No client found for model (Anthropic)

[britannio]

Setup

uv init && uv venv && source .venv/bin/activate && uv add -U "ell-ai[all]"

Code

import ell
print(ell.__version__)
@ell.simple("claude-3-5-sonnet-latest", max_tokens=1000)
def language_comparison():
    return "Python vs Mojo?"
print(language_comparison())

Logs

Using python main.py

0.0.15
WARNING: Model `claude-3-5-sonnet-latest` is used by LMP `language_comparison` but no client could be found that supports `claude-3-5-sonnet-latest`. Defaulting to use the OpenAI client `None` for `claude-3-5-sonnet-latest`. This is likely because you've spelled the model name incorrectly or are using a newer model from a provider added after this ell version was released. 
                            
* If this is a mistake either specify a client explicitly in the decorator:
```python
import ell
ell.simple(model, client=my_client)
def language_comparison(...):
    ...
```
or explicitly specify the client when the calling the LMP:

```python
ell.simple(model, client=my_client)(...)
```

Traceback (most recent call last):
  File "/private/tmp/ell-repro/main.py", line 6, in <module>
    print(language_comparison())
          ^^^^^^^^^^^^^^^^^^^^^
  File "/private/tmp/ell-repro/.venv/lib/python3.12/site-packages/ell/lmp/_track.py", line 70, in tracked_func
    res = func_to_track(
          ^^^^^^^^^^^^^^
  File "/private/tmp/ell-repro/.venv/lib/python3.12/site-packages/ell/lmp/complex.py", line 53, in model_call
    merged_client = _client_for_model(model, client or default_client_from_decorator)
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/private/tmp/ell-repro/.venv/lib/python3.12/site-packages/ell/lmp/complex.py", line 126, in _client_for_model
    raise ValueError(f"No client found for model '{model}'. Ensure the model is registered using 'register_model' in 'config.py' or specify a client directly using the 'client' argument in the decorator or function call.")
ValueError: No client found for model 'claude-3-5-sonnet-latest'. Ensure the model is registered using 'register_model' in 'config.py' or specify a client directly using the 'client' argument in the decorator or function call.

[apandy02]

I can reproduce this problem with the setup specifed, but not on master... hmm

[apandy02]

After logging the exception raised during model registration:
Failed to create default Anthropic client: Client.__init__() got an unexpected keyword argument 'proxies'

I did some digging, and the issue comes from httpx. If you downgrade to httpx < 0.28, this problem should be resolved. I think we should closing this issue for now since it is not ell related. @alex-dixon