diff --git a/riotfile.py b/riotfile.py
index af332c91..9c997f9d 100644
--- a/riotfile.py
+++ b/riotfile.py
@@ -11,6 +11,7 @@
                 "pytest": latest,
                 "pytest-cov": latest,
                 "mock": latest,
+                "typing-extensions": latest,
             },
         ),
         Venv(
diff --git a/tests/test_cli.py b/tests/test_cli.py
index db00a916..77832e98 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -57,72 +57,6 @@ def assert_args(args):
     )
 
 
-def test_main(cli: click.testing.CliRunner) -> None:
-    """Running main with no command returns usage."""
-    result = cli.invoke(riot.cli.main)
-    assert result.exit_code == 0
-    assert result.stdout.startswith("Usage: main")
-
-
-def test_main_help(cli: click.testing.CliRunner) -> None:
-    """Running main with --help returns usage."""
-    result = cli.invoke(riot.cli.main, ["--help"])
-    assert result.exit_code == 0
-    assert result.stdout.startswith("Usage: main")
-
-
-def test_main_version(cli: click.testing.CliRunner) -> None:
-    """Running main with --version returns version string."""
-    result = cli.invoke(riot.cli.main, ["--version"])
-    assert result.exit_code == 0
-    assert result.stdout.startswith("main, version ")
-
-
-def test_list_empty(cli: click.testing.CliRunner) -> None:
-    """Running list with an empty riotfile prints nothing."""
-    with with_riotfile(cli, "empty_riotfile.py"):
-        result = cli.invoke(riot.cli.main, ["list"])
-        assert result.exit_code == 0
-        assert result.stdout == ""
-
-
-def test_list_no_riotfile(cli: click.testing.CliRunner) -> None:
-    """Running list with no riotfile fails with an error."""
-    with without_riotfile(cli):
-        result = cli.invoke(riot.cli.main, ["list"])
-        assert result.exit_code == 2
-        assert result.stdout.startswith("Usage: main")
-        assert result.stdout.endswith(
-            "Error: Invalid value for '-f' / '--file': Path 'riotfile.py' does not exist.\n"
-        )
-
-
-def test_list_default_pattern(cli: click.testing.CliRunner) -> None:
-    """Running list with no pattern passes through the default pattern."""
-    with mock.patch("riot.cli.Session.list_venvs") as list_venvs:
-        with with_riotfile(cli, "empty_riotfile.py"):
-            result = cli.invoke(riot.cli.main, ["list"])
-            # Success, but no output because we don't have a matching pattern
-            assert result.exit_code == 0
-            assert result.stdout == ""
-
-            list_venvs.assert_called_once()
-            assert list_venvs.call_args.args[0].pattern == ".*"
-
-
-def test_list_with_pattern(cli: click.testing.CliRunner) -> None:
-    """Running list with a pattern passes through the pattern."""
-    with mock.patch("riot.cli.Session.list_venvs") as list_venvs:
-        with with_riotfile(cli, "empty_riotfile.py"):
-            result = cli.invoke(riot.cli.main, ["list", "^pattern.*"])
-            # Success, but no output because we don't have a matching pattern
-            assert result.exit_code == 0
-            assert result.stdout == ""
-
-            list_venvs.assert_called_once()
-            assert list_venvs.call_args.args[0].pattern == "^pattern.*"
-
-
 def test_list_with_venv_pattern(cli: click.testing.CliRunner) -> None:
     """Running list with a venv pattern passes."""
     with with_riotfile(cli, "simple_riotfile.py"):
@@ -170,26 +104,6 @@ def test_list_with_python(cli: click.testing.CliRunner) -> None:
             )
 
 
-def test_run(cli: click.testing.CliRunner) -> None:
-    """Running run with default options."""
-    with mock.patch("riot.cli.Session.run") as run:
-        with with_riotfile(cli, "empty_riotfile.py"):
-            result = cli.invoke(riot.cli.main, ["run"])
-            # Success, but no output because we mock run
-            assert result.exit_code == 0
-            assert result.stdout == ""
-
-            run.assert_called_once()
-            kwargs = run.call_args.kwargs
-            assert_args(kwargs)
-            assert kwargs["pattern"].pattern == ".*"
-            assert kwargs["venv_pattern"].pattern == ".*"
-            assert kwargs["recreate_venvs"] is False
-            assert kwargs["skip_base_install"] is False
-            assert kwargs["pass_env"] is False
-            assert kwargs["exit_first"] is False
-
-
 def test_run_with_long_args(cli: click.testing.CliRunner) -> None:
     """Running run with long option names uses those options."""
     with mock.patch("riot.cli.Session.run") as run:
diff --git a/tests/test_integration.py b/tests/test_integration.py
new file mode 100644
index 00000000..10c47222
--- /dev/null
+++ b/tests/test_integration.py
@@ -0,0 +1,540 @@
+import os
+import pathlib
+import re
+import subprocess
+import sys
+from typing import Any
+from typing import Dict
+from typing import Generator
+from typing import Optional
+from typing import Sequence
+from typing import Union
+
+import pytest
+from riot.riot import _T_CompletedProcess
+from typing_extensions import Protocol
+
+
+_T_Path = Union[str, "os.PathLike[Any]"]
+
+
+def run(
+    args: Union[str, Sequence[str]], cwd: _T_Path, env: Optional[Dict[str, str]] = None
+) -> _T_CompletedProcess:
+    return subprocess.run(
+        args,
+        env=env,
+        encoding=sys.getdefaultencoding(),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        cwd=cwd,
+        shell=isinstance(args, str),
+    )
+
+
+class _T_TmpRun(Protocol):
+    def __call__(
+        self,
+        args: Union[str, Sequence[str]],
+        cwd: Optional[_T_Path] = None,
+        env: Optional[Dict[str, str]] = None,
+    ) -> _T_CompletedProcess:
+        ...
+
+
+@pytest.fixture
+def tmp_run(tmp_path: pathlib.Path) -> Generator[_T_TmpRun, None, None]:
+    """Run a command by default in tmp_path."""
+
+    def _run(
+        args: Union[str, Sequence[str]],
+        cwd: Optional[_T_Path] = None,
+        env: Optional[Dict[str, str]] = None,
+    ) -> _T_CompletedProcess:
+        if cwd is None:
+            cwd = tmp_path
+        return run(args, cwd, env)
+
+    yield _run
+
+
+def test_no_riotfile(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    result = tmp_run("riot")
+    assert (
+        result.stdout
+        == """
+Usage: riot [OPTIONS] COMMAND [ARGS]...
+
+Options:
+  -f, --file PATH  [default: riotfile.py]
+  -v, --verbose
+  -d, --debug
+  --version        Show the version and exit.
+  --help           Show this message and exit.
+
+Commands:
+  generate  Generate base virtual environments.
+  list      List all virtual env instances matching a pattern.
+  run       Run virtualenv instances with names matching a pattern.
+""".lstrip()
+    )
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+    result = tmp_run("riot list")
+    assert (
+        result.stderr
+        == """
+Usage: riot [OPTIONS] COMMAND [ARGS]...
+Try 'riot --help' for help.
+
+Error: Invalid value for '-f' / '--file': Path 'riotfile.py' does not exist.
+""".lstrip()
+    )
+    assert result.stdout == ""
+    assert result.returncode == 2
+
+
+def test_bad_riotfile(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    result = tmp_run("riot --file rf.py", tmp_path)
+    assert (
+        result.stderr
+        == """
+Usage: riot [OPTIONS] COMMAND [ARGS]...
+Try 'riot --help' for help.
+
+Error: Invalid value for '-f' / '--file': Path 'rf.py' does not exist.
+""".lstrip()
+    )
+    assert result.returncode == 2
+
+    rf_path = tmp_path / "rf"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv()
+""",
+    )
+    result = tmp_run("riot --file rf list")
+    assert (
+        result.stderr
+        == """
+Failed to construct config file:
+Invalid file format for riotfile. Expected file with .py extension got 'rf'.
+""".lstrip()
+    )
+    assert result.returncode == 1
+
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv()typo1234
+""",
+    )
+    result = tmp_run("riot --file riotfile.py list")
+    assert (
+        """
+Failed to construct config file:
+Failed to parse riotfile 'riotfile.py'.
+""".lstrip()
+        in result.stderr
+    )
+    assert (
+        """
+SyntaxError: invalid syntax
+""".lstrip()
+        in result.stderr
+    )
+    assert result.returncode == 1
+
+
+def test_help(tmp_run: _T_TmpRun) -> None:
+    result = tmp_run("riot --help")
+    assert (
+        result.stdout
+        == """
+Usage: riot [OPTIONS] COMMAND [ARGS]...
+
+Options:
+  -f, --file PATH  [default: riotfile.py]
+  -v, --verbose
+  -d, --debug
+  --version        Show the version and exit.
+  --help           Show this message and exit.
+
+Commands:
+  generate  Generate base virtual environments.
+  list      List all virtual env instances matching a pattern.
+  run       Run virtualenv instances with names matching a pattern.
+""".lstrip()
+    )
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+
+def test_version(tmp_run: _T_TmpRun) -> None:
+    result = tmp_run("riot --version")
+    assert result.stdout.startswith("riot, version ")
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+
+def test_list_no_file_empty_file(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    result = tmp_run("riot list")
+    assert (
+        result.stderr
+        == """
+Usage: riot [OPTIONS] COMMAND [ARGS]...
+Try 'riot --help' for help.
+
+Error: Invalid value for '-f' / '--file': Path 'riotfile.py' does not exist.
+""".lstrip()
+    )
+    assert result.returncode == 2
+
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+""",
+    )
+    result = tmp_run("riot list")
+    assert result.stderr == ""
+    assert result.stdout == ""
+    assert result.returncode == 0
+
+
+def test_list_configurations(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    name="test",
+    pys=[3],
+    command="echo hi",
+)
+""",
+    )
+    result = tmp_run("riot list")
+    assert result.stderr == ""
+    assert result.stdout == "test  Python Interpreter(_hint='3') \n"
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    name="test",
+    pys=[3],
+    command="echo hi",
+    pkgs={
+        "pkg1": ["==1.0", "==2.0"],
+    }
+)
+""",
+    )
+    result = tmp_run("riot list")
+    assert result.stderr == ""
+    assert re.search(
+        r"""
+test  .* 'pkg1==1.0'
+test  .* 'pkg1==2.0'
+""".lstrip(),
+        result.stdout,
+    )
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    name="test",
+    pys=[3],
+    command="echo hi",
+    pkgs={
+        "pkg1": ["==1.0", "==2.0"],
+        "pkg2": ["==2.0", "==3.0"],
+    }
+)
+""",
+    )
+    result = tmp_run("riot list")
+    assert result.stderr == ""
+    assert re.search(
+        r"""
+test  .* 'pkg1==1.0' 'pkg2==2.0'
+test  .* 'pkg1==1.0' 'pkg2==3.0'
+test  .* 'pkg1==2.0' 'pkg2==2.0'
+test  .* 'pkg1==2.0' 'pkg2==3.0'
+""".lstrip(),
+        result.stdout,
+    )
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=[3],
+    venvs=[
+        Venv(
+            name="test1",
+            command="echo hi",
+            pkgs={
+                "pkg1": ["==1.0", "==2.0"],
+                "pkg2": ["==3.0", "==4.0"],
+            }
+        ),
+        Venv(
+            name="test2",
+            command="echo hi",
+            pkgs={
+                "pkg1": ["==1.0", "==2.0"],
+                "pkg2": ["==3.0", "==4.0"],
+            }
+        ),
+    ]
+)
+""",
+    )
+    result = tmp_run("riot list")
+    assert result.stderr == ""
+    assert re.search(
+        r"""
+test1  .* 'pkg1==1.0' 'pkg2==3.0'
+test1  .* 'pkg1==1.0' 'pkg2==4.0'
+test1  .* 'pkg1==2.0' 'pkg2==3.0'
+test1  .* 'pkg1==2.0' 'pkg2==4.0'
+test2  .* 'pkg1==1.0' 'pkg2==3.0'
+test2  .* 'pkg1==1.0' 'pkg2==4.0'
+test2  .* 'pkg1==2.0' 'pkg2==3.0'
+test2  .* 'pkg1==2.0' 'pkg2==4.0'
+""".lstrip(),
+        result.stdout,
+    )
+    assert result.returncode == 0
+
+
+def test_list_filter(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    name="test",
+    pys=[3],
+    command="echo hi",
+)
+""",
+    )
+    result = tmp_run("riot list test")
+    assert result.stderr == ""
+    assert re.search(r"test .*", result.stdout)
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    name="test",
+    pys=[3],
+    command="echo hi",
+    pkgs={
+        "pkg1": ["==1.0", "==2.0"],
+        "pkg2": ["==2.0", "==3.0"],
+    }
+)
+""",
+    )
+    result = tmp_run("riot list test")
+    assert result.stderr == ""
+    assert re.search(
+        r"""
+test  .* 'pkg1==1.0' 'pkg2==2.0'
+test  .* 'pkg1==1.0' 'pkg2==3.0'
+test  .* 'pkg1==2.0' 'pkg2==2.0'
+test  .* 'pkg1==2.0' 'pkg2==3.0'
+""".lstrip(),
+        result.stdout,
+    )
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=[3],
+    venvs=[
+        Venv(
+            name="test1",
+            command="echo hi",
+            pkgs={
+                "pkg1": ["==1.0", "==2.0"],
+                "pkg2": ["==3.0", "==4.0"],
+            }
+        ),
+        Venv(
+            name="test2",
+            command="echo hi",
+            pkgs={
+                "pkg1": ["==1.0", "==2.0"],
+                "pkg2": ["==3.0", "==4.0"],
+            }
+        ),
+    ]
+)
+""",
+    )
+    result = tmp_run("riot list test2")
+    assert result.stderr == ""
+    assert re.search(
+        r"""
+test2  .* 'pkg1==1.0' 'pkg2==3.0'
+test2  .* 'pkg1==1.0' 'pkg2==4.0'
+test2  .* 'pkg1==2.0' 'pkg2==3.0'
+test2  .* 'pkg1==2.0' 'pkg2==4.0'
+""".lstrip(),
+        result.stdout,
+    )
+    assert result.returncode == 0
+
+
+def test_run(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=[3],
+    pkgs={
+        "pytest": [""],
+    },
+    venvs=[
+        Venv(
+            name="pass",
+            command="pytest test_success.py",
+        ),
+        Venv(
+            name="fail",
+            command="pytest test_failure.py",
+        ),
+    ],
+)
+""",
+    )
+    success_path = tmp_path / "test_success.py"
+    success_path.write_text(
+        """
+def test_success():
+    assert 1 == 1
+""",
+    )
+    fail_path = tmp_path / "test_failure.py"
+    fail_path.write_text(
+        """
+def test_failure():
+    assert 1 == 0
+""",
+    )
+    result = tmp_run("riot run -s pass")
+    print(result.stdout)
+    assert re.search(
+        r"""
+============================= test session starts ==============================
+platform.*
+rootdir:.*
+collected 1 item
+
+test_success.py .*
+
+============================== 1 passed in .*s ===============================
+
+-------------------summary-------------------
+✓ pass: .*
+1 passed with 0 warnings, 0 failed\n""".lstrip(),
+        result.stdout,
+    )
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+    result = tmp_run("riot run -s fail")
+    assert "x fail:  pythonInterpreter(_hint='3') 'pytest'\n" in result.stdout
+    assert result.stderr == ""
+    assert result.returncode == 1
+
+
+def test_run_cmdargs(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=[3],
+    name="test_cmdargs",
+    command="echo hi",
+)
+""",
+    )
+    result = tmp_run("riot run -s test_cmdargs -- -k filter")
+    assert "cmdargs=-k filter" not in result.stdout
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=3,
+    name="test_cmdargs",
+    command="echo cmdargs={cmdargs}",
+)
+""",
+    )
+    result = tmp_run("riot run -s test_cmdargs -- -k filter")
+    assert "cmdargs=-k filter" in result.stdout
+    assert result.stderr == ""
+    assert result.returncode == 0
+
+
+def test_dev_install_fail(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys=3,
+    name="test",
+    command="echo hello",
+)
+""",
+    )
+    result = tmp_run("riot run test")
+    assert 'ERROR: File "setup.py"' in result.stderr
+    assert "Dev install failed, aborting!" in result.stderr
+    assert result.stdout == ""
+    assert result.returncode == 1
+
+
+def test_bad_interpreter(tmp_path: pathlib.Path, tmp_run: _T_TmpRun) -> None:
+    rf_path = tmp_path / "riotfile.py"
+    rf_path.write_text(
+        """
+from riot import Venv
+venv = Venv(
+    pys="DNE",
+    name="test",
+    command="echo hello",
+)
+""",
+    )
+    result = tmp_run("riot run -s -pDNE test")
+    assert (
+        """
+FileNotFoundError: Python interpreter DNE not found
+""".strip()
+        in result.stderr
+    )
+    assert result.stdout == ""
+    assert result.returncode == 1