mod_http3 -- HTTP/3 module for Apache httpd

An Apache httpd module that adds HTTP/3 support over QUIC.

Status: experimental.

Build

Default build compiles all dependencies (OpenSSL, APR, APR-util, httpd) from submodules:

git submodule update --init --recursive
cmake -B build
cmake --build build

Output: build/lib/mod_http3.so

To use system-installed dependencies instead, provide WITH_* paths:

cmake -B build -DWITH_SSL=/opt/openssl -DWITH_HTTPD=/opt/httpd
cmake --build build

See INSTALL for full build instructions.

CMake Options

Option	Default	Description
CMAKE_BUILD_TYPE	Debug	Debug, Release
BUILD_MODULE	ON	Build mod_http3.so
BUILD_EXAMPLES	ON	Build example programs
BUILD_TESTS	ON	Build test suite
WITH_SSL	(empty)	Path to OpenSSL prefix (overrides source build)
WITH_HTTPD	(empty)	Path to httpd prefix (overrides source build)
WITH_APR	(empty)	Path to APR prefix (overrides source build)
WITH_APU	(empty)	Path to APR-util prefix (overrides source build)
WITH_NGHTTP3	(empty)	Path to nghttp3 prefix (overrides source build)
ENABLE_ASAN	OFF	Address Sanitizer (requires Debug)
ENABLE_UBSAN	OFF	UB Sanitizer (requires Debug)
ENABLE_WERROR	OFF	Treat warnings as errors

See CONFIGURATION.md for advanced options and dependency internals.

Deploy

cmake --install build --prefix /opt/mod_http3

Minimal VirtualHost configuration:

LoadModule ssl_module     modules/mod_ssl.so
LoadModule http3_module   modules/mod_http3.so

EnableMMAP Off
Listen 4433 https

<VirtualHost *:4433>
    ServerName localhost

    SSLEngine on
    SSLCertificateFile    conf/server.crt
    SSLCertificateKeyFile conf/server.key

    Protocols h3 h2 http/1.1

    H3CertificatePath     conf/server.crt
    H3CertificateKeyPath  conf/server.key

    DocumentRoot htdocs
    <Directory htdocs>
        Require all granted
    </Directory>
</VirtualHost>

HTTP/3 support is advertised to clients automatically via an Alt-Svc response header (H3AltSvc, on by default). See CONFIGURATION_HTTPD.md for all directives and INSTALL for complete deployment steps.

Contributing

We welcome contributions of all forms, including bug reports, documentation updates, code changes, and release testing. For guidelines on our community governance, voting procedures, and coding style, please refer to CONTRIBUTING.md.

License

Apache License 2.0. See LICENSE and NOTICE.