cpp-httplib v0.35.0

Static File Server

cpp-httplib can serve static files too — HTML, CSS, images, you name it. No complicated configuration required. One call to set_mount_point() is all it takes.

The basics of set_mount_point

Let's jump right in. set_mount_point() maps a URL path to a local directory.

#include "httplib.h"
#include <iostream>

int main() {
    httplib::Server svr;

    svr.set_mount_point("/", "./html");

    std::cout << "Listening on port 8080..." << std::endl;
    svr.listen("0.0.0.0", 8080);
}

#include "httplib.h"
#include <iostream>

int main() {
    httplib::Server svr;

    svr.set_mount_point("/", "./html");

    std::cout << "Listening on port 8080..." << std::endl;
    svr.listen("0.0.0.0", 8080);
}

The first argument is the URL mount point. The second is the local directory path. In this example, requests to / are served from the ./html directory.

Let's try it out. First, create an html directory and add an index.html file.

mkdir html

mkdir html

<!DOCTYPE html>
<html>
<head><title>My Page</title></head>
<body>
    <h1>Hello from cpp-httplib!</h1>
    <p>This is a static file.</p>
</body>
</html>

<!DOCTYPE html>
<html>
<head><title>My Page</title></head>
<body>
    <h1>Hello from cpp-httplib!</h1>
    <p>This is a static file.</p>
</body>
</html>

Compile and start the server.

g++ -std=c++17 -o server server.cpp -pthread
./server

g++ -std=c++17 -o server server.cpp -pthread
./server

Open http://localhost:8080 in your browser. You should see the contents of html/index.html. Visiting http://localhost:8080/index.html returns the same page.

You can also access it with the client code from the previous chapter, or with curl.

httplib::Client cli("http://localhost:8080");
auto res = cli.Get("/");
if (res) {
    std::cout << res->body << std::endl;  // HTML is displayed
}

httplib::Client cli("http://localhost:8080");
auto res = cli.Get("/");
if (res) {
    std::cout << res->body << std::endl;  // HTML is displayed
}

curl http://localhost:8080

curl http://localhost:8080

Multiple mount points

You can call set_mount_point() as many times as you like. Each URL path gets its own directory.

svr.set_mount_point("/", "./public");
svr.set_mount_point("/assets", "./static/assets");
svr.set_mount_point("/docs", "./documentation");

svr.set_mount_point("/", "./public");
svr.set_mount_point("/assets", "./static/assets");
svr.set_mount_point("/docs", "./documentation");

A request to /assets/style.css serves ./static/assets/style.css. A request to /docs/guide.html serves ./documentation/guide.html.

Combining with handlers

Static file serving and routing handlers — the kind you learned about in the previous chapter — work side by side.

httplib::Server svr;

// API endpoint
svr.Get("/api/hello", [](const auto &, auto &res) {
    res.set_content(R"({"message":"Hello!"})", "application/json");
});

// Static file serving
svr.set_mount_point("/", "./public");

svr.listen("0.0.0.0", 8080);

httplib::Server svr;

// API endpoint
svr.Get("/api/hello", [](const auto &, auto &res) {
    res.set_content(R"({"message":"Hello!"})", "application/json");
});

// Static file serving
svr.set_mount_point("/", "./public");

svr.listen("0.0.0.0", 8080);

Handlers take priority. The handler responds to /api/hello. For every other path, the server looks for a file in ./public.

Adding response headers

Pass headers as the third argument to set_mount_point() and they get attached to every static file response. This is great for cache control.

svr.set_mount_point("/", "./public", {
    {"Cache-Control", "max-age=3600"}
});

svr.set_mount_point("/", "./public", {
    {"Cache-Control", "max-age=3600"}
});

With this in place, the browser caches served files for one hour.

A Dockerfile for your static file server

The cpp-httplib repository includes a Dockerfile built for static file serving. We also publish a pre-built image on Docker Hub, so you can get up and running with a single command.

> docker run -p 8080:80 -v ./my-site:/html yhirose4dockerhub/cpp-httplib-server
Serving HTTP on 0.0.0.0:80
Mount point: / -> ./html
Press Ctrl+C to shutdown gracefully...
192.168.65.1 - - [22/Feb/2026:12:00:00 +0000] "GET / HTTP/1.1" 200 256 "-" "Mozilla/5.0 ..."
192.168.65.1 - - [22/Feb/2026:12:00:00 +0000] "GET /style.css HTTP/1.1" 200 1024 "-" "Mozilla/5.0 ..."
192.168.65.1 - - [22/Feb/2026:12:00:01 +0000] "GET /favicon.ico HTTP/1.1" 404 152 "-" "Mozilla/5.0 ..."

> docker run -p 8080:80 -v ./my-site:/html yhirose4dockerhub/cpp-httplib-server
Serving HTTP on 0.0.0.0:80
Mount point: / -> ./html
Press Ctrl+C to shutdown gracefully...
192.168.65.1 - - [22/Feb/2026:12:00:00 +0000] "GET / HTTP/1.1" 200 256 "-" "Mozilla/5.0 ..."
192.168.65.1 - - [22/Feb/2026:12:00:00 +0000] "GET /style.css HTTP/1.1" 200 1024 "-" "Mozilla/5.0 ..."
192.168.65.1 - - [22/Feb/2026:12:00:01 +0000] "GET /favicon.ico HTTP/1.1" 404 152 "-" "Mozilla/5.0 ..."

Everything in your ./my-site directory gets served on port 8080. The access log follows the same format as NGINX, so you can see exactly what's happening.

What's next

You can now serve static files. A web server that delivers HTML, CSS, and JavaScript — built with this little code.

Next, let's encrypt your connections with HTTPS. We'll start by setting up a TLS library.

Next: TLS Setup

ESC