How can I create a FastAPI 2 router with the same prefix?

To create a FastAPI 2 router with the same prefix, you can use the APIRouter class provided by FastAPI and define a common prefix that applies to all routes within that router. Here's a step-by-step guide and example:

1. Create an APIRouter Instance:

First, import the APIRouter class from FastAPI and create an instance. You'll specify the prefix when you create the router.

2. Define Routes within the Router:

Next, use the @router.get(), @router.post(), etc. decorators to define routes that belong to this router. These routes will automatically inherit the specified prefix.

3. Include the Router in your FastAPI Application:

Finally, include the router in your FastAPI application using the app.include_router() method. You do not need to specify the prefix here; it's already defined in the router itself.

4. Example code:

from fastapi import FastAPI, APIRouter

router = APIRouter(prefix="/items")

@router.get("/")
async def read_items():
   return {"message": "List of items"}

@router.get("/{item_id}")
async def read_item(item_id: int):
   return {"item_id": item_id, "message": "Item details"}

app = FastAPI()
app.include_router(router)



5. Explanation:

- We create an APIRouter instance with the prefix /items.
- The read_items endpoint becomes accessible at /items/, and the read_item endpoint at /items/{item_id}.
- We include this router in the main FastAPI app, and all routes defined in this router will get the prefix of /items automatically.

6. Benefits of Using Router:

- Organization: Routers help keep your codebase organized by grouping related endpoints.
- Reusability: You can reuse routers in different parts of your application or even in multiple applications.
- Modularity: Easier to manage and scale your API by dividing it into smaller functional modules.

By using the APIRouter with a defined prefix, you can effectively manage and organize your FastAPI routes, making your code cleaner and easier to maintain.

Learn more about this