language-learning-app/api/app/outbound/anthropic/anthropic_client.py

import asyncio
import anthropic


class AnthropicClient():
    def __init__(self, api_key: str):
        self._client = anthropic.Anthropic(api_key=api_key)

    @classmethod
    def new(cls, api_key: str) -> "AnthropicClient":
        return cls(api_key)

    def _create_summarise_text_system_prompt(
            self,
            complexity_level: str,
            from_language: str,
            to_language: str,
            length_preference="200-400 words",
    ) -> str:
        return (
            f"You are a language learning content creator.\n"
            f"You generate markdown summaries of user-provided content.\n"
            f"You will provide content in {to_language} at {complexity_level} proficiency level on the CEFR scale.\n"
            f"The text you generate will:\n"
            f"- Contain ONLY the generated summary text in {to_language}.\n"
            f"- Never contain inappropriate (hateful, sexual, violent) content.  It is preferable to return no text than to generate such content.\n"
            f"- Speak directly to the reader/listener, adopting the tone and style of a semi-formal news reporter or podcaster.\n"
            f"- Where appropriate (fluency level, content), use a small number of idiomatic expressions.\n"
            f"- Where appropriate use at least one additional tense, beyond the default of the content.\n"
            f"- Be formatted in markdown.  Contain a single level 1 header (#) at the top, followed by paragraphs and line breaks.\n"
            f"- Be around {length_preference} long.\n"
            f"- Be inspired by the content, but not the tone, of the source material."
        )

    def _create_prompt_summarise_text(
            self,
            source_material: str,
    ) -> str:
        return (
            f"Source material follows: \n\n"
            f"{source_material}"
        )

    async def generate_summary_text(
            self,
            content_to_summarise: str,
            complexity_level: str,
            from_language: str,
            to_language: str,
            length_preference="200-400 words") -> str:
        """Generate text using Anthropic."""
        def _call() -> str:
            message = self._client.messages.create(
                model="claude-sonnet-4-6",
                max_tokens=1024,
                system=self._create_summarise_text_system_prompt(
                    complexity_level=complexity_level,
                    from_language=from_language,
                    to_language=to_language,
                    length_preference=length_preference,
                ),
                messages=[
                    {
                        "role": "user",
                        "content": self._create_prompt_summarise_text(
                            content_to_summarise
                        )
                    }
                ],
            )
            return message.content[0].text

        return await asyncio.to_thread(_call)