diff --git a/config/detekt/baseline.xml b/config/detekt/baseline.xml
index b805dc4..717fd7b 100644
--- a/config/detekt/baseline.xml
+++ b/config/detekt/baseline.xml
@@ -19,8 +19,8 @@
     <ID>FunctionParameterNaming:UpdateDeeplinks.kt$UpdateDeeplinks$brand_guid: String</ID>
     <ID>FunctionParameterNaming:UpdateDeeplinks.kt$UpdateDeeplinks$install_type: InstallType</ID>
     <ID>FunctionParameterNaming:UpdateDeeplinks.kt$UpdateDeeplinks$install_url: String</ID>
-    <ID>LongParameterList:Bitlinks.kt$Bitlinks$( bitlink: String, title: String = Constants.EMPTY, archived: Boolean = false, tags: Array&lt;String&gt; = emptyArray(), deeplinks: UpdateDeeplinks = UpdateDeeplinks(), toJson: Boolean = false )</ID>
-    <ID>LongParameterList:Bitlinks.kt$Bitlinks$( long_url: String, domain: String = Constants.EMPTY, group_guid: String = Constants.EMPTY, title: String = Constants.EMPTY, tags: Array&lt;String&gt; = emptyArray(), deeplinks: CreateDeeplinks = CreateDeeplinks(), toJson: Boolean = false )</ID>
+    <ID>LongParameterList:Bitlinks.kt$Bitlinks$( bitlink: String, title: String = Constants.EMPTY, archived: Boolean = false, tags: List&lt;String&gt; = emptyList(), deeplinks: UpdateDeeplinks = UpdateDeeplinks(), toJson: Boolean = false )</ID>
+    <ID>LongParameterList:Bitlinks.kt$Bitlinks$( long_url: String, domain: String = Constants.EMPTY, group_guid: String = Constants.EMPTY, title: String = Constants.EMPTY, tags: List&lt;String&gt; = emptyList(), deeplinks: CreateDeeplinks = CreateDeeplinks(), toJson: Boolean = false )</ID>
     <ID>MagicNumber:CallResponse.kt$CallResponse$200</ID>
     <ID>MagicNumber:CallResponse.kt$CallResponse$201</ID>
     <ID>MagicNumber:CallResponse.kt$CallResponse$299</ID>
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt b/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
index 78ec984..f7cb3a4 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/Bitlinks.kt
@@ -136,7 +136,7 @@ open class Bitlinks(private val accessToken: String) {
         domain: String = Constants.EMPTY,
         group_guid: String = Constants.EMPTY,
         title: String = Constants.EMPTY,
-        tags: Array<String> = emptyArray(),
+        tags: List<String> = emptyList(),
         deeplinks: CreateDeeplinks = CreateDeeplinks(),
         toJson: Boolean = false
     ): String {
@@ -282,7 +282,7 @@ open class Bitlinks(private val accessToken: String) {
         bitlink: String,
         title: String = Constants.EMPTY,
         archived: Boolean = false,
-        tags: Array<String> = emptyArray(),
+        tags: List<String> = emptyList(),
         deeplinks: UpdateDeeplinks = UpdateDeeplinks(),
         toJson: Boolean = false
     ): String {
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt b/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
index dca27c2..956a640 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/Utils.kt
@@ -124,7 +124,7 @@ object Utils {
         var message = response.message
         var description = ""
         var json = Constants.EMPTY_JSON
-        response.body?.string()?.let { body ->
+        response.body.string().let { body ->
             json = body
             if (!response.isSuccessful && body.isNotEmpty()) {
                 try {
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt b/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
index 25503b7..928cee1 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/CreateConfig.kt
@@ -60,7 +60,7 @@ class CreateConfig private constructor(builder: Builder) {
         var domain: String = Constants.EMPTY
         var group_guid: String = Constants.EMPTY
         var title: String = Constants.EMPTY
-        var tags: Array<String> = emptyArray()
+        var tags: List<String> = emptyList()
         var deeplinks: CreateDeeplinks = CreateDeeplinks()
         var toJson: Boolean = false
 
@@ -76,7 +76,7 @@ class CreateConfig private constructor(builder: Builder) {
 
         fun title(title: String): Builder = apply { this.title = title }
 
-        fun tags(tags: Array<String>): Builder = apply { this.tags = tags }
+        fun tags(tags: List<String>): Builder = apply { this.tags = tags }
 
         fun deeplinks(deeplinks: CreateDeeplinks): Builder = apply { this.deeplinks = deeplinks }
 
diff --git a/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt b/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
index d531d1b..52ba5ab 100644
--- a/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
+++ b/src/main/kotlin/net/thauvin/erik/bitly/config/UpdateConfig.kt
@@ -57,7 +57,7 @@ class UpdateConfig private constructor(builder: Builder) {
     data class Builder(var bitlink: String) {
         var title: String = Constants.EMPTY
         var archived: Boolean = false
-        var tags: Array<String> = emptyArray()
+        var tags: List<String> = emptyList()
         var deeplinks: UpdateDeeplinks = UpdateDeeplinks()
         var toJson: Boolean = false
 
@@ -68,7 +68,7 @@ class UpdateConfig private constructor(builder: Builder) {
 
         fun title(title: String): Builder = apply { this.title = title }
         fun archived(archived: Boolean): Builder = apply { this.archived = archived }
-        fun tags(tags: Array<String>): Builder = apply { this.tags = tags }
+        fun tags(tags: List<String>): Builder = apply { this.tags = tags }
         fun deeplinks(deeplinks: UpdateDeeplinks): Builder = apply { this.deeplinks = deeplinks }
 
         /**
diff --git a/src/test/kotlin/net/thauvin/erik/bitly/BitlinksTests.kt b/src/test/kotlin/net/thauvin/erik/bitly/BitlinksTests.kt
index ac33bd3..9c0bec0 100644
--- a/src/test/kotlin/net/thauvin/erik/bitly/BitlinksTests.kt
+++ b/src/test/kotlin/net/thauvin/erik/bitly/BitlinksTests.kt
@@ -47,10 +47,12 @@ import org.junit.jupiter.api.Test
 import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable
 import org.junit.jupiter.api.extension.ExtendWith
 import java.io.File
+import java.util.*
 import kotlin.test.assertEquals
 import kotlin.test.assertFailsWith
 import kotlin.test.assertTrue
 
+
 @ExtendWith(BeforeAllTests::class)
 class BitlinksTests {
     private val bitly = with(File("local.properties")) {
@@ -91,9 +93,113 @@ class BitlinksTests {
         }
     }
 
+    @Nested
+    @DisplayName("Constructor Tests")
+    inner class ConstructorTests {
+        @Test
+        fun `Constructor with access token string should set the token correctly`() {
+            // Arrange
+            val expectedToken = "my-secret-token"
+
+            // Act
+            val bitly = Bitly(expectedToken)
+
+            // Assert
+            assertThat(bitly.accessToken).isEqualTo(expectedToken)
+        }
+
+        @Test
+        fun `Constructor with Path should not change token if file does not exist`() {
+            // Arrange
+            val nonExistentPath = File("non/existent/path/file.properties").toPath()
+            val bitlyWithDefaultToken = Bitly()
+            val initialToken = bitlyWithDefaultToken.accessToken
+
+            // Act
+            val bitly = Bitly(nonExistentPath)
+
+            // Assert
+            assertThat(bitly.accessToken).isEqualTo(initialToken)
+        }
+
+        @Test
+        fun `Constructor with Properties and custom key should set token correctly`() {
+            // Arrange
+            val customKey = "MY_CUSTOM_BITLY_KEY"
+            val expectedToken = "token-from-custom-key"
+            val properties = Properties().apply {
+                setProperty(customKey, expectedToken)
+            }
+
+            // Act
+            val bitly = Bitly(properties, customKey)
+
+            // Assert
+            assertThat(bitly.accessToken).isEqualTo(expectedToken)
+        }
+
+        @Test
+        fun `Constructor with Properties should keep default token if key not found`() {
+            // Arrange
+            val properties = Properties() // Empty properties
+            val bitlyWithDefaultToken = Bitly() // Has "" as token by default
+            val initialToken = bitlyWithDefaultToken.accessToken
+
+            // Act
+            val bitly = Bitly(properties, "non-existent-key")
+
+            // Assert
+            // The token should remain the default empty string
+            assertThat(bitly.accessToken).isEqualTo(initialToken)
+        }
+
+        @Test
+        fun `Constructor with Properties should set token using default key`() {
+            // Arrange
+            val expectedToken = "token-from-props"
+            val properties = Properties().apply {
+                setProperty(Constants.ENV_ACCESS_TOKEN, expectedToken)
+            }
+
+            // Act
+            val bitly = Bitly(properties)
+
+            // Assert
+            assertThat(bitly.accessToken).isEqualTo(expectedToken)
+        }
+
+        @Test
+        fun `Default constructor should default to empty string if no token is provided`() {
+            // Arrange: Ensure no env var or system property is set
+            System.clearProperty(Constants.ENV_ACCESS_TOKEN)
+            // Note: Testing environment variables directly is often avoided in unit tests.
+            // This test verifies the fallback mechanism.
+
+            // Act
+            val bitly = Bitly()
+
+            // Assert
+            assertThat(bitly.accessToken).isEmpty()
+        }
+
+        @Test
+        fun `Default constructor should use system property if env var is not set`() {
+            // Arrange
+            val expectedToken = "token-from-property"
+            System.setProperty(Constants.ENV_ACCESS_TOKEN, expectedToken)
+
+            // Act
+            val bitly = Bitly()
+
+            // Assert
+            assertThat(bitly.accessToken).isEqualTo(expectedToken)
+        }
+    }
+
     @Nested
     @DisplayName("Create Bitlink Tests")
     inner class CreateBitlinkTests {
+
         @Test
         fun `Create bitlink`() {
             assertThat(bitly.bitlinks().create(long_url = longUrl), "create(longUrl)")
@@ -103,7 +209,7 @@ class BitlinksTests {
                 bitly.bitlinks().create(
                     domain = "bit.ly",
                     title = "Erik's Blog",
-                    tags = arrayOf("erik", "thauvin", "blog", "weblog"),
+                    tags = listOf("erik", "thauvin", "blog", "weblog"),
                     long_url = longUrl
                 )
             )
@@ -118,7 +224,7 @@ class BitlinksTests {
             config = CreateConfig.Builder(longUrl)
                 .domain("bit.ly")
                 .title("Erik's Blog")
-                .tags(arrayOf("erik", "thauvin", "blog", "weblog"))
+                .tags(listOf("erik", "thauvin", "blog", "weblog"))
                 .build()
             assertEquals(
                 shortUrl,
@@ -148,6 +254,7 @@ class BitlinksTests {
     @Nested
     @DisplayName("Expand Test")
     inner class ExpandTests {
+
         @Test
         fun `Expand as json`() {
             assertTrue(
@@ -165,6 +272,7 @@ class BitlinksTests {
     @Nested
     @DisplayName("Shorten Tests")
     inner class ShortenTests {
+
         @Test
         fun `Shorten as json`() {
             assertTrue(
@@ -218,17 +326,18 @@ class BitlinksTests {
     @Nested
     @DisplayName("Update Bitlink Tests")
     inner class UpdateBitlinkTests {
+
         @Test
         fun `Update bitlink`() {
             val bl = bitly.bitlinks()
             assertEquals(
                 Constants.TRUE,
                 bl.update(
-                    shortUrl, title = "Erik's Weblog", tags = arrayOf("blog", "weblog"), archived = true
+                    shortUrl, title = "Erik's Weblog", tags = listOf("blog", "weblog"), archived = true
                 )
             )
 
-            assertThat(bl.update(shortUrl, tags = emptyArray(), toJson = true), "update(tags)")
+            assertThat(bl.update(shortUrl, tags = emptyList(), toJson = true), "update(tags)")
                 .contains("\"tags\":[]")
         }
 
@@ -237,7 +346,7 @@ class BitlinksTests {
             val bl = bitly.bitlinks()
             var config = UpdateConfig.Builder(shortUrl)
                 .archived(true)
-                .tags(arrayOf("blog", "weblog"))
+                .tags(listOf("blog", "weblog"))
                 .title("Erik's Weblog")
                 .build()
 
@@ -279,6 +388,7 @@ class BitlinksTests {
     @Nested
     @DisplayName("Validation Tests")
     inner class ValidationTests {
+
         @Test
         fun `Empty URL should not shorten`() {
             assertEquals(Constants.EMPTY, bitly.bitlinks().shorten(Constants.EMPTY))
@@ -289,13 +399,6 @@ class BitlinksTests {
             assertEquals(shortUrl, bitly.bitlinks().shorten(shortUrl))
         }
 
-        @Test
-        fun `Token not specified with API call`() {
-            assertFailsWith(IllegalArgumentException::class, "Utils.call()") {
-                Utils.call("", "foo")
-            }
-        }
-
         @Test
         @DisableOnCi
         fun `Token not specified`() {
@@ -316,6 +419,13 @@ class BitlinksTests {
             }
         }
 
+        @Test
+        fun `Token not specified with API call`() {
+            assertFailsWith(IllegalArgumentException::class, "Utils.call()") {
+                Utils.call("", "foo")
+            }
+        }
+
         @Test
         fun `Token should be valid`() {
             val test = Bitly().apply { accessToken = "12345679" }
diff --git a/src/test/kotlin/net/thauvin/erik/bitly/UtilsTests.kt b/src/test/kotlin/net/thauvin/erik/bitly/UtilsTests.kt
index a9a878b..66f31e5 100644
--- a/src/test/kotlin/net/thauvin/erik/bitly/UtilsTests.kt
+++ b/src/test/kotlin/net/thauvin/erik/bitly/UtilsTests.kt
@@ -51,6 +51,11 @@ class UtilsTests {
             assertThat("".toEndPoint()).isEqualTo("")
         }
 
+        @Test
+        fun `Convert endpoint with blank string`() {
+            assertThat(" ".toEndPoint()).isEqualTo(" ")
+        }
+
         @Test
         fun `Convert endpoint with full URL`() {
             assertThat("https://example.com/path".toEndPoint()).isEqualTo("https://example.com/path")
@@ -102,13 +107,17 @@ class UtilsTests {
         }
     }
 
-    @Test
-    fun `Validate invalid URL`() {
-        assertFalse("this is a test".isValidUrl(), "invalid url")
-    }
+    @Nested
+    @DisplayName("URL Validation Tests")
+    inner class URLValidationTests {
+        @Test
+        fun `Validate invalid URL`() {
+            assertFalse("this is a test".isValidUrl(), "invalid url")
+        }
 
-    @Test
-    fun `Validate URL`() {
-        assertTrue("https://www.example.com".isValidUrl(), "valid url")
+        @Test
+        fun `Validate URL`() {
+            assertTrue("https://www.example.com".isValidUrl(), "valid url")
+        }
     }
 }
diff --git a/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTests.kt b/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTests.kt
index 09c45ed..42f9b13 100644
--- a/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTests.kt
+++ b/src/test/kotlin/net/thauvin/erik/bitly/config/ConfigTests.kt
@@ -61,7 +61,7 @@ class ConfigTests {
                 .deeplinks(deeplinks)
                 .domain("domain")
                 .groupGuid("group_guid")
-                .tags(arrayOf("tag", "tag2"))
+                .tags(listOf("tag", "tag2"))
                 .title("title")
                 .build()
 
@@ -70,13 +70,13 @@ class ConfigTests {
                 prop(CreateConfig::domain).isEqualTo("domain")
                 prop(CreateConfig::group_guid).isEqualTo("group_guid")
                 prop(CreateConfig::long_url).isEqualTo("long_url")
-                prop(CreateConfig::tags).isEqualTo(arrayOf("tag", "tag2"))
+                prop(CreateConfig::tags).isEqualTo(listOf("tag", "tag2"))
                 prop(CreateConfig::title).isEqualTo("title")
                 prop(CreateConfig::toJson).isEqualTo(false)
             }
 
             val map = mapOf(
-                "deeplinks" to arrayOf(deeplinks.links()),
+                "deeplinks" to listOf(deeplinks.links()),
                 "domain" to config.domain,
                 "group_guid" to config.group_guid,
                 "long_url" to config.long_url,
@@ -103,7 +103,7 @@ class ConfigTests {
         val config = UpdateConfig.Builder("blink")
             .archived(true)
             .deeplinks(deeplinks)
-            .tags(arrayOf("tag", "tag2"))
+            .tags(listOf("tag", "tag2"))
             .title("title")
             .build()
 
@@ -111,7 +111,7 @@ class ConfigTests {
             prop(UpdateConfig::archived).isTrue()
             prop(UpdateConfig::bitlink).isEqualTo("blink")
             prop(UpdateConfig::deeplinks).isEqualTo(deeplinks)
-            prop(UpdateConfig::tags).isEqualTo(arrayOf("tag", "tag2"))
+            prop(UpdateConfig::tags).isEqualTo(listOf("tag", "tag2"))
             prop(UpdateConfig::title).isEqualTo("title")
             prop(UpdateConfig::toJson).isEqualTo(false)
         }
@@ -119,7 +119,7 @@ class ConfigTests {
         val map = mapOf(
             "archived" to config.archived,
             "bitlink" to config.bitlink,
-            "deeplinks" to arrayOf(deeplinks.links()),
+            "deeplinks" to listOf(deeplinks.links()),
             "tags" to config.tags,
             "title" to config.title
         )
@@ -145,7 +145,7 @@ class ConfigTests {
                 .deeplinks(deeplinks)
                 .domain("domain")
                 .groupGuid("group_guid")
-                .tags(arrayOf("tag", "tag2"))
+                .tags(listOf("tag", "tag2"))
                 .title("title")
                 .toJson(true)
 
@@ -154,7 +154,7 @@ class ConfigTests {
                 prop(CreateConfig.Builder::domain).isEqualTo("domain")
                 prop(CreateConfig.Builder::group_guid).isEqualTo("group_guid")
                 prop(CreateConfig.Builder::long_url).isEqualTo("long_url")
-                prop(CreateConfig.Builder::tags).isEqualTo(arrayOf("tag", "tag2"))
+                prop(CreateConfig.Builder::tags).isEqualTo(listOf("tag", "tag2"))
                 prop(CreateConfig.Builder::title).isEqualTo("title")
                 prop(CreateConfig.Builder::toJson).isTrue()
             }
@@ -172,7 +172,7 @@ class ConfigTests {
                 prop(CreateConfig.Builder::domain).isEqualTo(Constants.EMPTY)
                 prop(CreateConfig.Builder::group_guid).isEqualTo(Constants.EMPTY)
                 prop(CreateConfig.Builder::title).isEqualTo(Constants.EMPTY)
-                prop(CreateConfig.Builder::tags).isEqualTo(emptyArray())
+                prop(CreateConfig.Builder::tags).isEqualTo(emptyList())
                 prop(CreateConfig.Builder::deeplinks).prop(CreateDeeplinks::links).isEqualTo(CreateDeeplinks().links())
                 prop(CreateConfig.Builder::toJson).isEqualTo(false)
             }
@@ -189,7 +189,7 @@ class ConfigTests {
             val config = UpdateConfig.Builder("bitlink")
                 .title("title")
                 .archived(true)
-                .tags(arrayOf("tag", "tag2"))
+                .tags(listOf("tag", "tag2"))
                 .deeplinks(deeplinks)
                 .toJson(true)
 
@@ -197,7 +197,7 @@ class ConfigTests {
                 prop(UpdateConfig.Builder::bitlink).isEqualTo("bitlink")
                 prop(UpdateConfig.Builder::title).isEqualTo("title")
                 prop(UpdateConfig.Builder::archived).isTrue()
-                prop(UpdateConfig.Builder::tags).isEqualTo(arrayOf("tag", "tag2"))
+                prop(UpdateConfig.Builder::tags).isEqualTo(listOf("tag", "tag2"))
                 prop(UpdateConfig.Builder::deeplinks).isEqualTo(deeplinks)
                 prop(UpdateConfig.Builder::toJson).isTrue()
             }
@@ -214,7 +214,7 @@ class ConfigTests {
                 prop(UpdateConfig.Builder::bitlink).isEqualTo("bitlink")
                 prop(UpdateConfig.Builder::title).isEqualTo(Constants.EMPTY)
                 prop(UpdateConfig.Builder::archived).isEqualTo(false)
-                prop(UpdateConfig.Builder::tags).isEqualTo(emptyArray())
+                prop(UpdateConfig.Builder::tags).isEqualTo(emptyList())
                 prop(UpdateConfig.Builder::deeplinks).prop(UpdateDeeplinks::links).isEqualTo(UpdateDeeplinks().links())
                 prop(UpdateConfig.Builder::toJson).isEqualTo(false)
             }