# Environments

> Select the STX exchange the client connects to.

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

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

| Exchange | `Region`, `Environment` | `region`, `env` |
|---|---|---|
| STX US demo | `STXRegion.US`, `STXEnvironment.Demo` | `us`, `demo` |
| STX Ontario demo | `STXRegion.Ontario`, `STXEnvironment.Demo` | `ontario`, `demo` |
| STX Ontario | `STXRegion.Ontario`, `STXEnvironment.Production` | `ontario`, `production` |

```csharp
using var client = new STXClient(new STXClientOptions
{
    Region = STXRegion.US,
    Environment = STXEnvironment.Demo,
    KeyId = keyId,
    PrivateKey = privateKey,
});
```

An API key works on one exchange only, so keep one credentials profile per exchange and switch with `Profile`.

To reach any other host, such as a local server, set `Host = "http://localhost:4000"` (or `STX_HOST`). The URL's scheme is kept for both HTTP and the socket. `VerifyTls = false` accepts a self-signed certificate; use it only locally.