diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 360d91e..aaef2dc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -88,11 +88,125 @@ jobs:
 
         pip install "jupyterlab>=4.0.0,<5" jupyterlite_xeus*.whl
 
-
         jupyter labextension list
         jupyter labextension list 2>&1 | grep -ie "@jupyterlite/xeus.*OK"
         python -m jupyterlab.browser_check --no-browser-test
 
+  python-tests-mamba-python:
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - uses: actions/download-artifact@v2
+        with:
+          name: extension-artifacts
+
+      - name: Install Conda environment with Micromamba
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          micromamba-version: '1.5.1-0'
+          environment-file: environment-dev.yaml
+          cache-environment: true
+
+      - name: Install mamba
+        run: conda install -c conda-forge mamba
+
+      - name: Make sure the Mamba Python API is available
+        run: |
+          mamba install mamba
+          python -c "from mamba.api import create"
+
+      - name: Install
+        run: pip install jupyterlite_xeus*.whl
+
+      - name: Run tests
+        run: pytest -rP test_xeus.py
+        working-directory: tests
+
+  python-tests-mamba:
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - uses: actions/download-artifact@v2
+        with:
+          name: extension-artifacts
+
+      - name: Install Conda environment with Micromamba
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          micromamba-version: '1.5.1-0'
+          environment-file: environment-dev.yaml
+          cache-environment: true
+
+      - name: Install mamba
+        run: conda install -c conda-forge mamba
+
+      - name: Install
+        run: pip install jupyterlite_xeus*.whl
+
+      - name: Run tests
+        run: pytest -rP test_xeus.py
+        working-directory: tests
+
+  python-tests-micromamba:
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - uses: actions/download-artifact@v2
+        with:
+          name: extension-artifacts
+
+      - name: Install mamba
+        uses: mamba-org/provision-with-micromamba@main
+        with:
+          micromamba-version: '0.22.0'
+          environment-file: environment-dev.yaml
+          environment-name: xeus-lite-dev
+
+      - name: Install
+        run: pip install jupyterlite_xeus*.whl
+
+      - name: Run tests
+        run: pytest -rP test_xeus.py
+        working-directory: tests
+
+  python-tests-conda:
+    needs: build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - uses: actions/download-artifact@v2
+        with:
+          name: extension-artifacts
+
+      - name: Install Conda environment with Micromamba
+        uses: mamba-org/setup-micromamba@v1
+        with:
+          micromamba-version: '1.5.1-0'
+          environment-file: environment-dev.yaml
+          cache-environment: true
+
+      - name: Install
+        run: pip install jupyterlite_xeus*.whl
+
+      - name: Run tests
+        run: pytest -rP test_xeus.py
+        working-directory: tests
+
   integration-tests:
     name: Integration tests
     needs: build
diff --git a/README.md b/README.md
index d32ea8a..05c70fb 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ This workflow usually starts with creating a local conda environment / prefix fo
 micromamba create -n xeus-python-dev \
     --platform=emscripten-wasm32 \
     -c https://repo.mamba.pm/emscripten-forge \
-    -c https://repo.mamba.pm/conda-forge \
+    -c conda-forge \
     --yes \
     "python>=3.11" pybind11 nlohmann_json pybind11_json numpy pytest \
     bzip2 sqlite zlib libffi xtl pyjs \
diff --git a/environment-dev.yaml b/environment-dev.yaml
index da603fe..f4df578 100644
--- a/environment-dev.yaml
+++ b/environment-dev.yaml
@@ -9,7 +9,6 @@ dependencies:
   - hatch-nodejs-version
   - jupyterlab >=4.0
   - jupyterlite-core
-  - mamba
   - nodejs
   - pip
   - pytest
diff --git a/jupyterlite_xeus/add_on.py b/jupyterlite_xeus/add_on.py
index 06439f5..941d2fa 100644
--- a/jupyterlite_xeus/add_on.py
+++ b/jupyterlite_xeus/add_on.py
@@ -20,7 +20,11 @@
 )
 from traitlets import List, Unicode
 
-from .create_conda_env import create_conda_env_from_yaml, create_conda_env_from_specs
+from .create_conda_env import (
+    create_conda_env_from_env_file,
+    create_conda_env_from_specs,
+)
+from .constants import EXTENSION_NAME
 from .constants import EXTENSION_NAME
 
 from empack.pack import (
@@ -110,15 +114,18 @@ def post_build(self, manager):
     def create_prefix(self):
         # read the environment file
         root_prefix = Path(self.cwd.name) / "env"
-        env_name = "xeus-env"
+        env_file = Path(self.environment_file)
+
+        # open the env yaml file
+        with open(env_file, "r") as file:
+            yaml_content = yaml.safe_load(file)
+
+        env_name = yaml_content.get("name", "xeus-env")
         env_prefix = root_prefix / "envs" / env_name
         self.prefix = str(env_prefix)
 
-        env_file = Path(self.environment_file)
         if env_file.exists():
-            create_conda_env_from_yaml(
-                env_name=env_name, root_prefix=root_prefix, env_file=env_file
-            )
+            create_conda_env_from_env_file(root_prefix, yaml_content, env_file.parent)
         # this is atm for debugging
         else:
             create_conda_env_from_specs(
diff --git a/jupyterlite_xeus/create_conda_env.py b/jupyterlite_xeus/create_conda_env.py
index e7637ea..3e0844e 100644
--- a/jupyterlite_xeus/create_conda_env.py
+++ b/jupyterlite_xeus/create_conda_env.py
@@ -3,7 +3,6 @@
 from pathlib import Path
 from subprocess import run as subprocess_run
 import os
-import yaml
 
 from ._pip import _install_pip_dependencies
 
@@ -33,24 +32,25 @@ def _extract_specs(env_location, env_data):
                 # If it's a local Python package, make its path relative to the environment file
                 if (env_location / pip_dependency).is_dir():
                     pip_dependencies.append(
-                        env_location.parent / pip_dependency
-                    ).resolve()
+                        (env_location / pip_dependency).resolve()
+                    )
                 else:
                     pip_dependencies.append(pip_dependency)
 
     return specs, pip_dependencies
 
 
-def create_conda_env_from_yaml(env_name, root_prefix, env_file):
-    # open the env yaml file
-    with open(env_file, "r") as file:
-        yaml_content = yaml.safe_load(file)
+def create_conda_env_from_env_file(root_prefix, env_file_content, env_file_location):
+    # get the name of the environment
+    env_name = env_file_content.get("name", "xeus-env")
 
     # get the channels
-    channels = yaml_content.get("channels", [])
+    channels = env_file_content.get(
+        "channels", ["https://repo.mamba.pm/emscripten-forge", "conda-forge"]
+    )
 
     # get the specs
-    specs, pip_dependencies = _extract_specs(env_file.parent, yaml_content)
+    specs, pip_dependencies = _extract_specs(env_file_location, env_file_content)
 
     create_conda_env_from_specs(
         env_name=env_name,
diff --git a/tests/environment-1.yml b/tests/environment-1.yml
new file mode 100644
index 0000000..76be4ae
--- /dev/null
+++ b/tests/environment-1.yml
@@ -0,0 +1,16 @@
+name: xeus-python-kernel-1
+channels:
+  - https://repo.mamba.pm/emscripten-forge
+  - conda-forge
+dependencies:
+  - xeus-python
+  - xeus-lua
+  - numpy
+  - matplotlib
+  - pillow
+  - ipywidgets
+  - pip:
+    # Installing a python package that ships a lab extension under share/
+    - ipycanvas
+    # Installing a pure python package
+    - py2vega
diff --git a/tests/environment-2.yml b/tests/environment-2.yml
new file mode 100644
index 0000000..b2c8593
--- /dev/null
+++ b/tests/environment-2.yml
@@ -0,0 +1,9 @@
+name: xeus-python-kernel-2
+channels:
+  - https://repo.mamba.pm/emscripten-forge
+  - conda-forge
+dependencies:
+  - xeus-python
+  - pip:
+    # Installing NumPy with pip should fail
+    - numpy
diff --git a/tests/test_package/environment-3.yml b/tests/test_package/environment-3.yml
new file mode 100644
index 0000000..ef8904f
--- /dev/null
+++ b/tests/test_package/environment-3.yml
@@ -0,0 +1,9 @@
+name: xeus-python-kernel-3
+channels:
+  - https://repo.mamba.pm/emscripten-forge
+  - conda-forge
+dependencies:
+  - xeus-python
+  - numpy
+  - pip:
+    - .
diff --git a/tests/test_package/pyproject.toml b/tests/test_package/pyproject.toml
new file mode 100644
index 0000000..f9a8f17
--- /dev/null
+++ b/tests/test_package/pyproject.toml
@@ -0,0 +1,3 @@
+[project]
+name = "test-package"
+version = "0.1.0"
diff --git a/tests/test_package/test_package/__init__.py b/tests/test_package/test_package/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/tests/test_package/test_package/hey.py b/tests/test_package/test_package/hey.py
new file mode 100644
index 0000000..71910a6
--- /dev/null
+++ b/tests/test_package/test_package/hey.py
@@ -0,0 +1 @@
+print("Hey")
diff --git a/tests/test_xeus.py b/tests/test_xeus.py
new file mode 100644
index 0000000..70cdd48
--- /dev/null
+++ b/tests/test_xeus.py
@@ -0,0 +1,79 @@
+"""Test creating Python envs for jupyterlite-xeus-python."""
+
+import os
+from tempfile import TemporaryDirectory
+from pathlib import Path
+
+import pytest
+
+from jupyterlite_core.app import LiteStatusApp
+
+from jupyterlite_xeus.add_on import XeusAddon
+
+
+def test_python_env_from_file_1():
+    app = LiteStatusApp(log_level="DEBUG")
+    app.initialize()
+    manager = app.lite_manager
+
+    addon = XeusAddon(manager)
+    addon.environment_file = "environment-1.yml"
+
+    for step in addon.post_build(manager):
+        pass
+
+    # Check env
+    assert os.path.isdir(addon.prefix)
+
+    assert os.path.isfile(Path(addon.prefix) / "bin/xpython.js")
+    assert os.path.isfile(Path(addon.prefix) / "bin/xpython.wasm")
+
+    assert os.path.isfile(Path(addon.prefix) / "bin/xlua.js")
+    assert os.path.isfile(Path(addon.prefix) / "bin/xlua.wasm")
+
+    # Checking pip packages
+    assert os.path.isdir(Path(addon.prefix) / "lib/python3.11")
+    assert os.path.isdir(Path(addon.prefix) / "lib/python3.11/site-packages")
+    assert os.path.isdir(Path(addon.prefix) / "lib/python3.11/site-packages/ipywidgets")
+    assert os.path.isdir(Path(addon.prefix) / "lib/python3.11/site-packages/ipycanvas")
+    assert os.path.isdir(Path(addon.prefix) / "lib/python3.11/site-packages/py2vega")
+
+    # Checking labextensions
+    assert os.path.isdir(
+        Path(addon.prefix)
+        / "share/jupyter/labextensions/@jupyter-widgets/jupyterlab-manager"
+    )
+    assert os.path.isdir(Path(addon.prefix) / "share/jupyter/labextensions/ipycanvas")
+
+
+def test_python_env_from_file_3():
+    app = LiteStatusApp(log_level="DEBUG")
+    app.initialize()
+    manager = app.lite_manager
+
+    addon = XeusAddon(manager)
+    addon.environment_file = "test_package/environment-3.yml"
+
+    for step in addon.post_build(manager):
+        pass
+
+    # Test
+    assert os.path.isdir(
+        Path(addon.prefix) / "lib/python3.11/site-packages/test_package"
+    )
+    assert os.path.isfile(
+        Path(addon.prefix) / "lib/python3.11/site-packages/test_package/hey.py"
+    )
+
+
+def test_python_env_from_file_2():
+    app = LiteStatusApp(log_level="DEBUG")
+    app.initialize()
+    manager = app.lite_manager
+
+    addon = XeusAddon(manager)
+    addon.environment_file = "environment-2.yml"
+
+    with pytest.raises(RuntimeError, match="Cannot install binary PyPI package"):
+        for step in addon.post_build(manager):
+            pass