diff --git a/src/host_error_monitor.cpp b/src/host_error_monitor.cpp
new file mode 100644
index 0000000..308c3c9
--- /dev/null
+++ b/src/host_error_monitor.cpp
@@ -0,0 +1,309 @@
+/*
+// Copyright (c) 2019 Intel Corporation
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+*/
+#include <boost/asio/posix/stream_descriptor.hpp>
+#include <gpiod.hpp>
+#include <iostream>
+#include <sdbusplus/asio/object_server.hpp>
+
+namespace host_error_monitor
+{
+static boost::asio::io_service io;
+static std::shared_ptr<sdbusplus::asio::connection> conn;
+
+static bool hostOff = true;
+
+const static constexpr size_t caterrTimeoutMs = 2000;
+const static constexpr size_t crashdumpTimeoutS = 300;
+
+// Timers
+// Timer for CATERR asserted
+static boost::asio::steady_timer caterrAssertTimer(io);
+
+// GPIO Lines and Event Descriptors
+static gpiod::line caterrLine;
+static boost::asio::posix::stream_descriptor caterrEvent(io);
+
+static void initializeHostState()
+{
+    conn->async_method_call(
+        [](boost::system::error_code ec,
+           const std::variant<std::string>& property) {
+            if (ec)
+            {
+                return;
+            }
+            const std::string* state = std::get_if<std::string>(&property);
+            if (state == nullptr)
+            {
+                std::cerr << "Unable to read host state value\n";
+                return;
+            }
+            hostOff = *state == "xyz.openbmc_project.State.Host.HostState.Off";
+        },
+        "xyz.openbmc_project.State.Host", "/xyz/openbmc_project/state/host0",
+        "org.freedesktop.DBus.Properties", "Get",
+        "xyz.openbmc_project.State.Host", "CurrentHostState");
+}
+
+static std::shared_ptr<sdbusplus::bus::match::match> startHostStateMonitor()
+{
+    return std::make_shared<sdbusplus::bus::match::match>(
+        *conn,
+        "type='signal',interface='org.freedesktop.DBus.Properties',"
+        "member='PropertiesChanged',arg0namespace='xyz.openbmc_project.State."
+        "Host'",
+        [](sdbusplus::message::message& msg) {
+            std::string interfaceName;
+            boost::container::flat_map<std::string, std::variant<std::string>>
+                propertiesChanged;
+            std::string state;
+            try
+            {
+                msg.read(interfaceName, propertiesChanged);
+                state =
+                    std::get<std::string>(propertiesChanged.begin()->second);
+            }
+            catch (std::exception& e)
+            {
+                std::cerr << "Unable to read host state\n";
+                return;
+            }
+            hostOff = state == "xyz.openbmc_project.State.Host.HostState.Off";
+
+            // No host events should fire while off, so cancel any pending
+            // timers
+            if (hostOff)
+            {
+                caterrAssertTimer.cancel();
+            }
+        });
+}
+
+static bool requestGPIOEvents(
+    const std::string& name, const std::function<void()>& handler,
+    gpiod::line& gpioLine,
+    boost::asio::posix::stream_descriptor& gpioEventDescriptor)
+{
+    // Find the GPIO line
+    gpioLine = gpiod::find_line(name);
+    if (!gpioLine)
+    {
+        std::cerr << "Failed to find the " << name << " line\n";
+        return false;
+    }
+
+    try
+    {
+        gpioLine.request(
+            {"host-error-monitor", gpiod::line_request::EVENT_BOTH_EDGES});
+    }
+    catch (std::exception&)
+    {
+        std::cerr << "Failed to request events for " << name << "\n";
+        return false;
+    }
+
+    int gpioLineFd = gpioLine.event_get_fd();
+    if (gpioLineFd < 0)
+    {
+        std::cerr << "Failed to get " << name << " fd\n";
+        return false;
+    }
+
+    gpioEventDescriptor.assign(gpioLineFd);
+
+    gpioEventDescriptor.async_wait(
+        boost::asio::posix::stream_descriptor::wait_read,
+        [&name, handler](const boost::system::error_code ec) {
+            if (ec)
+            {
+                std::cerr << name << " fd handler error: " << ec.message()
+                          << "\n";
+                return;
+            }
+            handler();
+        });
+    return true;
+}
+
+static void startPowerCycle()
+{
+    conn->async_method_call(
+        [](boost::system::error_code ec) {
+            if (ec)
+            {
+                std::cerr << "failed to set Chassis State\n";
+            }
+        },
+        "xyz.openbmc_project.State.Chassis",
+        "/xyz/openbmc_project/state/chassis0",
+        "org.freedesktop.DBus.Properties", "Set",
+        "xyz.openbmc_project.State.Chassis", "RequestedPowerTransition",
+        std::variant<std::string>{
+            "xyz.openbmc_project.State.Chassis.Transition.PowerCycle"});
+}
+
+static void startCrashdumpAndRecovery(bool recoverSystem)
+{
+    std::cout << "Starting crashdump\n";
+    static std::shared_ptr<sdbusplus::bus::match::match> crashdumpCompleteMatch;
+    static boost::asio::steady_timer crashdumpTimer(io);
+
+    crashdumpCompleteMatch = std::make_shared<sdbusplus::bus::match::match>(
+        *conn,
+        "type='signal',interface='org.freedesktop.DBus.Properties',"
+        "member='PropertiesChanged',arg0namespace='com.intel.crashdump'",
+        [recoverSystem](sdbusplus::message::message& msg) {
+            crashdumpTimer.cancel();
+            std::cout << "Crashdump completed\n";
+            if (recoverSystem)
+            {
+                std::cout << "Recovering the system\n";
+                startPowerCycle();
+            }
+            crashdumpCompleteMatch.reset();
+        });
+
+    crashdumpTimer.expires_after(std::chrono::seconds(crashdumpTimeoutS));
+    crashdumpTimer.async_wait([](const boost::system::error_code ec) {
+        if (ec)
+        {
+            // operation_aborted is expected if timer is canceled
+            if (ec != boost::asio::error::operation_aborted)
+            {
+                std::cerr << "Crashdump async_wait failed: " << ec.message()
+                          << "\n";
+            }
+            std::cout << "Crashdump timer canceled\n";
+            return;
+        }
+        std::cerr << "Crashdump failed to complete before timeout\n";
+        crashdumpCompleteMatch.reset();
+    });
+
+    conn->async_method_call(
+        [](boost::system::error_code ec) {
+            if (ec)
+            {
+                std::cerr << "failed to start Crashdump\n";
+                crashdumpTimer.cancel();
+                crashdumpCompleteMatch.reset();
+            }
+        },
+        "com.intel.crashdump", "/com/intel/crashdump",
+        "com.intel.crashdump.Stored", "GenerateStoredLog");
+}
+
+static void caterrHandler()
+{
+    if (!hostOff)
+    {
+        gpiod::line_event gpioLineEvent = caterrLine.event_read();
+
+        bool caterr =
+            gpioLineEvent.event_type == gpiod::line_event::FALLING_EDGE;
+        if (caterr)
+        {
+            std::cout << "CPU CATERR detected, starting timer\n";
+            caterrAssertTimer.expires_after(
+                std::chrono::milliseconds(caterrTimeoutMs));
+            caterrAssertTimer.async_wait(
+                [](const boost::system::error_code ec) {
+                    if (ec)
+                    {
+                        // operation_aborted is expected if timer is canceled
+                        // before completion.
+                        if (ec != boost::asio::error::operation_aborted)
+                        {
+                            std::cerr << "caterr timeout async_wait failed: "
+                                      << ec.message() << "\n";
+                        }
+                        std::cout << "CATERR assert timer canceled\n";
+                        return;
+                    }
+                    std::cout << "CATERR asset timer completed\n";
+                    conn->async_method_call(
+                        [](boost::system::error_code ec,
+                           const std::variant<bool>& property) {
+                            if (ec)
+                            {
+                                return;
+                            }
+                            const bool* reset = std::get_if<bool>(&property);
+                            if (reset == nullptr)
+                            {
+                                std::cerr
+                                    << "Unable to read reset on CATERR value\n";
+                                return;
+                            }
+                            startCrashdumpAndRecovery(*reset);
+                        },
+                        "xyz.openbmc_project.Settings",
+                        "/xyz/openbmc_project/control/processor_error_config",
+                        "org.freedesktop.DBus.Properties", "Get",
+                        "xyz.openbmc_project.Control.Processor.ErrConfig",
+                        "ResetOnCATERR");
+                });
+        }
+        else
+        {
+            caterrAssertTimer.cancel();
+        }
+    }
+    caterrEvent.async_wait(boost::asio::posix::stream_descriptor::wait_read,
+                           [](const boost::system::error_code ec) {
+                               if (ec)
+                               {
+                                   std::cerr << "caterr handler error: "
+                                             << ec.message() << "\n";
+                                   return;
+                               }
+                               caterrHandler();
+                           });
+}
+} // namespace host_error_monitor
+
+int main(int argc, char* argv[])
+{
+    // setup connection to dbus
+    host_error_monitor::conn =
+        std::make_shared<sdbusplus::asio::connection>(host_error_monitor::io);
+
+    // Host Error Monitor Object
+    host_error_monitor::conn->request_name(
+        "xyz.openbmc_project.HostErrorMonitor");
+    sdbusplus::asio::object_server server =
+        sdbusplus::asio::object_server(host_error_monitor::conn);
+
+    // Start tracking host state
+    std::shared_ptr<sdbusplus::bus::match::match> hostStateMonitor =
+        host_error_monitor::startHostStateMonitor();
+
+    // Initialize the host state
+    host_error_monitor::initializeHostState();
+
+    // Request CPU_CATERR GPIO events
+    if (!host_error_monitor::requestGPIOEvents(
+            "CPU_CATERR", host_error_monitor::caterrHandler,
+            host_error_monitor::caterrLine, host_error_monitor::caterrEvent))
+    {
+        return -1;
+    }
+
+    host_error_monitor::io.run();
+
+    return 0;
+}