```Python hl_lines="3"
{!../../../docs_src/behind_a_proxy/tutorial002.py!}
```

Passing the `root_path` to `FastAPI` would be the equivalent of passing the `--root-path` command line option to Uvicorn or Hypercorn.

### About `root_path`

### Step 3: create a *path operation*

#### Path

"Path" here refers to the last part of the URL starting from the first `/`.

So, in a URL like:

```
https://example.com/items/foo
```

...the path would be:

```
/items/foo
```

!!! info
    A "path" is also commonly called an "endpoint" or a "route".

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> run <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>
<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>

from .param_functions import Depends as Depends
from .param_functions import File as File
from .param_functions import Form as Form
from .param_functions import Header as Header
from .param_functions import Path as Path
from .param_functions import Query as Query
from .param_functions import Security as Security
from .requests import Request as Request
from .responses import Response as Response
from .routing import APIRouter as APIRouter

* Fix support for *paths* in *path parameters* without needing explicit `Path(...)`.
    * PR [#256](https://github.com/tiangolo/fastapi/pull/256).
    * Documented in PR [#272](https://github.com/tiangolo/fastapi/pull/272) by [@wshayes](https://github.com/wshayes).
    * New documentation at: [Path Parameters containing paths](https://fastapi.tiangolo.com/tutorial/path-params/#path-parameters-containing-paths).

"docs_src/dependencies/tutorial010.py" = ["F821"]
"docs_src/custom_response/tutorial007.py" = ["B007"]
"docs_src/dataclasses/tutorial003.py" = ["I001"]
"docs_src/path_operation_advanced_configuration/tutorial007.py" = ["B904"]
"docs_src/path_operation_advanced_configuration/tutorial007_pv1.py" = ["B904"]
"docs_src/custom_request_and_route/tutorial002.py" = ["B904"]
"docs_src/dependencies/tutorial008_an.py" = ["F821"]

And still, you would probably not want the application to stay dead because there was an error in one place, you probably want it to **continue running** at least for the *path operations* that are not broken.

### Restart After Crash

```Python hl_lines="3  25"
{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

### Create the callback *path operation*

To create the callback *path operation* use the same `APIRouter` you created above.

It should look just like a normal FastAPI *path operation*:

* It should probably have a declaration of the body it should receive, e.g. `body: InvoiceEvent`.

Notice that with webhooks you are actually not declaring a *path* (like `/items/`), the text you pass there is just an **identifier** of the webhook (the name of the event), for example in `@app.webhooks.post("new-subscription")`, the webhook name is `new-subscription`.

This is because it is expected that **your users** would define the actual **URL path** where they want to receive the webhook request in some other way (e.g. a web dashboard).

  - learn/index.md
  - python-types.md
  - async.md
  - Tutorial - User Guide:
    - tutorial/index.md
    - tutorial/first-steps.md
    - tutorial/path-params.md
    - tutorial/query-params.md
    - tutorial/body.md
    - tutorial/query-params-str-validations.md
    - tutorial/path-params-numeric-validations.md
    - tutorial/body-multiple-params.md
    - tutorial/body-fields.md
    - tutorial/body-nested-models.md