# Client

```python
class Client(object)
```

## is\_closed

```python
is_closed(self)
```

Check if the client is closed.

**Returns**

True if the client is closed, False otherwise.

## hello

```python
hello(self)
```

Connect to server and retrieve version information; raise appropriate error for various failures.

**Usage**

```python
client = modal.Client.from_env()
client.hello()
```

## from\_credentials

```python
from_credentials(cls, token_id, token_secret)
```

Constructor based on token credentials; useful for managing Modal on behalf of third-party users.

Also useful when it's necessary to explicitly manage the lifecycle of the client
(e.g. when running Modal in a forked subprocess) — see
[troubleshooting](/docs/guide/troubleshooting#connection-issues-in-forked-processes).

**Parameters**

<Parameter name="token_id" type="str" description="API token ID." />
<Parameter name="token_secret" type="str" description="API token secret." />

**Returns**

An authenticated `Client` with its connection opened.

**Usage**

```python notest
client = modal.Client.from_credentials("my_token_id", "my_token_secret")

modal.Sandbox.create("echo", "hi", client=client, app=app)
```

## from\_oauth\_credentials

```python
from_oauth_credentials(cls, refresh_token, *, oauth_client_id,
    oauth_client_secret=None, oauth_jwt_key=None)
```

Constructor based on OAuth credentials; useful for managing Modal on behalf of third-party users.

**Parameters**

<Parameter name="refresh_token" type="str" description="OAuth refresh token returned by Modal&#x27;s token endpoint." />
<Parameter name="oauth_client_id" type="str" description="Modal-issued OAuth client ID, with an `oc-` prefix." />
<Parameter name="oauth_client_secret" type="str | None" defaultValue="None" description="Modal-issued OAuth client secret, with an `ov-` prefix." />
<Parameter name="oauth_jwt_key" type="str | None" defaultValue="None" description="Unencrypted RSA private key encoded as PEM, with literal or escaped newlines. Requires `modal[oauth]`." />

**Returns**

An authenticated `Client` with its connection opened.

**Usage**

```python notest
client = modal.Client.from_oauth_credentials(
    refresh_token,
    oauth_client_id=oauth_client_id,
    oauth_client_secret=oauth_client_secret,
)

modal.Sandbox.create("echo", "hi", client=client, app=app)
```

## get\_input\_plane\_metadata

```python
get_input_plane_metadata(self, input_plane_region)
```

Get the metadata for the input plane.

**Parameters**

<Parameter name="input_plane_region" type="str" description="The region of the input plane." />

**Returns**

The metadata for the input plane as a list of header/value tuples.