diff --git a/include/ylt/standalone/cinatra/coro_http_connection.hpp b/include/ylt/standalone/cinatra/coro_http_connection.hpp
index c0cf383b8..482b3b9f3 100644
--- a/include/ylt/standalone/cinatra/coro_http_connection.hpp
+++ b/include/ylt/standalone/cinatra/coro_http_connection.hpp
@@ -204,7 +204,7 @@ class coro_http_connection
         }
         else {
           if (default_handler_) {
-            default_handler_(request_, response_);
+            co_await default_handler_(request_, response_);
           }
           else {
             bool is_exist = false;
@@ -409,7 +409,8 @@ class coro_http_connection
   void set_multi_buf(bool r) { multi_buf_ = r; }
 
   void set_default_handler(
-      std::function<void(coro_http_request &, coro_http_response &)> &handler) {
+      std::function<async_simple::coro::Lazy<void>(
+          coro_http_request &, coro_http_response &)> &handler) {
     default_handler_ = handler;
   }
 
@@ -904,7 +905,8 @@ class coro_http_connection
 #endif
   bool need_shrink_every_time_ = false;
   bool multi_buf_ = true;
-  std::function<void(coro_http_request &, coro_http_response &)>
+  std::function<async_simple::coro::Lazy<void>(coro_http_request &,
+                                               coro_http_response &)>
       default_handler_ = nullptr;
   std::string chunk_size_str_;
   std::string remote_addr_;
diff --git a/include/ylt/standalone/cinatra/coro_http_response.hpp b/include/ylt/standalone/cinatra/coro_http_response.hpp
index 0da9eba52..b3a55e46f 100644
--- a/include/ylt/standalone/cinatra/coro_http_response.hpp
+++ b/include/ylt/standalone/cinatra/coro_http_response.hpp
@@ -173,13 +173,6 @@ class coro_http_response {
                 : resp_str.append(CONN_CLOSE_SV);
     }
 
-    if (content_view_.empty()) {
-      resp_str.append(content_);
-    }
-    else {
-      resp_str.append(content_view_);
-    }
-
     append_header_str(resp_str, resp_headers_);
 
     if (!resp_header_span_.empty()) {
@@ -187,7 +180,12 @@ class coro_http_response {
     }
 
     resp_str.append(CRCF);
-    resp_str.append(content_);
+    if (content_view_.empty()) {
+      resp_str.append(content_);
+    }
+    else {
+      resp_str.append(content_view_);
+    }
   }
 
   void append_header_str(auto &resp_str, auto &resp_headers) {
diff --git a/include/ylt/standalone/cinatra/coro_http_server.hpp b/include/ylt/standalone/cinatra/coro_http_server.hpp
index 0bb6b66cb..7c2aea83b 100644
--- a/include/ylt/standalone/cinatra/coro_http_server.hpp
+++ b/include/ylt/standalone/cinatra/coro_http_server.hpp
@@ -550,8 +550,9 @@ class coro_http_server {
 
   void set_shrink_to_fit(bool r) { need_shrink_every_time_ = r; }
 
-  void set_default_handler(
-      std::function<void(coro_http_request &, coro_http_response &)> handler) {
+  void set_default_handler(std::function<async_simple::coro::Lazy<void>(
+                               coro_http_request &, coro_http_response &)>
+                               handler) {
     default_handler_ = std::move(handler);
   }
 
@@ -923,7 +924,8 @@ class coro_http_server {
 #endif
   coro_http_router router_;
   bool need_shrink_every_time_ = false;
-  std::function<void(coro_http_request &, coro_http_response &)>
+  std::function<async_simple::coro::Lazy<void>(coro_http_request &,
+                                               coro_http_response &)>
       default_handler_ = nullptr;
 };
 
diff --git a/src/coro_http/examples/example.cpp b/src/coro_http/examples/example.cpp
index 09efa802a..38f8d7062 100644
--- a/src/coro_http/examples/example.cpp
+++ b/src/coro_http/examples/example.cpp
@@ -352,6 +352,22 @@ async_simple::coro::Lazy<void> basic_usage() {
         response.set_status_and_content(status_type::ok, "ok");
       });
 
+  server.set_http_handler<POST>(
+      "/view",
+      [](coro_http_request &req,
+         coro_http_response &resp) -> async_simple::coro::Lazy<void> {
+        resp.set_delay(true);
+        resp.set_status_and_content_view(status_type::ok,
+                                         req.get_body());  // no copy
+        co_await resp.get_conn()->reply();
+      });
+  server.set_default_handler(
+      [](coro_http_request &req,
+         coro_http_response &resp) -> async_simple::coro::Lazy<void> {
+        resp.set_status_and_content(status_type::ok, "default response");
+        co_return;
+      });
+
   person_t person{};
   server.set_http_handler<GET>("/person", &person_t::foo, person);
 
@@ -377,6 +393,11 @@ async_simple::coro::Lazy<void> basic_usage() {
   assert(result.status == 200);
   assert(result.resp_body == "post string");
 
+  result = co_await client.async_post("/view", "post string",
+                                      req_content_type::string);
+  assert(result.status == 200);
+  assert(result.resp_body == "post string");
+
   client.add_header("name", "tom");
   client.add_header("age", "20");
   result = co_await client.async_get("/headers");
@@ -389,6 +410,10 @@ async_simple::coro::Lazy<void> basic_usage() {
       "http://127.0.0.1:9001/users/ultramarines/subscriptions/guilliman");
   assert(result.status == 200);
 
+  result = co_await client.async_get("/not_exist");
+  assert(result.status == 200);
+  assert(result.resp_body == "default response");
+
   // make sure you have install openssl and enable CINATRA_ENABLE_SSL
 #ifdef CINATRA_ENABLE_SSL
   coro_http_client client2{};