diff --git a/Tests/LocalDataTests/KeychainHelperTests.swift b/Tests/LocalDataTests/KeychainHelperTests.swift
new file mode 100644
index 0000000..3ed5148
--- /dev/null
+++ b/Tests/LocalDataTests/KeychainHelperTests.swift
@@ -0,0 +1,143 @@
+import Foundation
+import Testing
+@testable import LocalData
+
+struct KeychainHelperTests {
+    private let testService = "LocalDataTests.Keychain.\(UUID().uuidString)"
+    
+    // MARK: - Basic Round Trip
+    
+    @Test func keychainRoundTrip() async throws {
+        let key = "test.credential"
+        let data = Data("secret-password".utf8)
+        
+        defer {
+            try? KeychainHelper.shared.delete(service: testService, key: key)
+        }
+        
+        try await KeychainHelper.shared.set(
+            data,
+            service: testService,
+            key: key,
+            accessibility: .afterFirstUnlock
+        )
+        
+        let retrieved = try await KeychainHelper.shared.get(service: testService, key: key)
+        #expect(retrieved == data)
+    }
+    
+    @Test func keychainNotFoundReturnsNil() async throws {
+        let result = try await KeychainHelper.shared.get(
+            service: testService,
+            key: "nonexistent.\(UUID().uuidString)"
+        )
+        #expect(result == nil)
+    }
+    
+    @Test func keychainDeleteNonexistentDoesNotThrow() async throws {
+        // Should not throw even if item doesn't exist
+        try await KeychainHelper.shared.delete(
+            service: testService,
+            key: "nonexistent.\(UUID().uuidString)"
+        )
+    }
+    
+    @Test func keychainExists() async throws {
+        let key = "test.exists.\(UUID().uuidString)"
+        let data = Data("test".utf8)
+        
+        defer {
+            try? KeychainHelper.shared.delete(service: testService, key: key)
+        }
+        
+        let beforeExists = try await KeychainHelper.shared.exists(service: testService, key: key)
+        #expect(beforeExists == false)
+        
+        try await KeychainHelper.shared.set(
+            data,
+            service: testService,
+            key: key,
+            accessibility: .whenUnlocked
+        )
+        
+        let afterExists = try await KeychainHelper.shared.exists(service: testService, key: key)
+        #expect(afterExists == true)
+    }
+    
+    @Test func keychainUpdateReplacesData() async throws {
+        let key = "test.update.\(UUID().uuidString)"
+        let originalData = Data("original".utf8)
+        let updatedData = Data("updated".utf8)
+        
+        defer {
+            try? KeychainHelper.shared.delete(service: testService, key: key)
+        }
+        
+        try await KeychainHelper.shared.set(
+            originalData,
+            service: testService,
+            key: key,
+            accessibility: .afterFirstUnlock
+        )
+        
+        try await KeychainHelper.shared.set(
+            updatedData,
+            service: testService,
+            key: key,
+            accessibility: .afterFirstUnlock
+        )
+        
+        let retrieved = try await KeychainHelper.shared.get(service: testService, key: key)
+        #expect(retrieved == updatedData)
+    }
+    
+    @Test func keychainDeleteAll() async throws {
+        let deleteAllService = "LocalDataTests.DeleteAll.\(UUID().uuidString)"
+        let data = Data("test".utf8)
+        
+        // Create multiple items
+        for i in 0..<3 {
+            try await KeychainHelper.shared.set(
+                data,
+                service: deleteAllService,
+                key: "key\(i)",
+                accessibility: .afterFirstUnlock
+            )
+        }
+        
+        // Verify they exist
+        let exists0 = try await KeychainHelper.shared.exists(service: deleteAllService, key: "key0")
+        #expect(exists0 == true)
+        
+        // Delete all
+        try await KeychainHelper.shared.deleteAll(service: deleteAllService)
+        
+        // Verify they're gone
+        for i in 0..<3 {
+            let exists = try await KeychainHelper.shared.exists(service: deleteAllService, key: "key\(i)")
+            #expect(exists == false)
+        }
+    }
+    
+    // MARK: - Accessibility Options
+    
+    @Test(arguments: KeychainAccessibility.allCases)
+    func keychainAccessibilityOptions(accessibility: KeychainAccessibility) async throws {
+        let key = "test.accessibility.\(accessibility).\(UUID().uuidString)"
+        let data = Data("data-for-\(accessibility)".utf8)
+        
+        defer {
+            try? KeychainHelper.shared.delete(service: testService, key: key)
+        }
+        
+        try await KeychainHelper.shared.set(
+            data,
+            service: testService,
+            key: key,
+            accessibility: accessibility
+        )
+        
+        let retrieved = try await KeychainHelper.shared.get(service: testService, key: key)
+        #expect(retrieved == data)
+    }
+}
diff --git a/Tests/LocalDataTests/StorageCatalogTests.swift b/Tests/LocalDataTests/StorageCatalogTests.swift
new file mode 100644
index 0000000..45f3d34
--- /dev/null
+++ b/Tests/LocalDataTests/StorageCatalogTests.swift
@@ -0,0 +1,95 @@
+import Foundation
+import Testing
+@testable import LocalData
+
+// MARK: - Test Keys
+
+private struct TestCatalogKey: StorageKey {
+    typealias Value = String
+    
+    let name: String
+    let domain: StorageDomain = .userDefaults(suite: nil)
+    let security: SecurityPolicy = .none
+    let serializer: Serializer<String> = .json
+    let owner: String = "CatalogTests"
+    let description: String
+    let availability: PlatformAvailability = .all
+    let syncPolicy: SyncPolicy = .never
+    
+    init(name: String, description: String = "Test key") {
+        self.name = name
+        self.description = description
+    }
+}
+
+// MARK: - Test Catalogs
+
+private struct ValidCatalog: StorageKeyCatalog {
+    static var allKeys: [AnyStorageKey] {
+        [
+            .key(TestCatalogKey(name: "valid.key1", description: "First test key")),
+            .key(TestCatalogKey(name: "valid.key2", description: "Second test key"))
+        ]
+    }
+}
+
+private struct DuplicateNameCatalog: StorageKeyCatalog {
+    static var allKeys: [AnyStorageKey] {
+        [
+            .key(TestCatalogKey(name: "duplicate.name", description: "First instance")),
+            .key(TestCatalogKey(name: "duplicate.name", description: "Second instance"))
+        ]
+    }
+}
+
+private struct EmptyCatalog: StorageKeyCatalog {
+    static var allKeys: [AnyStorageKey] { [] }
+}
+
+// MARK: - Tests
+
+struct StorageCatalogTests {
+    
+    @Test func auditReportContainsAllKeys() {
+        let items = StorageAuditReport.items(for: ValidCatalog.self)
+        
+        #expect(items.count == 2)
+        #expect(items[0].name == "valid.key1")
+        #expect(items[1].name == "valid.key2")
+    }
+    
+    @Test func auditReportRendersText() {
+        let report = StorageAuditReport.renderText(for: ValidCatalog.self)
+        
+        #expect(report.contains("valid.key1"))
+        #expect(report.contains("valid.key2"))
+        #expect(report.contains("First test key"))
+        #expect(report.contains("Second test key"))
+    }
+    
+    @Test func descriptorCapturesKeyMetadata() {
+        let key = TestCatalogKey(name: "metadata.test", description: "Metadata test key")
+        let anyKey = AnyStorageKey.key(key)
+        let descriptor = anyKey.descriptor
+        
+        #expect(descriptor.name == "metadata.test")
+        #expect(descriptor.owner == "CatalogTests")
+        #expect(descriptor.description == "Metadata test key")
+        #expect(descriptor.valueType == "String")
+    }
+    
+    @Test func emptyReportForEmptyCatalog() {
+        let items = StorageAuditReport.items(for: EmptyCatalog.self)
+        #expect(items.isEmpty)
+        
+        let report = StorageAuditReport.renderText(for: EmptyCatalog.self)
+        #expect(report.isEmpty)
+    }
+    
+    @Test func catalogRegistrationDetectsDuplicates() async {
+        // Attempting to register a catalog with duplicate key names should throw
+        await #expect(throws: StorageError.self) {
+            try await StorageRouter.shared.registerCatalog(DuplicateNameCatalog.self)
+        }
+    }
+}