diff --git a/Cargo.toml b/Cargo.toml
index 4623413..2b50738 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,7 @@ name = "dialogflow"
 [dependencies]
 # artful = "0.1.1"
 anyhow = "1.0"
-axum = {version = "0.7", features = ["query", "tokio", "macros"]}
+axum = {version = "0.7", features = ["query", "tokio", "macros", "multipart"]}
 bigdecimal = "0.4"
 # candle-core = { git = "https://github.com/huggingface/candle.git", version = "0.5.1" }
 # candle = { version = "0.6", package = "candle-core", default-features = false }
@@ -57,7 +57,7 @@ scraper = "0.20"
 # strsim = "0.10.0"
 # textdistance = "1.0.2"
 time = { version = "0.3", features = ["formatting"] }
-tower-http = { version = "0.5", features = ["cors"] }
+tower-http = { version = "0.5", features = ["cors", "limit"] }
 # typetag = "0.2"
 tokio = { version = "1", features = ["fs", "io-util", "macros", "net", "rt", "rt-multi-thread", "signal", "time"] }
 tokio-stream = "0.1"
diff --git a/src/flow/rt/context.rs b/src/flow/rt/context.rs
index 17f99ff..a35ba1e 100644
--- a/src/flow/rt/context.rs
+++ b/src/flow/rt/context.rs
@@ -108,6 +108,7 @@ impl Context {
 
     pub(in crate::flow::rt) fn pop_node(&mut self) -> Option<RuntimeNnodeEnum> {
         // log::info!("nodes len {}", self.nodes.len());
+        let now = std::time::Instant::now();
         if self.node.is_some() {
             let node = std::mem::replace(&mut self.node, None);
             let v = node.unwrap();
@@ -121,6 +122,7 @@ impl Context {
         if let Some(node_id) = self.nodes.pop_front() {
             // log::info!("main_flow_id {} node_id {}", &self.main_flow_id, &node_id);
             if let Ok(r) = super::crud::get_runtime_node(&self.main_flow_id, &node_id) {
+                log::info!("pop_node time {:?}", now.elapsed());
                 return r;
             }
         }
diff --git a/src/flow/rt/executor.rs b/src/flow/rt/executor.rs
index 4503508..6eb8a43 100644
--- a/src/flow/rt/executor.rs
+++ b/src/flow/rt/executor.rs
@@ -6,20 +6,20 @@ use crate::intent::detector;
 use crate::result::{Error, Result};
 
 pub(in crate::flow::rt) async fn process(req: &mut Request) -> Result<Response> {
-    // let now = std::time::Instant::now();
+    let now = std::time::Instant::now();
     if req.session_id.is_empty() {
         req.session_id = scru128::new_string();
     }
     let mut ctx = Context::get(&req.robot_id, &req.session_id);
-    // println!("get ctx {:?}", now.elapsed());
-    // let now = std::time::Instant::now();
+    log::info!("get ctx {:?}", now.elapsed());
+    let now = std::time::Instant::now();
     if ctx.no_node() {
         if ctx.main_flow_id.is_empty() {
             ctx.main_flow_id.push_str(&req.main_flow_id);
         }
         ctx.add_node(&req.main_flow_id);
     }
-    // println!("add_node {:?}", now.elapsed());
+    log::info!("add_node {:?}", now.elapsed());
     let now = std::time::Instant::now();
     if req.user_input_intent.is_none() {
         req.user_input_intent = detector::detect(&req.robot_id, &req.user_input).await?;
@@ -52,13 +52,14 @@ pub(in crate::flow::rt) async fn process(req: &mut Request) -> Result<Response>
         }
     }
     // println!("exec {:?}", now.elapsed());
-    // let now = std::time::Instant::now();
+    let now = std::time::Instant::now();
     ctx.save()?;
-    // println!("ctx save {:?}", now.elapsed());
+    log::info!("ctx save {:?}", now.elapsed());
     r
 }
 
 pub(in crate::flow::rt) fn exec(req: &Request, ctx: &mut Context) -> Result<Response> {
+    let now = std::time::Instant::now();
     let mut response = Response::new(req);
     for _i in 0..100 {
         // let now = std::time::Instant::now();
@@ -67,6 +68,7 @@ pub(in crate::flow::rt) fn exec(req: &Request, ctx: &mut Context) -> Result<Resp
             let ret = n.exec(&req, ctx, &mut response);
             // println!("node exec {:?}", now.elapsed());
             if ret {
+                log::info!("exec time {:?}", now.elapsed());
                 return Ok(response);
             }
         } else {
diff --git a/src/flow/rt/node.rs b/src/flow/rt/node.rs
index 22dc6ba..6649147 100644
--- a/src/flow/rt/node.rs
+++ b/src/flow/rt/node.rs
@@ -538,10 +538,12 @@ impl RuntimeNode for LlmChatNode {
 }
 
 pub(crate) fn deser_node(bytes: &[u8]) -> Result<RuntimeNnodeEnum> {
+    let now = std::time::Instant::now();
     let mut v = AlignedVec::<256>::with_capacity(bytes.len());
     v.extend_from_slice(bytes);
     let r = rkyv::from_bytes::<RuntimeNnodeEnum, rkyv::rancor::Error>(&v).unwrap();
     // let archived = rkyv::access::<ArchivedRuntimeNnodeEnum, rkyv::rancor::Error>(bytes).unwrap();
     // let deserialized = rkyv::deserialize::<RuntimeNnodeEnum, rkyv::rancor::Error>(archived).unwrap();
+    log::info!("deser_node time {:?}", now.elapsed());
     return Ok(r);
 }
diff --git a/src/intent/detector.rs b/src/intent/detector.rs
index 6093a87..9bd73d6 100644
--- a/src/intent/detector.rs
+++ b/src/intent/detector.rs
@@ -41,6 +41,9 @@ pub(crate) async fn detect(robot_id: &str, s: &str) -> Result<Option<String>> {
         }
     }
     let embedding = embedding(robot_id, s).await?;
+    if embedding.0.is_empty() {
+        return Ok(None);
+    }
     // log::info!("Generate embedding cost {:?}", now.elapsed());
     // let s = format!("{:?}", &embedding);
     // let regex = regex::Regex::new(r"\s").unwrap();
diff --git a/src/kb/crud.rs b/src/kb/crud.rs
new file mode 100644
index 0000000..cfc5b04
--- /dev/null
+++ b/src/kb/crud.rs
@@ -0,0 +1,28 @@
+use axum::{extract::Multipart, response::IntoResponse};
+
+use crate::result::Error;
+use crate::web::server::to_res;
+
+pub(crate) async fn upload(mut multipart: Multipart) -> impl IntoResponse {
+    loop {
+        let r = multipart.next_field().await;
+        if r.is_err() {
+            let m = format!("Upload failed, err: {:?}.", r.unwrap_err());
+            return to_res(Err(Error::ErrorWithMessage(m)));
+        }
+        let field = r.unwrap();
+        if field.is_none() {
+            return to_res(Ok("Upload successfully."));
+        }
+        let field = field.unwrap();
+        let name = field.name().unwrap().to_string();
+        let file_name = field.file_name().unwrap().to_string();
+        let content_type = field.content_type().unwrap().to_string();
+        let data = field.bytes().await.unwrap();
+
+        println!(
+            "Length of `{name}` (`{file_name}`: `{content_type}`) is {} bytes",
+            data.len()
+        );
+    }
+}
\ No newline at end of file
diff --git a/src/kb/mod.rs b/src/kb/mod.rs
new file mode 100644
index 0000000..9706a3c
--- /dev/null
+++ b/src/kb/mod.rs
@@ -0,0 +1 @@
+pub(crate) mod crud;
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index d2d6829..996ab38 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,6 +6,7 @@ pub(crate) mod db;
 pub(crate) mod external;
 pub(crate) mod flow;
 pub(crate) mod intent;
+pub(crate) mod kb;
 pub(crate) mod man;
 pub(crate) mod result;
 pub(crate) mod robot;
diff --git a/src/man/settings.rs b/src/man/settings.rs
index 4706941..ac0f040 100644
--- a/src/man/settings.rs
+++ b/src/man/settings.rs
@@ -45,6 +45,7 @@ pub(crate) struct GlobalSettings {
 
 #[derive(Clone, Deserialize, Serialize)]
 pub(crate) struct Settings {
+    settings_version: u8,
     #[serde(rename = "maxSessionIdleSec")]
     pub(crate) max_session_idle_sec: u32,
     #[serde(rename = "chatProvider")]
@@ -206,6 +207,7 @@ impl Default for GlobalSettings {
 impl Default for Settings {
     fn default() -> Self {
         Settings {
+            settings_version: 1u8,
             max_session_idle_sec: 1800,
             chat_provider: ChatProvider {
                 provider: chat::ChatProvider::HuggingFace(
diff --git a/src/web/asset.rs b/src/web/asset.rs
index 09e40fe..222d6d2 100644
--- a/src/web/asset.rs
+++ b/src/web/asset.rs
@@ -3,22 +3,18 @@ use std::collections::HashMap;
 use std::sync::LazyLock;
 
 pub(crate) static ASSETS_MAP: LazyLock<HashMap<&str, usize>> = LazyLock::new(|| {
-    HashMap::from([
-        (r"/assets/inbound-bot-PJJg_rST.png", 0),
-        (r"/assets/index-B4PwGmOZ.css", 1),
-        (r"/assets/index-DaTxxXw1.js", 2),
-        (r"/assets/outbound-bot-EmsLuWRN.png", 3),
-        (r"/assets/text-bot-CWb_Poym.png", 4),
-        (r"/assets/usedByDialogNodeTextGeneration-DrFqkTqi.png", 5),
-        (
-            r"/assets/usedByDialogNodeTextGeneration-thumbnail-C1iQCVQO.png",
-            6,
-        ),
-        (r"/assets/usedByLlmChatNode-Bv2Fg5P7.png", 7),
-        (r"/assets/usedBySentenceEmbedding-Dmju1hVB.png", 8),
-        (r"/assets/usedBySentenceEmbedding-thumbnail-DVXz_sh0.png", 9),
-        (r"/favicon.ico", 10),
-        ("/", 11),
-        (r"/index.html", 11),
-    ])
-});
+HashMap::from([
+(r"/assets/inbound-bot-PJJg_rST.png", 0),
+(r"/assets/index-B4PwGmOZ.css", 1),
+(r"/assets/index-DaTxxXw1.js", 2),
+(r"/assets/outbound-bot-EmsLuWRN.png", 3),
+(r"/assets/text-bot-CWb_Poym.png", 4),
+(r"/assets/usedByDialogNodeTextGeneration-DrFqkTqi.png", 5),
+(r"/assets/usedByDialogNodeTextGeneration-thumbnail-C1iQCVQO.png", 6),
+(r"/assets/usedByLlmChatNode-Bv2Fg5P7.png", 7),
+(r"/assets/usedBySentenceEmbedding-Dmju1hVB.png", 8),
+(r"/assets/usedBySentenceEmbedding-thumbnail-DVXz_sh0.png", 9),
+(r"/favicon.ico", 10),
+("/", 11),
+(r"/index.html", 11),
+])});
diff --git a/src/web/server.rs b/src/web/server.rs
index 102fd97..0786c0b 100644
--- a/src/web/server.rs
+++ b/src/web/server.rs
@@ -2,6 +2,7 @@
 use std::sync::LazyLock;
 use std::vec::Vec;
 
+use axum::extract::DefaultBodyLimit;
 use axum::http::{header, HeaderMap, HeaderValue, Method, StatusCode, Uri};
 use axum::response::{IntoResponse, Response};
 use axum::routing::{get, post};
@@ -9,6 +10,7 @@ use axum::Router;
 use colored::Colorize;
 use serde::{Deserialize, Serialize};
 use tower_http::cors::{AllowOrigin, CorsLayer};
+use tower_http::limit::RequestBodyLimitLayer;
 
 use super::asset::ASSETS_MAP;
 use crate::ai::crud as ai;
@@ -17,6 +19,7 @@ use crate::flow::mainflow::crud as mainflow;
 use crate::flow::rt::facade as rt;
 use crate::flow::subflow::crud as subflow;
 use crate::intent::crud as intent;
+use crate::kb::crud as kb;
 use crate::man::settings;
 use crate::result::Error;
 use crate::robot::crud as robot;
@@ -230,6 +233,10 @@ fn gen_router() -> Router {
             "/management/settings/model/check/embedding",
             get(settings::check_embedding_model),
         )
+        .route(
+            "/kb/doc/upload",
+            post(kb::upload),
+        )
         .route("/management/settings/smtp/test", post(settings::smtp_test))
         .route("/flow/answer", post(rt::answer))
         .route("/flow/answer/sse", post(rt::answer_sse))
@@ -237,6 +244,10 @@ fn gen_router() -> Router {
         .route("/version.json", get(version))
         .route("/check-new-version.json", get(check_new_version))
         // .route("/o", get(subflow::output))
+        .layer(DefaultBodyLimit::disable())
+        .layer(RequestBodyLimitLayer::new(
+            250 * 1024 * 1024, /* 250mb */
+        ))
         .layer(
             CorsLayer::new()
                 .allow_origin(AllowOrigin::predicate(