diff --git a/great-docs.yml b/great-docs.yml
index a83178b..00b43f0 100644
--- a/great-docs.yml
+++ b/great-docs.yml
@@ -129,7 +129,7 @@ tags:
 
 # CLI Documentation
 # -----------------
-# cli:
-#   enabled: true              # Enable CLI documentation
-#   module: my_package.cli     # Module containing Click commands
-#   name: cli                  # Name of the Click command object
+cli:
+  enabled: true
+  module: multimark._cli
+  name: main
diff --git a/pyproject.toml b/pyproject.toml
index 533230c..0c17020 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ description = "Python bindings to cmark: CommonMark parsing and rendering (HTML,
 readme = "README.md"
 license = {text = "MIT AND BSD-2-Clause"}
 requires-python = ">=3.9"
-dependencies = ["cffi>=1.15"]
+dependencies = ["cffi>=1.15", "click>=8.0"]
 authors = [{name = "Rich Iannone"}]
 keywords = ["markdown", "commonmark", "cmark-gfm", "html", "latex", "gfm"]
 classifiers = [
@@ -27,6 +27,9 @@ classifiers = [
     "Topic :: Text Processing :: Markup :: Markdown",
 ]
 
+[project.scripts]
+multimark = "multimark._cli:main"
+
 [project.urls]
 Homepage = "https://github.com/posit-dev/multimark"
 Issues = "https://github.com/posit-dev/multimark/issues"
diff --git a/src/multimark/__init__.py b/src/multimark/__init__.py
index 6be6101..6813e96 100644
--- a/src/multimark/__init__.py
+++ b/src/multimark/__init__.py
@@ -1,8 +1,3 @@
-"""multimark — Python bindings to the cmark-gfm CommonMark/GFM C library.
-
-Provides parsing and rendering of CommonMark and GitHub Flavored Markdown
-to HTML, LaTeX, groff man, XML, and normalized CommonMark.
-"""
 from enum import IntFlag
 from importlib.metadata import PackageNotFoundError, version as _get_version
 
diff --git a/src/multimark/_build_cmark.py b/src/multimark/_build_cmark.py
index 1d7248e..09618ca 100644
--- a/src/multimark/_build_cmark.py
+++ b/src/multimark/_build_cmark.py
@@ -1,4 +1,3 @@
-"""CFFI build script — compiles the vendored cmark-gfm C library + extensions."""
 import os
 import glob
 from cffi import FFI
diff --git a/src/multimark/_cli.py b/src/multimark/_cli.py
new file mode 100644
index 0000000..34acc4c
--- /dev/null
+++ b/src/multimark/_cli.py
@@ -0,0 +1,87 @@
+from __future__ import annotations
+
+import click
+
+from multimark import (
+    __version__,
+    markdown_to_html,
+    markdown_to_latex,
+    markdown_to_man,
+    markdown_to_commonmark,
+    markdown_to_xml,
+    VALID_EXTENSIONS,
+)
+
+RENDERERS = {
+    "html": markdown_to_html,
+    "latex": markdown_to_latex,
+    "man": markdown_to_man,
+    "commonmark": markdown_to_commonmark,
+    "xml": markdown_to_xml,
+}
+
+
+@click.command()
+@click.argument("file", type=click.File("r"), default="-")
+@click.option(
+    "-t",
+    "--to",
+    "format",
+    type=click.Choice(list(RENDERERS.keys()), case_sensitive=False),
+    default="html",
+    help="Output format.",
+)
+@click.option(
+    "-o",
+    "--output",
+    type=click.File("w"),
+    default="-",
+    help="Output file (stdout if omitted).",
+)
+@click.option(
+    "-e",
+    "--extension",
+    "extensions",
+    multiple=True,
+    type=click.Choice(sorted(VALID_EXTENSIONS), case_sensitive=False),
+    help="Enable a GFM extension (repeatable).",
+)
+@click.option("--smart", is_flag=True, help="Use smart punctuation.")
+@click.option("--unsafe", is_flag=True, help="Allow raw HTML and dangerous URLs.")
+@click.option("--hardbreaks", is_flag=True, help="Render softbreaks as hard line breaks.")
+@click.option("--sourcepos", is_flag=True, help="Include source position attributes (html/xml only).")
+@click.option("--footnotes", is_flag=True, help="Enable footnote parsing.")
+@click.version_option(__version__, prog_name="multimark")
+def main(
+    file,
+    format: str,
+    output,
+    extensions: tuple[str, ...],
+    smart: bool,
+    unsafe: bool,
+    hardbreaks: bool,
+    sourcepos: bool,
+    footnotes: bool,
+) -> None:
+    """Convert CommonMark/GFM Markdown to various output formats.
+
+    Reads Markdown from FILE (or stdin if omitted) and writes the converted
+    output to stdout or the file specified by --output.
+    """
+    text = file.read()
+
+    renderer = RENDERERS[format]
+    kwargs: dict = dict(
+        extensions=list(extensions) or None,
+        smart=smart,
+        unsafe=unsafe,
+        hardbreaks=hardbreaks,
+        footnotes=footnotes,
+    )
+
+    # sourcepos is only supported by html and xml renderers
+    if format in ("html", "xml"):
+        kwargs["sourcepos"] = sourcepos
+
+    result = renderer(text, **kwargs)
+    output.write(result)
diff --git a/src/multimark/_cmark.py b/src/multimark/_cmark.py
index 933849a..d895359 100644
--- a/src/multimark/_cmark.py
+++ b/src/multimark/_cmark.py
@@ -1,4 +1,3 @@
-"""Low-level CFFI wrapper around the cmark-gfm C library."""
 from __future__ import annotations
 
 from typing import Sequence
diff --git a/tests/spec_parser.py b/tests/spec_parser.py
index cd38948..9ec7162 100644
--- a/tests/spec_parser.py
+++ b/tests/spec_parser.py
@@ -1,16 +1,3 @@
-"""Parser for CommonMark spec-format test fixtures.
-
-The spec format uses 32 backtick delimiters around examples:
-
-    ```````````````````````````````` example
-    markdown input
-    .
-    expected html output
-    ````````````````````````````````
-
-Section headings (# Heading) provide grouping context.
-The → character represents a literal tab.
-"""
 from __future__ import annotations
 
 import os
diff --git a/tests/test_cli.py b/tests/test_cli.py
new file mode 100644
index 0000000..22bbbd0
--- /dev/null
+++ b/tests/test_cli.py
@@ -0,0 +1,140 @@
+import pytest
+from click.testing import CliRunner
+
+from multimark._cli import main
+from multimark import __version__
+
+
+@pytest.fixture
+def runner():
+    return CliRunner()
+
+
+class TestBasicConversion:
+    def test_stdin_to_html(self, runner):
+        result = runner.invoke(main, input="# Hello\n")
+        assert result.exit_code == 0
+        assert "<h1>Hello</h1>" in result.output
+
+    def test_file_argument(self, runner, tmp_path):
+        md_file = tmp_path / "test.md"
+        md_file.write_text("**bold**\n")
+        result = runner.invoke(main, [str(md_file)])
+        assert result.exit_code == 0
+        assert "<strong>bold</strong>" in result.output
+
+    def test_output_to_file(self, runner, tmp_path):
+        out_file = tmp_path / "out.html"
+        result = runner.invoke(main, ["-o", str(out_file)], input="*italic*\n")
+        assert result.exit_code == 0
+        assert "<em>italic</em>" in out_file.read_text()
+
+
+class TestOutputFormats:
+    def test_html(self, runner):
+        result = runner.invoke(main, ["--to", "html"], input="# Title\n")
+        assert result.exit_code == 0
+        assert "<h1>Title</h1>" in result.output
+
+    def test_latex(self, runner):
+        result = runner.invoke(main, ["--to", "latex"], input="# Title\n")
+        assert result.exit_code == 0
+        assert "\\section{Title}" in result.output
+
+    def test_man(self, runner):
+        result = runner.invoke(main, ["--to", "man"], input="# Title\n")
+        assert result.exit_code == 0
+        assert ".SH" in result.output
+
+    def test_commonmark(self, runner):
+        result = runner.invoke(main, ["--to", "commonmark"], input="*italic*\n")
+        assert result.exit_code == 0
+        assert "*italic*" in result.output
+
+    def test_xml(self, runner):
+        result = runner.invoke(main, ["--to", "xml"], input="hello\n")
+        assert result.exit_code == 0
+        assert "<?xml" in result.output
+        assert "<text" in result.output
+
+
+class TestOptions:
+    def test_smart(self, runner):
+        result = runner.invoke(main, ["--smart"], input='"Hello" -- world\n')
+        assert result.exit_code == 0
+        assert "\u201c" in result.output  # curly open quote
+        assert "\u2013" in result.output  # en-dash
+
+    def test_unsafe(self, runner):
+        result = runner.invoke(main, ["--unsafe"], input="<div>raw</div>\n")
+        assert result.exit_code == 0
+        assert "<div>raw</div>" in result.output
+
+    def test_safe_by_default(self, runner):
+        result = runner.invoke(main, input="<script>alert('x')</script>\n")
+        assert result.exit_code == 0
+        assert "<script>" not in result.output
+
+    def test_hardbreaks(self, runner):
+        result = runner.invoke(main, ["--hardbreaks"], input="line1\nline2\n")
+        assert result.exit_code == 0
+        assert "<br />" in result.output
+
+    def test_sourcepos_html(self, runner):
+        result = runner.invoke(main, ["--sourcepos"], input="hello\n")
+        assert result.exit_code == 0
+        assert "data-sourcepos" in result.output
+
+    def test_sourcepos_xml(self, runner):
+        result = runner.invoke(main, ["--to", "xml", "--sourcepos"], input="hello\n")
+        assert result.exit_code == 0
+        assert 'sourcepos="' in result.output
+
+    def test_sourcepos_ignored_for_latex(self, runner):
+        result = runner.invoke(main, ["--to", "latex", "--sourcepos"], input="# Hi\n")
+        assert result.exit_code == 0
+        assert "\\section{Hi}" in result.output
+
+    def test_footnotes(self, runner):
+        md = "Text[^1]\n\n[^1]: A footnote.\n"
+        result = runner.invoke(main, ["--footnotes"], input=md)
+        assert result.exit_code == 0
+        assert "footnote" in result.output.lower()
+
+
+class TestExtensions:
+    def test_table(self, runner):
+        md = "| A | B |\n|---|---|\n| 1 | 2 |\n"
+        result = runner.invoke(main, ["-e", "table"], input=md)
+        assert result.exit_code == 0
+        assert "<table>" in result.output
+
+    def test_strikethrough(self, runner):
+        result = runner.invoke(main, ["-e", "strikethrough"], input="~~del~~\n")
+        assert result.exit_code == 0
+        assert "<del>del</del>" in result.output
+
+    def test_autolink(self, runner):
+        result = runner.invoke(main, ["-e", "autolink"], input="Visit https://example.com\n")
+        assert result.exit_code == 0
+        assert 'href="https://example.com"' in result.output
+
+    def test_multiple_extensions(self, runner):
+        md = "~~del~~\n\n| A |\n|---|\n| 1 |\n"
+        result = runner.invoke(main, ["-e", "strikethrough", "-e", "table"], input=md)
+        assert result.exit_code == 0
+        assert "<del>" in result.output
+        assert "<table>" in result.output
+
+
+class TestMetadata:
+    def test_version(self, runner):
+        result = runner.invoke(main, ["--version"])
+        assert result.exit_code == 0
+        assert __version__ in result.output
+
+    def test_help(self, runner):
+        result = runner.invoke(main, ["--help"])
+        assert result.exit_code == 0
+        assert "Convert CommonMark/GFM" in result.output
+        assert "--to" in result.output
diff --git a/tests/test_errors.py b/tests/test_errors.py
index 0374f49..78f67df 100644
--- a/tests/test_errors.py
+++ b/tests/test_errors.py
@@ -1,8 +1,3 @@
-"""Tests for error handling and type safety.
-
-Verify that our Python bindings raise clear errors for invalid inputs
-rather than segfaulting or producing undefined behavior.
-"""
 import pytest
 
 from multimark import (
diff --git a/tests/test_extensions.py b/tests/test_extensions.py
index 6b6dcf0..15a584e 100644
--- a/tests/test_extensions.py
+++ b/tests/test_extensions.py
@@ -1,4 +1,3 @@
-"""Tests for GFM extensions (table, strikethrough, autolink, tagfilter, tasklist)."""
 import pytest
 
 from multimark import markdown_to_html, markdown_to_latex, markdown_to_xml, VALID_EXTENSIONS
diff --git a/tests/test_html.py b/tests/test_html.py
index 5f4b3d5..262f38c 100644
--- a/tests/test_html.py
+++ b/tests/test_html.py
@@ -1,4 +1,3 @@
-"""Smoke tests for options, edge cases, and behavior the spec doesn't cover."""
 from multimark import markdown_to_html, Options
 
 
diff --git a/tests/test_latex.py b/tests/test_latex.py
index 4cdc925..15e6129 100644
--- a/tests/test_latex.py
+++ b/tests/test_latex.py
@@ -1,4 +1,3 @@
-"""Smoke tests for LaTeX renderer — format-specific behavior and width parameter."""
 from multimark import markdown_to_latex, Options
 
 
diff --git a/tests/test_man.py b/tests/test_man.py
index ac7da91..1c64656 100644
--- a/tests/test_man.py
+++ b/tests/test_man.py
@@ -1,4 +1,3 @@
-"""Smoke tests for man page renderer — format-specific behavior and width parameter."""
 from multimark import markdown_to_man, Options
 
 
diff --git a/tests/test_package.py b/tests/test_package.py
index 81b723e..96aabdb 100644
--- a/tests/test_package.py
+++ b/tests/test_package.py
@@ -1,4 +1,3 @@
-"""Smoke tests for package-level API: version, imports, cmark_version."""
 from multimark import (
     markdown_to_html,
     markdown_to_latex,
diff --git a/tests/test_param_combos.py b/tests/test_param_combos.py
index fde7236..710ff45 100644
--- a/tests/test_param_combos.py
+++ b/tests/test_param_combos.py
@@ -1,8 +1,3 @@
-"""Comprehensive tests for parameter combinations.
-
-Exercises the cross-product of boolean flags, options, extensions, and width
-to verify correct interactions and absence of crashes.
-"""
 import itertools
 
 import pytest
diff --git a/tests/test_pathological.py b/tests/test_pathological.py
index 6d5004c..e420e16 100644
--- a/tests/test_pathological.py
+++ b/tests/test_pathological.py
@@ -1,8 +1,3 @@
-"""Tests for pathological and adversarial inputs.
-
-These verify that cmark's protections against algorithmic complexity attacks
-and stack overflow are working correctly through our bindings.
-"""
 import pytest
 
 from multimark import (
diff --git a/tests/test_regressions.py b/tests/test_regressions.py
index 5d404be..13cb0a5 100644
--- a/tests/test_regressions.py
+++ b/tests/test_regressions.py
@@ -1,10 +1,3 @@
-"""Regression tests derived from closed R commonmark issues.
-
-These ensure bugs reported against the R package don't affect multimark.
-Each test references the original GitHub issue for context.
-
-See: https://github.com/r-lib/commonmark/issues?q=is%3Aissue+state%3Aclosed
-"""
 import pytest
 
 from multimark import (
diff --git a/tests/test_spec_html.py b/tests/test_spec_html.py
index 4c1bca8..71ab38b 100644
--- a/tests/test_spec_html.py
+++ b/tests/test_spec_html.py
@@ -1,8 +1,3 @@
-"""Spec-driven tests: HTML rendering against the CommonMark specification.
-
-Tests all examples from spec.txt, smart_punct.txt, and regression.txt.
-Each example provides markdown input and expected HTML output.
-"""
 import pytest
 
 from multimark import markdown_to_html, Options
diff --git a/tests/test_spec_renderers.py b/tests/test_spec_renderers.py
index e1d6998..b0bb25a 100644
--- a/tests/test_spec_renderers.py
+++ b/tests/test_spec_renderers.py
@@ -1,14 +1,3 @@
-"""Spec-driven tests: verify all renderers handle every spec example without error.
-
-For non-HTML renderers we don't have expected output from the spec, but we verify:
-1. No crashes or exceptions on any spec example
-2. Non-empty output for non-empty input
-3. Structural properties (XML well-formedness, LaTeX balanced envs)
-4. Width parameter doesn't break output
-5. Options (SOURCEPOS, SMART) don't crash
-6. CommonMark roundtrip: markdown → commonmark → HTML == markdown → HTML
-7. Determinism: same input always produces same output
-"""
 import re
 
 import pytest
diff --git a/tests/test_threads.py b/tests/test_threads.py
index 9a456aa..1df78fd 100644
--- a/tests/test_threads.py
+++ b/tests/test_threads.py
@@ -1,8 +1,3 @@
-"""Tests for thread safety.
-
-cmark should be safe to call from multiple threads simultaneously
-since each parse/render is independent (no shared mutable state).
-"""
 import concurrent.futures
 
 from multimark import (
diff --git a/tests/test_xml.py b/tests/test_xml.py
index 491a979..e3d6b15 100644
--- a/tests/test_xml.py
+++ b/tests/test_xml.py
@@ -1,4 +1,3 @@
-"""Smoke tests for XML renderer — structure, options, and edge cases."""
 from multimark import markdown_to_xml, Options
 
 
diff --git a/user_guide/06-cli.qmd b/user_guide/06-cli.qmd
new file mode 100644
index 0000000..07ce8be
--- /dev/null
+++ b/user_guide/06-cli.qmd
@@ -0,0 +1,163 @@
+---
+title: "Command-Line Interface"
+guide-section: "Core Concepts"
+tags: [CLI, Tutorial]
+---
+
+Multimark includes a command-line tool for quick Markdown conversions without writing Python code. It reads from a file or stdin and writes the rendered output to stdout or a file.
+
+## Basic Usage
+
+The simplest invocation converts Markdown to HTML:
+
+```bash
+echo '# Hello **world**' | multimark
+```
+
+```html
+<h1>Hello <strong>world</strong></h1>
+```
+
+You can also pass a filename directly:
+
+```bash
+multimark README.md
+```
+
+## Choosing an Output Format
+
+Use the `-t` / `--to` flag to select the output format. The available formats are
+`html` (the default), `latex`, `man`, `commonmark`, and `xml`.
+
+```bash
+echo '# Hello' | multimark --to latex
+```
+
+```latex
+\section{Hello}
+```
+
+```bash
+echo '**bold** and *italic*' | multimark --to xml
+```
+
+```xml
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE document SYSTEM "CommonMark.dtd">
+<document xmlns="http://commonmark.org/xml/1.0">
+  <paragraph>
+    <strong>
+      <text xml:space="preserve">bold</text>
+    </strong>
+    <text xml:space="preserve"> and </text>
+    <emph>
+      <text xml:space="preserve">italic</text>
+    </emph>
+  </paragraph>
+</document>
+```
+
+## Writing to a File
+
+Use `-o` / `--output` to write results to a file instead of stdout:
+
+```bash
+multimark README.md --to html -o README.html
+```
+
+## Enabling GFM Extensions
+
+GFM extensions are enabled with the `-e` / `--extension` flag. It can be repeated to
+enable multiple extensions at once.
+
+```bash
+echo '| A | B |\n|---|---|\n| 1 | 2 |' | multimark -e table
+```
+
+The available extensions are `autolink`, `strikethrough`, `table`, `tagfilter`, and
+`tasklist`.
+
+```bash
+multimark doc.md -e table -e strikethrough -e autolink
+```
+
+## Rendering Options
+
+Several flags control how the Markdown is parsed and rendered:
+
+| Flag | Effect |
+|------|--------|
+| `--smart` | Convert straight quotes to curly, `--` to en-dash, `---` to em-dash, `...` to ellipsis |
+| `--unsafe` | Allow raw HTML and potentially dangerous URLs to pass through |
+| `--hardbreaks` | Render soft line breaks as hard breaks |
+| `--sourcepos` | Add source position attributes (html and xml only) |
+| `--footnotes` | Enable footnote syntax |
+
+These can be combined freely:
+
+```bash
+echo '"Hello" -- world...' | multimark --smart
+```
+
+```html
+<p>\u201cHello\u201d \u2013 world\u2026</p>
+```
+
+```bash
+echo '<div>raw</div>' | multimark --unsafe
+```
+
+```html
+<div>raw</div>
+```
+
+## Reading from stdin
+
+When no file argument is provided, multimark reads from stdin. This makes it easy to
+use in shell pipelines:
+
+```bash
+curl -s https://example.com/README.md | multimark --to html > output.html
+```
+
+```bash
+cat doc.md | multimark --smart --to latex | tee output.tex
+```
+
+## Version
+
+Check the installed version with:
+
+```bash
+multimark --version
+```
+
+## Full Help
+
+```bash
+multimark --help
+```
+
+```
+Usage: multimark [OPTIONS] [FILE]
+
+  Convert CommonMark/GFM Markdown to various output formats.
+
+  Reads Markdown from FILE (or stdin if omitted) and writes the converted
+  output to stdout or the file specified by --output.
+
+Options:
+  -t, --to [html|latex|man|commonmark|xml]
+                                  Output format.
+  -o, --output FILENAME           Output file (stdout if omitted).
+  -e, --extension [autolink|strikethrough|table|tagfilter|tasklist]
+                                  Enable a GFM extension (repeatable).
+  --smart                         Use smart punctuation.
+  --unsafe                        Allow raw HTML and dangerous URLs.
+  --hardbreaks                    Render softbreaks as hard line breaks.
+  --sourcepos                     Include source position attributes (html/xml
+                                  only).
+  --footnotes                     Enable footnote parsing.
+  --version                       Show the version and exit.
+  --help                          Show this message and exit.
+```
diff --git a/user_guide/06-security.qmd b/user_guide/07-security.qmd
similarity index 100%
rename from user_guide/06-security.qmd
rename to user_guide/07-security.qmd
diff --git a/user_guide/07-recipes.qmd b/user_guide/08-recipes.qmd
similarity index 100%
rename from user_guide/07-recipes.qmd
rename to user_guide/08-recipes.qmd
diff --git a/user_guide/08-performance.qmd b/user_guide/09-performance.qmd
similarity index 100%
rename from user_guide/08-performance.qmd
rename to user_guide/09-performance.qmd