diff --git a/backend/src/generator.rs b/backend/src/generator.rs
new file mode 100644
index 0000000..4201606
--- /dev/null
+++ b/backend/src/generator.rs
@@ -0,0 +1,33 @@
+use std::fmt::Error;
+use std::os::unix::fs::MetadataExt;
+use pathdiff::diff_paths;
+use std::path::{Path, PathBuf};
+
+const DOT_PATH: &str = ".meow_index";
+
+/// Generate thumbnail for a file if absent
+pub fn generate_thumb(base: PathBuf, file: PathBuf) -> Result<(), String>
+{
+    let ext = file.extension().unwrap_or("".as_ref()).to_str().unwrap_or("");
+    let relative = diff_paths(&file, &base).ok_or("Cannot unwrap path")?;
+    let thumb = base.join(DOT_PATH).join(relative)
+        .with_extension(format!("thumb.{}", ext));
+
+    if thumb.is_file() {
+        match (thumb.metadata(), file.metadata()) {
+            // Thumbnail already up to date
+            (Ok(tm), Ok(fm)) => if tm.mtime() >= fm.mtime() { return Ok(()) },
+            _ => {}
+        }
+    }
+
+    // Generate new thumbnail
+    println!("Generating thumbnail for {}\nto {}", file.display(), thumb.display());
+
+    Ok(())
+}
+
+fn generate(base: PathBuf, dir: PathBuf)
+{
+    // Check if already up-to-date
+}