# `APIRouter` class

Here's the reference information for the `APIRouter` class, with all its parameters, attributes and methods.

You can import the `APIRouter` class directly from `fastapi`:

```python
from fastapi import APIRouter
```

::: fastapi.APIRouter
    options:
        members:
            - websocket
            - include_router
            - get
            - put
            - post
            - delete

from typing import Annotated

from fastapi import FastAPI, Path

app = FastAPI()


@app.get("/items/{item_id}")
async def read_items(
    item_id: Annotated[int, Path(title="The ID of the item to get", gt=0, le=1000)],
    q: str,
):
    results = {"item_id": item_id}
    if q:
        results.update({"q": q})

from fastapi import FastAPI
from fastapi.responses import RedirectResponse

app = FastAPI()


@app.get("/teleport")
async def get_teleport() -> RedirectResponse:

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[list[str], Query()] = ["foo", "bar"]):
    query_items = {"q": q}

from fastapi import FastAPI
from fastapi.routing import APIRoute

app = FastAPI()


@app.get("/items/")
async def read_items():
    return [{"item_id": "Foo"}]


def use_route_names_as_operation_ids(app: FastAPI) -> None:
    """
    Simplify operation IDs so that generated API clients have simpler function
    names.

    Should be called only after all routes have been added.
    """
    for route in app.routes:

from datetime import datetime, time, timedelta
from uuid import UUID

from fastapi import Body, FastAPI

app = FastAPI()


@app.put("/items/{item_id}")
async def read_items(
    item_id: UUID,
    start_datetime: datetime = Body(),
    end_datetime: datetime = Body(),
    process_after: timedelta = Body(),
    repeat_at: time | None = Body(default=None),
):
    start_process = start_datetime + process_after

from typing import Annotated

from fastapi import Header, HTTPException


async def get_token_header(x_token: Annotated[str, Header()]):
    if x_token != "fake-super-secret-token":
        raise HTTPException(status_code=400, detail="X-Token header invalid")


async def get_query_token(token: str):
    if token != "jessica":

   */
  void putCoalescing(Range<K> range, V value);

  /** Puts all the associations from {@code rangeMap} into this range map (optional operation). */
  void putAll(RangeMap<K, ? extends V> rangeMap);

  /** Removes all associations from this range map (optional operation). */
  void clear();

  /**
   * Removes all associations from this range map in the specified range (optional operation).
   *

import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

/**
 * Tests that the {@code ClassLoader} of {@link FinalizableReferenceQueue} can be unloaded. These
 * tests are separate from {@link FinalizableReferenceQueueTest} so that they can be excluded from
 * coverage runs, as the coverage system interferes with them.
 *
 * @author Eamonn McManus
 */
@AndroidIncompatible
@GwtIncompatible
@J2ktIncompatible
@RunWith(JUnit4.class)

from fastapi import FastAPI

app = FastAPI()


@app.get("/app")
def read_main():
    return {"message": "Hello World from main app"}


subapi = FastAPI()


@subapi.get("/sub")
def read_sub():
    return {"message": "Hello World from sub API"}