Success Status Codes (2xx) ✅

Success codes indicate that the request was successful. They range from 200-299.

Common Success Codes

200 OK

The request succeeded and returned data.

@app.get("/items/{item_id}")
async def get_item(item_id: int):
    # Default - 200 OK
    return {"id": item_id, "name": "Item"}

201 Created

A new resource was created successfully.

@app.post("/users", status_code=201)
async def create_user(user: dict):
    # 201 indicates a new resource was created
    return {"id": 1, **user}

204 No Content

The request succeeded but there's no content to return.

@app.delete("/users/{user_id}", status_code=204)
async def delete_user(user_id: int):
    # Delete successful, no response body
    return None

Success Code Comparison

Using Status Codes

from fastapi import status

# Explicit status code
@app.post("/items", status_code=status.HTTP_201_CREATED)
async def create_item(item: dict):
    return item

# Return data with custom status
@app.post("/process", status_code=status.HTTP_202_ACCEPTED)
async def process_data(data: dict):
    # 202 = request accepted but still processing
    return {"status": "processing"}

🔑 Key Takeaways

• ✅ 200 = OK (most common)

• ✅ 201 = Created (new resource)

• ✅ 204 = No Content (success, no data)

• ✅ Use status_code parameter in decorators

• ✅ Codes guide client behavior