Resolves the server URL for the Amiibo Live client in the library target once as a static constant.

Sources/AmiiboService/Public/Clients/AmiiboLiveClient.swift

@@ -19,6 +19,19 @@ import OpenAPIURLSession
 /// A type that implements a live client to the [Amiibo API](https://www.amiiboapi.org) online service.
 public struct AmiiboLiveClient: Sendable {
     
+    // MARK: Constants
+    
+    /// The base URL of the live service, resolved once from the server defined in the OpenAPI specification.
+    ///
+    /// The validity of the URL is guaranteed by the bundled `openapi.yaml` specification and enforced by a unit test, so resolution is not expected to fail at runtime.
+    static let serverURL: URL = {
+        guard let url = try? Servers.Server1.url() else {
+            fatalError("The server URL defined in the OpenAPI specification could not be resolved. Verify that the 'openapi.yaml' server definition is valid.")
+        }
+        
+        return url
+    }()
+    
     // MARK: Properties
     
     /// A client generated by the OpenAPI Runtime library to perform API calls.
@@ -29,12 +42,8 @@ public struct AmiiboLiveClient: Sendable {
     /// Initializes this client with a transport for performing HTTP operations.
     /// - Parameter transport: A transport that performs HTTP operations. Defaults to a `URLSessionTransport` using the shared session.
     public init(transport: any ClientTransport = URLSessionTransport()) {
-        guard let serverURL = try? Servers.Server1.url() else {
-            fatalError("The server URL defined in the OpenAPI specification could not be resolved. Verify that the 'openapi.yaml' server definition is valid.")
-        }
-        
         self.client = .init(
-            serverURL: serverURL,
+            serverURL: Self.serverURL,
             configuration: .init(dateTranscoder: ISODateTimeTranscoder()),
             transport: transport
         )

Tests/AmiiboService/Cases/Public/Clients/AmiiboLiveClientTests.swift

@@ -0,0 +1,46 @@
+// ===----------------------------------------------------------------------===
+// 
+// This source file is part of the Amiibo Service open source project
+// 
+// Copyright (c) 2026 Röck+Cöde VoF. and the Amiibo Service project authors
+// Licensed under Apache license v2.0
+// 
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of Amiibo Service project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+// 
+// ===----------------------------------------------------------------------===
+
+@testable import AmiiboService
+import Foundation
+import Testing
+
+@Suite("Amiibo Live Client")
+struct AmiiboLiveClientTests {
+    
+    // MARK: Server URL tests
+    
+    @Test("resolves the server URL defined in the OpenAPI specification")
+    func serverURLResolves() throws {
+        // GIVEN
+        // WHEN
+        let url = try Servers.Server1.url()
+        
+        // THEN
+        #expect(url.absoluteString == "https://www.amiiboapi.org/api")
+    }
+    
+    @Test("uses the server URL from the OpenAPI specification")
+    func serverURLMatchesSpecification() throws {
+        // GIVEN
+        let expected = try Servers.Server1.url()
+        
+        // WHEN
+        let url = AmiiboLiveClient.serverURL
+        
+        // THEN
+        #expect(url == expected)
+    }
+    
+}