// Copyright 2011 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. /* Package http provides HTTP client and server implementations. [Get], [Head], [Post], and [PostForm] make HTTP (or HTTPS) requests: resp, err := http.Get("http://example.com/") ... resp, err := http.Post("http://example.com/upload", "image/jpeg", &buf) ... resp, err := http.PostForm("http://example.com/form", url.Values{"key": {"Value"}, "id": {"123"}}) The caller must close the response body when finished with it: resp, err := http.Get("http://example.com/") if err != nil { // handle error } defer resp.Body.Close() body, err := io.ReadAll(resp.Body) // ... # Clients and Transports For control over HTTP client headers, redirect policy, and other settings, create a [Client]: client := &http.Client{ CheckRedirect: redirectPolicyFunc, } resp, err := client.Get("http://example.com") // ... req, err := http.NewRequest("GET", "http://example.com", nil) // ... req.Header.Add("If-None-Match", `W/"wyzzy"`) resp, err := client.Do(req) // ... For control over proxies, TLS configuration, keep-alives, compression, and other settings, create a [Transport]: tr := &http.Transport{ MaxIdleConns: 10, IdleConnTimeout: 30 * time.Second, DisableCompression: true, } client := &http.Client{Transport: tr} resp, err := client.Get("https://example.com") Clients and Transports are safe for concurrent use by multiple goroutines and for efficiency should only be created once and re-used. # Servers ListenAndServe starts an HTTP server with a given address and handler. The handler is usually nil, which means to use [DefaultServeMux]. [Handle] and [HandleFunc] add handlers to [DefaultServeMux]: http.Handle("/foo", fooHandler) http.HandleFunc("/bar", func(w http.ResponseWriter, r *http.Request) { fmt.Fprintf(w, "Hello, %q", html.EscapeString(r.URL.Path)) }) log.Fatal(http.ListenAndServe(":8080", nil)) More control over the server's behavior is available by creating a custom Server: s := &http.Server{ Addr: ":8080", Handler: myHandler, ReadTimeout: 10 * time.Second, WriteTimeout: 10 * time.Second, MaxHeaderBytes: 1 << 20, } log.Fatal(s.ListenAndServe()) # HTTP/2 Starting with Go 1.6, the http package has transparent support for the HTTP/2 protocol when using HTTPS. Programs that must disable HTTP/2 can do so by setting [Transport.TLSNextProto] (for clients) or [Server.TLSNextProto] (for servers) to a non-nil, empty map. Alternatively, the following GODEBUG settings are currently supported: GODEBUG=http2client=0 # disable HTTP/2 client support GODEBUG=http2server=0 # disable HTTP/2 server support GODEBUG=http2debug=1 # enable verbose HTTP/2 debug logs GODEBUG=http2debug=2 # ... even more verbose, with frame dumps Please report any issues before disabling HTTP/2 support: https://golang.org/s/http2bug The http package's [Transport] and [Server] both automatically enable HTTP/2 support for simple configurations. To enable HTTP/2 for more complex configurations, to use lower-level HTTP/2 features, or to use a newer version of Go's http2 package, import "golang.org/x/net/http2" directly and use its ConfigureTransport and/or ConfigureServer functions. Manually configuring HTTP/2 via the golang.org/x/net/http2 package takes precedence over the net/http package's built-in HTTP/2 support. */ package http