diff --git a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIChatCompletion.scala b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIChatCompletion.scala
index 57837ad276..703fc7f471 100644
--- a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIChatCompletion.scala
+++ b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIChatCompletion.scala
@@ -38,7 +38,7 @@ class OpenAIChatCompletion(override val uid: String) extends OpenAIServicesBase(
     s"${getUrl}openai/deployments/${getValue(row, deploymentName)}/chat/completions"
   }
 
-  override protected def prepareEntity: Row => Option[AbstractHttpEntity] = {
+  override protected[openai] def prepareEntity: Row => Option[AbstractHttpEntity] = {
     r =>
       lazy val optionalParams: Map[String, Any] = getOptionalParams(r)
       val messages = r.getAs[Seq[Row]](getMessagesCol)
diff --git a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAICompletion.scala b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAICompletion.scala
index 304addaf66..953138bc36 100644
--- a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAICompletion.scala
+++ b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAICompletion.scala
@@ -37,7 +37,7 @@ class OpenAICompletion(override val uid: String) extends OpenAIServicesBase(uid)
     s"${getUrl}openai/deployments/${getValue(row, deploymentName)}/completions"
   }
 
-  override protected def prepareEntity: Row => Option[AbstractHttpEntity] = {
+  override protected[openai] def prepareEntity: Row => Option[AbstractHttpEntity] = {
     r =>
       lazy val optionalParams: Map[String, Any] = getOptionalParams(r)
       getValueOpt(r, prompt)
diff --git a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPrompt.scala b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPrompt.scala
index b17b5c59c1..47f2de6204 100644
--- a/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPrompt.scala
+++ b/cognitive/src/main/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPrompt.scala
@@ -9,12 +9,13 @@ import com.microsoft.azure.synapse.ml.core.spark.Functions
 import com.microsoft.azure.synapse.ml.io.http.{ConcurrencyParams, HasErrorCol, HasURL}
 import com.microsoft.azure.synapse.ml.logging.{FeatureNames, SynapseMLLogging}
 import com.microsoft.azure.synapse.ml.param.StringStringMapParam
+import org.apache.http.entity.AbstractHttpEntity
 import org.apache.spark.ml.param.{BooleanParam, Param, ParamMap, ParamValidators}
 import org.apache.spark.ml.util.Identifiable
 import org.apache.spark.ml.{ComplexParamsReadable, ComplexParamsWritable, Transformer}
 import org.apache.spark.sql.functions.udf
 import org.apache.spark.sql.types.{DataType, StructType}
-import org.apache.spark.sql.{Column, DataFrame, Dataset, functions => F, types => T}
+import org.apache.spark.sql.{Column, DataFrame, Dataset, Row, functions => F, types => T}
 
 import scala.collection.JavaConverters._
 
@@ -25,6 +26,7 @@ class OpenAIPrompt(override val uid: String) extends Transformer
   with HasErrorCol with HasOutputCol
   with HasURL with HasCustomCogServiceDomain with ConcurrencyParams
   with HasSubscriptionKey with HasAADToken with HasCustomAuthHeader
+  with HasOpenAICognitiveServiceInput
   with ComplexParamsWritable with SynapseMLLogging {
 
   logClass(FeatureNames.AiServices.OpenAI)
@@ -174,6 +176,16 @@ class OpenAIPrompt(override val uid: String) extends Transformer
     completion
   }
 
+  override protected def prepareEntity: Row => Option[AbstractHttpEntity] = {
+    r =>
+      openAICompletion match {
+        case chatCompletion: OpenAIChatCompletion =>
+          chatCompletion.prepareEntity(r)
+        case completion: OpenAICompletion =>
+          completion.prepareEntity(r)
+      }
+  }
+
   private def getParser: OutputParser = {
     val opts = getPostProcessingOptions
 
diff --git a/cognitive/src/test/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPromptSuite.scala b/cognitive/src/test/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPromptSuite.scala
index 6282067b0d..773cbe7547 100644
--- a/cognitive/src/test/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPromptSuite.scala
+++ b/cognitive/src/test/scala/com/microsoft/azure/synapse/ml/services/openai/OpenAIPromptSuite.scala
@@ -112,6 +112,33 @@ class OpenAIPromptSuite extends TransformerFuzzing[OpenAIPrompt] with OpenAIAPIK
       .foreach(r => assert(r.get(0) != null))
   }
 
+  ignore("Custom EndPoint") {
+    lazy val accessToken: String = sys.env.getOrElse("CUSTOM_ACCESS_TOKEN", "")
+    lazy val customRootUrlValue: String = sys.env.getOrElse("CUSTOM_ROOT_URL", "")
+    lazy val customHeadersValues: Map[String, String] = Map("X-ModelType" -> "gpt-4-turbo-chat-completions")
+
+    lazy val customPromptGpt4: OpenAIPrompt = new OpenAIPrompt()
+      .setCustomUrlRoot(customRootUrlValue)
+      .setOutputCol("outParsed")
+      .setTemperature(0)
+
+    if (accessToken.isEmpty) {
+      customPromptGpt4.setSubscriptionKey(openAIAPIKey)
+        .setDeploymentName(deploymentNameGpt4)
+        .setCustomServiceName(openAIServiceName)
+    } else {
+      customPromptGpt4.setAADToken(accessToken)
+        .setCustomHeaders(customHeadersValues)
+    }
+
+    customPromptGpt4.setPromptTemplate("here is a comma separated list of 5 {category}: {text}, ")
+      .setPostProcessing("csv")
+      .transform(df)
+      .select("outParsed")
+      .collect()
+      .count(r => Option(r.getSeq[String](0)).isDefined)
+  }
+
   override def assertDFEq(df1: DataFrame, df2: DataFrame)(implicit eq: Equality[DataFrame]): Unit = {
     super.assertDFEq(df1.drop("out", "outParsed"), df2.drop("out", "outParsed"))(eq)
   }