【AI】Claude APIで会話の途中でツールを変更する方法

import anthropic

client = anthropic.Anthropic()

response = client.beta.messages.create(
    model="claude-opus-5",
    max_tokens=1024,
    betas=["mid-conversation-tool-changes-2026-07-01"],
    tools=[
        {
            "name": "get_weather",
            "description": "指定した都市の現在の天気を返す",
            "input_schema": {
                "type": "object",
                "properties": {
                    "location": {"type": "string", "description": "都市名"},
                },
                "required": ["location"],
            },
        },
    ],
    messages=[
        {"role": "user", "content": "東京の天気を教えて"},
        {"role": "assistant", "content": "東京は晴れです。"},
        {"role": "user", "content": "ありがとう。次はコードレビューを手伝って"},
        {
            "role": "system",
            "content": [
                {
                    "type": "tool_removal",
                    "tool": {"type": "tool_reference", "name": "get_weather"},
                },
            ],
        },
    ],
)

for block in response.content:
    if block.type == "text":
        print(block.text)

tools = [
    {
        "name": "run_sql",
        "description": "分析用DBに対して読み取りクエリを実行する",
        "input_schema": {
            "type": "object",
            "properties": {"query": {"type": "string"}},
            "required": ["query"],
        },
        "defer_loading": True,
    },
]

# 調査フェーズに入ったターンで run_sql を提供する
system_message = {
    "role": "system",
    "content": [
        {"type": "text", "text": "ここから調査フェーズに入る。run_sqlは参照系クエリだけで使うこと。"},
        {
            "type": "tool_addition",
            "tool": {"type": "tool_reference", "name": "run_sql"},
        },
    ],
}