support claude 4.* models

[jfbloom22]

Claude 4.5 (and Claude Opus 4.1) has a strict API constraint that prevents specifying both temperature and top_p parameters simultaneously.
updated your anthropic/main.py pipe with intelligent parameter handling

Smart Detection: The pipe detects if both parameters are provided by checking if they're different from their defaults
Priority Logic: If both are provided, it prioritizes temperature (most common use case)
Fallback: If only top_p is provided, it uses top_p instead

• Extended Thinking Support for Claude 4.5
• Cache Control
• Beta Features Support
• Enhanced Model Handling
• 6 New Valves

[christian-taillon]

Hello @jfbloom22! Thank you so much for your work on this. The community needs a better go to Anthropic integration that is supported/updated. If this is approved, I'll reach out to Justin to suggest this as a consideration for the update to our Pipe on the Open WebUI community site.

One problem I have with your implementation of Opus4.1 (for all the API token rich out there): Claude Opus 4.1 has the same constraint and returns 400: “temperature and top_p cannot both be specified for this model.” Please gate Opus 4.x the same way as Sonnet 4.5 so only one sampler is sent.

Suggested change:

# Handle temperature/top_p settings
ONE_SAMPLER_PREFIXES = ("claude-sonnet-4-5", "claude-opus-4")

if api_model_name.startswith(ONE_SAMPLER_PREFIXES):
    if is_thinking_model:
        payload.pop("top_p", None)
        payload["temperature"] = 1.0
    elif self.valves.CLAUDE_45_USE_TEMPERATURE:
        payload.pop("top_p", None)
        payload["temperature"] = body.get("temperature", 0.8)
    else:
        payload.pop("temperature", None)
        payload["top_p"] = body.get("top_p", 0.9)
else:
    # Other Claude models support both
    payload["temperature"] = body.get("temperature", 0.8)
    payload["top_p"] = body.get("top_p", 0.9)

This will prevent the 400 on Opus 4.1 while keeping existing behavior for 4.5.

Thank you!

[jfbloom22]

@christian-taillon Thanks for the feedback. I am trying to make this a bit more future proof and as best I can tell Anthropic intends to only support top_p or temperature for all 4.* models. I added a dedicated pattern match:

    def _is_claude_4x_model(self, model_name: str) -> bool:
        """
        Determine if a model is a Claude 4.x generation model that has temperature/top_p constraints.
        Uses a more future-proof approach than simple prefix matching.

        Args:
            model_name: The model name to check

        Returns:
            True if this is a Claude 4.x model with constraints
        """
        import re

        # Pattern to match Claude 4.x models with various version suffixes
        # Examples: claude-opus-4, claude-opus-4-1-20250805, claude-sonnet-4-5, claude-sonnet-4-5-20250929
        # The pattern allows for optional sub-versions (like -1, -5) and dates
        pattern = r"^claude-(opus|sonnet)-4(?:-\d+)?(?:-\d{8})?$"

        return bool(re.match(pattern, model_name))
        ```
        
        What do you think?