body and schema helpers, OpenAPI generation, cookie and session producers, and a listen() shortcut that wires the app into serve(). See the routing guide.

Making outbound HTTP requests — either use the global fetch() for one-shot requests, or HttpClient from fino:net/http/client for reusable policy, protocol control, rich response metadata, persistent logical sessions, and built-in SSE and WebSocket helpers. See the client guide.

WebSockets — the WebSocket global covers the client side. The server side goes through serve() or a route().websocket() operation, which surface an IncomingWebSocketRequest whose accept() method returns a WebSocketConnection from fino:net/http/websocket. See the WebSockets guide.

Server-sent events — route().sse() registers a streaming operation whose handler writes events through an EventSourceWriter. The EventSource global covers client-side SSE, and parseEventStream from fino:net/http/eventstream parses streaming SSE bodies (POST-based APIs included). Streaming agent responses over SSE is shown in the AI section. See the server-sent events guide.

WebTransport — the WebTransport global is the client entry point (also importable from fino:net/http/webtransport). The server side surfaces an IncomingWebTransportRequest through serve(). Requires HTTP/3 and QUIC. See the WebTransport guide.

Protocol details — HTTP/1.1 keep-alive, HTTP/2 ALPN negotiation and h2c, HTTP/3 activation, and TLS configuration are all handled by serve() and HttpClient without internal-module imports. See the protocols guide.

Public modules

HTTP/1.1, HTTP/2, and HTTP/3 protocol drivers, connection pools, and internal ALPN machinery are implementation details exposed only through fino:net/http/server and fino:net/http/client. Do not import internal: modules directly.