raise_for_status param in client constructor

[aeshna-cyanea]

imo it would be convenient if we could tell the client to have raise_for_status() enabled by default on all requests when initializing it

[wellkilo]

This is already achievable with a response event hook, without adding a constructor flag:

import httpx

def raise_on_error(response: httpx.Response) -> None:
    response.raise_for_status()

with httpx.Client(event_hooks={"response": [raise_on_error]}) as client:
    response = client.get("https://example.com")

For AsyncClient the hook must be async:

async def raise_on_error(response: httpx.Response) -> None:
    response.raise_for_status()

async with httpx.AsyncClient(event_hooks={"response": [raise_on_error]}) as client:
    response = await client.get("https://example.com")

Response hooks run after the response headers are available and apply to every request made by that client. This is the documented use case: Event Hooks.

If the hook also needs the error body, explicitly read it first (response.read() / await response.aread()) because a streamed response body may not have been consumed yet. A built-in boolean would still need to answer policy questions such as redirects, 4xx vs 5xx, streaming, and error-body parsing, while the hook expresses those choices directly.