diff --git a/.env b/.env
index 644bd22..a396b77 100644
--- a/.env
+++ b/.env
@@ -1 +1 @@
-DEFAULT_DB_PATH=test
+DEFAULT_DB_PATH=test.db
diff --git a/src/modules/mod.rs b/src/modules/mod.rs
index 2ee385a..838bce4 100644
--- a/src/modules/mod.rs
+++ b/src/modules/mod.rs
@@ -1,2 +1,2 @@
 pub mod config;
-pub mod database;
+pub mod source;
diff --git a/src/modules/source/mod.rs b/src/modules/source/mod.rs
index 28b5008..70c4e9e 100644
--- a/src/modules/source/mod.rs
+++ b/src/modules/source/mod.rs
@@ -1,11 +1,60 @@
-pub struct Database {
+#[derive(Clone, Copy)]
+pub struct Word(String, String);
+
+pub struct FileDatabase {
     path: String,
+    cached_words: Option<Vec<Word>>,
 }
 
 // TruthSource
 pub trait WordSource {
-    fn find_word(&self, word: &str) -> Result<(), ()>;
-    fn insert_word(&self, word: &str) -> Result<(), ()>;
+    fn load(&self) -> Result<(), ()>;
+    fn find_word(&self, word: &str) -> Result<Word, ()>;
+    fn insert_word(&mut self, word: Word) -> Result<(), ()>;
     fn remove_word(&self, word: &str) -> Result<(), ()>;
-    fn get_all_words(&self) -> Vec<String>;
+    fn edit_word(&mut self, word: Word) -> Result<(), ()>;
+    fn get_all_words(&self) -> Vec<Word>;
+}
+
+impl WordSource for FileDatabase {
+    fn load(&self) -> Result<(), ()> {}
+
+    fn find_word(&self, word: &str) -> Result<Word, ()> {
+        if let Some(words) = &self.cached_words {
+            if let Some(w) = words.into_iter().find(|&w| word == w.0) {
+                return Ok(w.clone());
+            }
+        }
+        // TODO: implement db alternative access
+        Err(())
+    }
+
+    fn insert_word(&mut self, word: Word) -> Result<(), ()> {
+        self.cached_words.get_or_insert(vec![]).push(word);
+        // TODO: insert into db
+        Ok(())
+    }
+
+    fn edit_word(&mut self, word: Word) -> Result<(), ()> {
+        if let Some(w) = self
+            .cached_words
+            .get_or_insert(vec![])
+            .iter()
+            .find(|&w| w.0 == word.0)
+        {
+            // ...
+        }
+        Ok(())
+    }
+
+    fn remove_word(&self, word: &str) -> Result<(), ()> {}
+
+    fn get_all_words(&self) -> Vec<Word> {
+        if let Some(words) = self.cached_words {
+            words
+        } else {
+            // Check db
+            ()
+        }
+    }
 }