Add HTTPVersion type and HTTPVersionInfo server capability

Sources/HTTPAPIs/Server/HTTPServerCapability+HTTPVersionInfo.swift

@@ -0,0 +1,24 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift HTTP API Proposal open source project
+//
+// Copyright (c) 2026 Apple Inc. and the Swift HTTP API Proposal project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+public import NetworkTypes
+
+@available(anyAppleOS 26.0, *)
+extension HTTPServerCapability {
+    /// A capability for request contexts that expose the HTTP version used for the
+    /// connection a request arrived on.
+    public protocol HTTPVersionInfo: RequestContext, ~Copyable, ~Escapable {
+        /// The HTTP version used for this request
+        var httpVersion: HTTPVersion { get }
+    }
+}

Sources/NetworkTypes/HTTPVersion.swift

@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift HTTP API Proposal open source project
+//
+// Copyright (c) 2026 Apple Inc. and the Swift HTTP API Proposal project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// Representation of an HTTP version.
+public struct HTTPVersion: Sendable, Hashable {
+    private enum Representation: UInt8, Sendable, Hashable {
+        case http1_0
+        case http1_1
+        case http2
+        case http3
+    }
+
+    private let representation: Representation
+
+    private init(_ representation: Representation) {
+        self.representation = representation
+    }
+
+    /// HTTP/1.0, as defined in RFC 1945.
+    public static var http1_0: HTTPVersion {
+        .init(.http1_0)
+    }
+
+    /// HTTP/1.1, as defined in RFC 9112.
+    public static var http1_1: HTTPVersion {
+        .init(.http1_1)
+    }
+
+    /// HTTP/2, as defined in RFC 9113.
+    public static var http2: HTTPVersion {
+        .init(.http2)
+    }
+
+    /// HTTP/3, as defined in RFC 9114.
+    public static var http3: HTTPVersion {
+        .init(.http3)
+    }
+}
+
+extension HTTPVersion: CustomStringConvertible {
+    public var description: String {
+        switch self.representation {
+        case .http1_0: "HTTP/1.0"
+        case .http1_1: "HTTP/1.1"
+        case .http2: "HTTP/2"
+        case .http3: "HTTP/3"
+        }
+    }
+}

Tests/HTTPAPIsTests/Helpers/HTTPClientAndServerTests.swift

@@ -17,6 +17,7 @@ import ContainersPreview
 import DequeModule
 import HTTPAPIs
 import HTTPTypes
+import NetworkTypes
 import Synchronization
 import Testing
 
@@ -30,10 +31,16 @@ final class TestClientAndServer: HTTPClient, HTTPServer {
     struct HTTPRequestContext: HTTPServerCapability.RequestContext {
         var remoteAddress: String?
         var localAddress: String?
+        var httpVersion: HTTPVersion
 
-        init(remoteAddress: String? = nil, localAddress: String? = nil) {
+        init(
+            remoteAddress: String? = nil,
+            localAddress: String? = nil,
+            httpVersion: HTTPVersion = .http1_1
+        ) {
             self.remoteAddress = remoteAddress
             self.localAddress = localAddress
+            self.httpVersion = httpVersion
         }
     }
 
@@ -333,7 +340,8 @@ final class TestClientAndServer: HTTPClient, HTTPServer {
                         request: httpRequest,
                         requestContext: HTTPRequestContext(
                             remoteAddress: "127.0.0.1:54321",
-                            localAddress: "0.0.0.0:8080"
+                            localAddress: "0.0.0.0:8080",
+                            httpVersion: .http2
                         ),
                         reader: requestReader,
                         responseSender: responseSender

Tests/HTTPAPIsTests/ServerCapabilityTests.swift

@@ -14,6 +14,7 @@
 import BasicContainers
 import Foundation
 import HTTPAPIs
+import NetworkTypes
 import Testing
 
 @available(anyAppleOS 26.0, *)
@@ -27,12 +28,16 @@ extension HTTPServerCapability {
 @available(anyAppleOS 26.0, *)
 extension TestClientAndServer.HTTPRequestContext: HTTPServerCapability.ConnectionInfo {}
 
+@available(anyAppleOS 26.0, *)
+extension TestClientAndServer.HTTPRequestContext: HTTPServerCapability.HTTPVersionInfo {}
+
 @available(anyAppleOS 26.0, *)
 extension TestClientAndServer {
     func serveWithContextAssertions() async throws {
         try await self.serve { request, requestContext, reader, responseSender in
             #expect(requestContext.remoteAddress == "127.0.0.1:54321")
             #expect(requestContext.localAddress == "0.0.0.0:8080")
+            #expect(requestContext.httpVersion == .http2)
 
             try await responseSender.sendAndFinish(.init(status: .ok))
         }