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# CLI Arguments with Environment Variables
You can also configure a *CLI argument* to read a value from an environment variable if it is not provided in the command line as a *CLI argument*.
/// tip
You can learn more about environment variables in the [Environment Variables](../../environment-variables.md){.internal-link target=_blank} page.
///
To do that, use the `envvar` parameter for `typer.Argument()`:
{* docs_src/arguments/envvar/tutorial001_an.py hl[5] *}
In this case, the *CLI argument* `name` will have a default value of `"World"`, but will also read any value passed to the environment variable `AWESOME_NAME` if no value is provided in the command line:
<div class="termy">
```console
// Check the help
$ python main.py --help
Usage: main.py [OPTIONS] [NAME]
Arguments:
[NAME] [env var: AWESOME_NAME;default: World]
Options:
--help Show this message and exit.
// Call it without a CLI argument
$ python main.py
Hello Mr. World
// Now pass a value for the CLI argument
$ python main.py Czernobog
Hello Mr. Czernobog
// And now use the environment variable
$ AWESOME_NAME=Wednesday python main.py
Hello Mr. Wednesday
// CLI arguments take precedence over env vars
$ AWESOME_NAME=Wednesday python main.py Czernobog
Hello Mr. Czernobog
```
</div>
## Multiple environment variables
You are not restricted to a single environment variable, you can declare a list of environment variables that could be used to get a value if it was not passed in the command line:
{* docs_src/arguments/envvar/tutorial002_an.py hl[6] *}
Check it:
<div class="termy">
```console
// Check the help
$ python main.py --help
Usage: main.py [OPTIONS] [NAME]
Arguments:
[NAME] [env var: AWESOME_NAME, GOD_NAME;default: World]
Options:
--help Show this message and exit.
// Try the first env var
$ AWESOME_NAME=Wednesday python main.py
Hello Mr. Wednesday
// Try the second env var
$ GOD_NAME=Anubis python main.py
Hello Mr. Anubis
```
</div>
## Hide an env var from the help text
By default, environment variables used will be shown in the help text, but you can disable them with `show_envvar=False`:
{* docs_src/arguments/envvar/tutorial003_an.py hl[7] *}
Check it:
<div class="termy">
```console
//Check the help
$ python main.py --help
// It won't show the env var
Usage: main.py [OPTIONS] [NAME]
Arguments:
[NAME] [default: World]
Options:
--help Show this message and exit.
// But it will still be able to use it
$ AWESOME_NAME=Wednesday python main.py
Hello Mr. Wednesday
```
</div>
/// note | Technical Details
In Click applications the env vars are hidden by default. 🙈
In **Typer** these env vars are shown by default. 👀
///
|
