diff --git a/GuruChandra/__pycache__/day2.cpython-313.pyc b/GuruChandra/__pycache__/day2.cpython-313.pyc
new file mode 100644
index 00000000..38aa1e66
Binary files /dev/null and b/GuruChandra/__pycache__/day2.cpython-313.pyc differ
diff --git a/GuruChandra/__pycache__/day4.cpython-313.pyc b/GuruChandra/__pycache__/day4.cpython-313.pyc
new file mode 100644
index 00000000..582deabb
Binary files /dev/null and b/GuruChandra/__pycache__/day4.cpython-313.pyc differ
diff --git a/GuruChandra/__pycache__/day5.cpython-313.pyc b/GuruChandra/__pycache__/day5.cpython-313.pyc
new file mode 100644
index 00000000..52ee3bb3
Binary files /dev/null and b/GuruChandra/__pycache__/day5.cpython-313.pyc differ
diff --git a/GuruChandra/day4.py b/GuruChandra/day4.py
new file mode 100644
index 00000000..7a3fa0c1
--- /dev/null
+++ b/GuruChandra/day4.py
@@ -0,0 +1,25 @@
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+# Structure of the incoming JSON data
+class UserData(BaseModel):
+    name: str
+    age: int
+
+@app.get("/")
+def home():
+    return {"message": "Day 4: API Testing with POSTMAN"}
+
+@app.post("/user-info")
+def create_user(user: UserData):
+    # This function accepts a JSON object matching the UserData model
+    return {
+        "status": "Success",
+        "received_data": {
+            "name": user.name,
+            "age": user.age
+        },
+        "message": f"Hello {user.name}, you are {user.age} years old!"
+    }
\ No newline at end of file
diff --git a/GuruChandra/day5.py b/GuruChandra/day5.py
new file mode 100644
index 00000000..c56a1d70
--- /dev/null
+++ b/GuruChandra/day5.py
@@ -0,0 +1,30 @@
+from fastapi import FastAPI
+from fastapi.responses import JSONResponse
+
+app = FastAPI(title="Calculator API")
+
+@app.get("/")
+def home():
+    return {"message": "Welcome to Calculator API"}
+
+@app.get("/add")
+def add(a: float, b: float):
+    result = a + b
+    return {"operation": "addition", "a": a, "b": b, "result": result}
+
+@app.get("/subtract")
+def subtract(a: float, b: float):
+    result = a - b
+    return {"operation": "subtraction", "a": a, "b": b, "result": result}
+
+@app.get("/multiply")
+def multiply(a: float, b: float):
+    result = a * b
+    return {"operation": "multiplication", "a": a, "b": b, "result": result}
+
+@app.get("/divide")
+def divide(a: float, b: float):
+    if b == 0:
+        return JSONResponse(status_code=400, content={"error": "Cannot divide by zero"})
+    result = a / b
+    return {"operation": "division", "a": a, "b": b, "result": result}
\ No newline at end of file