diff --git a/koucha/src/lib.rs b/koucha/src/lib.rs
index 4d4a38b..392e221 100644
--- a/koucha/src/lib.rs
+++ b/koucha/src/lib.rs
@@ -5,12 +5,104 @@ use reqwest::{
 };
 use rss::Channel as RawChannel;
 
+type Result<T> = std::result::Result<T, Box<dyn Error>>;
+
+pub struct AdapterOptions {
+  database_url: String,
+}
+
+impl AdapterOptions {
+  pub fn new() -> Self {
+    Self {
+      database_url: "sqlite:test.db".to_string(),
+    }
+  }
+
+  pub fn database_url(mut self, url: &str) -> Self {
+    self.database_url = url.to_string();
+    self
+  }
+
+  pub async fn create(self) -> Result<Adapter> {
+    let db = sqlx::sqlite::SqlitePoolOptions::new()
+      .connect(&self.database_url).await?;
+
+    Ok(Adapter { db })
+  }
+}
+
+pub struct Adapter {
+  db: sqlx::SqlitePool,
+}
+
+impl Adapter {
+  pub async fn get_all_users(&self) -> Result<Vec<User>> {
+      let users_query = sqlx::query!("SELECT id, name FROM users")
+        .fetch_all(&self.db).await?;
+
+      let mut all_users: Vec<User> = Vec::with_capacity(users_query.len());
+
+      for user in users_query {
+        all_users.push(User {
+          id: user.id,
+          name: user.name,
+        })
+      }
+
+      Ok(all_users)
+  }
+
+  fn get_pool(&self) -> &sqlx::SqlitePool { &self.db }
+}
+
+pub struct User {
+  id: i64,
+  name: String,
+}
+
+impl User {
+  pub async fn get_by_id(adapter: &Adapter, id: i64) -> Result<Self> {
+    let user = sqlx::query!("SELECT name FROM users WHERE id = ?", id)
+      .fetch_one(adapter.get_pool()).await?;
+
+    Ok(Self {
+      id: id,
+      name: user.name,
+    })
+  }
+
+  pub async fn create(adapter: &Adapter, name: &str) -> Result<Self> {
+    let result = sqlx::query!("INSERT INTO users (name) VALUES (?)", name)
+      .execute(adapter.get_pool()).await?;
+
+    Ok(Self {
+      id: result.last_insert_rowid(),
+      name: name.to_string()
+    })
+  }
+
+  pub async fn change_name(
+      &mut self, adapter: &Adapter, new_name: &str) -> Result<()> {
+    sqlx::query!(
+      "UPDATE users SET name = ? WHERE id = ?",
+      new_name, self.id
+    ).execute(adapter.get_pool()).await?;
+
+    self.name = new_name.to_string();
+
+    Ok(())
+  }
+
+  pub fn name(&self) -> &str { &self.name }
+  pub fn id(&self) -> i64 { self.id }
+}
+
 pub struct Channel {
   pub channel: rss::Channel,
 }
 
 pub async fn fetch_channel<T: IntoUrl>(
-  client: &Client, url: T) -> Result<Channel, Box<dyn Error>> {
+  client: &Client, url: T) -> Result<Channel> {
   let content = client.get(url)
     .send().await?
     .bytes().await?;