Create app.py

app.py

@@ -0,0 +1,57 @@
+from fastapi import FastAPI, HTTPException
+from pydantic import BaseModel
+import json
+from pathlib import Path
+
+app = FastAPI()
+
+# Path to store users (persistent across HF Spaces runs)
+USERS_FILE = Path("users.json")
+
+# Ensure the file exists
+if not USERS_FILE.exists():
+    USERS_FILE.write_text("[]")  # empty list
+
+# Pydantic model for input
+class User(BaseModel):
+    username: str
+    num1: float
+    num2: float
+
+# Helper function to load users
+def load_users():
+    with USERS_FILE.open("r") as f:
+        return json.load(f)
+
+# Helper function to save users
+def save_users(users):
+    with USERS_FILE.open("w") as f:
+        json.dump(users, f, indent=2)
+
+# Endpoint to add user and sum numbers
+@app.post("/add-user")
+def add_user(user: User):
+    users = load_users()
+
+    # Check if username already exists
+    if any(u["username"] == user.username for u in users):
+        raise HTTPException(status_code=400, detail="Username already exists")
+
+    # Add user
+    users.append({
+        "username": user.username,
+        "num1": user.num1,
+        "num2": user.num2,
+        "sum": user.num1 + user.num2
+    })
+    save_users(users)
+
+    return {
+        "message": f"User {user.username} added successfully!",
+        "sum": user.num1 + user.num2
+    }
+
+# Endpoint to list all users
+@app.get("/users")
+def get_users():
+    return load_users()