diff --git a/README.md b/README.md
index 1a0e2f0..bdd2218 100644
--- a/README.md
+++ b/README.md
@@ -5,43 +5,51 @@
 [![check](https://github.com/tox-dev/tox-uv/actions/workflows/check.yaml/badge.svg)](https://github.com/tox-dev/tox-uv/actions/workflows/check.yaml)
 [![Downloads](https://static.pepy.tech/badge/tox-uv/month)](https://pepy.tech/project/tox-uv)
 
-**tox-uv** is a tox plugin which replaces virtualenv and pip with uv in your tox environments. Note that you will get
-both the benefits (performance) or downsides (bugs) of uv.
+**tox-uv** is a `tox` plugin, which replaces `virtualenv` and pip with `uv` in your `tox` environments. Note that you
+will get both the benefits (performance) or downsides (bugs) of `uv`.
 
 <!--ts-->
 
 - [How to use](#how-to-use)
-- [Configuration](#configuration)
-  - [uv.lock support](#uvlock-support)
+- [tox environment types provided](#tox-environment-types-provided)
+- [uv.lock support](#uvlock-support)
+  - [extras](#extras)
+  - [with_dev](#with_dev)
+  - [External package support](#external-package-support)
+- [Environment creation](#environment-creation)
   - [uv_seed](#uv_seed)
-  - [uv_resolution](#uv_resolution)
   - [uv_python_preference](#uv_python_preference)
+- [Package installation](#package-installation)
+  - [uv_resolution](#uv_resolution)
   <!--te-->
 
 ## How to use
 
-Install `tox-uv` into the environment of your tox and it will replace virtualenv and pip for all runs:
+Install `tox-uv` into the environment of your tox, and it will replace `virtualenv` and `pip` for all runs:
 
 ```bash
-python -m pip install tox-uv
-python -m tox r -e py312 # will use uv
+uv tool install tox --with tox-uv # use uv to install
+tox --version # validate you are using the installed tox
+tox r -e py312 # will use uv
 ```
 
-## Configuration
+## tox environment types provided
+
+This package will provide the following new tox environments:
 
 - `uv-venv-runner` is the ID for the tox environments [runner](https://tox.wiki/en/4.12.1/config.html#runner) for
-  environments not using lock file.
+  environments not using a lock file.
 - `uv-venv-lock-runner` is the ID for the tox environments [runner](https://tox.wiki/en/4.12.1/config.html#runner) for
-  environments using `uv.lock` (note we cannot detect the presence of the `uv.lock` file to enable this because that
+  environments using `uv.lock` (note we can’t detect the presence of the `uv.lock` file to enable this because that
   would break environments not using the lock file - such as your linter).
 - `uv-venv-pep-517` is the ID for the PEP-517 packaging environment.
 - `uv-venv-cmd-builder` is the ID for the external cmd builder.
 
-### uv.lock support
+## uv.lock support
 
 If you want for a tox environment to use `uv sync` with a `uv.lock` file you need to change for that tox environment the
-`runner` to `uv-venv-lock-runner`. Furthermore, should in such environments you can use the `extras` config to instruct
-`uv` to also install the specified extras, for example:
+`runner` to `uv-venv-lock-runner`. Furthermore, should in such environments you use the `extras` config to instruct `uv`
+to install the specified extras, for example:
 
 ```ini
 
@@ -79,32 +87,57 @@ In this example:
   `test` and `type` extra groups.
 
 Note that when using `uv-venv-lock-runner`, _all_ dependencies will come from the lock file, controlled by `extras`.
-Therefore, options like `deps` are ignored.
+Therefore, options like `deps` are ignored (and all others
+[enumerated here](https://tox.wiki/en/stable/config.html#python-run) as Python run flags).
 
-### uv_seed
+### `extras`
 
-This flag, set on a tox environment level, controls if the created virtual environment injects pip/setuptools/wheel into
-the created virtual environment or not. By default, is off. You will need to set this if you have a project that uses
-the old legacy editable mode, or your project does not support the `pyproject.toml` powered isolated build model.
+A list of string that selects, which extra groups you want to install with `uv sync`. By default, it is empty.
 
-### uv_resolution
+### `with_dev`
 
-This flag, set on a tox environment level, informs uv of the desired [resolution strategy]:
+A boolean flag to toggle installation of the `uv` development dependencies. By default, it is false.
 
-- `highest` - (default) selects the highest version of a package that satisfies the constraints
-- `lowest` - install the **lowest** compatible versions for all dependencies, both **direct** and **transitive**
-- `lowest-direct` - opt for the **lowest** compatible versions for all **direct** dependencies, while using the
-  **latest** compatible versions for all **transitive** dependencies
+### External package support
 
-This is a uv specific feature that may be used as an alternative to frozen constraints for test environments, if the
-intention is to validate the lower bounds of your dependencies during test executions.
+Should tox be invoked with the [`--installpkg`](https://tox.wiki/en/stable/cli_interface.html#tox-run---installpkg) flag
+(the argument **must** be either a wheel or source distribution) the sync operation will run with `--no-install-project`
+and `uv pip install` will be used afterward to install the provided package.
 
-[resolution strategy]: https://github.com/astral-sh/uv/blob/0.1.20/README.md#resolution-strategy
+## Environment creation
+
+We use `uv venv` to create virtual environments. This process can be configured with the following options:
+
+### `uv_seed`
 
-### uv_python_preference
+This flag, set on a tox environment level, controls if the created virtual environment injects `pip`, `setuptools` and
+`wheel` into the created virtual environment or not. By default, it is off. You will need to set this if you have a
+project that uses the old legacy-editable mode, or your project doesn’t support the `pyproject.toml` powered isolated
+build model.
 
-This flag, set on a tox environment level, controls how uv select the Python interpreter.
+### `uv_python_preference`
 
-By default, uv will attempt to use Python versions found on the system and only download managed interpreters when
-necessary. However, It's possible to adjust uv's Python version selection preference with the
+This flag, set on a tox environment level, controls how `uv` select the Python interpreter.
+
+By default, `uv` will attempt to use Python versions found on the system and only download managed interpreters when
+necessary. However, It is possible to adjust `uv`'s Python version selection preference with the
 [python-preference](https://docs.astral.sh/uv/concepts/python-versions/#adjusting-python-version-preferences) option.
+
+## Package installation
+
+We use `uv pip` to install packages into the virtual environment. The behavior of this can be configured via the
+following options:
+
+### `uv_resolution`
+
+This flag, set on a tox environment level, informs `uv` of the desired [resolution strategy]:
+
+- `highest` - (default) selects the highest version of a package satisfying the constraints.
+- `lowest` - install the **lowest** compatible versions for all dependencies, both **direct** and **transitive**.
+- `lowest-direct` - opt for the **lowest** compatible versions for all **direct** dependencies, while using the
+  **latest** compatible versions for all **transitive** dependencies.
+
+This is an `uv` specific feature that may be used as an alternative to frozen constraints for test environments if the
+intention is to validate the lower bounds of your dependencies during test executions.
+
+[resolution strategy]: https://github.com/astral-sh/uv/blob/0.1.20/README.md#resolution-strategy
diff --git a/src/tox_uv/_installer.py b/src/tox_uv/_installer.py
index 44a6cbd..976380e 100644
--- a/src/tox_uv/_installer.py
+++ b/src/tox_uv/_installer.py
@@ -11,7 +11,7 @@
 from tox.config.types import Command
 from tox.tox_env.errors import Fail, Recreate
 from tox.tox_env.python.package import EditableLegacyPackage, EditablePackage, SdistPackage, WheelPackage
-from tox.tox_env.python.pip.pip_install import Pip, PythonInstallerListDependencies
+from tox.tox_env.python.pip.pip_install import Pip
 from tox.tox_env.python.pip.req_file import PythonDeps
 from uv import find_uv_bin
 
@@ -21,7 +21,9 @@
     from tox.tox_env.python.api import Python
 
 
-class ReadOnlyUvInstaller(PythonInstallerListDependencies):
+class UvInstaller(Pip):
+    """Pip is a python installer that can install packages as defined by PEP-508 and PEP-517."""
+
     def __init__(self, tox_env: Python, with_list_deps: bool = True) -> None:  # noqa: FBT001, FBT002
         self._with_list_deps = with_list_deps
         super().__init__(tox_env)
@@ -33,13 +35,6 @@ def freeze_cmd(self) -> list[str]:
     def uv(self) -> str:
         return find_uv_bin()
 
-    def install(self, arguments: Any, section: str, of_type: str) -> None:  # noqa: ANN401
-        raise NotImplementedError  # not supported
-
-
-class UvInstaller(ReadOnlyUvInstaller, Pip):
-    """Pip is a python installer that can install packages as defined by PEP-508 and PEP-517."""
-
     def _register_config(self) -> None:
         super()._register_config()
 
@@ -140,6 +135,5 @@ def _install_list_of_deps(  # noqa: C901
 
 
 __all__ = [
-    "ReadOnlyUvInstaller",
     "UvInstaller",
 ]
diff --git a/src/tox_uv/_run_lock.py b/src/tox_uv/_run_lock.py
index 6854a3b..c043ec1 100644
--- a/src/tox_uv/_run_lock.py
+++ b/src/tox_uv/_run_lock.py
@@ -2,13 +2,14 @@
 
 from __future__ import annotations
 
+from pathlib import Path
 from typing import TYPE_CHECKING, Set, cast
 
 from tox.execute.request import StdinSource
+from tox.tox_env.python.package import SdistPackage, WheelPackage
 from tox.tox_env.python.runner import add_extras_to_env, add_skip_missing_interpreters_to_core
 from tox.tox_env.runner import RunToxEnv
 
-from ._installer import ReadOnlyUvInstaller
 from ._venv import UvVenv
 
 if TYPE_CHECKING:
@@ -16,8 +17,6 @@
 
 
 class UvVenvLockRunner(UvVenv, RunToxEnv):
-    InstallerClass = ReadOnlyUvInstaller
-
     @staticmethod
     def id() -> str:
         return "uv-venv-lock-runner"
@@ -54,8 +53,15 @@ def _setup_env(self) -> None:
             cmd.extend(("--extra", extra))
         if not self.conf["with_dev"]:
             cmd.append("--no-dev")
+        install_pkg = getattr(self.options, "install_pkg", None)
+        if install_pkg is not None:
+            cmd.append("--no-install-project")
         outcome = self.execute(cmd, stdin=StdinSource.OFF, run_id="uv-sync", show=False)
         outcome.assert_success()
+        if install_pkg is not None:
+            path = Path(install_pkg)
+            pkg = (WheelPackage if path.suffix == ".whl" else SdistPackage)(path, deps=[])
+            self.installer.install([pkg], "install-pkg", of_type="external")
 
     @property
     def environment_variables(self) -> dict[str, str]:
diff --git a/src/tox_uv/_venv.py b/src/tox_uv/_venv.py
index f168666..f69e8c5 100644
--- a/src/tox_uv/_venv.py
+++ b/src/tox_uv/_venv.py
@@ -18,7 +18,7 @@
 from uv import find_uv_bin
 from virtualenv.discovery.py_spec import PythonSpec
 
-from ._installer import ReadOnlyUvInstaller, UvInstaller
+from ._installer import UvInstaller
 
 if sys.version_info >= (3, 10):  # pragma: no cover (py310+)
     from typing import TypeAlias
@@ -45,11 +45,9 @@
 
 
 class UvVenv(Python, ABC):
-    InstallerClass: type[ReadOnlyUvInstaller] = UvInstaller
-
     def __init__(self, create_args: ToxEnvCreateArgs) -> None:
         self._executor: Execute | None = None
-        self._installer: ReadOnlyUvInstaller | None = None
+        self._installer: UvInstaller | None = None
         self._created = False
         super().__init__(create_args)
 
@@ -91,7 +89,7 @@ def executor(self) -> Execute:
     @property
     def installer(self) -> Installer[Any]:
         if self._installer is None:
-            self._installer = self.InstallerClass(self)
+            self._installer = UvInstaller(self)
         return self._installer
 
     @property
diff --git a/tests/test_tox_uv_lock.py b/tests/test_tox_uv_lock.py
index f41d0c0..212703a 100644
--- a/tests/test_tox_uv_lock.py
+++ b/tests/test_tox_uv_lock.py
@@ -3,6 +3,7 @@
 import sys
 from typing import TYPE_CHECKING
 
+import pytest
 from uv import find_uv_bin
 
 if TYPE_CHECKING:
@@ -91,3 +92,41 @@ def test_uv_lock_with_dev(tox_project: ToxProjectCreator) -> None:
         ("py", "uv-sync", ["uv", "sync", "--frozen"]),
     ]
     assert calls == expected
+
+
+@pytest.mark.parametrize(
+    "name",
+    [
+        "tox_uv-1.12.2-py3-none-any.whl",
+        "tox_uv-1.12.2.tar.gz",
+    ],
+)
+def test_uv_lock_with_install_pkg(tox_project: ToxProjectCreator, name: str) -> None:
+    project = tox_project({
+        "tox.ini": """
+    [testenv]
+    runner = uv-venv-lock-runner
+    """
+    })
+    execute_calls = project.patch_execute(lambda r: 0 if r.run_id != "venv" else None)
+    wheel = project.path / name
+    wheel.write_text("")
+    result = project.run("-vv", "run", "--installpkg", str(wheel))
+    result.assert_success()
+
+    calls = [(i[0][0].conf.name, i[0][3].run_id, i[0][3].cmd) for i in execute_calls.call_args_list]
+    uv = find_uv_bin()
+    expected = [
+        (
+            "py",
+            "venv",
+            [uv, "venv", "-p", sys.executable, "--allow-existing", "-v", str(project.path / ".tox" / "py")],
+        ),
+        ("py", "uv-sync", ["uv", "sync", "--frozen", "--no-dev", "--no-install-project"]),
+        (
+            "py",
+            "install_external",
+            [uv, "pip", "install", "--reinstall", "--no-deps", f"tox-uv@{wheel}", "-v"],
+        ),
+    ]
+    assert calls == expected