Remove custom_llm_provider as it's not needed

Author: Motta Kin

docs/models/openai.md

@@ -568,6 +568,8 @@ print(result.output)
 
 To use [LiteLLM](https://www.litellm.ai/), set the configs as outlined in the [doc](https://docs.litellm.ai/docs/set_keys). In `LiteLLMProvider`, you can pass `api_base` and `api_key`. The value of these configs will depend on your setup. For example, if you are using OpenAI models, then you need to pass `https://api.openai.com/v1` as the `api_base` and your OpenAI API key as the `api_key`. If you are using a LiteLLM proxy server running on your local machine, then you need to pass `http://localhost:<port>` as the `api_base` and your LiteLLM API key (or a placeholder) as the `api_key`.
 
+To use custom LLMs, use `custom/` prefix in the model name.
+
 Once you have the configs, use the [`LiteLLMProvider`][pydantic_ai.providers.litellm.LiteLLMProvider] as follows:
 
 ```python

pydantic_ai_slim/pydantic_ai/providers/litellm.py

@@ -87,7 +87,6 @@ def __init__(
         *,
         api_key: str | None = None,
         api_base: str | None = None,
-        custom_llm_provider: str | None = None,
     ) -> None: ...
 
     @overload
@@ -96,7 +95,6 @@ def __init__(
         *,
         api_key: str | None = None,
         api_base: str | None = None,
-        custom_llm_provider: str | None = None,
         http_client: AsyncHTTPClient,
     ) -> None: ...
 
@@ -108,7 +106,6 @@ def __init__(
         *,
         api_key: str | None = None,
         api_base: str | None = None,
-        custom_llm_provider: str | None = None,
         openai_client: AsyncOpenAI | None = None,
         http_client: AsyncHTTPClient | None = None,
     ) -> None:
@@ -117,7 +114,6 @@ def __init__(
         Args:
             api_key: API key for the model provider. If None, LiteLLM will try to get it from environment variables.
             api_base: Base URL for the model provider. Use this for custom endpoints or self-hosted models.
-            custom_llm_provider: Custom LLM provider name for LiteLLM. Use this if LiteLLM can't auto-detect the provider.
             openai_client: Pre-configured OpenAI client. If provided, other parameters are ignored.
             http_client: Custom HTTP client to use.
         """

tests/providers/test_litellm.py

@@ -22,11 +22,6 @@ def test_init_with_api_config():
     assert provider.client.api_key == 'test-key'
 
 
-def test_init_with_custom_llm_provider():
-    provider = LiteLLMProvider(api_key='test-key', custom_llm_provider='anthropic')
-    assert provider.name == 'litellm'
-
-
 def test_init_without_api_key():
     provider = LiteLLMProvider()
     assert provider.name == 'litellm'