diff --git a/.github/workflows/coordo-py.yml b/.github/workflows/coordo-py.yml
index 5bbb328..462b85a 100644
--- a/.github/workflows/coordo-py.yml
+++ b/.github/workflows/coordo-py.yml
@@ -34,3 +34,6 @@ jobs:
 
       - name: Run tests
         run: uv run test.py
+      
+      - name: Run pytest
+        run: uv run pytest
diff --git a/coordo-py/pyproject.toml b/coordo-py/pyproject.toml
index 61b1534..6f05be6 100644
--- a/coordo-py/pyproject.toml
+++ b/coordo-py/pyproject.toml
@@ -28,7 +28,12 @@ coordo = "coordo.cli:app"
 [tool.setuptools.package-data]
 "coordo" = ["static/*", "**/*.sql"]
 
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+addopts = ["-s"]
+
 [dependency-groups]
 dev = [
     "ruff>=0.15.8",
+    "pytest>=8.0",
 ]
diff --git a/coordo-py/tests/__init__.py b/coordo-py/tests/__init__.py
new file mode 100644
index 0000000..e5a1d76
--- /dev/null
+++ b/coordo-py/tests/__init__.py
@@ -0,0 +1,2 @@
+# Copyright COORDONNÉES 2025, 2026
+# SPDX-License-Identifier: MPL-2.0
\ No newline at end of file
diff --git a/coordo-py/tests/conftest.py b/coordo-py/tests/conftest.py
new file mode 100644
index 0000000..37ed756
--- /dev/null
+++ b/coordo-py/tests/conftest.py
@@ -0,0 +1,24 @@
+# Copyright COORDONNÉES 2025, 2026
+# SPDX-License-Identifier: MPL-2.0
+
+import pytest 
+from pathlib import Path
+
+DATA_DIR = Path("tests/test_data")
+INVENTORY_DIR = DATA_DIR / "inventory"
+
+@pytest.fixture
+def inventory_package():
+    return "catalog/inventory"
+
+@pytest.fixture
+def inventory_inquiry():
+    return INVENTORY_DIR / "inquiry.xlsx"
+
+@pytest.fixture
+def inventory_data():
+    return INVENTORY_DIR / "data.xlsx"
+
+@pytest.fixture
+def inventory_file():
+    return INVENTORY_DIR / "file.csv"
\ No newline at end of file
diff --git a/coordo-py/tests/test_cli.py b/coordo-py/tests/test_cli.py
new file mode 100644
index 0000000..67fd1fc
--- /dev/null
+++ b/coordo-py/tests/test_cli.py
@@ -0,0 +1,33 @@
+# Copyright COORDONNÉES 2025, 2026
+# SPDX-License-Identifier: MPL-2.0
+
+import shutil
+from typer.testing import CliRunner
+from coordo.cli import app 
+
+runner = CliRunner()
+
+def get_output_and_check_exitcode(result):
+    print(result.stdout_bytes.decode())
+    assert result.exit_code == 0
+
+def test_add_data_to_package(inventory_package, inventory_inquiry, inventory_data, inventory_file):
+    """
+    Test the following workflow:
+    - Load data from a kobotoolbox inquiry and a file into a package.
+    - Add a foreign key between two fields.
+    - Remove the foreign key.
+    - Add the foreign key again.
+    """
+    result = runner.invoke(app, ["load", "kobotoolbox", str(inventory_inquiry), str(inventory_data), "--package", inventory_package, "--action", "add"])
+    get_output_and_check_exitcode(result)
+    result = runner.invoke(app, ["load", "file", str(inventory_file), "--package", inventory_package, "--action", "add"])
+    get_output_and_check_exitcode(result)
+    result = runner.invoke(app, ["add-foreignkey", "ind.ess_arb", "file.ess_arb", "--package", inventory_package])
+    get_output_and_check_exitcode(result)
+    result = runner.invoke(app, ["remove-foreignkey", "ind.ess_arb", "file.ess_arb", "--package", inventory_package])
+    get_output_and_check_exitcode(result)
+    result = runner.invoke(app, ["add-foreignkey", "ind.ess_arb", "file.ess_arb", "--package", inventory_package])
+    get_output_and_check_exitcode(result)
+    print(f"Removing package '{inventory_package}'")
+    shutil.rmtree(inventory_package)
\ No newline at end of file
diff --git a/coordo-py/tests/test_data/inventory/data.xlsx b/coordo-py/tests/test_data/inventory/data.xlsx
new file mode 100644
index 0000000..cb13bd6
Binary files /dev/null and b/coordo-py/tests/test_data/inventory/data.xlsx differ
diff --git a/coordo-py/tests/test_data/inventory/file.csv b/coordo-py/tests/test_data/inventory/file.csv
new file mode 100644
index 0000000..e2ef7b7
--- /dev/null
+++ b/coordo-py/tests/test_data/inventory/file.csv
@@ -0,0 +1,37 @@
+ess_arb,value
+1,0.422
+2,0.694
+4,0.607
+5,0.607
+7,0.56
+8,0.738
+9,0.723
+10,0.56
+16,0.642
+25,0.8
+33,0.636
+35,0.627
+37,0.56
+39,0.886
+58,0.56
+67,0.56
+70,0.682
+72,0.736
+77,0.56
+93,0.854
+96,0.8
+105,0.681
+111,0.671
+127,0.55
+133,0.681
+145,0.465
+166,0.56
+173,0.56
+187,0.56
+194,0.641
+195,0.664
+198,0.56
+213,0.49
+243,0.56
+248,0.646
+251,0.56
diff --git a/coordo-py/tests/test_data/inventory/inquiry.xlsx b/coordo-py/tests/test_data/inventory/inquiry.xlsx
new file mode 100644
index 0000000..73db790
Binary files /dev/null and b/coordo-py/tests/test_data/inventory/inquiry.xlsx differ
diff --git a/coordo-py/uv.lock b/coordo-py/uv.lock
index 76198da..4b6488a 100644
--- a/coordo-py/uv.lock
+++ b/coordo-py/uv.lock
@@ -225,6 +225,7 @@ dependencies = [
 
 [package.dev-dependencies]
 dev = [
+    { name = "pytest" },
     { name = "ruff" },
 ]
 
@@ -249,7 +250,10 @@ requires-dist = [
 ]
 
 [package.metadata.requires-dev]
-dev = [{ name = "ruff", specifier = ">=0.15.8" }]
+dev = [
+    { name = "pytest", specifier = ">=8.0" },
+    { name = "ruff", specifier = ">=0.15.8" },
+]
 
 [[package]]
 name = "dateparser"
@@ -555,6 +559,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/0e/61/66938bbb5fc52dbdf84594873d5b51fb1f7c7794e9c0f5bd885f30bc507b/idna-3.11-py3-none-any.whl", hash = "sha256:771a87f49d9defaf64091e6e6fe9c18d4833f140bd19464795bc32d966ca37ea", size = 71008, upload-time = "2025-10-12T14:55:18.883Z" },
 ]
 
+[[package]]
+name = "iniconfig"
+version = "2.3.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/72/34/14ca021ce8e5dfedc35312d08ba8bf51fdd999c576889fc2c24cb97f4f10/iniconfig-2.3.0.tar.gz", hash = "sha256:c76315c77db068650d49c5b56314774a7804df16fee4402c1f19d6d15d8c4730", size = 20503, upload-time = "2025-10-18T21:55:43.219Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/cb/b1/3846dd7f199d53cb17f49cba7e651e9ce294d8497c8c150530ed11865bb8/iniconfig-2.3.0-py3-none-any.whl", hash = "sha256:f631c04d2c48c52b84d0d0549c99ff3859c98df65b3101406327ecc7d53fbf12", size = 7484, upload-time = "2025-10-18T21:55:41.639Z" },
+]
+
 [[package]]
 name = "itsdangerous"
 version = "2.2.0"
@@ -984,6 +997,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/e6/3f/a80ac00acbc6b35166b42850e98a4f466e2c0d9c64054161ba9620f95680/pandas-3.0.0-cp314-cp314t-win_arm64.whl", hash = "sha256:1c39eab3ad38f2d7a249095f0a3d8f8c22cc0f847e98ccf5bbe732b272e2d9fa", size = 9441003, upload-time = "2026-01-21T15:52:02.281Z" },
 ]
 
+[[package]]
+name = "pluggy"
+version = "1.6.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/f9/e2/3e91f31a7d2b083fe6ef3fa267035b518369d9511ffab804f839851d2779/pluggy-1.6.0.tar.gz", hash = "sha256:7dcc130b76258d33b90f61b658791dede3486c3e6bfb003ee5c9bfb396dd22f3", size = 69412, upload-time = "2025-05-15T12:30:07.975Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/54/20/4d324d65cc6d9205fabedc306948156824eb9f0ee1633355a8f7ec5c66bf/pluggy-1.6.0-py3-none-any.whl", hash = "sha256:e920276dd6813095e9377c0bc5566d94c932c33b27a3e3945d8389c374dd4746", size = 20538, upload-time = "2025-05-15T12:30:06.134Z" },
+]
+
 [[package]]
 name = "propcache"
 version = "0.4.1"
@@ -1395,6 +1417,22 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/15/73/a7141a1a0559bf1a7aa42a11c879ceb19f02f5c6c371c6d57fd86cefd4d1/pyproj-3.7.2-cp314-cp314t-win_arm64.whl", hash = "sha256:d9d25bae416a24397e0d85739f84d323b55f6511e45a522dd7d7eae70d10c7e4", size = 6391844, upload-time = "2025-08-14T12:05:40.745Z" },
 ]
 
+[[package]]
+name = "pytest"
+version = "9.0.3"
+source = { registry = "https://pypi.org/simple" }
+dependencies = [
+    { name = "colorama", marker = "sys_platform == 'win32'" },
+    { name = "iniconfig" },
+    { name = "packaging" },
+    { name = "pluggy" },
+    { name = "pygments" },
+]
+sdist = { url = "https://files.pythonhosted.org/packages/7d/0d/549bd94f1a0a402dc8cf64563a117c0f3765662e2e668477624baeec44d5/pytest-9.0.3.tar.gz", hash = "sha256:b86ada508af81d19edeb213c681b1d48246c1a91d304c6c81a427674c17eb91c", size = 1572165, upload-time = "2026-04-07T17:16:18.027Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/d4/24/a372aaf5c9b7208e7112038812994107bc65a84cd00e0354a88c2c77a617/pytest-9.0.3-py3-none-any.whl", hash = "sha256:2c5efc453d45394fdd706ade797c0a81091eccd1d6e4bccfcd476e2b8e0ab5d9", size = 375249, upload-time = "2026-04-07T17:16:16.13Z" },
+]
+
 [[package]]
 name = "python-dateutil"
 version = "2.9.0.post0"