diff --git a/CMakeLists.txt b/CMakeLists.txt
index aa72f65..3f4f55b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,9 +14,7 @@ include_directories(
 )
 
 # === Source files ===
-set(SOURCE_FILES
-        src/main.cpp
-
+set(LIB_SOURCES
         include/agents/QLearningAgent.cpp
         include/core/ExecutionSimulator.cpp
         include/env/MarketEnvironment.cpp
@@ -24,8 +22,12 @@ set(SOURCE_FILES
         include/utils/MathUtils.cpp
 )
 
+add_library(executionrl_lib ${LIB_SOURCES})
+target_compile_definitions(executionrl_lib PRIVATE DATA_PATH="${CMAKE_SOURCE_DIR}/data/price_series.csv")
+
 # === Executable ===
-add_executable(ExecutionRL ${SOURCE_FILES})
+add_executable(ExecutionRL src/main.cpp)
+target_link_libraries(ExecutionRL PRIVATE executionrl_lib)
 
 # === Tests ===
 enable_testing()
@@ -34,6 +36,10 @@ add_executable(test_agent tests/test_agent.cpp)
 add_executable(test_env tests/test_env.cpp)
 add_executable(test_simulation tests/test_simulation.cpp)
 
+target_link_libraries(test_agent PRIVATE executionrl_lib)
+target_link_libraries(test_env PRIVATE executionrl_lib)
+target_link_libraries(test_simulation PRIVATE executionrl_lib)
+
 target_include_directories(test_agent PRIVATE include)
 target_include_directories(test_env PRIVATE include)
 target_include_directories(test_simulation PRIVATE include)
@@ -41,3 +47,6 @@ target_include_directories(test_simulation PRIVATE include)
 add_test(NAME AgentTest COMMAND test_agent)
 add_test(NAME EnvTest COMMAND test_env)
 add_test(NAME SimulationTest COMMAND test_simulation)
+
+set_tests_properties(AgentTest EnvTest SimulationTest
+    PROPERTIES WORKING_DIRECTORY ${CMAKE_SOURCE_DIR})
diff --git a/include/core/ExecutionSimulator.cpp b/include/core/ExecutionSimulator.cpp
index 0fd5277..5871c37 100644
--- a/include/core/ExecutionSimulator.cpp
+++ b/include/core/ExecutionSimulator.cpp
@@ -3,13 +3,15 @@
 ExecutionSimulator::ExecutionSimulator(MarketEnvironment& env, QLearningAgent& agent)
     : env(env), agent(agent) {}
 
-void ExecutionSimulator::run() {
-    env.reset();
-    while (!env.isDone()) {
-        auto state = env.getState();
-        int action = agent.chooseAction(state);
-        double reward = env.step(action);
-        auto nextState = env.getState();
-        agent.update(state, action, reward, nextState);
+void ExecutionSimulator::run(int episodes) {
+    for (int i = 0; i < episodes; ++i) {
+        env.reset();
+        while (!env.isDone()) {
+            auto state = env.getState();
+            int action = agent.chooseAction(state);
+            double reward = env.step(action);
+            auto nextState = env.getState();
+            agent.update(state, action, reward, nextState);
+        }
     }
 }
diff --git a/include/core/ExecutionSimulator.hpp b/include/core/ExecutionSimulator.hpp
index 0ae0fe3..ccdbe16 100644
--- a/include/core/ExecutionSimulator.hpp
+++ b/include/core/ExecutionSimulator.hpp
@@ -8,7 +8,7 @@
 class ExecutionSimulator {
 public:
     ExecutionSimulator(MarketEnvironment& env, QLearningAgent& agent);
-    void run();
+    void run(int episodes = 1);
 
 private:
     MarketEnvironment& env;
diff --git a/include/env/MarketEnvironment.cpp b/include/env/MarketEnvironment.cpp
index c1bc781..8d7c66b 100644
--- a/include/env/MarketEnvironment.cpp
+++ b/include/env/MarketEnvironment.cpp
@@ -40,15 +40,25 @@ bool MarketEnvironment::isDone() const {
 }
 
 void MarketEnvironment::loadMarketData() {
-    std::ifstream file("prices.csv");
+    std::ifstream file(DATA_PATH);
     std::string line;
 
     prices.clear();
+    bool firstLine = true;
     while (std::getline(file, line)) {
+        if (firstLine) { // skip header if present
+            firstLine = false;
+            if (line.find_first_not_of("0123456789-.") != std::string::npos)
+                continue;
+        }
         std::stringstream ss(line);
         std::string cell;
         if (std::getline(ss, cell, ',')) {
-            prices.push_back(std::stod(cell));
+            try {
+                prices.push_back(std::stod(cell));
+            } catch (const std::invalid_argument&) {
+                // ignore malformed lines
+            }
         }
     }
 
diff --git a/src/main.cpp b/src/main.cpp
index f93774d..a08fd40 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,6 +1,6 @@
-#include "include/core/ExecutionSimulator.hpp"
-#include "include/env/MarketEnvironment.hpp"
-#include "include/agents/QLearningAgent.hpp"
+#include "core/ExecutionSimulator.hpp"
+#include "env/MarketEnvironment.hpp"
+#include "agents/QLearningAgent.hpp"
 
 int main() {
     MarketEnvironment env;
diff --git a/tests/test_agent.cpp b/tests/test_agent.cpp
index 9ee59bd..e95ea36 100644
--- a/tests/test_agent.cpp
+++ b/tests/test_agent.cpp
@@ -1,4 +1,4 @@
-#include "../include/agents/QLearningAgent.hpp"
+#include "agents/QLearningAgent.hpp"
 #include <cassert>
 #include <iostream>
 
diff --git a/tests/test_env.cpp b/tests/test_env.cpp
index fbf9148..3746010 100644
--- a/tests/test_env.cpp
+++ b/tests/test_env.cpp
@@ -1,4 +1,4 @@
-#include "../include/env/MarketEnvironment.hpp"
+#include "env/MarketEnvironment.hpp"
 #include <cassert>
 #include <iostream>
 
diff --git a/tests/test_simulation.cpp b/tests/test_simulation.cpp
index 7eac0bd..4d2e7f6 100644
--- a/tests/test_simulation.cpp
+++ b/tests/test_simulation.cpp
@@ -1,7 +1,7 @@
-#include "../include/core/ExecutionSimulator.hpp"
-#include "../include/env/MarketEnvironment.hpp"
-#include "../include/agents/QLearningAgent.hpp"
-#include "../include/config.hpp"
+#include "core/ExecutionSimulator.hpp"
+#include "env/MarketEnvironment.hpp"
+#include "agents/QLearningAgent.hpp"
+#include "config.hpp"
 #include <iostream>
 
 int main() {