diff --git a/app/gitignore-gen/src/core/error.rs b/app/gitignore-gen/src/core/error.rs
new file mode 100644
index 0000000..ba41c8f
--- /dev/null
+++ b/app/gitignore-gen/src/core/error.rs
@@ -0,0 +1,16 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum AppError {
+    #[error("Configuration error: {message}")]
+    ConfigError { message: String },
+
+    #[error("Template error: {message}")]
+    TemplateError { message: String },
+
+    #[error("IO error: {message}")]
+    IoError { message: String },
+
+    #[error("Unknown error occurred")]
+    Unknown,
+}