---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

{!../../../docs_src/openapi_callbacks/tutorial001.py!}
```

There are 2 main differences from a normal *path operation*:

* It doesn't need to have any actual code, because your app will never call this code. It's only used to document the *external API*. So, the function could just have `pass`.

| HOST_PROBE_SNAT_IPV6 | "fd16:9254:7127:1337:ffff:ffff:ffff:ffff" | IPv6 link local ranges are designed to be collision-resistant by default, and so this probably never needs to be overridden |

## Sidecar Mode Implementation Details

Istio CNI injection is currently based on the same Pod annotations used in init-container/inject mode.

### Selection API

Muthuraman, Kbhute-Ibm, khanhlvg, Koock Yoon, kstuedem, Kyuwon Kim, Lakshay
Tokas, leike666666, leonard951, Leslie-Fang, Leslie-Fang-Intel, Li, Guizi, Lukas
Folle, Lukas Geiger, Mahmoud Abuzaina, Manraj Singh Grover, Margaret
Maynard-Reid, Mark Ryan, Matt Conley, Matthew Bentham, Matthew Denton, mbhuiyan,
mdfaijul, Mei Jie, merturl, MichaelKonobeev, Michal W. Tarnowski, minds, mpppk,

- Secure File Transfer Protocol (SFTP) – Defined by the Internet Engineering Task Force (IETF) as an
  extended version of SSH 2.0, allowing file transfer over SSH and for use with Transport Layer
  Security (TLS) and VPN applications.

- File Transfer Protocol over SSL/TLS (FTPS) – Encrypted FTP communication via TLS certificates.

- File Transfer Protocol (FTP) – Defined by RFC114 originally, and replaced by RFC765 and RFC959

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"

And of course, the same machine would probably have **other processes** running as well, apart from your application.

An interesting detail is that the percentage of the **CPU used** by each process can **vary** a lot over time, but the **memory (RAM)** normally stays more or less **stable**.

---

"_I’m over the moon excited about **FastAPI**. It’s so fun!_"