diff --git a/openai-client/src/commonMain/kotlin/com.aallam.openai.client/OpenAIConfig.kt b/openai-client/src/commonMain/kotlin/com.aallam.openai.client/OpenAIConfig.kt
index a3e20d7b..28a02a2c 100644
--- a/openai-client/src/commonMain/kotlin/com.aallam.openai.client/OpenAIConfig.kt
+++ b/openai-client/src/commonMain/kotlin/com.aallam.openai.client/OpenAIConfig.kt
@@ -99,6 +99,11 @@ public class OpenAIHost(
          */
         public val OpenAI: OpenAIHost = OpenAIHost(baseUrl = "https://api.openai.com/v1/")
 
+        /**
+         * A pre-configured instance of [OpenAIHost] for Google Gemini`.
+         */
+        public val Gemini: OpenAIHost = OpenAIHost(baseUrl = "https://generativelanguage.googleapis.com/v1beta/openai/")
+
         /**
          * Creates an instance of [OpenAIHost] configured for Azure hosting with the given resource name, deployment ID,
          * and API version.
diff --git a/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletion.kt b/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletion.kt
index eb0c94b8..5f8285ae 100644
--- a/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletion.kt
+++ b/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletion.kt
@@ -15,7 +15,7 @@ public data class ChatCompletion(
     /**
      * A unique id assigned to this completion
      */
-    @SerialName("id") public val id: String,
+    @SerialName("id") public val idOrNull: String? = null,
     /**
      * The creation time in epoch milliseconds.
      */
@@ -43,4 +43,9 @@ public data class ChatCompletion(
      * might impact determinism.
      */
     @SerialName("system_fingerprint") public val systemFingerprint: String? = null,
-)
+
+    @SerialName("citations") public val citations: List<String>? = null,
+) {
+    val id: String
+        get() = requireNotNull(idOrNull)
+}
diff --git a/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionChunk.kt b/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionChunk.kt
index bdde1808..c4fe5364 100644
--- a/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionChunk.kt
+++ b/openai-core/src/commonMain/kotlin/com.aallam.openai.api/chat/ChatCompletionChunk.kt
@@ -16,7 +16,7 @@ public data class ChatCompletionChunk(
      * A unique id assigned to this completion
      */
     @SerialName("id")
-    public val id: String,
+    public val id: String? = null,
 
     /**
      * The creation time in epoch milliseconds.
@@ -48,4 +48,7 @@ public data class ChatCompletionChunk(
      */
     @SerialName("system_fingerprint")
     public val systemFingerprint: String? = null,
+
+    @SerialName("citations")
+    public val citations: List<String>? = null,
 )