Implement AuthenticationMiddleware (#117)

Package.swift

@@ -204,5 +204,10 @@ let package = Package(
  dependencies: ["SyntaxKit", "DocumentationHarness"],
  swiftSettings: swiftSettings
  ),
+ .testTarget(
+ name: "AiSTKitTests",
+ dependencies: ["AiSTKit"],
+ swiftSettings: swiftSettings
+ ),
  ]
 )

Sources/AiSTKit/AuthenticationMiddleware.swift

@@ -0,0 +1,96 @@
+//
+// AuthenticationMiddleware.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+public import HTTPTypes
+public import OpenAPIRuntime
+
+#if os(Linux)
+ @preconcurrency public import struct Foundation.URL
+#else
+ public import struct Foundation.URL
+#endif
+
+/// OpenAPI client middleware that adds Anthropic API authentication headers.
+///
+/// Injects the `x-api-key` and `anthropic-version` headers into every
+/// outgoing request before forwarding it to the next handler in the chain.
+public struct AuthenticationMiddleware: ClientMiddleware {
+ /// The Anthropic API version sent with every request.
+ private static let anthropicVersion = "2023-06-01"
+
+ /// The `x-api-key` header name, constructed once. `"x-api-key"` is a valid
+ /// RFC 9110 token, so this is always non-`nil`.
+ private static let apiKeyFieldName = HTTPField.Name("x-api-key")
+
+ /// The `anthropic-version` header name, constructed once. `"anthropic-version"`
+ /// is a valid RFC 9110 token, so this is always non-`nil`.
+ private static let anthropicVersionFieldName = HTTPField.Name("anthropic-version")
+
+ /// The Anthropic API key used to authenticate requests.
+ private let apiKey: String
+
+ /// Creates a middleware that authenticates requests with the given API key.
+ /// - Parameter apiKey: The Anthropic API key to send in the `x-api-key` header.
+ public init(apiKey: String) {
+ self.apiKey = apiKey
+ }
+
+ /// Adds the Anthropic authentication headers, then forwards the request.
+ ///
+ /// Any `x-api-key` or `anthropic-version` header already present on the
+ /// request is silently overwritten with this middleware's values.
+ /// - Parameters:
+ /// - request: The outgoing HTTP request.
+ /// - body: The outgoing HTTP request body, if any.
+ /// - baseURL: The base URL of the server.
+ /// - operationID: The OpenAPI operation identifier for the request.
+ /// - next: The next handler in the middleware chain.
+ /// - Returns: The HTTP response and body from the next handler.
+ /// - Throws: Any error thrown by the `next` handler.
+ public func intercept(
+ _ request: HTTPRequest,
+ body: HTTPBody?,
+ baseURL: URL,
+ operationID: String,
+ next: @Sendable (HTTPRequest, HTTPBody?, URL) async throws -> (HTTPResponse, HTTPBody?)
+ ) async throws -> (HTTPResponse, HTTPBody?) {
+ var request = request
+ if let apiKeyFieldName = Self.apiKeyFieldName {
+ request.headerFields[apiKeyFieldName] = apiKey
+ } else {
+ assertionFailure("\"x-api-key\" is a valid header name and must never be nil.")
+ }
+ if let anthropicVersionFieldName = Self.anthropicVersionFieldName {
+ request.headerFields[anthropicVersionFieldName] = Self.anthropicVersion
+ } else {
+ assertionFailure("\"anthropic-version\" is a valid header name and must never be nil.")
+ }
+ return try await next(request, body, baseURL)
+ }
+}

Sources/SyntaxKit/Core/Architecture.swift

@@ -0,0 +1,42 @@
+//
+// Architecture.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+/// CPU-architecture identifiers used in `arch(...)` checks.
+public enum Architecture: String, Sendable {
+ /// `arch(arm64)`
+ case arm64
+ /// `arch(x86_64)`
+ case x86 = "x86_64"
+ /// `arch(i386)`
+ case i386
+ /// `arch(arm)`
+ case arm
+ /// `arch(wasm32)`
+ case wasm32
+}

Sources/SyntaxKit/Core/Comparison.swift

@@ -0,0 +1,43 @@
+//
+// Comparison.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+/// The comparison operator used between a keyword and a version in a
+/// `swift(...)` / `compiler(...)` version check.
+public enum Comparison: String, Sendable {
+ /// `>=`
+ case greaterThanOrEqual = ">="
+ /// `>`
+ case greaterThan = ">"
+ /// `<=`
+ case lessThanOrEqual = "<="
+ /// `<`
+ case lessThan = "<"
+ /// `==`
+ case equal = "=="
+}

Sources/SyntaxKit/Core/OperatingSystem.swift

@@ -0,0 +1,54 @@
+//
+// OperatingSystem.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+/// Operating-system identifiers used in `os(...)` checks.
+public enum OperatingSystem: String, Sendable {
+ /// `os(iOS)`
+ case iOS
+ /// `os(macOS)`
+ case macOS
+ /// `os(tvOS)`
+ case tvOS
+ /// `os(watchOS)`
+ case watchOS
+ /// `os(visionOS)`
+ case visionOS
+ /// `os(anyAppleOS)` — matches any Apple operating system (Swift 6.4+).
+ case anyAppleOS
+ /// `os(Linux)`
+ case linux = "Linux"
+ /// `os(Windows)`
+ case windows = "Windows"
+ /// `os(FreeBSD)`
+ case freeBSD = "FreeBSD"
+ /// `os(Android)`
+ case android = "Android"
+ /// `os(WASI)`
+ case wasi = "WASI"
+}

Sources/SyntaxKit/Core/TargetEnvironment.swift

@@ -0,0 +1,36 @@
+//
+// TargetEnvironment.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+/// Target-environment identifiers used in `targetEnvironment(...)` checks.
+public enum TargetEnvironment: String, Sendable {
+ /// `targetEnvironment(simulator)`
+ case simulator
+ /// `targetEnvironment(macCatalyst)`
+ case macCatalyst
+}

Sources/SyntaxKit/Core/Version.swift

@@ -0,0 +1,64 @@
+//
+// Version.swift
+// SyntaxKit
+//
+// Created by Leo Dion.
+// Copyright © 2026 BrightDigit.
+//
+// Permission is hereby granted, free of charge, to any person
+// obtaining a copy of this software and associated documentation
+// files (the “Software”), to deal in the Software without
+// restriction, including without limitation the rights to use,
+// copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the
+// Software is furnished to do so, subject to the following
+// conditions:
+//
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+// OTHER DEALINGS IN THE SOFTWARE.
+//
+
+/// A `major.minor.patch` version, with optional minor and patch components.
+public struct Version: Sendable, CustomStringConvertible {
+ /// The major version component.
+ public let major: Int
+ /// The optional minor version component.
+ public let minor: Int?
+ /// The optional patch version component.
+ public let patch: Int?
+
+ /// The dotted string form, e.g. `5`, `5.9`, or `5.9.1`.
+ public var description: String {
+ var result = String(major)
+ if let minor = minor {
+ result += ".\(minor)"
+ if let patch = patch {
+ result += ".\(patch)"
+ }
+ }
+ return result
+ }
+
+ /// The dotted string form, e.g. `5`, `5.9`, or `5.9.1`.
+ internal var versionString: String { description }
+
+ /// Create a version from its components.
+ /// - Parameters:
+ /// - major: The major version component.
+ /// - minor: The optional minor version component.
+ /// - patch: The optional patch version component.
+ public init(_ major: Int, _ minor: Int? = nil, _ patch: Int? = nil) {
+ self.major = major
+ self.minor = minor
+ self.patch = patch
+ }
+}