diff --git a/libs/appflowy-ai-client/src/client.rs b/libs/appflowy-ai-client/src/client.rs
index 8622cc45..a3d5c2eb 100644
--- a/libs/appflowy-ai-client/src/client.rs
+++ b/libs/appflowy-ai-client/src/client.rs
@@ -1,6 +1,6 @@
 use crate::dto::{
   AIModel, ChatAnswer, ChatQuestion, CompleteTextResponse, CompletionType, CreateTextChatContext,
-  Document, EmbeddingRequest, EmbeddingResponse, LocalAIConfig, MessageData,
+  CustomPrompt, Document, EmbeddingRequest, EmbeddingResponse, LocalAIConfig, MessageData,
   RepeatedLocalAIPackage, RepeatedRelatedQuestion, SearchDocumentsRequest, SummarizeRowResponse,
   TranslateRowData, TranslateRowResponse,
 };
@@ -49,19 +49,29 @@ impl AppFlowyAIClient {
     Ok(())
   }
 
-  pub async fn completion_text(
+  pub async fn completion_text<T: Into<Option<CompletionType>>>(
     &self,
     text: &str,
-    completion_type: CompletionType,
+    completion_type: T,
+    custom_prompt: Option<CustomPrompt>,
     model: AIModel,
   ) -> Result<CompleteTextResponse, AIError> {
+    let completion_type = completion_type.into();
+
+    if completion_type.is_some() && custom_prompt.is_some() {
+      return Err(AIError::InvalidRequest(
+        "Cannot specify both completion_type and custom_prompt".to_string(),
+      ));
+    }
+
     if text.is_empty() {
       return Err(AIError::InvalidRequest("Empty text".to_string()));
     }
 
     let params = json!({
       "text": text,
-      "type": completion_type as u8,
+      "type": completion_type.map(|t| t as u8),
+      "custom_prompt": custom_prompt,
     });
 
     let url = format!("{}/completion", self.url);
@@ -76,19 +86,22 @@ impl AppFlowyAIClient {
       .into_data()
   }
 
-  pub async fn stream_completion_text(
+  pub async fn stream_completion_text<T: Into<Option<CompletionType>>>(
     &self,
     text: &str,
-    completion_type: CompletionType,
+    completion_type: T,
+    custom_prompt: Option<CustomPrompt>,
     model: AIModel,
   ) -> Result<impl Stream<Item = Result<Bytes, AIError>>, AIError> {
+    let completion_type = completion_type.into();
     if text.is_empty() {
       return Err(AIError::InvalidRequest("Empty text".to_string()));
     }
 
     let params = json!({
       "text": text,
-      "type": completion_type as u8,
+      "type": completion_type.map(|t| t as u8),
+      "custom_prompt": custom_prompt,
     });
 
     let url = format!("{}/completion/stream", self.url);
@@ -201,7 +214,7 @@ impl AppFlowyAIClient {
     chat_id: &str,
     content: &str,
     model: &AIModel,
-    metadata: Option<serde_json::Value>,
+    metadata: Option<Value>,
   ) -> Result<ChatAnswer, AIError> {
     let json = ChatQuestion {
       chat_id: chat_id.to_string(),
@@ -226,7 +239,7 @@ impl AppFlowyAIClient {
     &self,
     chat_id: &str,
     content: &str,
-    metadata: Option<serde_json::Value>,
+    metadata: Option<Value>,
     model: &AIModel,
   ) -> Result<impl Stream<Item = Result<Bytes, AIError>>, AIError> {
     let json = ChatQuestion {
@@ -251,7 +264,7 @@ impl AppFlowyAIClient {
     &self,
     chat_id: &str,
     content: &str,
-    metadata: Option<serde_json::Value>,
+    metadata: Option<Value>,
     model: &AIModel,
   ) -> Result<impl Stream<Item = Result<Bytes, AIError>>, AIError> {
     let json = ChatQuestion {
@@ -337,7 +350,7 @@ pub struct AIResponse<T> {
 
 impl<T> AIResponse<T>
 where
-  T: serde::de::DeserializeOwned + 'static,
+  T: DeserializeOwned + 'static,
 {
   pub async fn from_response(resp: reqwest::Response) -> Result<Self, anyhow::Error> {
     let status_code = resp.status();
diff --git a/libs/appflowy-ai-client/src/dto.rs b/libs/appflowy-ai-client/src/dto.rs
index 408bbcbe..b7b78dfa 100644
--- a/libs/appflowy-ai-client/src/dto.rs
+++ b/libs/appflowy-ai-client/src/dto.rs
@@ -205,7 +205,7 @@ impl Display for EmbeddingsModel {
 pub enum AIModel {
   #[default]
   DefaultModel = 0,
-  GPT35 = 1,
+  GPT4oMini = 1,
   GPT4o = 2,
   Claude3Sonnet = 3,
   Claude3Opus = 4,
@@ -215,7 +215,7 @@ impl AIModel {
   pub fn to_str(&self) -> &str {
     match self {
       AIModel::DefaultModel => "default-model",
-      AIModel::GPT35 => "gpt-3.5-turbo",
+      AIModel::GPT4oMini => "gpt-4o-mini",
       AIModel::GPT4o => "gpt-4o",
       AIModel::Claude3Sonnet => "claude-3-sonnet",
       AIModel::Claude3Opus => "claude-3-opus",
@@ -228,7 +228,8 @@ impl FromStr for AIModel {
 
   fn from_str(s: &str) -> Result<Self, Self::Err> {
     match s {
-      "gpt-3.5-turbo" => Ok(AIModel::GPT35),
+      "gpt-3.5-turbo" => Ok(AIModel::GPT4oMini),
+      "gpt-4o-mini" => Ok(AIModel::GPT4oMini),
       "gpt-4o" => Ok(AIModel::GPT4o),
       "claude-3-sonnet" => Ok(AIModel::Claude3Sonnet),
       "claude-3-opus" => Ok(AIModel::Claude3Opus),
@@ -364,3 +365,9 @@ impl Display for CreateTextChatContext {
     ))
   }
 }
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct CustomPrompt {
+  pub system: String,
+  pub user: Option<String>,
+}
diff --git a/libs/appflowy-ai-client/tests/chat_test/completion_test.rs b/libs/appflowy-ai-client/tests/chat_test/completion_test.rs
index 41f8d167..9a6d36a1 100644
--- a/libs/appflowy-ai-client/tests/chat_test/completion_test.rs
+++ b/libs/appflowy-ai-client/tests/chat_test/completion_test.rs
@@ -8,6 +8,7 @@ async fn continue_writing_test() {
     .completion_text(
       "I feel hungry",
       CompletionType::ContinueWriting,
+      None,
       AIModel::Claude3Sonnet,
     )
     .await
@@ -23,7 +24,8 @@ async fn improve_writing_test() {
     .completion_text(
       "I fell tired because i sleep not very well last night",
       CompletionType::ImproveWriting,
-      AIModel::GPT35,
+      None,
+      AIModel::GPT4oMini,
     )
     .await
     .unwrap();
@@ -39,7 +41,8 @@ async fn make_text_shorter_text() {
     .stream_completion_text(
       "I have an immense passion and deep-seated affection for Rust, a modern, multi-paradigm, high-performance programming language that I find incredibly satisfying to use due to its focus on safety, speed, and concurrency",
       CompletionType::MakeShorter,
-      AIModel::GPT35
+      None,
+      AIModel::GPT4oMini
     )
     .await
     .unwrap();
diff --git a/libs/appflowy-ai-client/tests/chat_test/context_test.rs b/libs/appflowy-ai-client/tests/chat_test/context_test.rs
index e82cda1c..61ba0717 100644
--- a/libs/appflowy-ai-client/tests/chat_test/context_test.rs
+++ b/libs/appflowy-ai-client/tests/chat_test/context_test.rs
@@ -14,7 +14,7 @@ async fn create_chat_context_test() {
   };
   client.create_chat_text_context(context).await.unwrap();
   let resp = client
-    .send_question(&chat_id, "Where I live?", &AIModel::GPT35, None)
+    .send_question(&chat_id, "Where I live?", &AIModel::GPT4oMini, None)
     .await
     .unwrap();
   // response will be something like:
diff --git a/libs/appflowy-ai-client/tests/chat_test/qa_test.rs b/libs/appflowy-ai-client/tests/chat_test/qa_test.rs
index 54a400e0..a01c2120 100644
--- a/libs/appflowy-ai-client/tests/chat_test/qa_test.rs
+++ b/libs/appflowy-ai-client/tests/chat_test/qa_test.rs
@@ -10,13 +10,13 @@ async fn qa_test() {
   client.health_check().await.unwrap();
   let chat_id = uuid::Uuid::new_v4().to_string();
   let resp = client
-    .send_question(&chat_id, "I feel hungry", &AIModel::GPT35, None)
+    .send_question(&chat_id, "I feel hungry", &AIModel::GPT4o, None)
     .await
     .unwrap();
   assert!(!resp.content.is_empty());
 
   let questions = client
-    .get_related_question(&chat_id, &1, &AIModel::GPT35)
+    .get_related_question(&chat_id, &1, &AIModel::GPT4oMini)
     .await
     .unwrap()
     .items;
@@ -29,7 +29,7 @@ async fn stop_stream_test() {
   client.health_check().await.unwrap();
   let chat_id = uuid::Uuid::new_v4().to_string();
   let mut stream = client
-    .stream_question(&chat_id, "I feel hungry", None, &AIModel::GPT35)
+    .stream_question(&chat_id, "I feel hungry", None, &AIModel::GPT4oMini)
     .await
     .unwrap();
 
@@ -51,7 +51,7 @@ async fn stream_test() {
   client.health_check().await.unwrap();
   let chat_id = uuid::Uuid::new_v4().to_string();
   let stream = client
-    .stream_question_v2(&chat_id, "I feel hungry", None, &AIModel::GPT35)
+    .stream_question_v2(&chat_id, "I feel hungry", None, &AIModel::GPT4oMini)
     .await
     .unwrap();
   let json_stream = JsonStream::<serde_json::Value>::new(stream);
diff --git a/libs/appflowy-ai-client/tests/row_test/summarize_test.rs b/libs/appflowy-ai-client/tests/row_test/summarize_test.rs
index 7945d93e..223debe0 100644
--- a/libs/appflowy-ai-client/tests/row_test/summarize_test.rs
+++ b/libs/appflowy-ai-client/tests/row_test/summarize_test.rs
@@ -9,7 +9,7 @@ async fn summarize_row_test() {
   let json = json!({"name": "Jack", "age": 25, "city": "New York"});
 
   let result = client
-    .summarize_row(json.as_object().unwrap(), AIModel::GPT35)
+    .summarize_row(json.as_object().unwrap(), AIModel::GPT4oMini)
     .await
     .unwrap();
   result.text.contains("Jack");
diff --git a/libs/appflowy-ai-client/tests/row_test/translate_test.rs b/libs/appflowy-ai-client/tests/row_test/translate_test.rs
index 2045fc53..e4951812 100644
--- a/libs/appflowy-ai-client/tests/row_test/translate_test.rs
+++ b/libs/appflowy-ai-client/tests/row_test/translate_test.rs
@@ -20,6 +20,9 @@ async fn translate_row_test() {
     include_header: false,
   };
 
-  let result = client.translate_row(data, AIModel::GPT35).await.unwrap();
+  let result = client
+    .translate_row(data, AIModel::GPT4oMini)
+    .await
+    .unwrap();
   assert_eq!(result.items.len(), 2);
 }
diff --git a/libs/client-api/src/http.rs b/libs/client-api/src/http.rs
index c8c30bbb..01c720a5 100644
--- a/libs/client-api/src/http.rs
+++ b/libs/client-api/src/http.rs
@@ -172,7 +172,7 @@ impl Client {
       );
     }
 
-    let ai_model = Arc::new(RwLock::new(AIModel::GPT35));
+    let ai_model = Arc::new(RwLock::new(AIModel::GPT4oMini));
 
     Self {
       base_url: base_url.to_string(),
diff --git a/libs/shared-entity/src/dto/ai_dto.rs b/libs/shared-entity/src/dto/ai_dto.rs
index a889a1e4..dcb6253c 100644
--- a/libs/shared-entity/src/dto/ai_dto.rs
+++ b/libs/shared-entity/src/dto/ai_dto.rs
@@ -34,7 +34,18 @@ pub struct SummarizeRowResponse {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct CompleteTextParams {
   pub text: String,
-  pub completion_type: CompletionType,
+  pub completion_type: Option<CompletionType>,
+  pub custom_prompt: Option<CustomPrompt>,
+}
+
+impl CompleteTextParams {
+  pub fn new_with_completion_type(text: String, completion_type: CompletionType) -> Self {
+    Self {
+      text,
+      completion_type: Some(completion_type),
+      custom_prompt: None,
+    }
+  }
 }
 
 #[derive(Debug)]
diff --git a/src/api/ai.rs b/src/api/ai.rs
index 99fe8d4a..109fc59b 100644
--- a/src/api/ai.rs
+++ b/src/api/ai.rs
@@ -36,7 +36,7 @@ async fn complete_text_handler(
   let params = payload.into_inner();
   let resp = state
     .ai_client
-    .completion_text(&params.text, params.completion_type, ai_model)
+    .completion_text(&params.text, params.completion_type, None, ai_model)
     .await
     .map_err(|err| AppError::Internal(err.into()))?;
   Ok(AppResponse::Ok().with_data(resp).into())
@@ -51,7 +51,12 @@ async fn stream_complete_text_handler(
   let params = payload.into_inner();
   match state
     .ai_client
-    .stream_completion_text(&params.text, params.completion_type, ai_model)
+    .stream_completion_text(
+      &params.text,
+      params.completion_type,
+      params.custom_prompt,
+      ai_model,
+    )
     .await
   {
     Ok(stream) => Ok(
diff --git a/src/api/util.rs b/src/api/util.rs
index 73df5225..7b57ea62 100644
--- a/src/api/util.rs
+++ b/src/api/util.rs
@@ -179,5 +179,5 @@ pub(crate) fn ai_model_from_header(req: &HttpRequest) -> AIModel {
       let header = header.to_str().ok()?;
       AIModel::from_str(header).ok()
     })
-    .unwrap_or(AIModel::GPT35)
+    .unwrap_or(AIModel::GPT4oMini)
 }
diff --git a/tests/ai_test/complete_text.rs b/tests/ai_test/complete_text.rs
index 8930f58c..a055c421 100644
--- a/tests/ai_test/complete_text.rs
+++ b/tests/ai_test/complete_text.rs
@@ -8,13 +8,13 @@ async fn improve_writing_test() {
     return;
   }
   let test_client = TestClient::new_user().await;
-  test_client.api_client.set_ai_model(AIModel::GPT4o);
+  test_client.api_client.set_ai_model(AIModel::GPT4oMini);
 
   let workspace_id = test_client.workspace_id().await;
-  let params = CompleteTextParams {
-    text: "I feel hungry".to_string(),
-    completion_type: CompletionType::ImproveWriting,
-  };
+  let params = CompleteTextParams::new_with_completion_type(
+    "I feel hungry".to_string(),
+    CompletionType::ImproveWriting,
+  );
 
   let resp = test_client
     .api_client