diff --git a/src/python.rs b/src/python.rs
index ceaa0ac..b44c5c8 100644
--- a/src/python.rs
+++ b/src/python.rs
@@ -52,8 +52,8 @@ fn is_git_repo(path: String) -> PyResult<bool> {
 }
 
 #[pyfunction]
-fn is_clean(_path: String) -> PyResult<bool> {
-    todo!("repo::is_clean (gix status, empty)")
+fn is_clean(path: String) -> PyResult<bool> {
+    Ok(crate::repo::is_clean(std::path::Path::new(&path))?)
 }
 
 #[pyfunction]
diff --git a/src/repo/is_clean.rs b/src/repo/is_clean.rs
new file mode 100644
index 0000000..52284c1
--- /dev/null
+++ b/src/repo/is_clean.rs
@@ -0,0 +1,62 @@
+use crate::error::GitxtendError;
+use crate::repo::Result;
+use std::path::Path;
+
+/// True iff the working tree is clean — no staged, modified, or untracked
+/// entries — i.e. `git status --porcelain` would be empty.
+pub fn is_clean(path: &Path) -> Result<bool> {
+    let repo = gix::open(path).map_err(GitxtendError::from_err)?;
+    let mut iter = repo
+        .status(gix::progress::Discard)
+        .map_err(GitxtendError::from_err)?
+        .untracked_files(gix::status::UntrackedFiles::Files)
+        .into_iter(Vec::<gix::bstr::BString>::new())
+        .map_err(GitxtendError::from_err)?;
+    // clean == the status iterator yields no entries (staged, modified, or untracked)
+    Ok(iter.next().is_none())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::repo::fixtures::{self, repo, write};
+
+    fn porcelain_clean(p: &std::path::Path) -> bool {
+        fixtures::git(p, &["status", "--porcelain"]).is_empty()
+    }
+
+    #[test]
+    fn test_is_clean_fresh_repo() {
+        let td = repo();
+        assert!(is_clean(td.path()).unwrap());
+        assert_eq!(is_clean(td.path()).unwrap(), porcelain_clean(td.path()));
+    }
+
+    #[test]
+    fn test_is_clean_untracked_file() {
+        let td = repo();
+        write(td.path(), "new.txt", "x");
+        assert!(!is_clean(td.path()).unwrap());
+        assert_eq!(is_clean(td.path()).unwrap(), porcelain_clean(td.path()));
+    }
+
+    #[test]
+    fn test_is_clean_modified_tracked_file() {
+        let td = repo();
+        write(td.path(), "README.md", "orig");
+        fixtures::git(td.path(), &["add", "README.md"]);
+        fixtures::git(td.path(), &["commit", "-m", "Add README"]);
+        write(td.path(), "README.md", "Modified content");
+        assert!(!is_clean(td.path()).unwrap());
+        assert_eq!(is_clean(td.path()).unwrap(), porcelain_clean(td.path()));
+    }
+
+    #[test]
+    fn test_is_clean_staged_change() {
+        let td = repo();
+        write(td.path(), "new.txt", "x");
+        fixtures::git(td.path(), &["add", "new.txt"]);
+        assert!(!is_clean(td.path()).unwrap());
+        assert_eq!(is_clean(td.path()).unwrap(), porcelain_clean(td.path()));
+    }
+}
diff --git a/src/repo/mod.rs b/src/repo/mod.rs
index 34701cc..a4284ad 100644
--- a/src/repo/mod.rs
+++ b/src/repo/mod.rs
@@ -44,6 +44,9 @@ pub use rev_list_count::rev_list_count;
 mod log_subjects;
 pub use log_subjects::log_subjects;
 
+mod is_clean;
+pub use is_clean::is_clean;
+
 /// Temp-dir git fixtures shared by the per-method parity tests.
 ///
 /// Fixtures are built with the real `git` CLI, so each parity test asserts