diff --git a/backend/src/api.js b/backend/src/api.js
index c55c85e..970fc7e 100644
--- a/backend/src/api.js
+++ b/backend/src/api.js
@@ -51,15 +51,15 @@ router.get("/healthcheck", (req, res) => {
  *               input_method: 1
  */
 router.post("/users", async (req, res) => {
-    const { username, input_method = 0 } = req.body;
-
     const [result] = await pool.query(
-        "INSERT INTO users (username, input_method) VALUES (?, ?)",
+        `INSERT INTO users (username, input_method) 
+         VALUES (?, ?)
+         ON DUPLICATE KEY UPDATE id = LAST_INSERT_ID(id)`,
         [username, input_method]
     );
 
     const [userRow] = await pool.query("SELECT * FROM users WHERE id = ?", [result.insertId]);
-    res.status(201).json(userRow[0]);
+    res.status(200).json(userRow[0]);
 });
 
 /**
diff --git a/backend/src/db.js b/backend/src/db.js
index f54a33f..abba8da 100644
--- a/backend/src/db.js
+++ b/backend/src/db.js
@@ -23,7 +23,7 @@ const migrations = [
       await conn.query(`
         CREATE TABLE users (
           id INT PRIMARY KEY AUTO_INCREMENT,
-          username VARCHAR(32),
+          username VARCHAR(32) UNIQUE,
           input_method INT
         )
       `);
diff --git a/backend/src/index.js b/backend/src/index.js
index 6d9dc5b..6ca2ed7 100644
--- a/backend/src/index.js
+++ b/backend/src/index.js
@@ -11,6 +11,7 @@ import { fileURLToPath } from 'url';
 
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.join(path.dirname(__filename), ".."); // going back a dir cuz code is in src/
+
 const app = express();
 const specs = swaggerJsdoc({
   definition: {