diff --git a/CHANGELOG.md b/CHANGELOG.md
index c3b280e..991b139 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@ All notable changes to TextUI are documented here.
 
 ### Added
 
+- A checkout `./showcase` launcher for macOS/Linux that installs the locked project through isolated Poetry and launches via `python -m textui`, including from another working directory. Setup instructions now use the same managed environment instead of assuming a global command or `.venv/bin/textui`.
 - Log `on-selection-ended` actions receive completed pointer selections without polling or redraw-triggered callbacks. Copying remains opt-in through asynchronous `window.copy(text)` or the exported `copy_to_clipboard(app, text)` helper, with native clipboard tools and OSC 52 transport.
 - `ProjectApp(source, context=...)` exposes a host-supplied object through read-only `window.context` from controller script loading onward.
 - Linked controllers may define synchronous or asynchronous `on_resize(width, height)` to respond after terminal resize layout refreshes, without polling.
diff --git a/README.md b/README.md
index 9deb724..a14cec5 100644
--- a/README.md
+++ b/README.md
@@ -10,17 +10,35 @@ The [roadmap](docs/roadmap.md) records current priorities, completion gates, and
 
 Python `>=3.11,<4` is required; the release matrix covers 3.11, 3.12, and 3.14. Core dependencies are Textual `>=8.2.8,<9` and lxml `>=6.1.3,<7`. Core installation does not require Pillow or textual-imageview; image components are a future extension.
 
-From a checkout:
+For a checkout on macOS or Linux, install [uv](https://docs.astral.sh/uv/getting-started/installation/) once, then run:
 
 ```sh
-python -m pip install .
-textui run examples/project/app.ui
-textui run examples/controls/app.ui
-textui run examples/data/app.ui
-textui run examples/showcase/app.ui
-python -m examples.editor
+./showcase
 ```
 
+The launcher uses Python 3.12 and isolated Poetry 2.4.3, installs the locked project and test dependencies, and runs `python -m textui`. Its Poetry-managed environment lives in Poetry's cache, outside the checkout. No shell activation or globally available `textui` command is needed. The first run may download Python, Poetry and dependencies; later runs check the locked install before opening the app. Ctrl+Q quits.
+
+From another directory, use the launcher's absolute path, for example:
+
+```sh
+/Users/abeihl/Development/TextUI/showcase
+```
+
+For other examples or development commands, use the same environment policy from the repository root:
+
+```sh
+unset VIRTUAL_ENV CONDA_PREFIX
+export POETRY_VIRTUALENVS_CREATE=true
+export POETRY_VIRTUALENVS_IN_PROJECT=false
+export POETRY_VIRTUALENVS_USE_POETRY_PYTHON=true
+uvx --python 3.12 --from poetry==2.4.3 poetry env use 3.12
+uvx --python 3.12 --from poetry==2.4.3 poetry install --with test --no-interaction
+uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run examples/project/app.ui
+uvx --python 3.12 --from poetry==2.4.3 poetry run python -m examples.editor
+```
+
+Replace `examples/project/app.ui` with `examples/controls/app.ui`, `examples/data/app.ui` or `examples/components/app.ui` to try those projects. Run tests with `uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest -q`. To locate the managed environment, run `uvx --python 3.12 --from poetry==2.4.3 poetry env info --path`; do not assume `.venv/bin/textui` exists. An installed library also supports `python -m textui run /absolute/path/app.ui` using the Python interpreter where it was installed.
+
 The [showcase](examples/showcase/app.ui) combines every built-in widget family in one navigable project: components, layouts, controls, tables, trees, lists, logs, modals, actions, and timers. The project example demonstrates a linked Python controller, local TCSS, an included view, sidebar navigation, a resizable split, and a timer; see the [project runtime guide](docs/project-runtime.md). The [component example](examples/components/app.ui) demonstrates imported `.ui` components, literal properties, and slots. The [controls example](examples/controls/app.ui) demonstrates form controls, tabs, radio choices, collapsible content, progress bars, and rules. The [data example](examples/data/app.ui) demonstrates an API-backed runtime table beside seeded native tables and trees; see the [controls guide](docs/controls.md). The separate editor is a small form demonstrating a Save action that updates a status label; it does not write a file. Press Ctrl+Q to quit. Its XML path is relative to the example module, independent of the working directory. Examples are included in the source distribution, not the installed library wheel.
 
 For a linked-script project launched from Python, `ProjectApp(source, context=host_value)` makes `host_value` available as read-only `window.context` in the controller. Controllers may also define `on_resize(width, height)` to update width-sensitive content after the screen refreshes; see the [runtime lifecycle guide](docs/project-runtime.md).
diff --git a/docs/testing.md b/docs/testing.md
index 4a947bb..55e2d87 100644
--- a/docs/testing.md
+++ b/docs/testing.md
@@ -1,6 +1,6 @@
 # Testing TextUI
 
-Run the normal headless suite from the repository root:
+Follow the [checkout setup](../README.md#install-and-run), then run the normal headless suite from the repository root. All commands use Poetry's managed environment; no checkout `.venv` path is assumed:
 
 ```sh
 uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest -q
@@ -9,18 +9,18 @@ uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest -q
 Normal tests do not create screenshots. The visual suite is collected only when `TEXTUI_VISUAL_TESTS=1` is set and compares exported Textual SVGs with reviewed baselines:
 
 ```sh
-TEXTUI_VISUAL_TESTS=1 .venv/bin/python -m pytest tests/visual -q
+TEXTUI_VISUAL_TESTS=1 uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest tests/visual -q
 ```
 
 The four baselines are stored under `tests/visual/__snapshots__/`: the showcase at 120×50 and 80×24, plus its first and reopened help modal at 80×24. They use Textual's built-in `App.export_screenshot()` rather than an additional snapshot package because the available `pytest-textual-snapshot` release requires pytest below TextUI's supported pytest 9 range.
 
-To intentionally update a baseline, run the command below, then render and inspect every changed SVG before committing it. The update command is local-only; CI never updates baselines.
+To intentionally update a baseline, run the commands below, then render and inspect every changed SVG before committing it. CI may regenerate SVG artifacts after a failure for inspection; it does not change committed baselines.
 
 ```sh
-TEXTUI_VISUAL_TESTS=1 .venv/bin/python -m pytest tests/visual --snapshot-update -q
-TEXTUI_VISUAL_TESTS=1 .venv/bin/python -m pytest tests/visual -q
+TEXTUI_VISUAL_TESTS=1 uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest tests/visual --snapshot-update -q
+TEXTUI_VISUAL_TESTS=1 uvx --python 3.12 --from poetry==2.4.3 poetry run python -m pytest tests/visual -q
 ```
 
 Generate and review baselines using the same supported Python and Textual lockfile as CI. A changed SVG should correspond to a deliberate visible behavior change and include the relevant interaction test.
 
-GitHub Actions compares the visual suite on Ubuntu 24.04 with Python 3.12. On a visual failure, it uploads the reviewed SVG baselines so the failing run can be reproduced locally with the exact command above.
+GitHub Actions compares the visual suite on Ubuntu 24.04 with Python 3.12. On a visual failure, it regenerates and uploads SVG artifacts for review. Reproduce the comparison locally with the same command above, using the matching platform baselines.
diff --git a/examples/README.md b/examples/README.md
index 55c5c81..34c69ae 100644
--- a/examples/README.md
+++ b/examples/README.md
@@ -1,13 +1,15 @@
 # Examples
 
-The examples use the public TextUI 0.2 API and should be run from the repository root after installing the project.
+The examples use the public TextUI 0.6 API. Follow the [checkout setup](../README.md#install-and-run) once, then run the commands below from the repository root. They use the installed project through Poetry rather than relying on a `textui` command on your shell's PATH.
+
+For the full showcase on macOS or Linux, `./showcase` handles setup and launch automatically. Its absolute path also works from another directory; Ctrl+Q quits. Examples ship in the source distribution, not the library wheel.
 
 ## Editor
 
 Run the normal Textual host example:
 
 ```sh
-python -m examples.editor
+uvx --python 3.12 --from poetry==2.4.3 poetry run python -m examples.editor
 ```
 
 Enter a name and press **Save**. The action updates the mounted `status` label. The example loads `form.xml` relative to its own module, so it also works when launched from another working directory. Press Ctrl+Q to quit.
@@ -26,18 +28,18 @@ TextUI(document).run()
 ```
 
 The sample has no actions, so it is useful for checking structure and styling without application callbacks. See the main [README](../README.md) for custom components and explicit event forwarding.
-# Project runtime example
+## Project runtime example
 
-Run `textui run examples/project/app.ui` from the repository root. The entry file loads `shell.tcss` and `controller.py`, then includes `views/form.ui`. The sidebar selects a page with the mouse or keyboard; the ☰ button hides or shows it, and the divider can be dragged or resized with arrow keys. The controller also shows a greeting and updates the clock once per second. Paths inside the project resolve from their declaring files, so the absolute entry path also works from another directory. See the [runtime guide](../docs/project-runtime.md).
+Run `uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run examples/project/app.ui` from the repository root. The entry file loads `shell.tcss` and `controller.py`, then includes `views/form.ui`. The sidebar selects a page with the mouse or keyboard; the ☰ button hides or shows it, and the divider can be dragged or resized with arrow keys. The controller also shows a greeting and updates the clock once per second. Paths inside the project resolve from their declaring files, so the absolute entry path also works from another directory. See the [runtime guide](../docs/project-runtime.md).
 
-Run `textui run examples/controls/app.ui` to try native select, switch, text area, tabs, radio choices, collapsible content, progress bars, and rules. Their `on-*` actions update the feedback label. See the [controls guide](../docs/controls.md).
+Run `uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run examples/controls/app.ui` to try native select, switch, text area, tabs, radio choices, collapsible content, progress bars, and rules. Their `on-*` actions update the feedback label. See the [controls guide](../docs/controls.md).
 
-Run `textui run examples/data/app.ui` to try a native table and tree. Select a row or node to update the feedback label, then press **Add job and file** to change both widgets from linked Python. See [tables and trees](../docs/controls.md#tables-and-trees).
+Run `uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run examples/data/app.ui` to try a native table and tree. Select a row or node to update the feedback label, then press **Add job and file** to change both widgets from linked Python. See [tables and trees](../docs/controls.md#tables-and-trees).
 
 ## Reusable components
 
-Run `textui run examples/components/app.ui` to see a project-local `agent-card` component. The entry file imports the component, passes literal properties, and supplies a named action slot. See the [project runtime guide](../docs/project-runtime.md#reusable-components) for the authoring contract.
+Run `uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run examples/components/app.ui` to see a project-local `agent-card` component. The entry file imports the component, passes literal properties, and supplies a named action slot. See the [project runtime guide](../docs/project-runtime.md#reusable-components) for the authoring contract.
 
 ## Feature showcase
 
-Run `textui run examples/showcase/app.ui` for a single application that exercises the full built-in surface. The sidebar is hideable and resizable, includes **Borders** (`Ctrl+B`) and **Quit** (`Ctrl+Q`) command buttons, and the right-justified top bar contains **Compact** (`Ctrl+D`) and Help controls. Compact toggles the framework's dense TCSS preset; Borders toggles rounded button outlines. Its pages cover imported components and includes, inputs and choices, tabs and indicators, API-backed runtime table records, seeded tables and trees, runtime lists, logs, modal screens, linked actions, and a repeating timer. It is the quickest manual smoke test after changing framework behavior.
+Run `./showcase` for a single application that exercises the full built-in surface. The sidebar is hideable and resizable, includes **Borders** (`Ctrl+B`) and **Quit** (`Ctrl+Q`) command buttons, and the right-justified top bar contains **Compact** (`Ctrl+D`) and Help controls. Compact toggles the framework's dense TCSS preset; Borders toggles rounded button outlines. Its pages cover imported components and includes, inputs and choices, tabs and indicators, API-backed runtime table records, seeded tables and trees, runtime lists, logs, modal screens, linked actions, and a repeating timer. It is the quickest manual smoke test after changing framework behavior.
diff --git a/pyproject.toml b/pyproject.toml
index a7cc504..f2c1fa1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,6 +17,8 @@ textui = "textui.__main__:main"
 [tool.poetry]
 packages = [{ include = "textui" }]
 include = [
+    { path = "showcase", format = "sdist" },
+    { path = "poetry.lock", format = "sdist" },
     { path = "examples", format = "sdist" },
     { path = "docs", format = "sdist" },
 ]
diff --git a/showcase b/showcase
new file mode 100755
index 0000000..1694a98
--- /dev/null
+++ b/showcase
@@ -0,0 +1,21 @@
+#!/bin/sh
+# Launch the checkout's showcase through an isolated, locked environment.
+set -eu
+
+if ! command -v uvx >/dev/null 2>&1; then
+    echo "Install uv (which provides uvx): https://docs.astral.sh/uv/getting-started/installation/" >&2
+    exit 127
+fi
+
+repo_root=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd -P)
+cd "$repo_root"
+
+# Avoid borrowing an activated environment or a stale checkout .venv.
+unset VIRTUAL_ENV CONDA_PREFIX
+export POETRY_VIRTUALENVS_CREATE=true
+export POETRY_VIRTUALENVS_IN_PROJECT=false
+export POETRY_VIRTUALENVS_USE_POETRY_PYTHON=true
+
+uvx --python 3.12 --from poetry==2.4.3 poetry env use 3.12
+uvx --python 3.12 --from poetry==2.4.3 poetry install --with test --no-interaction
+exec uvx --python 3.12 --from poetry==2.4.3 poetry run python -m textui run "$repo_root/examples/showcase/app.ui"
diff --git a/tests/test_showcase_launcher.py b/tests/test_showcase_launcher.py
new file mode 100644
index 0000000..502216d
--- /dev/null
+++ b/tests/test_showcase_launcher.py
@@ -0,0 +1,100 @@
+"""Run the checkout launcher with only the external installer replaced."""
+
+import json
+import os
+from pathlib import Path
+import shutil
+import subprocess
+import sys
+
+def run_launcher(tmp_path, *, env_exit=0, install_exit=0, run_exit=0, missing_uvx=False):
+    source = Path(__file__).parents[1] / "showcase"
+    assert source.is_file(), "The checkout needs a showcase launcher"
+    checkout = tmp_path / "checkout with spaces"
+    checkout.mkdir()
+    launcher = checkout / "showcase"
+    shutil.copy2(source, launcher)
+    caller = tmp_path / "another directory"
+    caller.mkdir()
+    tools = tmp_path / "tools"
+    tools.mkdir()
+    calls = tmp_path / "calls.jsonl"
+    fake = tools / "uvx"
+    fake.write_text(
+        f"#!{sys.executable}\n"
+        "import json, os, sys\n"
+        "with open(os.environ['LAUNCH_CALLS'], 'a') as output:\n"
+        "    output.write(json.dumps({'args': sys.argv[1:], 'cwd': os.getcwd(), "
+        "'active_env': os.environ.get('VIRTUAL_ENV'), "
+        "'conda_env': os.environ.get('CONDA_PREFIX'), "
+        "'create': os.environ.get('POETRY_VIRTUALENVS_CREATE'), "
+        "'in_project': os.environ.get('POETRY_VIRTUALENVS_IN_PROJECT'), "
+        "'poetry_python': os.environ.get('POETRY_VIRTUALENVS_USE_POETRY_PYTHON')}) + '\\n')\n"
+        "stage = 'ENV_EXIT' if 'env' in sys.argv else 'INSTALL_EXIT' if 'install' in sys.argv else 'RUN_EXIT'\n"
+        "sys.exit(int(os.environ[stage]))\n",
+        encoding="utf-8",
+    )
+    fake.chmod(0o755)
+    environment = {
+        **os.environ,
+        "PATH": "" if missing_uvx else f"{tools}{os.pathsep}/usr/bin{os.pathsep}/bin",
+        "LAUNCH_CALLS": str(calls),
+        "ENV_EXIT": str(env_exit),
+        "INSTALL_EXIT": str(install_exit),
+        "RUN_EXIT": str(run_exit),
+        "VIRTUAL_ENV": str(tmp_path / "unrelated environment"),
+        "CONDA_PREFIX": str(tmp_path / "unrelated conda"),
+        "POETRY_VIRTUALENVS_CREATE": "false",
+        "POETRY_VIRTUALENVS_IN_PROJECT": "true",
+        "POETRY_VIRTUALENVS_USE_POETRY_PYTHON": "false",
+    }
+    result = subprocess.run(
+        [str(launcher)], cwd=caller, env=environment, capture_output=True, text=True,
+    )
+    recorded = [json.loads(line) for line in calls.read_text().splitlines()] if calls.exists() else []
+    return result, recorded, checkout
+
+
+def test_launcher_installs_then_runs_showcase_from_another_directory(tmp_path):
+    result, calls, checkout = run_launcher(tmp_path)
+
+    assert result.returncode == 0, result.stderr
+    prefix = ["--python", "3.12", "--from", "poetry==2.4.3", "poetry"]
+    assert [call["args"] for call in calls] == [
+        prefix + ["env", "use", "3.12"],
+        prefix + ["install", "--with", "test", "--no-interaction"],
+        prefix + ["run", "python", "-m", "textui", "run", str(checkout / "examples/showcase/app.ui")],
+    ]
+    assert all(call["cwd"] == str(checkout) for call in calls)
+    assert all(call["active_env"] is None and call["conda_env"] is None for call in calls)
+    assert all(call["create"] == "true" and call["in_project"] == "false" for call in calls)
+    assert all(call["poetry_python"] == "true" for call in calls)
+
+
+def test_launcher_does_not_run_after_installation_fails(tmp_path):
+    result, calls, _ = run_launcher(tmp_path, install_exit=17)
+
+    assert result.returncode == 17
+    assert len(calls) == 2
+
+
+def test_launcher_preserves_application_exit_status(tmp_path):
+    result, calls, _ = run_launcher(tmp_path, run_exit=23)
+
+    assert result.returncode == 23
+    assert len(calls) == 3
+
+
+def test_launcher_stops_when_python_environment_selection_fails(tmp_path):
+    result, calls, _ = run_launcher(tmp_path, env_exit=19)
+
+    assert result.returncode == 19
+    assert len(calls) == 1
+
+
+def test_launcher_explains_missing_uvx_without_attempting_setup(tmp_path):
+    result, calls, _ = run_launcher(tmp_path, missing_uvx=True)
+
+    assert result.returncode == 127
+    assert "uv" in result.stderr and "https://docs.astral.sh/uv/" in result.stderr
+    assert not calls