SwiftNIO HTTP/3

SwiftNIO HTTP/3 provides an implementation of the HTTP/3 protocol. You can use it with SwiftNIO QUIC and SwiftNIO to create HTTP/3 clients and servers.

Quick Start

The following snippet contains a Swift Package manifest to use SwiftNIO HTTP/3 with SwiftNIO QUIC.

// swift-tools-version: 6.3
import PackageDescription

let package = Package(
    name: "Application",
    dependencies: [
        .package(url: "https://github.com/apple/swift-nio.git", from: "2.100.0"),
        .package(url: "https://github.com/apple/swift-nio-http3", .upToNextMinor(from: "0.1.0")),
        .package(url: "https://github.com/apple/swift-nio-quic", .upToNextMinor(from: "0.1.0")),
    ],
    targets: [
        .executableTarget(
            name: "H3Server",
            dependencies: [
                .product(name: "NIOQUIC", package: "swift-nio-quic"),
                .product(name: "NIOCore", package: "swift-nio"),
                .product(name: "NIOHTTP3", package: "swift-nio-http3"),
            ]
        )
    ]
)

Getting Started

Prerequisites

• Swift 6.3 and up
• macOS 26.0 and up or Linux (Ubuntu 22.04+)
• Xcode 26.0 and up (Apple platforms only)

Building and testing

Packages in the dependency tree depend on a beta release of swift-crypto. Set the environment variable SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA to allow swift-certificates (in the dependency tree) to adopt swift-crypto beta releases as well.

To build via the command line (for all platforms), run at the root of the package:

SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA=1 swift build

To run all unit tests, run

SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA=1 swift test

Unit tests can also be run by filtering a specific class or function:

SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA=1 swift test --filter EncoderTests
SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA=1 swift test --filter EncoderTests.maxBlockedStreams

Use SWIFT_CERTIFICATES_ALLOW_SWIFT_CRYPTO_BETA=1 xed Package.swift to open the project in Xcode with the environment variable set.

Versioning

While the library is in the 0.x.x version range, you should adopt it using the .upToNextMinor(from: "0.1.0") specifier. During this period, breaking changes are intended to map to minor version bumps, so depending on the library this way picks up smaller, non-breaking changes automatically while protecting against API-breaking ones.