diff --git a/src/cli.rs b/src/cli.rs
new file mode 100644
index 0000000..c70041e
--- /dev/null
+++ b/src/cli.rs
@@ -0,0 +1,85 @@
+use crate::commands::CommandMap;
+use bnum::types::U512;
+
+pub fn run(args: &[String]) -> Result<String, Error> {
+    let input = ParsedInput::try_from(args)?;
+    let cmd_map = CommandMap::default();
+    match cmd_map.get(&input.command_name) {
+        Some(cmd) => Ok(format!("{}\n{}", input, cmd.run(&input.number))),
+        None => Err(Error::CommandNotFound(cmd_map.available_commands())),
+    }
+}
+
+struct ParsedInput {
+    number: U512,
+    digit_len: usize,
+    command_name: String,
+}
+
+impl TryFrom<&[String]> for ParsedInput {
+    type Error = Error;
+
+    fn try_from(value: &[String]) -> Result<Self, Self::Error> {
+        let slice: &[String; 3] = value.try_into().map_err(|_| Error::IncorrectNumArgs)?;
+        Ok(ParsedInput {
+            number: slice[2].parse().map_err(|_| Error::ParseIntErr)?,
+            digit_len: slice[2].len(),
+            command_name: slice[1].to_string(),
+        })
+    }
+}
+
+impl std::fmt::Display for ParsedInput {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "Using command {} with number {} ({} digits)",
+            self.command_name, self.number, self.digit_len
+        )
+    }
+}
+
+#[derive(PartialEq, Debug)]
+pub enum Error {
+    CommandNotFound(String),
+    ParseIntErr,
+    IncorrectNumArgs,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn happy_cases() {
+        let cmap = CommandMap::default();
+        for command in cmap.available_commands().split(", ") {
+            assert!(run(&[
+                String::from("rustic_factors"),
+                String::from(command),
+                String::from("123")
+            ])
+            .is_ok());
+        }
+    }
+
+    #[test]
+    fn unsupported_command() {
+        match run(&[
+            String::from("rustic_factors"),
+            String::from("unsupported command"),
+            String::from("123"),
+        ]) {
+            Err(Error::CommandNotFound(_)) => (),
+            _ => panic!(),
+        }
+    }
+
+    #[test]
+    fn too_few_args() {
+        assert_eq!(
+            run(&[String::from("rustic_factors")]).unwrap_err(),
+            Error::IncorrectNumArgs,
+        );
+    }
+}
diff --git a/src/lib.rs b/src/lib.rs
index 2172799..f347aad 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 pub mod algorithms;
+pub mod cli;
 pub mod commands;
 pub mod factorization;
 pub mod orchestration;
diff --git a/src/main.rs b/src/main.rs
index ce5d347..e891fae 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,98 +1,14 @@
-use bnum::types::U512;
-use rustic_factors::commands::CommandMap;
+use rustic_factors::cli;
 use std::env;
 
 fn main() {
     let args: Vec<String> = env::args().collect();
-    match cli(&args) {
+    match cli::run(&args) {
         Ok(result) => println!("{result}"),
-        Err(CliErr::ParseIntErr) => eprintln!("Please provide a number in range [0, 2⁵¹²)"),
-        Err(CliErr::IncorrectNumArgs) => eprintln!("Usage: {} <command> <number>", args[0]),
-        Err(CliErr::CommandNotFound(commands)) => {
+        Err(cli::Error::ParseIntErr) => eprintln!("Please provide a number in range [0, 2⁵¹²)"),
+        Err(cli::Error::IncorrectNumArgs) => eprintln!("Usage: {} <command> <number>", args[0]),
+        Err(cli::Error::CommandNotFound(commands)) => {
             eprintln!("Unknown command. Available options: {commands}.")
         }
     }
 }
-
-fn cli(args: &[String]) -> Result<String, CliErr> {
-    let input = ParsedInput::try_from(args)?;
-    let cmd_map = CommandMap::default();
-    match cmd_map.get(&input.command_name) {
-        Some(cmd) => Ok(format!("{}\n{}", input, cmd.run(&input.number))),
-        None => Err(CliErr::CommandNotFound(cmd_map.available_commands())),
-    }
-}
-
-struct ParsedInput {
-    number: U512,
-    digit_len: usize,
-    command_name: String,
-}
-
-impl TryFrom<&[String]> for ParsedInput {
-    type Error = CliErr;
-
-    fn try_from(value: &[String]) -> Result<Self, Self::Error> {
-        let slice: &[String; 3] = value.try_into().map_err(|_| CliErr::IncorrectNumArgs)?;
-        Ok(ParsedInput {
-            number: slice[2].parse().map_err(|_| CliErr::ParseIntErr)?,
-            digit_len: slice[2].len(),
-            command_name: slice[1].to_string(),
-        })
-    }
-}
-
-impl std::fmt::Display for ParsedInput {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        write!(
-            f,
-            "Using command {} with number {} ({} digits)",
-            self.command_name, self.number, self.digit_len
-        )
-    }
-}
-
-#[derive(PartialEq, Debug)]
-enum CliErr {
-    CommandNotFound(String),
-    ParseIntErr,
-    IncorrectNumArgs,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn happy_cases() {
-        let cmap = CommandMap::default();
-        for command in cmap.available_commands().split(", ") {
-            assert!(cli(&[
-                String::from("rustic_factors"),
-                String::from(command),
-                String::from("123")
-            ])
-            .is_ok());
-        }
-    }
-
-    #[test]
-    fn unsupported_command() {
-        match cli(&[
-            String::from("rustic_factors"),
-            String::from("unsupported command"),
-            String::from("123"),
-        ]) {
-            Err(CliErr::CommandNotFound(_)) => (),
-            _ => panic!(),
-        }
-    }
-
-    #[test]
-    fn too_few_args() {
-        assert_eq!(
-            cli(&[String::from("rustic_factors")]).unwrap_err(),
-            CliErr::IncorrectNumArgs,
-        );
-    }
-}