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backend/app/services/llm/claude_vision.py

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+"""Anthropic Claude Vision provider."""
+
+import base64
+import json
+import re
+from anthropic import AsyncAnthropic
+
+from app.config import get_settings
+from app.schemas.transaction import TransactionExtractItem
+from app.services.llm.base import BaseLLMProvider
+from app.prompts.extract_transaction import get_extract_messages
+from app.services.llm.openai_vision import _parse_json_array
+
+
+class ClaudeVisionProvider(BaseLLMProvider):
+    async def extract_from_image(self, image_bytes: bytes) -> list[TransactionExtractItem]:
+        settings = get_settings()
+        if not settings.anthropic_api_key:
+            raise ValueError("ANTHROPIC_API_KEY is not set")
+        client = AsyncAnthropic(api_key=settings.anthropic_api_key)
+        b64 = base64.standard_b64encode(image_bytes).decode("ascii")
+        messages = get_extract_messages(b64)
+        # Claude API: user message with content block list
+        user_content = messages[1]["content"]
+        content_blocks = []
+        for block in user_content:
+            if block["type"] == "text":
+                content_blocks.append({"type": "text", "text": block["text"]})
+            elif block["type"] == "image_url":
+                # Claude expects base64 without data URL prefix
+                content_blocks.append({
+                    "type": "image",
+                    "source": {
+                        "type": "base64",
+                        "media_type": "image/jpeg",
+                        "data": block["image_url"]["url"].split(",", 1)[-1],
+                    },
+                })
+        response = await client.messages.create(
+            model=settings.anthropic_model,
+            max_tokens=4096,
+            system=messages[0]["content"],
+            messages=[{"role": "user", "content": content_blocks}],
+        )
+        text = ""
+        for block in response.content:
+            if hasattr(block, "text"):
+                text += block.text
+        return _parse_json_array(text or "[]")