When the URL contains request parameters and the `params` parameter is set, the request parameters in the URL will disappear unexpectedly.

[Kludex]

Originally opened by @2513502304 on 2025-08-05 14:03:35 in encode/httpx

The starting point for issues should usually be a discussion...

https://github.com/encode/httpx/discussions

Possible bugs may be raised as a "Potential Issue" discussion, feature requests may be raised as an "Ideas" discussion. We can then determine if the discussion needs to be escalated into an "Issue" or not.

This will help us ensure that the "Issues" list properly reflects ongoing or needed work on the project.

---

• Initially raised as discussion #...

[Kludex]

Originally posted by @2513502304 on 2025-08-05T14:10:22Z

As shown in the following Python code, my expected output should be to reasonably concatenate the request parameters in params with those in the url. requests handled this part well, but httpx gave the following unexpected output:

import requests
import httpx

url = 'https://safebooru.org/index.php?page=post&s=list'
params = {
    'pid': 0,
    'tags': 'k-on!',
}

response = requests.get(url=url, params=params)
print(response.request.url)  # As expected: https://safebooru.org/index.php?page=post&s=list&pid=0&tags=k-on%21

response = httpx.get(url=url, params=params)
print(response.request.url)  # Unexpectedly, the request parameters in the URL were overridden by params: https://safebooru.org/index.php?pid=0&tags=k-on%21

My httpx version is 0.28.1

[mgedmin]

I've just switched from httpxyz to httpx2 and was surprised by this issue.