diff --git a/focus/internals/src/lib/model/repo.rs b/focus/internals/src/lib/model/repo.rs
index 50e92608..7bea8934 100644
--- a/focus/internals/src/lib/model/repo.rs
+++ b/focus/internals/src/lib/model/repo.rs
@@ -71,6 +71,12 @@ pub const PROJECT_CACHE_INCLUDE_HEADERS_FILE_CONFIG_KEY: &str =
     "focus.project-cache.include-headers-from";
 pub const BAZEL_ONE_SHOT_RESOLUTION_CONFIG_KEY: &str = "focus.bazel.one-shot";
 
+#[derive(Copy, Clone, Debug, Eq, PartialEq)]
+pub enum WorkingTreeKind {
+    Sparse,
+    Dense,
+}
+
 /// Models a Git working tree.
 pub struct WorkingTree {
     repo: git2::Repository,
@@ -110,6 +116,14 @@ impl WorkingTree {
         Self::new(repo)
     }
 
+    pub fn kind(&self) -> WorkingTreeKind {
+        if self.sparse_checkout_path().is_file() {
+            WorkingTreeKind::Sparse
+        } else {
+            WorkingTreeKind::Dense
+        }
+    }
+
     fn info_dir(&self) -> PathBuf {
         self.repo.path().join("info")
     }