Sync fastapi docs from 3e8d1526 on 2026-08-11

docs/en/docs/fastapi-cli.md

@@ -2,7 +2,7 @@
 
 **FastAPI <abbr title="command line interface">CLI</abbr>** is a command line program that you can use to serve your FastAPI app, manage your FastAPI project, and more.
 
-When you install FastAPI (e.g. with `pip install "fastapi[standard]"`), it comes with a command line program you can run in the terminal.
+When you add FastAPI to your project (e.g. with `uv add "fastapi[standard]"`), it comes with a command line program you can run in the terminal.
 
 To run your FastAPI app for development, you can use the `fastapi dev` command:
 
@@ -52,7 +52,7 @@ For production you would use `fastapi run` instead of `fastapi dev`. 🚀
 
 ///
 
-Internally, **FastAPI CLI** uses [Uvicorn](https://www.uvicorn.dev), a high-performance, production-ready, ASGI server. 😎
+Internally, **FastAPI CLI** uses [Uvicorn](https://uvicorn.dev), a high-performance, production-ready, ASGI server. 😎
 
 The `fastapi` CLI will try to detect automatically the FastAPI app to run, assuming it's an object called `app` in a file `main.py` (or a couple other variants).
 
@@ -100,13 +100,13 @@ from backend.main import app
 You can also pass the file path to the `fastapi dev` command, and it will guess the FastAPI app object to use:
 
 ```console
-$ fastapi dev main.py
+$ uv run fastapi dev main.py
 ```
 
 Or, you can also pass the `--entrypoint` option to the `fastapi dev` command:
 
 ```console
-$ fastapi dev --entrypoint main:app
+$ uv run fastapi dev --entrypoint main:app
 ```
 
 But you would have to remember to pass the correct path\entrypoint every time you call the `fastapi` command.
@@ -119,6 +119,10 @@ Running `fastapi dev` initiates development mode.
 
 By default, **auto-reload** is enabled, automatically reloading the server when you make changes to your code. This is resource-intensive and could be less stable than when it's disabled. You should only use it for development. It also listens on the IP address `127.0.0.1`, which is the IP for your machine to communicate with itself alone (`localhost`).
 
+Before importing your app, `fastapi dev` sets the `FASTAPI_ENV` environment variable to `development`. If `FASTAPI_ENV` is already set, its existing value is preserved. This lets app startup code choose development-friendly behavior while allowing you to provide an app-specific environment such as `staging`.
+
+The conventional `FASTAPI_ENV` values are `development` and `production`. `fastapi run` currently leaves `FASTAPI_ENV` unchanged, so set it explicitly if your app needs to detect production mode.
+
 ## `fastapi run` { #fastapi-run }
 
 Executing `fastapi run` starts FastAPI in production mode.