By default it will listen on the IP address `127.0.0.1`, which is the IP for your machine to communicate with itself alone (`localhost`).

## `fastapi run`

When you run `fastapi run`, it will run on production mode by default.

It will have **auto-reload disabled** by default.

Then create a file `traefik.toml` with:

```TOML hl_lines="3"
[entryPoints]
  [entryPoints.http]
    address = ":9999"

[providers]
  [providers.file]
    filename = "routes.toml"
```

This tells Traefik to listen on port 9999 and to use another file `routes.toml`.

!!! tip

### Worker Processes and Ports

Remember from the docs [About HTTPS](https.md){.internal-link target=_blank} that only one process can be listening on one combination of port and IP address in a server?

This is still true.

* Update and simplify translations docs. PR [#1171](https://github.com/tiangolo/fastapi/pull/1171).
* Update development of FastAPI docs, set address to `127.0.0.1` to improve Windows support. PR [#1169](https://github.com/tiangolo/fastapi/pull/1169) by [@mariacamilagl](https://github.com/mariacamilagl).

## Dépendances facultatives

Utilisées par Pydantic:

* <a href="https://github.com/JoshData/python-email-validator" target="_blank"><code>email_validator</code></a> - pour la validation des adresses email.

Utilisées par Starlette :

* <a href="https://requests.readthedocs.io" target="_blank"><code>requests</code></a> - Obligatoire si vous souhaitez utiliser `TestClient`.

⤴️ ✍ 📁 `traefik.toml` ⏮️:

```TOML hl_lines="3"
[entryPoints]
  [entryPoints.http]
    address = ":9999"

[providers]
  [providers.file]
    filename = "routes.toml"
```

👉 💬 Traefik 👂 🔛 ⛴ 9️⃣9️⃣9️⃣9️⃣ & ⚙️ ➕1️⃣ 📁 `routes.toml`.

!!! tip

然后创建包含如下内容的 `traefik.toml` 文件：

```TOML hl_lines="3"
[entryPoints]
  [entryPoints.http]
    address = ":9999"

[providers]
  [providers.file]
    filename = "routes.toml"
```

这个文件把 Traefik 监听端口设置为 `9999`，并设置要使用另一个文件 `routes.toml`。

!!! tip "提示"