diff --git a/app/ipm/lib/linux/libR12.so b/app/ipm/lib/linux/libR12.so
new file mode 100644
index 0000000..808f462
Binary files /dev/null and b/app/ipm/lib/linux/libR12.so differ
diff --git a/app/ipm/lib/linux/libR1233zd.so b/app/ipm/lib/linux/libR1233zd.so
new file mode 100644
index 0000000..a631106
Binary files /dev/null and b/app/ipm/lib/linux/libR1233zd.so differ
diff --git a/app/ipm/lib/linux/libR1234ze.so b/app/ipm/lib/linux/libR1234ze.so
new file mode 100644
index 0000000..4c21d0b
Binary files /dev/null and b/app/ipm/lib/linux/libR1234ze.so differ
diff --git a/app/ipm/lib/linux/libR134a.so b/app/ipm/lib/linux/libR134a.so
new file mode 100644
index 0000000..3fcd62f
Binary files /dev/null and b/app/ipm/lib/linux/libR134a.so differ
diff --git a/app/ipm/lib/linux/libR22.so b/app/ipm/lib/linux/libR22.so
new file mode 100644
index 0000000..9300f76
Binary files /dev/null and b/app/ipm/lib/linux/libR22.so differ
diff --git a/app/ipm/lib/linux/libR290.so b/app/ipm/lib/linux/libR290.so
new file mode 100644
index 0000000..a5e09a0
Binary files /dev/null and b/app/ipm/lib/linux/libR290.so differ
diff --git a/app/ipm/lib/linux/libR32.so b/app/ipm/lib/linux/libR32.so
new file mode 100644
index 0000000..902a685
Binary files /dev/null and b/app/ipm/lib/linux/libR32.so differ
diff --git a/app/ipm/lib/linux/libR404A.so b/app/ipm/lib/linux/libR404A.so
new file mode 100644
index 0000000..8fbbc41
Binary files /dev/null and b/app/ipm/lib/linux/libR404A.so differ
diff --git a/app/ipm/lib/linux/libR410A.so b/app/ipm/lib/linux/libR410A.so
new file mode 100644
index 0000000..acc91bd
Binary files /dev/null and b/app/ipm/lib/linux/libR410A.so differ
diff --git a/app/ipm/lib/linux/libR502.so b/app/ipm/lib/linux/libR502.so
new file mode 100644
index 0000000..5be1062
Binary files /dev/null and b/app/ipm/lib/linux/libR502.so differ
diff --git a/app/ipm/lib/linux/libR507A.so b/app/ipm/lib/linux/libR507A.so
new file mode 100644
index 0000000..8b7a0d5
Binary files /dev/null and b/app/ipm/lib/linux/libR507A.so differ
diff --git a/app/ipm/lib/linux/libR717.so b/app/ipm/lib/linux/libR717.so
new file mode 100644
index 0000000..3739193
Binary files /dev/null and b/app/ipm/lib/linux/libR717.so differ
diff --git a/app/ipm/lib/linux/libR744.so b/app/ipm/lib/linux/libR744.so
new file mode 100644
index 0000000..1c1775c
Binary files /dev/null and b/app/ipm/lib/linux/libR744.so differ
diff --git a/app/ipm/lib/linux/librefifc.so b/app/ipm/lib/linux/librefifc.so
new file mode 100644
index 0000000..4f5fb53
Binary files /dev/null and b/app/ipm/lib/linux/librefifc.so differ
diff --git a/app/ipm/simple_refrig_api.py b/app/ipm/simple_refrig_api.py
index 3c0a9dd..385b316 100644
--- a/app/ipm/simple_refrig_api.py
+++ b/app/ipm/simple_refrig_api.py
@@ -101,7 +101,7 @@ class GenRefProperties(Structure):
 
 
 if os.name == 'nt':
-    REFIFC_LIB_NAME = "refifc"
+    REFIFC_LIB_NAME = "refifc.dll"
 else:  # 'posix'
     REFIFC_LIB_NAME = "librefifc.so"
 
@@ -113,10 +113,10 @@ class Refifc(object):
         # Sauvegardez le répertoire courant pour pouvoir y revenir plus tard
         self.original_directory = os.getcwd()
         # Determine candidate directories for the native library. Prefer
-        # app/ipm/lib/<platform> if present, otherwise fall back to the
-        # package directory (for compatibility with older layouts).
+        # app/ipm/lib/dll (Windows) or app/ipm/lib/so (POSIX) if present,
+        # otherwise fall back to the package directory (for compatibility).
         package_dir = os.path.dirname(os.path.abspath(__file__))
-        platform_dir = os.path.join(package_dir, 'lib', 'windows' if os.name == 'nt' else 'linux')
+        platform_dir = os.path.join(package_dir, 'lib', 'dll' if os.name == 'nt' else 'so')
         dll_directory = platform_dir if os.path.isdir(platform_dir) else package_dir
 
         # Change working directory to the chosen directory while loading
@@ -124,13 +124,22 @@ class Refifc(object):
 
         # Try to load the native library from the chosen directory; if that
         # fails, attempt to load by name (for system-installed libs) and
-        # otherwise raise the original exception.
+        # otherwise raise the original exception. Use RTLD_GLOBAL on POSIX
+        # to make symbols available for dependent shared objects.
         try:
-            self.lib = ctypes.cdll.LoadLibrary(os.path.join(dll_directory, REFIFC_LIB_NAME))
+            full_lib_path = os.path.join(dll_directory, REFIFC_LIB_NAME)
+            if os.name == 'nt':
+                self.lib = ctypes.cdll.LoadLibrary(full_lib_path)
+            else:
+                # Use RTLD_GLOBAL so dependent .so files can resolve symbols
+                self.lib = ctypes.CDLL(full_lib_path, mode=ctypes.RTLD_GLOBAL)
         except OSError:
             try:
-                self.lib = ctypes.cdll.LoadLibrary(REFIFC_LIB_NAME)
-            except Exception as e:
+                if os.name == 'nt':
+                    self.lib = ctypes.cdll.LoadLibrary(REFIFC_LIB_NAME)
+                else:
+                    self.lib = ctypes.CDLL(REFIFC_LIB_NAME, mode=ctypes.RTLD_GLOBAL)
+            except Exception:
                 # Restore cwd before raising
                 os.chdir(self.original_directory)
                 raise
@@ -145,12 +154,24 @@ class Refifc(object):
         try:
             ctypes.CDLL(os.path.join(dll_directory, REFIFC_LIB_NAME))
         except OSError:
+            # best-effort warning; not fatal here (the main loader already succeeded)
             print(f"Refrig {refrig_name} not found, please check!")
 
         func = self.lib.refdll_load
         func.restype = POINTER(c_void_p)
         func.argtypes = [c_char_p, c_void_p]
-        self.handle = func(c_char_p(refrig_name.encode('utf-8')), c_void_p())
+        # On POSIX the native loader often expects the full SO filename
+        # (e.g. "libR290.so"). We built `ctypes_refrig_name` above to match
+        # that convention; use it when calling the native loader.
+        name_to_pass = ctypes_refrig_name if ctypes_refrig_name else refrig_name
+        try:
+            self.handle = func(c_char_p(name_to_pass.encode('utf-8')), c_void_p())
+        finally:
+            # restore cwd even if the native call raises
+            try:
+                os.chdir(self.original_directory)
+            except Exception:
+                pass
 
     # def __del__(self):
 
diff --git a/scripts/container_check.py b/scripts/container_check.py
new file mode 100644
index 0000000..4768c61
--- /dev/null
+++ b/scripts/container_check.py
@@ -0,0 +1,12 @@
+import traceback, sys
+try:
+    from app.core.refrigerant_loader import RefrigerantLibrary
+    r = RefrigerantLibrary('R290')
+    print('Loaded Refifc OK')
+    try:
+        print('pbegin', r.p_begin())
+    except Exception as e:
+        print('p_begin failed:', e)
+except Exception:
+    traceback.print_exc()
+    sys.exit(1)
diff --git a/scripts/run_api_tests.py b/scripts/run_api_tests.py
new file mode 100644
index 0000000..e1f33cf
--- /dev/null
+++ b/scripts/run_api_tests.py
@@ -0,0 +1,58 @@
+import requests, json, base64, os
+base = 'http://127.0.0.1:8001'
+print('Health ->', requests.get(base + '/api/v1/health').json())
+# Diagram JSON
+body = {
+    'refrigerant': 'R290',
+    'pressure_range': {'min': 0.1, 'max': 10.0},
+    'format': 'json',
+    'include_isotherms': True,
+    'width': 800,
+    'height': 600,
+    'dpi': 100
+}
+print('\nRequesting diagram JSON...')
+r = requests.post(base + '/api/v1/diagrams/ph', json=body, timeout=60)
+print('Status', r.status_code)
+try:
+    j = r.json()
+    print('Keys in response:', list(j.keys()))
+    if 'data' in j:
+        print('Saturation curve length:', len(j['data'].get('saturation_curve', [])))
+except Exception as e:
+    print('Failed to parse JSON:', e, r.text[:200])
+
+# Diagram PNG
+body['format'] = 'png'
+print('\nRequesting diagram PNG...')
+r2 = requests.post(base + '/api/v1/diagrams/ph', json=body, timeout=60)
+print('Status', r2.status_code)
+try:
+    j2 = r2.json()
+    print('Keys in response:', list(j2.keys()))
+    if 'image' in j2:
+        img_b64 = j2['image']
+        os.makedirs('test_outputs', exist_ok=True)
+        path = os.path.join('test_outputs','sample_diagram.png')
+        with open(path, 'wb') as f:
+            f.write(base64.b64decode(img_b64))
+        print('Saved PNG to', path)
+except ValueError:
+    print('Response is not JSON, printing text length', len(r2.text))
+
+# Simple cycle (pressure mode)
+print('\nRequesting simple cycle...')
+cycle_body = {
+    'refrigerant': 'R290',
+    'evap_pressure': 0.2,  # bar
+    'cond_pressure': 6.0,  # bar
+    'superheat': 5.0,
+    'subcool': 2.0,
+    'mass_flow': 0.1
+}
+r3 = requests.post(base + '/api/v1/cycles/simple', json=cycle_body, timeout=60)
+print('Status', r3.status_code)
+try:
+    print('Simple cycle keys:', list(r3.json().keys()))
+except Exception as e:
+    print('Failed to parse cycle response:', e, r3.text[:200])
diff --git a/scripts/run_api_tests_docker.py b/scripts/run_api_tests_docker.py
new file mode 100644
index 0000000..2a351a9
--- /dev/null
+++ b/scripts/run_api_tests_docker.py
@@ -0,0 +1,78 @@
+import requests, json, base64, os
+base = 'http://127.0.0.1:8002'
+print('Health ->', requests.get(base + '/api/v1/health').json())
+# Diagram JSON
+body = {
+    'refrigerant': 'R290',
+    'pressure_range': {'min': 0.1, 'max': 10.0},
+    'format': 'json',
+    'include_isotherms': True,
+    'width': 800,
+    'height': 600,
+    'dpi': 100
+}
+print('\nRequesting diagram JSON...')
+r = requests.post(base + '/api/v1/diagrams/ph', json=body, timeout=120)
+print('Status', r.status_code)
+try:
+    j = r.json()
+    print('Keys in response:', list(j.keys()))
+    if 'data' in j:
+        print('Saturation curve length:', len(j['data'].get('saturation_curve', [])))
+except Exception as e:
+    print('Failed to parse JSON:', e, r.text[:200])
+
+# Diagram PNG
+body['format'] = 'png'
+print('\nRequesting diagram PNG...')
+r2 = requests.post(base + '/api/v1/diagrams/ph', json=body, timeout=120)
+print('Status', r2.status_code)
+try:
+    j2 = r2.json()
+    print('Keys in response:', list(j2.keys()))
+    if 'image' in j2:
+        img_b64 = j2['image']
+        os.makedirs('test_outputs', exist_ok=True)
+        path = os.path.join('test_outputs','docker_sample_diagram.png')
+        with open(path, 'wb') as f:
+            f.write(base64.b64decode(img_b64))
+        print('Saved PNG to', path)
+except Exception as e:
+    print('Failed to parse PNG response:', e, r2.text[:200])
+
+# Simple cycle (pressure mode)
+print('\nRequesting simple cycle (pressure mode)...')
+cycle_body = {
+    'refrigerant': 'R290',
+    'evap_pressure': 0.2,  # bar
+    'cond_pressure': 6.0,  # bar
+    'superheat': 5.0,
+    'subcool': 2.0,
+    'mass_flow': 0.1
+}
+r3 = requests.post(base + '/api/v1/cycles/simple', json=cycle_body, timeout=120)
+print('Status', r3.status_code)
+try:
+    print('Simple cycle keys:', list(r3.json().keys()))
+except Exception as e:
+    print('Failed to parse cycle response:', e, r3.text[:200])
+
+# Simple cycle (temperature mode)
+print('\nRequesting simple cycle (temperature mode)...')
+cycle_body2 = {
+    'refrigerant': 'R290',
+    'evap_temperature': -10.0,
+    'cond_temperature': 40.0,
+    'superheat': 5.0,
+    'subcool': 2.0,
+    'mass_flow': 0.1
+}
+r4 = requests.post(base + '/api/v1/cycles/simple', json=cycle_body2, timeout=120)
+print('Status', r4.status_code)
+try:
+    j4 = r4.json()
+    print('Keys:', list(j4.keys()))
+    if 'performance' in j4:
+        print('COP:', j4['performance'].get('cop'))
+except Exception as e:
+    print('Failed to parse cycle temp response:', e, r4.text[:200])
diff --git a/scripts/test_cycle_temp.py b/scripts/test_cycle_temp.py
new file mode 100644
index 0000000..d323e11
--- /dev/null
+++ b/scripts/test_cycle_temp.py
@@ -0,0 +1,25 @@
+import requests, json
+base = 'http://127.0.0.1:8001'
+print('Health ->', requests.get(base + '/api/v1/health').json())
+
+body = {
+    'refrigerant': 'R290',
+    'evap_temperature': -10.0,  # °C
+    'cond_temperature': 40.0,   # °C
+    'superheat': 5.0,
+    'subcool': 2.0,
+    'mass_flow': 0.1
+}
+print('\nRequesting simple cycle (temperature mode)...')
+r = requests.post(base + '/api/v1/cycles/simple', json=body, timeout=60)
+print('Status', r.status_code)
+try:
+    j = r.json()
+    print('Keys:', list(j.keys()))
+    if 'performance' in j:
+        print('COP:', j['performance'].get('cop'))
+        print('Compressor efficiency:', j['performance'].get('compressor_efficiency'))
+    if 'diagram_data' in j:
+        print('Diagram cycle points count:', len(j['diagram_data'].get('cycle_points', [])))
+except Exception as e:
+    print('Failed to parse JSON:', e, r.text[:200])
diff --git a/scripts/test_economizer.py b/scripts/test_economizer.py
new file mode 100644
index 0000000..289f1d2
--- /dev/null
+++ b/scripts/test_economizer.py
@@ -0,0 +1,28 @@
+import os
+import sys
+
+# Ensure project root is on sys.path so 'app' package is importable when running scripts
+ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
+if ROOT not in sys.path:
+    sys.path.insert(0, ROOT)
+
+from app.core.refrigerant_loader import RefrigerantLibrary
+from app.services.cycle_calculator import CycleCalculator
+
+# Create refrigerant and calculator
+refrig = RefrigerantLibrary('R290')
+calc = CycleCalculator(refrig)
+
+# Typical pressures in Pa (convert from bar)
+evap = 0.2 * 1e5
+cond = 6.0 * 1e5
+inter = 2.0 * 1e5
+
+res = calc.calculate_cycle_with_economizer(evap, cond, inter, superheat=5.0, subcool=3.0, mass_flow=0.1)
+
+print('Economizer result keys:', res.keys())
+print('Flash fraction:', res['performance'].get('flash_fraction'))
+print('COP:', res['performance'].get('cop'))
+print('Points:')
+for p in res['points']:
+    print(' -', p)
diff --git a/test_outputs/sample_diagram.png b/test_outputs/sample_diagram.png
new file mode 100644
index 0000000..4b2ad91
Binary files /dev/null and b/test_outputs/sample_diagram.png differ
diff --git a/tests/test_diagram_api.py b/tests/test_diagram_api.py
new file mode 100644
index 0000000..39ac869
--- /dev/null
+++ b/tests/test_diagram_api.py
@@ -0,0 +1,44 @@
+import base64
+import pytest
+from fastapi.testclient import TestClient
+
+from app.main import app
+
+client = TestClient(app)
+
+
+def test_diagram_json_no_image():
+    body = {
+        'refrigerant': 'R290',
+        'pressure_range': {'min': 0.1, 'max': 10.0},
+        'format': 'json',
+        'include_isotherms': True,
+        'width': 800,
+        'height': 600,
+        'dpi': 100
+    }
+    r = client.post('/api/v1/diagrams/ph', json=body)
+    assert r.status_code == 200
+    j = r.json()
+    # image key should not be present for json-only
+    assert 'image' not in j
+    assert 'data' in j
+
+
+def test_diagram_png_includes_image():
+    body = {
+        'refrigerant': 'R290',
+        'pressure_range': {'min': 0.1, 'max': 10.0},
+        'format': 'png',
+        'include_isotherms': True,
+        'width': 800,
+        'height': 600,
+        'dpi': 100
+    }
+    r = client.post('/api/v1/diagrams/ph', json=body)
+    assert r.status_code == 200
+    j = r.json()
+    assert 'image' in j
+    # Validate base64 decodes
+    decoded = base64.b64decode(j['image'])
+    assert len(decoded) > 10
diff --git a/tests/test_economizer_unit.py b/tests/test_economizer_unit.py
new file mode 100644
index 0000000..3f61264
--- /dev/null
+++ b/tests/test_economizer_unit.py
@@ -0,0 +1,19 @@
+import sys, os
+ROOT = os.path.abspath(os.path.join(os.path.dirname(__file__), '..'))
+if ROOT not in sys.path:
+    sys.path.insert(0, ROOT)
+
+from app.core.refrigerant_loader import RefrigerantLibrary
+from app.services.cycle_calculator import CycleCalculator
+
+
+def test_economizer_runs():
+    refrigerant = RefrigerantLibrary('R290')
+    calc = CycleCalculator(refrigerant)
+    evap = 0.2 * 1e5
+    cond = 6.0 * 1e5
+    inter = 2.0 * 1e5
+    res = calc.calculate_cycle_with_economizer(evap, cond, inter, mass_flow=0.1)
+    assert 'performance' in res
+    assert 'flash_fraction' in res['performance']
+    assert 0.0 <= res['performance']['flash_fraction'] <= 1.0