diff --git a/fud2/fud-core/src/cli.rs b/fud2/fud-core/src/cli.rs
index b0d835931..e3e538283 100644
--- a/fud2/fud-core/src/cli.rs
+++ b/fud2/fud-core/src/cli.rs
@@ -2,7 +2,7 @@ use crate::config;
 use crate::exec::{plan, Driver, Request, StateRef};
 use crate::run::Run;
 use anyhow::{anyhow, bail};
-use argh::{FromArgs, SubCommand};
+use argh::{DynamicSubCommand, FromArgs};
 use camino::Utf8PathBuf;
 use std::fmt::Display;
 use std::str::FromStr;
@@ -104,16 +104,34 @@ pub struct GetResource {
 #[argh(subcommand, name = "list")]
 pub struct ListCommand {}
 
-pub trait FakeSubCommand: SubCommand {
+pub trait FakeCliExt: DynamicSubCommand {
     fn run(&self, driver: &Driver) -> anyhow::Result<()>;
 }
 
 /// no extra command
-#[derive(FromArgs)]
-#[argh(subcommand, name = "none")]
-pub struct DefaultDynamic {}
+struct EmptyCliExt {}
+
+impl DynamicSubCommand for EmptyCliExt {
+    fn commands() -> &'static [&'static argh::CommandInfo] {
+        &[]
+    }
+
+    fn try_redact_arg_values(
+        _command_name: &[&str],
+        _args: &[&str],
+    ) -> Option<Result<Vec<String>, argh::EarlyExit>> {
+        None
+    }
+
+    fn try_from_args(
+        _command_name: &[&str],
+        _args: &[&str],
+    ) -> Option<Result<Self, argh::EarlyExit>> {
+        None
+    }
+}
 
-impl FakeSubCommand for DefaultDynamic {
+impl FakeCliExt for EmptyCliExt {
     fn run(&self, _driver: &Driver) -> anyhow::Result<()> {
         Ok(())
     }
@@ -124,7 +142,7 @@ impl FakeSubCommand for DefaultDynamic {
 #[argh(subcommand)]
 pub enum Subcommand<T>
 where
-    T: FakeSubCommand,
+    T: FakeCliExt,
 {
     /// edit the configuration file
     EditConfig(EditConfig),
@@ -135,6 +153,7 @@ where
     /// list the available states and ops
     List(ListCommand),
 
+    #[argh(dynamic)]
     Extended(T),
 }
 
@@ -142,7 +161,7 @@ where
 /// A generic compiler driver.
 pub struct FakeArgs<T>
 where
-    T: FakeSubCommand,
+    T: FakeCliExt,
 {
     #[argh(subcommand)]
     pub sub: Option<Subcommand<T>>,
@@ -228,7 +247,7 @@ fn get_states_with_errors(
     Ok(states)
 }
 
-fn from_states<T: FakeSubCommand>(
+fn from_states<T: FakeCliExt>(
     driver: &Driver,
     args: &FakeArgs<T>,
 ) -> anyhow::Result<Vec<StateRef>> {
@@ -242,7 +261,7 @@ fn from_states<T: FakeSubCommand>(
     )
 }
 
-fn to_state<T: FakeSubCommand>(
+fn to_state<T: FakeCliExt>(
     driver: &Driver,
     args: &FakeArgs<T>,
 ) -> anyhow::Result<Vec<StateRef>> {
@@ -256,7 +275,7 @@ fn to_state<T: FakeSubCommand>(
     )
 }
 
-fn get_request<T: FakeSubCommand>(
+fn get_request<T: FakeCliExt>(
     driver: &Driver,
     args: &FakeArgs<T>,
 ) -> anyhow::Result<Request> {
@@ -344,7 +363,11 @@ fn get_resource(driver: &Driver, cmd: GetResource) -> anyhow::Result<()> {
 }
 
 /// Given the name of a Driver, returns a config based on that name and CLI arguments.
-pub fn config_from_cli<T: FakeSubCommand>(
+pub fn config_from_cli(name: &str) -> anyhow::Result<figment::Figment> {
+    config_from_cli_ext::<EmptyCliExt>(name)
+}
+
+pub fn config_from_cli_ext<T: FakeCliExt>(
     name: &str,
 ) -> anyhow::Result<figment::Figment> {
     let args: FakeArgs<T> = argh::from_env();
@@ -364,7 +387,11 @@ pub fn config_from_cli<T: FakeSubCommand>(
     Ok(config)
 }
 
-pub fn cli<T: FakeSubCommand>(
+pub fn cli(driver: &Driver, config: &figment::Figment) -> anyhow::Result<()> {
+    cli_ext::<EmptyCliExt>(driver, config)
+}
+
+pub fn cli_ext<T: FakeCliExt>(
     driver: &Driver,
     config: &figment::Figment,
 ) -> anyhow::Result<()> {
diff --git a/fud2/fud-core/src/lib.rs b/fud2/fud-core/src/lib.rs
index a7b9ed3ba..161b8463f 100644
--- a/fud2/fud-core/src/lib.rs
+++ b/fud2/fud-core/src/lib.rs
@@ -5,5 +5,4 @@ pub mod run;
 pub mod script;
 pub mod utils;
 
-pub use cli::DefaultDynamic;
 pub use exec::{Driver, DriverBuilder};
diff --git a/fud2/src/cli_pyenv.rs b/fud2/src/cli_pyenv.rs
index 80bf4ae4a..a344d3256 100644
--- a/fud2/src/cli_pyenv.rs
+++ b/fud2/src/cli_pyenv.rs
@@ -1,68 +1,111 @@
-use std::{fs, path::Path, process::Command};
+use std::{fs, path::Path, process::Command, sync::OnceLock};
 
-use argh::FromArgs;
-use fud_core::{cli::FakeSubCommand, config};
+use argh::{CommandInfo, DynamicSubCommand, FromArgs};
+use fud_core::{cli::FakeCliExt, config};
 
 /// initialize a fud2 python environment
 #[derive(FromArgs)]
 #[argh(subcommand, name = "env")]
 pub struct PyenvCommand {}
 
-impl FakeSubCommand for PyenvCommand {
+pub enum Fud2CliExt {
+    Pyenv(PyenvCommand),
+}
+
+impl DynamicSubCommand for Fud2CliExt {
+    fn commands() -> &'static [&'static CommandInfo] {
+        static RET: OnceLock<Vec<&'static CommandInfo>> = OnceLock::new();
+        RET.get_or_init(|| {
+            vec![&*Box::leak(Box::new(CommandInfo {
+                name: "env",
+                description: "initialize a fud2 python environment",
+            }))]
+        })
+    }
+
+    fn try_redact_arg_values(
+        command_name: &[&str],
+        args: &[&str],
+    ) -> Option<Result<Vec<String>, argh::EarlyExit>> {
+        if let Some(&"env") = command_name.last() {
+            return Some(PyenvCommand::redact_arg_values(command_name, args));
+        }
+        None
+    }
+
+    fn try_from_args(
+        command_name: &[&str],
+        args: &[&str],
+    ) -> Option<Result<Self, argh::EarlyExit>> {
+        if let Some(&"env") = command_name.last() {
+            return Some(
+                PyenvCommand::from_args(command_name, args)
+                    .map(Fud2CliExt::Pyenv),
+            );
+        }
+        None
+    }
+}
+
+impl FakeCliExt for Fud2CliExt {
     fn run(&self, driver: &fud_core::Driver) -> anyhow::Result<()> {
-        let data_dir = config::data_dir(&driver.name);
-
-        fs::create_dir_all(&data_dir)?;
-
-        let pyenv = data_dir.join("venv");
-
-        // create new venv
-        Command::new("python3")
-            .args(["-m", "venv"])
-            .arg(&pyenv)
-            .stdout(std::io::stdout())
-            .output()?;
-
-        // install flit
-        Command::new(pyenv.join("bin").join("pip"))
-            .arg("install")
-            .arg("flit")
-            .stdout(std::io::stdout())
-            .output()?;
-
-        // grab the location of the calyx base install
-        let config = config::load_config(&driver.name);
-        let calyx_base: String = config.extract_inner("calyx.base")?;
-
-        // install fud python library
-        Command::new(pyenv.join("bin").join("python"))
-            .args(["-m", "flit", "install"])
-            .current_dir(Path::new(&calyx_base).join("fud"))
-            .stdout(std::io::stdout())
-            .output()?;
-
-        // install calyx-py library
-        Command::new(pyenv.join("bin").join("python"))
-            .args(["-m", "flit", "install"])
-            .current_dir(Path::new(&calyx_base).join("calyx-py"))
-            .stdout(std::io::stdout())
-            .output()?;
-
-        // add python location to fud2.toml
-        let config_path = config::config_path(&driver.name);
-        let contents = fs::read_to_string(&config_path)?;
-        let mut toml_doc: toml_edit::DocumentMut = contents.parse()?;
-
-        toml_doc["python"] = toml_edit::value(
-            pyenv
-                .join("bin")
-                .join("python")
-                .to_string_lossy()
-                .to_string(),
-        );
-
-        fs::write(&config_path, toml_doc.to_string())?;
-
-        Ok(())
+        match self {
+            Fud2CliExt::Pyenv(_cmd) => {
+                let data_dir = config::data_dir(&driver.name);
+
+                fs::create_dir_all(&data_dir)?;
+
+                let pyenv = data_dir.join("venv");
+
+                // create new venv
+                Command::new("python3")
+                    .args(["-m", "venv"])
+                    .arg(&pyenv)
+                    .stdout(std::io::stdout())
+                    .output()?;
+
+                // install flit
+                Command::new(pyenv.join("bin").join("pip"))
+                    .arg("install")
+                    .arg("flit")
+                    .stdout(std::io::stdout())
+                    .output()?;
+
+                // grab the location of the calyx base install
+                let config = config::load_config(&driver.name);
+                let calyx_base: String = config.extract_inner("calyx.base")?;
+
+                // install fud python library
+                Command::new(pyenv.join("bin").join("python"))
+                    .args(["-m", "flit", "install"])
+                    .current_dir(Path::new(&calyx_base).join("fud"))
+                    .stdout(std::io::stdout())
+                    .output()?;
+
+                // install calyx-py library
+                Command::new(pyenv.join("bin").join("python"))
+                    .args(["-m", "flit", "install"])
+                    .current_dir(Path::new(&calyx_base).join("calyx-py"))
+                    .stdout(std::io::stdout())
+                    .output()?;
+
+                // add python location to fud2.toml
+                let config_path = config::config_path(&driver.name);
+                let contents = fs::read_to_string(&config_path)?;
+                let mut toml_doc: toml_edit::DocumentMut = contents.parse()?;
+
+                toml_doc["python"] = toml_edit::value(
+                    pyenv
+                        .join("bin")
+                        .join("python")
+                        .to_string_lossy()
+                        .to_string(),
+                );
+
+                fs::write(&config_path, toml_doc.to_string())?;
+
+                Ok(())
+            }
+        }
     }
 }
diff --git a/fud2/src/lib.rs b/fud2/src/lib.rs
index be7000b0c..60b412f06 100644
--- a/fud2/src/lib.rs
+++ b/fud2/src/lib.rs
@@ -1,5 +1,5 @@
 mod cli_pyenv;
-pub use cli_pyenv::PyenvCommand;
+pub use cli_pyenv::Fud2CliExt;
 
 use std::str::FromStr;
 
diff --git a/fud2/src/main.rs b/fud2/src/main.rs
index c3f92b1c6..8e08b6ab7 100644
--- a/fud2/src/main.rs
+++ b/fud2/src/main.rs
@@ -1,4 +1,4 @@
-use fud2::PyenvCommand;
+use fud2::Fud2CliExt;
 use fud_core::{
     cli::{self},
     DriverBuilder,
@@ -41,7 +41,7 @@ fn main() -> anyhow::Result<()> {
     }
 
     // Get config values from cli.
-    let config = cli::config_from_cli::<PyenvCommand>(&bld.name)?;
+    let config = cli::config_from_cli_ext::<Fud2CliExt>(&bld.name)?;
 
     #[cfg(feature = "migrate_to_scripts")]
     {
@@ -49,5 +49,5 @@ fn main() -> anyhow::Result<()> {
     }
 
     let driver = bld.build();
-    cli::cli::<PyenvCommand>(&driver, &config)
+    cli::cli_ext::<Fud2CliExt>(&driver, &config)
 }