diff --git a/example/rest_book_async_client/main.cc b/example/rest_book_async_client/main.cc
index 266f41f..c3761f6 100644
--- a/example/rest_book_async_client/main.cc
+++ b/example/rest_book_async_client/main.cc
@@ -2,8 +2,8 @@
 
 #include "json/json.h"
 
-#include "webcc/rest_async_client.h"
 #include "webcc/logger.h"
+#include "webcc/rest_async_client.h"
 
 // -----------------------------------------------------------------------------
 
@@ -50,7 +50,7 @@ class BookListClient {
 // -----------------------------------------------------------------------------
 
 class BookDetailClient {
-public:
+ public:
   BookDetailClient(boost::asio::io_context& io_context,
                    const std::string& host, const std::string& port)
       : rest_client_(io_context, host, port) {
@@ -83,7 +83,7 @@ public:
     rest_client_.Delete("/book/" + id, handler);
   }
 
-private:
+ private:
   webcc::RestAsyncClient rest_client_;
 };
 
@@ -112,8 +112,7 @@ int main(int argc, char* argv[]) {
   BookDetailClient detail_client(io_context, host, port);
 
   // Response handler.
-  auto handler = [](std::shared_ptr<webcc::HttpResponse> response,
-                    webcc::Error error,
+  auto handler = [](webcc::HttpResponsePtr response, webcc::Error error,
                     bool timed_out) {
     if (error == webcc::kNoError) {
       std::cout << response->content() << std::endl;
diff --git a/example/soap_book_client/book_client.cc b/example/soap_book_client/book_client.cc
index c997c43..8871dfa 100644
--- a/example/soap_book_client/book_client.cc
+++ b/example/soap_book_client/book_client.cc
@@ -23,7 +23,8 @@ BookClient::BookClient(const std::string& host, const std::string& port)
   soap_client_.set_indent_str("  ");
 }
 
-bool BookClient::CreateBook(const std::string& title, double price, std::string* id) {
+bool BookClient::CreateBook(const std::string& title, double price,
+                            std::string* id) {
   PrintSeparateLine();
   std::cout << "CreateBook: " << title << ", " << price << std::endl;
 
@@ -91,7 +92,8 @@ bool BookClient::Call0(const std::string& operation, std::string* result_str) {
 }
 
 
-bool BookClient::Call1(const std::string& operation, webcc::SoapParameter&& parameter,
+bool BookClient::Call1(const std::string& operation,
+                       webcc::SoapParameter&& parameter,
                        std::string* result_str) {
   std::vector<webcc::SoapParameter> parameters{
     { std::move(parameter) }
diff --git a/webcc/CMakeLists.txt b/webcc/CMakeLists.txt
index 08b44b4..2d8b5cc 100644
--- a/webcc/CMakeLists.txt
+++ b/webcc/CMakeLists.txt
@@ -65,6 +65,7 @@ endif()
 
 if(WEBCC_ENABLE_SOAP)
 	set(SOAP_HEADERS
+		soap_async_client.h
 		soap_client.h
 		soap_message.h
 		soap_parameter.h
@@ -77,6 +78,7 @@ if(WEBCC_ENABLE_SOAP)
 		)
 
 	set(SOAP_SOURCES
+		soap_async_client.cc
 		soap_client.cc
 		soap_message.cc
 		soap_response.cc
diff --git a/webcc/http_async_client.h b/webcc/http_async_client.h
index 6526af9..ba43199 100644
--- a/webcc/http_async_client.h
+++ b/webcc/http_async_client.h
@@ -16,7 +16,7 @@
 
 namespace webcc {
 
-// Request handler/callback.
+// Response handler/callback.
 typedef std::function<void(HttpResponsePtr, Error, bool)> HttpResponseHandler;
 
 class HttpAsyncClient : public std::enable_shared_from_this<HttpAsyncClient> {
diff --git a/webcc/rest_async_client.cc b/webcc/rest_async_client.cc
index 5dfb680..ac97c2d 100644
--- a/webcc/rest_async_client.cc
+++ b/webcc/rest_async_client.cc
@@ -12,8 +12,6 @@ void RestAsyncClient::Request(const std::string& method,
                               const std::string& url,
                               std::string&& content,
                               HttpResponseHandler response_handler) {
-  response_handler_ = response_handler;
-
   HttpRequestPtr request(new webcc::HttpRequest());
 
   request->set_method(method);
@@ -33,7 +31,7 @@ void RestAsyncClient::Request(const std::string& method,
     http_client->set_timeout_seconds(timeout_seconds_);
   }
 
-  http_client->Request(request, response_handler_);
+  http_client->Request(request, response_handler);
 }
 
 }  // namespace webcc
diff --git a/webcc/rest_async_client.h b/webcc/rest_async_client.h
index 7d05994..b3525e8 100644
--- a/webcc/rest_async_client.h
+++ b/webcc/rest_async_client.h
@@ -51,8 +51,6 @@ class RestAsyncClient {
   std::string host_;
   std::string port_;
 
-  HttpResponseHandler response_handler_;
-
   // Timeout in seconds; only effective when > 0.
   int timeout_seconds_;
 };
diff --git a/webcc/rest_client.h b/webcc/rest_client.h
index 68dcecf..2e0f383 100644
--- a/webcc/rest_client.h
+++ b/webcc/rest_client.h
@@ -24,21 +24,7 @@ class RestClient {
     timeout_seconds_ = timeout_seconds;
   }
 
-  HttpResponsePtr response() const { return response_; }
-
-  int response_status() const {
-    assert(response_);
-    return response_->status();
-  }
-
-  const std::string& response_content() const {
-    assert(response_);
-    return response_->content();
-  }
-
-  bool timed_out() const { return timed_out_; }
-
-  Error error() const { return error_; }
+  // Requests
 
   inline bool Get(const std::string& url) {
     return Request(kHttpGet, url, "");
@@ -60,6 +46,24 @@ class RestClient {
     return Request(kHttpDelete, url, "");
   }
 
+  // Response & Result
+
+  HttpResponsePtr response() const { return response_; }
+
+  int response_status() const {
+    assert(response_);
+    return response_->status();
+  }
+
+  const std::string& response_content() const {
+    assert(response_);
+    return response_->content();
+  }
+
+  bool timed_out() const { return timed_out_; }
+
+  Error error() const { return error_; }
+
  private:
   bool Request(const std::string& method, const std::string& url,
                std::string&& content);
diff --git a/webcc/soap_async_client.cc b/webcc/soap_async_client.cc
new file mode 100644
index 0000000..0545b02
--- /dev/null
+++ b/webcc/soap_async_client.cc
@@ -0,0 +1,91 @@
+#include "webcc/soap_async_client.h"
+
+#include <cassert>
+#include <utility>  // for move()
+
+#include "webcc/http_async_client.h"
+#include "webcc/soap_request.h"
+#include "webcc/soap_response.h"
+
+namespace webcc {
+
+SoapAsyncClient::SoapAsyncClient(boost::asio::io_context& io_context,
+                                 const std::string& host,
+                                 const std::string& port)
+    : io_context_(io_context),
+      host_(host), port_(port),
+      soapenv_ns_(kSoapEnvNamespace),
+      format_raw_(true), timeout_seconds_(0) {
+  if (port_.empty()) {
+    std::size_t i = host_.find_last_of(':');
+    if (i != std::string::npos) {
+      port_ = host_.substr(i + 1);
+      host_ = host_.substr(0, i);
+    }
+  }
+}
+
+void SoapAsyncClient::Request(const std::string& operation,
+                              std::vector<SoapParameter>&& parameters,
+                              SoapResponseHandler soap_response_handler) {
+  assert(service_ns_.IsValid());
+  assert(!url_.empty() && !host_.empty());
+  assert(!result_name_.empty());
+
+  SoapRequest soap_request;
+
+  soap_request.set_soapenv_ns(soapenv_ns_);
+  soap_request.set_service_ns(service_ns_);
+
+  soap_request.set_operation(operation);
+
+  for (SoapParameter& p : parameters) {
+    soap_request.AddParameter(std::move(p));
+  }
+
+  std::string http_content;
+  soap_request.ToXml(format_raw_, indent_str_, &http_content);
+
+  HttpRequestPtr http_request;
+
+  http_request->set_method(kHttpPost);
+  http_request->set_url(url_);
+  http_request->SetContent(std::move(http_content), true);
+  http_request->SetContentType(kTextXmlUtf8);
+  http_request->SetHost(host_, port_);
+  http_request->SetHeader(kSoapAction, operation);
+  http_request->UpdateStartLine();
+
+  HttpAsyncClientPtr http_client(new HttpAsyncClient(io_context_));
+
+  if (timeout_seconds_ > 0) {
+    http_client->set_timeout_seconds(timeout_seconds_);
+  }
+
+  auto http_response_handler = std::bind(&SoapAsyncClient::ResponseHandler,
+                                         this, soap_response_handler,
+                                         std::placeholders::_1,
+                                         std::placeholders::_2,
+                                         std::placeholders::_3);
+
+  http_client->Request(http_request, http_response_handler);
+}
+
+void SoapAsyncClient::ResponseHandler(SoapResponseHandler soap_response_handler,
+                                      HttpResponsePtr http_response,
+                                      Error error, bool timed_out) {
+  if (error != kNoError) {
+    soap_response_handler("", error, timed_out);
+  } else {
+    SoapResponse soap_response;
+    soap_response.set_result_name(result_name_);
+
+    if (!soap_response.FromXml(http_response->content())) {
+      soap_response_handler("", kXmlError, false);
+    } else {
+      soap_response_handler(soap_response.result_moved(), kNoError, false);
+    }
+  }
+}
+
+}  // namespace webcc
diff --git a/webcc/soap_async_client.h b/webcc/soap_async_client.h
new file mode 100644
index 0000000..1d1451a
--- /dev/null
+++ b/webcc/soap_async_client.h
@@ -0,0 +1,85 @@
+#ifndef WEBCC_SOAP_ASYNC_CLIENT_H_
+#define WEBCC_SOAP_ASYNC_CLIENT_H_
+
+#include <functional>
+#include <string>
+#include <vector>
+
+#include "webcc/http_async_client.h"
+#include "webcc/soap_message.h"
+#include "webcc/soap_parameter.h"
+
+namespace webcc {
+
+// Response handler/callback.
+typedef std::function<void(std::string, Error, bool)> SoapResponseHandler;
+
+class SoapAsyncClient {
+ public:
+  // If |port| is empty, |host| will be checked to see if it contains port or
+  // not (separated by ':').
+  SoapAsyncClient(boost::asio::io_context& io_context,  // NOLINT
+                  const std::string& host, const std::string& port = "");
+
+  ~SoapAsyncClient() = default;
+
+  DELETE_COPY_AND_ASSIGN(SoapAsyncClient);
+
+  void set_timeout_seconds(int timeout_seconds) {
+    timeout_seconds_ = timeout_seconds;
+  }
+
+  void set_url(const std::string& url) { url_ = url; }
+
+  void set_service_ns(const SoapNamespace& service_ns) {
+    service_ns_ = service_ns;
+  }
+
+  void set_result_name(const std::string& result_name) {
+    result_name_ = result_name;
+  }
+
+  void set_format_raw(bool format_raw) { format_raw_ = format_raw; }
+
+  void set_indent_str(const std::string& indent_str) {
+    indent_str_ = indent_str;
+  }
+
+  void Request(const std::string& operation,
+               std::vector<SoapParameter>&& parameters,
+               SoapResponseHandler soap_response_handler);
+
+ private:
+  void ResponseHandler(SoapResponseHandler soap_response_handler,
+                       HttpResponsePtr http_response,
+                       Error error, bool timed_out);
+
+  boost::asio::io_context& io_context_;
+
+  std::string host_;
+  std::string port_;  // Leave this empty to use default 80.
+
+  // Request URL.
+  std::string url_;
+
+  SoapNamespace soapenv_ns_;  // SOAP envelope namespace.
+  SoapNamespace service_ns_;  // Namespace for your web service.
+
+  // Response result XML node name.
+  // E.g., "Result".
+  std::string result_name_;
+
+  // Format request XML without any indentation or line breaks.
+  bool format_raw_;
+
+  // Indent string for request XML.
+  // Applicable when |format_raw_| is false.
+  std::string indent_str_;
+
+  // Timeout in seconds; only effective when > 0.
+  int timeout_seconds_;
+};
+
+}  // namespace webcc
+
+#endif  // WEBCC_SOAP_ASYNC_CLIENT_H_
diff --git a/webcc/soap_client.cc b/webcc/soap_client.cc
index ea89f3b..5dfd283 100644
--- a/webcc/soap_client.cc
+++ b/webcc/soap_client.cc
@@ -4,8 +4,6 @@
 #include <utility>  // for move()
 
 #include "webcc/http_client.h"
-#include "webcc/http_request.h"
-#include "webcc/http_response.h"
 #include "webcc/soap_request.h"
 #include "webcc/soap_response.h"
 
diff --git a/webcc/soap_client.h b/webcc/soap_client.h
index d69506b..c90d431 100644
--- a/webcc/soap_client.h
+++ b/webcc/soap_client.h
@@ -39,14 +39,14 @@ class SoapClient {
     indent_str_ = indent_str;
   }
 
-  bool timed_out() const { return timed_out_; }
-
-  Error error() const { return error_; }
-
   bool Request(const std::string& operation,
                std::vector<SoapParameter>&& parameters,
                std::string* result);
 
+  bool timed_out() const { return timed_out_; }
+
+  Error error() const { return error_; }
+
  private:
   std::string host_;
   std::string port_;  // Leave this empty to use default 80.