diff --git a/server/src/http/io.rs b/server/src/http/io.rs
index a1ecb1a..85b209e 100644
--- a/server/src/http/io.rs
+++ b/server/src/http/io.rs
@@ -128,3 +128,221 @@ impl IoApi {
         Ok(Json(output))
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::http::context::AppContext;
+    use tempfile::TempDir;
+
+    fn make_api(dir: &TempDir) -> IoApi {
+        IoApi {
+            ctx: Arc::new(AppContext::new_test(dir.path().to_path_buf())),
+        }
+    }
+
+    // --- list_directory_absolute ---
+
+    #[tokio::test]
+    async fn list_directory_absolute_returns_entries_for_valid_path() {
+        let dir = TempDir::new().unwrap();
+        std::fs::create_dir(dir.path().join("subdir")).unwrap();
+        std::fs::write(dir.path().join("file.txt"), "content").unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: dir.path().to_string_lossy().to_string(),
+        });
+        let result = api.list_directory_absolute(payload).await.unwrap();
+        let entries = &result.0;
+
+        assert!(entries.len() >= 2);
+        assert!(entries.iter().any(|e| e.name == "subdir" && e.kind == "dir"));
+        assert!(entries.iter().any(|e| e.name == "file.txt" && e.kind == "file"));
+    }
+
+    #[tokio::test]
+    async fn list_directory_absolute_returns_empty_for_empty_dir() {
+        let dir = TempDir::new().unwrap();
+        let empty = dir.path().join("empty");
+        std::fs::create_dir(&empty).unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: empty.to_string_lossy().to_string(),
+        });
+        let result = api.list_directory_absolute(payload).await.unwrap();
+        assert!(result.0.is_empty());
+    }
+
+    #[tokio::test]
+    async fn list_directory_absolute_errors_on_nonexistent_path() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: dir.path().join("nonexistent").to_string_lossy().to_string(),
+        });
+        let result = api.list_directory_absolute(payload).await;
+        assert!(result.is_err());
+    }
+
+    #[tokio::test]
+    async fn list_directory_absolute_errors_on_file_path() {
+        let dir = TempDir::new().unwrap();
+        let file = dir.path().join("not_a_dir.txt");
+        std::fs::write(&file, "content").unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: file.to_string_lossy().to_string(),
+        });
+        let result = api.list_directory_absolute(payload).await;
+        assert!(result.is_err());
+    }
+
+    // --- create_directory_absolute ---
+
+    #[tokio::test]
+    async fn create_directory_absolute_creates_new_dir() {
+        let dir = TempDir::new().unwrap();
+        let new_dir = dir.path().join("new_dir");
+
+        let api = make_api(&dir);
+        let payload = Json(CreateDirectoryPayload {
+            path: new_dir.to_string_lossy().to_string(),
+        });
+        let result = api.create_directory_absolute(payload).await.unwrap();
+        assert!(result.0);
+        assert!(new_dir.is_dir());
+    }
+
+    #[tokio::test]
+    async fn create_directory_absolute_succeeds_for_existing_dir() {
+        let dir = TempDir::new().unwrap();
+        let existing = dir.path().join("existing");
+        std::fs::create_dir(&existing).unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(CreateDirectoryPayload {
+            path: existing.to_string_lossy().to_string(),
+        });
+        let result = api.create_directory_absolute(payload).await.unwrap();
+        assert!(result.0);
+    }
+
+    #[tokio::test]
+    async fn create_directory_absolute_creates_nested_dirs() {
+        let dir = TempDir::new().unwrap();
+        let nested = dir.path().join("a").join("b").join("c");
+
+        let api = make_api(&dir);
+        let payload = Json(CreateDirectoryPayload {
+            path: nested.to_string_lossy().to_string(),
+        });
+        let result = api.create_directory_absolute(payload).await.unwrap();
+        assert!(result.0);
+        assert!(nested.is_dir());
+    }
+
+    // --- get_home_directory ---
+
+    #[tokio::test]
+    async fn get_home_directory_returns_a_path() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let result = api.get_home_directory().await.unwrap();
+        let home = &result.0;
+        assert!(!home.is_empty());
+        assert!(std::path::Path::new(home).is_absolute());
+    }
+
+    // --- read_file (project-scoped) ---
+
+    #[tokio::test]
+    async fn read_file_returns_content() {
+        let dir = TempDir::new().unwrap();
+        std::fs::write(dir.path().join("hello.txt"), "hello world").unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: "hello.txt".to_string(),
+        });
+        let result = api.read_file(payload).await.unwrap();
+        assert_eq!(result.0, "hello world");
+    }
+
+    #[tokio::test]
+    async fn read_file_errors_on_missing_file() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: "nonexistent.txt".to_string(),
+        });
+        let result = api.read_file(payload).await;
+        assert!(result.is_err());
+    }
+
+    // --- write_file (project-scoped) ---
+
+    #[tokio::test]
+    async fn write_file_creates_file() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let payload = Json(WriteFilePayload {
+            path: "output.txt".to_string(),
+            content: "written content".to_string(),
+        });
+        let result = api.write_file(payload).await.unwrap();
+        assert!(result.0);
+        assert_eq!(
+            std::fs::read_to_string(dir.path().join("output.txt")).unwrap(),
+            "written content"
+        );
+    }
+
+    #[tokio::test]
+    async fn write_file_creates_parent_dirs() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let payload = Json(WriteFilePayload {
+            path: "sub/dir/file.txt".to_string(),
+            content: "nested".to_string(),
+        });
+        let result = api.write_file(payload).await.unwrap();
+        assert!(result.0);
+        assert_eq!(
+            std::fs::read_to_string(dir.path().join("sub/dir/file.txt")).unwrap(),
+            "nested"
+        );
+    }
+
+    // --- list_directory (project-scoped) ---
+
+    #[tokio::test]
+    async fn list_directory_returns_entries() {
+        let dir = TempDir::new().unwrap();
+        std::fs::create_dir(dir.path().join("adir")).unwrap();
+        std::fs::write(dir.path().join("bfile.txt"), "").unwrap();
+
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: ".".to_string(),
+        });
+        let result = api.list_directory(payload).await.unwrap();
+        let entries = &result.0;
+
+        assert!(entries.iter().any(|e| e.name == "adir" && e.kind == "dir"));
+        assert!(entries.iter().any(|e| e.name == "bfile.txt" && e.kind == "file"));
+    }
+
+    #[tokio::test]
+    async fn list_directory_errors_on_nonexistent() {
+        let dir = TempDir::new().unwrap();
+        let api = make_api(&dir);
+        let payload = Json(FilePathPayload {
+            path: "nonexistent_dir".to_string(),
+        });
+        let result = api.list_directory(payload).await;
+        assert!(result.is_err());
+    }
+}