diff --git a/src/bin/openapi.rs b/src/bin/openapi.rs
index 7e7dad69..e0da6aa3 100644
--- a/src/bin/openapi.rs
+++ b/src/bin/openapi.rs
@@ -1,28 +1,55 @@
 use actix_web::{App, HttpServer};
-use paperclip::actix::{
-    api_v2_operation,
-    web::{self, Json},
-    Apiv2Schema, OpenApiExt,
-};
-use serde::{Deserialize, Serialize};
-
-#[derive(Serialize, Deserialize, Apiv2Schema)]
-struct Pet {
-    name: String,
-    id: Option<i64>,
-}
-
-#[api_v2_operation]
-async fn echo_pet(body: Json<Pet>) -> Result<Json<Pet>, actix_web::Error> {
-    Ok(body)
-}
+use dingir_exchange::openapi::user::get_user;
+use dingir_exchange::restapi::state::{AppCache, AppState};
+use fluidex_common::non_blocking_tracing;
+use paperclip::actix::web::{self};
+use paperclip::actix::{api_v2_operation, OpenApiExt};
+use sqlx::postgres::Postgres;
+use sqlx::Pool;
+use std::collections::HashMap;
+use std::convert::TryFrom;
+use std::sync::Mutex;
 
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
-    HttpServer::new(|| {
+    dotenv::dotenv().ok();
+    let _guard = non_blocking_tracing::setup();
+
+    let db_url = dingir_exchange::config::Settings::new().db_history;
+    log::debug!("Prepared DB connection: {}", &db_url);
+
+    let config = dingir_exchange::restapi::config::Settings::default();
+    let manage_channel = if let Some(ep_str) = &config.manage_endpoint {
+        log::info!("Connect to manage channel {}", ep_str);
+        Some(
+            tonic::transport::Endpoint::try_from(ep_str.clone())
+                .ok()
+                .unwrap()
+                .connect()
+                .await
+                .unwrap(),
+        )
+    } else {
+        None
+    };
+
+    let user_map = web::Data::new(AppState {
+        user_addr_map: Mutex::new(HashMap::new()),
+        manage_channel,
+        db: Pool::<Postgres>::connect(&db_url).await.unwrap(),
+        config,
+    });
+
+    HttpServer::new(move || {
         App::new()
+            .app_data(user_map.clone())
+            .app_data(AppCache::new())
             .wrap_api()
-            .service(web::resource("/pets").route(web::post().to(echo_pet)))
+            .service(
+                web::scope("/openapi")
+                    .route("/ping", web::get().to(ping))
+                    .route("/user/{l1addr_or_l2pubkey}", web::get().to(get_user)),
+            )
             .with_json_spec_at("/api/spec")
             .build()
     })
@@ -30,3 +57,8 @@ async fn main() -> std::io::Result<()> {
     .run()
     .await
 }
+
+#[api_v2_operation]
+async fn ping() -> Result<&'static str, actix_web::Error> {
+    Ok("pong")
+}
diff --git a/src/lib.rs b/src/lib.rs
index a66eb58b..fc2a210c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -10,6 +10,7 @@ pub mod storage;
 pub use storage::{database, models, sqlxextend};
 pub mod config;
 pub mod message;
+pub mod openapi;
 pub mod restapi;
 pub mod types;
 pub mod utils;
diff --git a/src/openapi/mod.rs b/src/openapi/mod.rs
new file mode 100644
index 00000000..22d12a38
--- /dev/null
+++ b/src/openapi/mod.rs
@@ -0,0 +1 @@
+pub mod user;
diff --git a/src/openapi/user.rs b/src/openapi/user.rs
new file mode 100644
index 00000000..9a810a19
--- /dev/null
+++ b/src/openapi/user.rs
@@ -0,0 +1,33 @@
+use crate::models::{tablenames::ACCOUNT, AccountDesc};
+use crate::restapi::errors::RpcError;
+use crate::restapi::state::AppState;
+use paperclip::actix::api_v2_operation;
+use paperclip::actix::web::{self, HttpRequest, Json};
+
+#[api_v2_operation]
+pub async fn get_user(req: HttpRequest, data: web::Data<AppState>) -> Result<Json<AccountDesc>, actix_web::Error> {
+    let user_id: &str = req.match_info().get("l1addr_or_l2pubkey").unwrap();
+    let mut user_map = data.user_addr_map.lock().unwrap();
+    if user_map.contains_key(user_id) {
+        let user_info = &*user_map.get(user_id).unwrap();
+        return Ok(Json(user_info.clone()));
+    }
+
+    let sql_query = format!("select * from {} where l1_address = $1 OR l2_pubkey = $1", ACCOUNT);
+    let user: AccountDesc = sqlx::query_as(&sql_query).bind(user_id).fetch_one(&data.db).await.map_err(|e| {
+        log::error!("{:?}", e);
+        RpcError::bad_request("invalid user id or address")
+    })?;
+
+    // update cache
+    user_map.insert(
+        user.l1_address.clone(),
+        AccountDesc {
+            id: user.id,
+            l1_address: user.l1_address.clone(),
+            l2_pubkey: user.l2_pubkey.clone(),
+        },
+    );
+
+    Ok(Json(user))
+}
diff --git a/src/storage/models.rs b/src/storage/models.rs
index 4fefeea5..ab1841b2 100644
--- a/src/storage/models.rs
+++ b/src/storage/models.rs
@@ -1,6 +1,7 @@
 use crate::types::OrderSide;
 use chrono::NaiveDateTime;
-use serde::Serialize;
+use paperclip::actix::Apiv2Schema;
+use serde::{Deserialize, Serialize};
 
 pub type DecimalDbType = fluidex_common::rust_decimal::Decimal;
 // https://github.com/launchbadge/sqlx/blob/master/sqlx-core/src/postgres/types/mod.rs
@@ -51,7 +52,7 @@ pub struct MarketDesc {
     pub market_name: Option<String>,
 }
 
-#[derive(sqlx::FromRow, Debug, Clone, Serialize)]
+#[derive(sqlx::FromRow, Debug, Clone, Serialize, Deserialize, Apiv2Schema)]
 pub struct AccountDesc {
     pub id: i32, // TODO: i32 or i64?
     pub l1_address: String,