# Environments

> Select the STX exchange the client connects to.

Source: https://docs.stxapp.io/sdks/python/environments/

The exchanges, their hosts and which one to start with are listed on [Environments](/environments/). In the SDK, pick one with `region` and `env` (as keyword arguments, as `STX_REGION` and `STX_ENV`, or in a credentials profile):

| Exchange | `region` | `env` |
|---|---|---|
| STX US demo | `"us"` | `"demo"` |
| STX Ontario demo | `"ontario"` | `"demo"` |
| STX Ontario | `"ontario"` | `"production"` |

```python
from stx import STX, Environment, Region

with STX(region="us", env="demo") as client:
    print(client.base_url, client.socket_url)

# same exchange:
same = STX(region=Region.US, env=Environment.DEMO)
same.close()
```

`env` also accepts `"prod"` and `"live"` for production.

An API key works on one exchange only, so keep one credentials profile per exchange and switch with `profile`; see [Authentication](/sdks/python/authentication/).

To reach any other host, such as a local server, pass `host="http://localhost:4000"` (or set `STX_HOST`). The URL's scheme is kept for both HTTP and the socket, so `http://` talks plain HTTP and `ws://`. `verify_tls=False` (or `STX_VERIFY_TLS=false`) turns off certificate checks; use it only for a local server.