diff --git a/.gitignore b/.gitignore
index 9a421d7..1357f27 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,8 @@
 cmake-build-debug
 .idea
 ./.idea
+./cmake-build-release/
+cmake-build-release
+CMakeFiles
+CMakeLists.txt
+Makefile
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index af26149..bf3a9d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,4 +4,5 @@ set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -std=c++1z -O0 -DDEBUG=1")
 set(SOURCE_FILES Rex.cpp src/loaders/abstract/loaders.cpp src/loaders/abstract/loaders.h src/json/jsoncpp.cpp src/loaders/low_level/JSON_Loader.cpp src/loaders/low_level/JSON_Loader.h src/loaders/misc/helpers.cpp src/loaders/misc/helpers.h src/loaders/abstract/Suite.cpp src/loaders/abstract/Suite.h src/loaders/abstract/Plan.cpp src/loaders/abstract/Plan.h src/loaders/abstract/Conf.cpp src/loaders/abstract/Conf.h src/loaders/abstract/Unit.cpp src/loaders/abstract/Unit.h src/loaders/abstract/Task.cpp src/loaders/abstract/Task.h src/Sproc/Sproc.cpp src/Sproc/Sproc.h src/Logger/Logger.cpp src/Logger/Logger.h)
 
+
 add_executable(rex ${SOURCE_FILES})
diff --git a/src/loaders/abstract/Conf.cpp b/src/loaders/abstract/Conf.cpp
index 67dbbdd..d111e59 100644
--- a/src/loaders/abstract/Conf.cpp
+++ b/src/loaders/abstract/Conf.cpp
@@ -70,6 +70,8 @@ protected:
 Conf::Conf(std::string filename, int LOG_LEVEL ): JSON_Loader(LOG_LEVEL ), slog(LOG_LEVEL, "_conf_" )
 {
     this->LOG_LEVEL = LOG_LEVEL;
+    std::string jval_s;
+    bool jval_b;
 
     // prepare context spaghetti
     this->override_context = false;
@@ -83,65 +85,59 @@ Conf::Conf(std::string filename, int LOG_LEVEL ): JSON_Loader(LOG_LEVEL ), slog(
         throw ConfigLoadException("Config file not found.");
     }
 
-    if (this->get_serialized(this->config_version, "config_version" ) != 0)
-    {
-        throw ConfigLoadException("config_version string is not set in the config file supplied: " + filename);
-    }
-    if ( this->config_version.asString() != VERSION_STRING )
-    {
-        throw ConfigLoadException("config_version string expected was " + std::string(VERSION_STRING) + " in: " + filename);
-    }
-
     // find the path to the unit definitions file
-    if (this->get_serialized(this->units_path, "units_path" ) != 0 )
-    {
-        throw ConfigLoadException("units_path string is not set in the config file supplied: " + filename);
+    if (this->get_string(jval_s, "units_path") != 0 )
+    { throw ConfigLoadException("units_path string is not set in the config file supplied: " + filename); } else {
+        this->units_path = jval_s;
     }
+    jval_s = {0};
 
     // find the path to logs directory
-    if (this->get_serialized(this->logs_path, "logs_path" ) != 0 )
-    {
-        throw ConfigLoadException("logs_path string is not set in the config file supplied: " + filename);
+    if (this->get_string(jval_s, "logs_path") != 0 )
+    { throw ConfigLoadException("logs_path string is not set in the config file supplied: " + filename); } else {
+        this->logs_path = jval_s;
     }
+    jval_s = {0};
 
-    if ( this->get_serialized(this->override_execution_context, "execution_context_override" ) != 0 )
-    {
-        throw ConfigLoadException("execution_context_override boolean is not set in the config file supplied: " + filename);
-    } else {
-        this->override_context = true;
+    if (this->get_bool(jval_b, "execution_context_override") != 0 )
+    { throw ConfigLoadException("execution_context_override boolean is not set in the config file supplied: " + filename); } else {
+        this->override_context = jval_b;
     }
+    jval_b = {0};
 
-    if ( this->get_serialized(this->execution_context, "execution_context" ) != 0 )
-    {
-        throw ConfigLoadException("execution_context string is not set in the config file supplied: " + filename);
-    } else {
-            if ( is_dir( this->execution_context.asString() ) ) {
-                this->execution_context_literal = this->execution_context.asString();
-            } else {
-                throw ConfigLoadException( "The execution context supplied is an invalid directory.");
+    if (this->get_string(jval_s, "execution_context") != 0 )
+    { throw ConfigLoadException("execution_context string is not set in the config file supplied: " + filename); } else {
+            if ( ! is_dir( jval_s ) ) { throw ConfigLoadException( "The execution context supplied is an invalid directory."); } else {
+                this->execution_context = jval_s;
             }
     }
+    jval_s = {0};
+
+    interpolate( this->units_path );
+    interpolate( this->logs_path );
+    interpolate( this->execution_context );
+
 };
 
 /// Conf::has_context_override - Specifies whether or not the override context function is enabled in the Conf file.
 bool Conf::has_context_override() {
-    return this->override_execution_context.asBool();
+    return this->override_execution_context;
 }
 
 /// Conf::get_execution_context - Specifies the path to the current working directory to set for all unit executions.
 std::string Conf::get_execution_context() {
-    return this->execution_context_literal;
+    return this->execution_context;
 }
 
 /// Conf::get_units_path - Retrieves the path to the Unit definition file from the application configuration file.
-std::string Conf::get_units_path() { return this->units_path.asString(); }
+std::string Conf::get_units_path() { return this->units_path; }
 
 /// Conf::get_units_path - Retrieves the path to the Unit definition file from the application configuration file.
-std::string Conf::get_logs_path() { return this->logs_path.asString(); }
+std::string Conf::get_logs_path() { return this->logs_path; }
 
 /// Conf::set_execution_context- Sets the execution context.
 void Conf::set_execution_context(std::string execution_context )
 {
-    this->execution_context_literal = execution_context;
+    this->execution_context = execution_context;
 }
 
diff --git a/src/loaders/abstract/Conf.h b/src/loaders/abstract/Conf.h
index 37bd8aa..35a810a 100644
--- a/src/loaders/abstract/Conf.h
+++ b/src/loaders/abstract/Conf.h
@@ -28,28 +28,26 @@
 
 #define STRINGIZE2(s) #s
 #define STRINGIZE(s) STRINGIZE2(s)
-# define IMPL_CONFIG_VERSION 4
+# define IMPL_CONFIG_VERSION 5
 # define VERSION_STRING STRINGIZE(IMPL_CONFIG_VERSION)
 
 class Conf: public JSON_Loader
 {
 private:
-    Json::Value plan_path;
-    Json::Value units_path;
-    Json::Value execution_context;
-    Json::Value config_version;
-    Json::Value logs_path;
+    std::string plan_path;
+    std::string units_path;
+    std::string execution_context;
+    std::string logs_path;
 
     // flag to indicate if execution context should be overriden in config file
     // if set to true rex should use whats in the config file for current working directory
     // if set to false, rex should use the current working directory at time of execution
-    Json::Value override_execution_context;
+    bool override_execution_context;
 
     bool override_context;
-    std::string execution_context_literal;
 
 public:
-    Conf(std::string filename, int LOG_LEVEL );
+    Conf( std::string filename, int LOG_LEVEL );
 
     bool has_context_override();
 
diff --git a/src/loaders/low_level/JSON_Loader.cpp b/src/loaders/low_level/JSON_Loader.cpp
index 31aaf62..b85effd 100644
--- a/src/loaders/low_level/JSON_Loader.cpp
+++ b/src/loaders/low_level/JSON_Loader.cpp
@@ -130,7 +130,7 @@ std::string JSON_Loader::as_string()
 /// \param key - The JSON key name to assign the value to (the root of the json::value object by name)
 /// \param verbose - Whether or not to print verbose output to STDOUT.
 /// \return - Boolean indicator of success or failure (0|1)
-int JSON_Loader::get_serialized(Json::Value &input, std::string key )
+int JSON_Loader::get_serialized( Json::Value &input, std::string key )
 {
     // throw if the class is not ready to be used.
     if ( ! this->populated ) { throw JSON_Loader_NotReady(); }
@@ -147,6 +147,60 @@ int JSON_Loader::get_serialized(Json::Value &input, std::string key )
     // verbose mode tells the user what key we were looking for.
     this->slog.log( E_FATAL, "Failed to find key '" + key + "'." );
 
+    // exit code for failure
+    return 1;
+}
+
+/// JSON_Loader::get_string - assigns the serialized representation of the value of a key (json::value)
+///
+/// \param input - A reference to the json::value object to receive the new value.
+/// \param key - The JSON key name to assign the value to (the root of the json::value object by name)
+/// \param verbose - Whether or not to print verbose output to STDOUT.
+/// \return - Boolean indicator of success or failure (0|1)
+int JSON_Loader::get_string( std::string &input, std::string key )
+{
+    // throw if the class is not ready to be used.
+    if ( ! this->populated ) { throw JSON_Loader_NotReady(); }
+
+    if ( this->json_root.isMember( key ) )
+    {
+        // key was found so return it to the passed input ref
+        input = this->json_root[ key ].asString();
+        return 0;
+    }
+
+    // key was not found
+
+    // verbose mode tells the user what key we were looking for.
+    this->slog.log( E_FATAL, "Failed to find key '" + key + "'." );
+
+    // exit code for failure
+    return 1;
+}
+
+/// JSON_Loader::get_bool - assigns the serialized representation of the value of a key (json::value)
+///
+/// \param input - A reference to the json::value object to receive the new value.
+/// \param key - The JSON key name to assign the value to (the root of the json::value object by name)
+/// \param verbose - Whether or not to print verbose output to STDOUT.
+/// \return - Boolean indicator of success or failure (0|1)
+int JSON_Loader::get_bool( bool & input, std::string key )
+{
+    // throw if the class is not ready to be used.
+    if ( ! this->populated ) { throw JSON_Loader_NotReady(); }
+
+    if ( this->json_root.isMember( key ) )
+    {
+        // key was found so return it to the passed input ref
+        input = this->json_root[ key ].asBool();
+        return 0;
+    }
+
+    // key was not found
+
+    // verbose mode tells the user what key we were looking for.
+    this->slog.log( E_FATAL, "Failed to find key '" + key + "'." );
+
     // exit code for failure
     return 1;
 }
\ No newline at end of file
diff --git a/src/loaders/low_level/JSON_Loader.h b/src/loaders/low_level/JSON_Loader.h
index fd89990..ff87350 100644
--- a/src/loaders/low_level/JSON_Loader.h
+++ b/src/loaders/low_level/JSON_Loader.h
@@ -50,7 +50,9 @@ class JSON_Loader
         std::string as_string();
 
         // safely handle deserialized type retrieval (if we want it to be safe)
-        int get_serialized(Json::Value &input, std::string key );
+        int get_serialized( Json::Value & input, std::string key );
+        int get_string(std::string & input, std::string key );
+        int get_bool(bool & input, std::string key );
 
 private:
     Logger slog;
diff --git a/src/loaders/misc/helpers.cpp b/src/loaders/misc/helpers.cpp
index 39f8087..5fb2880 100644
--- a/src/loaders/misc/helpers.cpp
+++ b/src/loaders/misc/helpers.cpp
@@ -56,4 +56,17 @@ std::string get_8601()
     // ss << std::put_time(gmtime(&itt), "%FT%TZ");
     ss << std::put_time(localtime(&itt), "%Y-%m-%d_%H:%M:%S");
     return ss.str();
+}
+
+void interpolate( std::string & text )
+{
+    static std::regex env( "\\$\\{([^}]+)\\}" );
+    std::smatch match;
+    while ( std::regex_search( text, match, env ) )
+    {
+            const char * s = getenv( match[1].str().c_str() );
+            const std::string var( s == NULL ? "" : s );
+            text.replace( match[0].first, match[0].second, var );
+    }
+
 }
\ No newline at end of file
diff --git a/src/loaders/misc/helpers.h b/src/loaders/misc/helpers.h
index a62cfcc..42339b8 100644
--- a/src/loaders/misc/helpers.h
+++ b/src/loaders/misc/helpers.h
@@ -32,14 +32,22 @@
 #include <iomanip>
 #include <sstream>
 #include <vector>
+#include <regex>
+
 
 bool exists (const std::string& name);
 
 std::string get_working_path();
+
 bool is_file( std::string );
+
 bool is_dir( std::string );
 
+// expand environment variables in string
+void interpolate( std::string & text);
+
 std::string get_8601();
+
 const char * command2args( std::string input_string );
 
 #endif //REX_HELPERS_JH