diff --git a/Cargo.lock b/Cargo.lock
index 2c4bdfa6..26185582 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3571,6 +3571,13 @@ dependencies = [
  "windows 0.62.2",
 ]
 
+[[package]]
+name = "komorebic-core"
+version = "0.1.42"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "komorebic-no-console"
 version = "0.1.42"
diff --git a/Cargo.toml b/Cargo.toml
index e7eb78e1..37d30b9e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,6 +10,7 @@ members = [
   "komorebi-scrolling",
   "komorebic",
   "komorebic-no-console",
+  "crates/komorebic-core",
   "komorebi-bar",
   "komorebi-themes",
   "crates/komorebi-protocol",
diff --git a/crates/komorebic-core/Cargo.toml b/crates/komorebic-core/Cargo.toml
new file mode 100644
index 00000000..59cdf309
--- /dev/null
+++ b/crates/komorebic-core/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "komorebic-core"
+version = "0.1.42"
+description = "The command line definitions that the komorebic of every platform shares"
+edition = "2024"
+
+[dependencies]
+clap = { workspace = true }
diff --git a/crates/komorebic-core/src/docgen.rs b/crates/komorebic-core/src/docgen.rs
new file mode 100644
index 00000000..7ecff5db
--- /dev/null
+++ b/crates/komorebic-core/src/docgen.rs
@@ -0,0 +1,165 @@
+//! The pages of `docs/cli`: the long help of every subcommand, one Markdown file each.
+
+use clap::Command;
+use std::io;
+use std::path::Path;
+use std::path::PathBuf;
+
+/// The subcommands that get no page: the generator itself, and the ones that are hidden or
+/// platform plumbing that is not documented.
+pub const IGNORED: [&str; 12] = [
+    "docgen",
+    "splash",
+    "alt-focus-hack",
+    "identify-border-overflow-application",
+    "load-custom-layout",
+    "workspace-custom-layout",
+    "named-workspace-custom-layout",
+    "workspace-custom-layout-rule",
+    "named-workspace-custom-layout-rule",
+    "focus-follows-mouse",
+    "toggle-focus-follows-mouse",
+    "format-app-specific-configuration",
+];
+
+/// How a platform's pages look. Each tree keeps the format its checked-in pages have.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct DocFormat {
+    /// Wrap the help at this many columns whatever the width of the terminal, or at the width of
+    /// the terminal if there is none.
+    pub term_width: Option<usize>,
+    /// What the opening fence of a page says (`text`), or nothing.
+    pub fence_info: &'static str,
+    /// Whether a page ends with a newline after the closing fence.
+    pub trailing_newline: bool,
+    /// Whether a subcommand of a subcommand (`hotkeys compile`) gets a page of its own, named
+    /// `hotkeys-compile`.
+    pub nested: bool,
+}
+
+impl DocFormat {
+    /// The pages of komorebic for Windows and for macOS.
+    pub const PLAIN: Self = Self {
+        term_width: None,
+        fence_info: "",
+        trailing_newline: false,
+        nested: false,
+    };
+
+    /// The pages of komorebic for KDE: the same whatever the width of the terminal.
+    pub const KDE: Self = Self {
+        term_width: Some(100),
+        fence_info: "text",
+        trailing_newline: true,
+        nested: true,
+    };
+
+    fn render(&self, cmd: Command) -> String {
+        let mut cmd = match self.term_width {
+            Some(width) => cmd.term_width(width),
+            None => cmd,
+        };
+        let help_text = cmd.render_long_help().to_string();
+        let newline = if self.trailing_newline { "\n" } else { "" };
+        format!("```{}\n{help_text}\n```{newline}", self.fence_info)
+    }
+}
+
+/// The pages of a command line, as `(file name, content)` in the order of its subcommands.
+pub fn pages(mut cli: Command, format: &DocFormat) -> Vec<(String, String)> {
+    let mut pages = Vec::new();
+    for cmd in cli.get_subcommands_mut() {
+        let name = cmd.get_name().to_string();
+        if IGNORED.contains(&name.as_str()) {
+            continue;
+        }
+        pages.push((format!("{name}.md"), format.render(cmd.clone())));
+        if format.nested {
+            for sub in cmd.get_subcommands() {
+                pages.push((
+                    format!("{name}-{}.md", sub.get_name()),
+                    format.render(sub.clone()),
+                ));
+            }
+        }
+    }
+    pages
+}
+
+/// Write the pages into `dir` (made if it is not there) and return the paths written.
+pub fn write(cli: Command, format: &DocFormat, dir: &Path) -> io::Result<Vec<PathBuf>> {
+    std::fs::create_dir_all(dir)?;
+    pages(cli, format)
+        .into_iter()
+        .map(|(file, content)| {
+            let path = dir.join(file);
+            std::fs::write(&path, content)?;
+            Ok(path)
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use clap::CommandFactory;
+    use clap::Parser;
+    use clap::Subcommand;
+
+    #[derive(Parser)]
+    struct Cli {
+        #[command(subcommand)]
+        cmd: Cmd,
+    }
+
+    #[derive(Subcommand)]
+    enum Cmd {
+        /// Do the thing
+        Thing,
+        /// Group of things
+        Group {
+            #[command(subcommand)]
+            sub: Sub,
+        },
+        #[command(hide = true)]
+        Docgen,
+    }
+
+    #[derive(Subcommand)]
+    enum Sub {
+        /// Do one of the things
+        One,
+    }
+
+    #[test]
+    fn a_plain_page_has_a_bare_fence_and_no_final_newline() {
+        let pages = pages(Cli::command(), &DocFormat::PLAIN);
+        let names: Vec<_> = pages.iter().map(|(name, _)| name.as_str()).collect();
+        assert_eq!(names, ["thing.md", "group.md"]);
+        assert!(pages[0].1.starts_with("```\nDo the thing\n"));
+        assert!(pages[0].1.ends_with("\n```"));
+    }
+
+    #[test]
+    fn a_kde_page_says_text_ends_in_a_newline_and_nests() {
+        let pages = pages(Cli::command(), &DocFormat::KDE);
+        let names: Vec<_> = pages.iter().map(|(name, _)| name.as_str()).collect();
+        assert_eq!(names, ["thing.md", "group.md", "group-one.md"]);
+        assert!(pages[0].1.starts_with("```text\nDo the thing\n"));
+        assert!(pages[0].1.ends_with("\n```\n"));
+    }
+
+    #[test]
+    fn write_returns_the_paths_it_wrote() {
+        let dir =
+            std::env::temp_dir().join(format!("komorebic-core-docgen-{}", std::process::id()));
+        let written = write(Cli::command(), &DocFormat::PLAIN, &dir).unwrap();
+        assert_eq!(written.len(), 2);
+        assert!(
+            std::fs::read_to_string(dir.join("thing.md"))
+                .unwrap()
+                .contains("Do the thing")
+        );
+        std::fs::remove_dir_all(&dir).unwrap();
+    }
+}
diff --git a/crates/komorebic-core/src/lib.rs b/crates/komorebic-core/src/lib.rs
new file mode 100644
index 00000000..0765f689
--- /dev/null
+++ b/crates/komorebic-core/src/lib.rs
@@ -0,0 +1,8 @@
+//! The command line of `komorebic`, in one place for the three platforms.
+//!
+//! Every definition is plain clap code that is always compiled, with no `cfg`: what differs per
+//! platform is a type parameter, so one binary can render the help of all of them.
+//!
+//! - [`docgen`] renders the pages of `docs/cli`.
+
+pub mod docgen;