diff --git a/.clang-format b/.clang-format
new file mode 100644
index 0000000..ae9ad39
--- /dev/null
+++ b/.clang-format
@@ -0,0 +1,98 @@
+---
+Language:        Cpp
+# BasedOnStyle:  LLVM
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlinesLeft: false
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: false
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: true
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterClass:      true
+  AfterControlStatement: true
+  AfterEnum:       true
+  AfterFunction:   true
+  AfterNamespace:  true
+  AfterObjCDeclaration: true
+  AfterStruct:     true
+  AfterUnion:      true
+  BeforeCatch:     true
+  BeforeElse:      true
+  IndentBraces:    false
+BreakBeforeBinaryOperators: None
+BreakBeforeBraces: Custom
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializers: AfterColon
+ColumnLimit:     80
+CommentPragmas:  '^ IWYU pragma:'
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: true
+DerivePointerAlignment: false
+PointerAlignment: Left
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: true
+ForEachMacros:   [ foreach, Q_FOREACH, BOOST_FOREACH ]
+IncludeBlocks: Regroup
+IncludeCategories:
+  - Regex:           '^[<"](gtest|gmock)'
+    Priority:        5
+  - Regex:           '^"config.h"'
+    Priority:        -1
+  - Regex:           '^".*\.hpp"'
+    Priority:        1
+  - Regex:           '^<.*\.h>'
+    Priority:        2
+  - Regex:           '^<.*'
+    Priority:        3
+  - Regex:           '.*'
+    Priority:        4
+IndentCaseLabels: true
+IndentWidth:     4
+IndentWrappedFunctionNames: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: None
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+ReflowComments:  true
+SortIncludes:    true
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeParens: ControlStatements
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+Standard:        Cpp11
+TabWidth:        4
+UseTab:          Never
+...
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000..ce7dbc1
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,36 @@
+cmake_minimum_required (VERSION 3.6)
+project (host-error-monitor CXX)
+set (CMAKE_CXX_STANDARD 17)
+set (CMAKE_CXX_STANDARD_REQUIRED ON)
+
+add_executable (host-error-monitor src/host_error_monitor.cpp)
+
+target_include_directories (host-error-monitor PRIVATE ${CMAKE_SOURCE_DIR})
+
+target_link_libraries (host-error-monitor sdbusplus -lsystemd gpiodcxx)
+
+include_directories (${CMAKE_CURRENT_SOURCE_DIR}/include)
+
+install (TARGETS host-error-monitor
+         RUNTIME DESTINATION bin
+         LIBRARY DESTINATION lib
+         ARCHIVE DESTINATION lib/static)
+
+find_package (Boost 1.66 REQUIRED)
+include_directories (${BOOST_SRC_DIR})
+
+add_definitions (-DBOOST_ERROR_CODE_HEADER_ONLY)
+add_definitions (-DBOOST_SYSTEM_NO_DEPRECATED)
+add_definitions (-DBOOST_ALL_NO_LIB)
+add_definitions (-DBOOST_NO_RTTI)
+add_definitions (-DBOOST_NO_TYPEID)
+add_definitions (-DBOOST_ASIO_DISABLE_THREADS)
+
+set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fno-rtti")
+set (CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fno-rtti")
+
+set (
+    SERVICE_FILES
+    ${PROJECT_SOURCE_DIR}/service_files/xyz.openbmc_project.HostErrorMonitor.service
+)
+install (FILES ${SERVICE_FILES} DESTINATION /lib/systemd/system/)
diff --git a/cmake-format.json b/cmake-format.json
new file mode 100644
index 0000000..4a701ae
--- /dev/null
+++ b/cmake-format.json
@@ -0,0 +1,12 @@
+{
+  "enum_char": ".",
+  "line_ending": "unix",
+  "bullet_char": "*",
+  "max_subargs_per_line": 99,
+  "command_case": "lower",
+  "tab_size": 4,
+  "line_width": 80,
+  "separate_fn_name_with_space": true,
+  "dangle_parens": true,
+  "separate_ctrl_name_with_space": true
+}
diff --git a/service_files/xyz.openbmc_project.HostErrorMonitor.service b/service_files/xyz.openbmc_project.HostErrorMonitor.service
new file mode 100644
index 0000000..cf789e9
--- /dev/null
+++ b/service_files/xyz.openbmc_project.HostErrorMonitor.service
@@ -0,0 +1,10 @@
+[Unit]
+Description=Host Error Monitor
+
+[Service]
+Restart=always
+ExecStart=/usr/bin/host-error-monitor
+Type=simple
+
+[Install]
+WantedBy=multi-user.target
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;
+}