---
title: base
sidebarTitle: base
---

# `prefect.client.base`

## Functions

### `app_lifespan_context` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L63" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
app_lifespan_context(app: ASGIApp) -> AsyncGenerator[None, None]
```


A context manager that calls startup/shutdown hooks for the given application.

Lifespan contexts are cached per application to avoid calling the lifespan hooks
more than once if the context is entered in nested code. A no-op context will be
returned if the context for the given application is already being managed.

This manager is robust to concurrent access within the event loop. For example,
if you have concurrent contexts for the same application, it is guaranteed that
startup hooks will be called before their context starts and shutdown hooks will
only be called after their context exits.

A reference count is used to support nested use of clients without running
lifespan hooks excessively. The first client context entered will create and enter
a lifespan context. Each subsequent client will increment a reference count but will
not create a new lifespan context. When each client context exits, the reference
count is decremented. When the last client context exits, the lifespan will be
closed.

In simple nested cases, the first client context will be the one to exit the
lifespan. However, if client contexts are entered concurrently they may not exit
in a consistent order. If the first client context was responsible for closing
the lifespan, it would have to wait until all other client contexts to exit to
avoid firing shutdown hooks while the application is in use. Waiting for the other
clients to exit can introduce deadlocks, so, instead, the first client will exit
without closing the lifespan context and reference counts will be used to ensure
the lifespan is closed once all of the clients are done.


### `determine_server_type` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L672" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
determine_server_type() -> ServerType
```


Determine the server type based on the current settings.

**Returns:**
- - `ServerType.EPHEMERAL` if the ephemeral server is enabled
- - `ServerType.SERVER` if a API URL is configured and it is not a cloud URL
- - `ServerType.CLOUD` if an API URL is configured and it is a cloud URL
- - `ServerType.UNCONFIGURED` if no API URL is configured and ephemeral mode is
not enabled


## Classes

### `ASGIApp` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L58" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

### `PrefectResponse` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L146" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Prefect wrapper for the `httpx.Response` class.

Provides more informative error messages.


**Methods:**

#### `from_httpx_response` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L166" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
from_httpx_response(cls: type[Self], response: httpx.Response) -> Response
```

Create a `PrefectResponse` from an `httpx.Response`.

By changing the `__class__` attribute of the Response, we change the method
resolution order to look for methods defined in PrefectResponse, while leaving
everything else about the original Response instance intact.


#### `raise_for_status` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L153" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
raise_for_status(self) -> Response
```

Raise an exception if the response contains an HTTPStatusError.

The `PrefectHTTPStatusError` contains useful additional information that
is not contained in the `HTTPStatusError`.


### `PrefectHttpxAsyncClient` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L179" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Prefect wrapper for the async httpx client with support for retry-after headers
for the provided status codes (typically 429, 502 and 503).

Additionally, this client will always call `raise_for_status` on responses.

For more details on rate limit headers, see:
[Configuring Cloudflare Rate Limiting](https://support.cloudflare.com/hc/en-us/articles/115001635128-Configuring-Rate-Limiting-from-UI)


**Methods:**

#### `send` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L335" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
send(self, request: Request, *args: Any, **kwargs: Any) -> Response
```

Send a request with automatic retry behavior for the following status codes:

- 403 Forbidden, if the request failed due to CSRF protection
- 408 Request Timeout
- 429 CloudFlare-style rate limiting
- 502 Bad Gateway
- 503 Service unavailable
- Any additional status codes provided in `PREFECT_CLIENT_RETRY_EXTRA_CODES`


### `PrefectHttpxSyncClient` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L422" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Prefect wrapper for the async httpx client with support for retry-after headers
for the provided status codes (typically 429, 502 and 503).

Additionally, this client will always call `raise_for_status` on responses.

For more details on rate limit headers, see:
[Configuring Cloudflare Rate Limiting](https://support.cloudflare.com/hc/en-us/articles/115001635128-Configuring-Rate-Limiting-from-UI)


**Methods:**

#### `send` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L578" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
send(self, request: Request, *args: Any, **kwargs: Any) -> Response
```

Send a request with automatic retry behavior for the following status codes:

- 403 Forbidden, if the request failed due to CSRF protection
- 408 Request Timeout
- 429 CloudFlare-style rate limiting
- 502 Bad Gateway
- 503 Service unavailable
- Any additional status codes provided in `PREFECT_CLIENT_RETRY_EXTRA_CODES`


### `ServerType` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/client/base.py#L665" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

**Methods:**

#### `auto` <sup><a href="https://github.com/PrefectHQ/prefect/blob/main/src/prefect/utilities/collections.py#L69" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>

```python
auto() -> str
```

Exposes `enum.auto()` to avoid requiring a second import to use `AutoEnum`

