diff --git a/core/common/build.gradle.kts b/core/common/build.gradle.kts
index a22788079..ac0f99183 100644
--- a/core/common/build.gradle.kts
+++ b/core/common/build.gradle.kts
@@ -10,7 +10,10 @@ android {
 }
 
 dependencies {
+    implementation(projects.core.domain)
     implementation(libs.androidx.work.runtime.ktx)
+    implementation(libs.kakao.sdk.auth)
+    implementation(libs.kakao.sdk.user)
 
     // BiometricCryptoGate 가 BiometricPrompt.CryptoObject 를 공개 시그니처로 돌려주므로
     // 소비 모듈의 컴파일 클래스패스에도 올라가야 한다 — implementation 이면 반환 타입을 못 본다.
diff --git a/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/social/KakaoLinkHelper.kt b/core/common/src/main/kotlin/com/afternote/core/common/auth/KakaoAccessToken.kt
similarity index 58%
rename from feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/social/KakaoLinkHelper.kt
rename to core/common/src/main/kotlin/com/afternote/core/common/auth/KakaoAccessToken.kt
index 7a4335826..facdc58dc 100644
--- a/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/social/KakaoLinkHelper.kt
+++ b/core/common/src/main/kotlin/com/afternote/core/common/auth/KakaoAccessToken.kt
@@ -1,4 +1,4 @@
-package com.afternote.feature.setting.presentation.account.social
+package com.afternote.core.common.auth
 
 import android.app.Activity
 import com.afternote.core.domain.error.CoreAuthFailure
@@ -9,8 +9,22 @@ import com.kakao.sdk.user.UserApiClient
 import kotlinx.coroutines.suspendCancellableCoroutine
 import kotlin.coroutines.resume
 
-suspend fun requestKakaoAccessToken(activity: Activity): Result<String> =
+/**
+ * 카카오 SDK로부터 OAuth 액세스 토큰을 획득한다.
+ *
+ * 플랫폼 SDK가 [Activity] 컨텍스트를 요구하므로 이 함수는 UI 레이어(화면)에서 호출한다.
+ * Data 레이어(Repository)에는 획득한 액세스 토큰 문자열만 전달되어,
+ * Data 레이어가 UI 컴포넌트(Activity)에 의존하지 않도록 한다.
+ * 카카오 로그인(온보딩)과 카카오 계정 연결(설정)이 같은 흐름을 쓰므로 feature 가 아닌 core 에 한 벌을 둔다 (#2194).
+ *
+ * 디바이스에 카카오톡이 설치된 경우 앱 로그인을, 그 외에는 웹 계정 로그인을 수행하며,
+ * 앱 로그인이 비정상 종료된 경우에는 웹 계정 로그인으로 폴백한다.
+ * 사용자가 로그인을 취소하면 폴백 없이 [CoreAuthFailure.UserCancelledAuth] 로 실패한다.
+ * 콜백 기반 SDK API를 [suspendCancellableCoroutine]으로 감싸 코루틴 흐름으로 변환한다.
+ */
+public suspend fun requestKakaoAccessToken(activity: Activity): Result<String> =
     suspendCancellableCoroutine { continuation ->
+        // 공통 콜백: 카카오톡 앱 로그인·웹 계정 로그인 결과를 모두 처리한다.
         val callback: (OAuthToken?, Throwable?) -> Unit = { token, error ->
             if (continuation.isActive) {
                 when {
@@ -36,20 +50,24 @@ suspend fun requestKakaoAccessToken(activity: Activity): Result<String> =
         }
 
         if (UserApiClient.instance.isKakaoTalkLoginAvailable(activity)) {
+            // 카카오톡 앱이 설치된 경우: 앱 로그인 시도
             UserApiClient.instance.loginWithKakaoTalk(activity) { token, error ->
                 if (error != null) {
+                    // 사용자가 의도적으로 취소한 경우에는 폴백 없이 즉시 실패 처리
                     if (error is ClientError && error.reason == ClientErrorCause.Cancelled) {
                         if (continuation.isActive) {
                             continuation.resume(Result.failure(CoreAuthFailure.UserCancelledAuth()))
                         }
                         return@loginWithKakaoTalk
                     }
+                    // 그 외 에러(네트워크·앱 오류 등)는 웹 계정 로그인으로 폴백
                     UserApiClient.instance.loginWithKakaoAccount(activity, callback = callback)
                 } else {
                     callback(token, null)
                 }
             }
         } else {
+            // 카카오톡 앱이 없는 경우: 곧바로 웹 계정 로그인
             UserApiClient.instance.loginWithKakaoAccount(activity, callback = callback)
         }
     }
diff --git a/feature/setting/presentation/build.gradle.kts b/feature/setting/presentation/build.gradle.kts
index 4eb2c8004..abc770b98 100644
--- a/feature/setting/presentation/build.gradle.kts
+++ b/feature/setting/presentation/build.gradle.kts
@@ -33,8 +33,6 @@ dependencies {
     implementation(projects.core.ui)
     implementation(libs.androidx.hilt.navigation.compose)
     implementation(libs.androidx.compose.runtime)
-    implementation(libs.kakao.sdk.auth)
-    implementation(libs.kakao.sdk.user)
     implementation(libs.androidx.biometric)
     implementation(libs.androidx.credentials)
     implementation(libs.androidx.credentials.play.services.auth)
diff --git a/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/ConnectedAccountsScreen.kt b/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/ConnectedAccountsScreen.kt
index 6e6d6295f..38eafcf3a 100644
--- a/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/ConnectedAccountsScreen.kt
+++ b/feature/setting/presentation/src/main/kotlin/com/afternote/feature/setting/presentation/account/ConnectedAccountsScreen.kt
@@ -12,13 +12,13 @@ import androidx.compose.ui.res.stringResource
 import androidx.credentials.CredentialManager
 import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.afternote.core.common.auth.requestKakaoAccessToken
 import com.afternote.core.domain.error.CoreAuthFailure
 import com.afternote.core.ui.findActivity
 import com.afternote.feature.setting.presentation.BuildConfig
 import com.afternote.feature.setting.presentation.R
 import com.afternote.feature.setting.presentation.account.social.KakaoAuthResult
 import com.afternote.feature.setting.presentation.account.social.requestGoogleIdToken
-import com.afternote.feature.setting.presentation.account.social.requestKakaoAccessToken
 import com.afternote.feature.setting.presentation.account.social.toKakaoAuthResult
 
 @Composable