Box AI for HubsをCopilot Studioで作ったエージェントに連携させてみた話

① 環境変数からJWT秘密鍵を取得
② JWTアサーション生成 → Boxアクセストークン取得
③ Copilot Studioからpromptを受け取る
④ POST https://api.box.com/2.0/ai/ask でBox AIに質問
⑤ answerをCopilot Studioに返す

import os
import json
import logging
import jwt
import requests
import uuid
import time

import azure.functions as func

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

app = func.FunctionApp(http_auth_level=func.AuthLevel.FUNCTION)


def get_box_access_token() -> str:
    """JWT認証でBoxアクセストークンを取得する（変更なし）"""
    client_id     = os.environ.get('BOX_CLIENT_ID')
    client_secret = os.environ.get('BOX_CLIENT_SECRET')
    private_key   = os.environ.get('BOX_PRIVATE_KEY', '').replace('\\n', '\n')
    public_key_id = os.environ.get('BOX_PUBLIC_KEY_ID')
    enterprise_id = os.environ.get('BOX_ENTERPRISE_ID')

    missing = [
        k for k, v in {
            'BOX_CLIENT_ID': client_id,
            'BOX_CLIENT_SECRET': client_secret,
            'BOX_PRIVATE_KEY': private_key,
            'BOX_PUBLIC_KEY_ID': public_key_id,
            'BOX_ENTERPRISE_ID': enterprise_id,
        }.items() if not v
    ]
    if missing:
        raise ValueError(f"Missing environment variables: {', '.join(missing)}")

    claims = {
        "iss": client_id,
        "sub": enterprise_id,
        "box_sub_type": "enterprise",
        "aud": "https://api.box.com/oauth2/token",
        "jti": uuid.uuid4().hex,
        "exp": int(time.time()) + 60,
    }
    jwt_token = jwt.encode(claims, private_key, algorithm="RS512", headers={"kid": public_key_id})

    resp = requests.post(
        "https://api.box.com/oauth2/token",
        data={
            "grant_type": "urn:ietf:params:oauth:grant-type:jwt-bearer",
            "assertion": jwt_token,
            "client_id": client_id,
            "client_secret": client_secret,
        },
    )
    resp.raise_for_status()
    token = resp.json().get("access_token")
    if not token:
        raise RuntimeError("access_token not found in Box token response")
    return token


@app.route(route="boxai_ask")
def boxai_ask(req: func.HttpRequest) -> func.HttpResponse:
    """
    Copilot Studio から呼び出されるエンドポイント。

    リクエストボディ（JSON）:
        prompt           : str  - ユーザーの質問（必須）
        hub_id           : str  - Box Hub ID（省略時は環境変数 BOX_HUB_ID を使用）
        dialogue_history : list - 会話履歴（省略時は空リスト）

    レスポンス（JSON）:
        answer           : str  - Box AIの回答
        citations        : list - 引用元リスト（include_citations=true の場合）
    """
    logger.info("boxai_ask function triggered.")

    # --- リクエストのパース ---
    try:
        body = req.get_json()
    except ValueError:
        return func.HttpResponse("Request body must be valid JSON.", status_code=400)

    prompt = body.get("prompt", "").strip()
    if not prompt:
        return func.HttpResponse("'prompt' is required.", status_code=400)

    logger.info(f"Received prompt: {prompt}")

    hub_id = body.get("hub_id") or os.environ.get("BOX_HUB_ID")
    if not hub_id:
        return func.HttpResponse(
            "'hub_id' is required (body or BOX_HUB_ID env var).", status_code=400
        )

    dialogue_history = body.get("dialogue_history") or []

    # --- Boxアクセストークン取得 ---
    try:
        access_token = get_box_access_token()
        logger.info("Box access token obtained.")
    except ValueError as e:
        logger.error(f"Config error: {e}")
        return func.HttpResponse(str(e), status_code=400)
    except requests.HTTPError as e:
        logger.error(f"Box token request failed: {e}")
        return func.HttpResponse(f"Failed to get Box token: {e}", status_code=502)
    except Exception as e:
        logger.error(f"Unexpected error getting token: {e}", exc_info=True)
        return func.HttpResponse(f"Internal error: {e}", status_code=500)

    # --- Box AI API 呼び出し ---
    ai_payload = {
        "mode": "single_item_qa",
        "prompt": prompt,
        "include_citations": True,
        "items": [{"type": "hubs", "id": hub_id}],
        "dialogue_history": dialogue_history,
    }

    try:
        ai_resp = requests.post(
            "https://api.box.com/2.0/ai/ask",
            headers={
                "Authorization": f"Bearer {access_token}",
                "Content-Type": "application/json",
            },
            json=ai_payload,
            timeout=30,
        )
        ai_resp.raise_for_status()
        ai_data = ai_resp.json()
        logger.info("Box AI response received.")
        logger.info(f"Citations: {json.dumps(ai_data.get('citations', []), ensure_ascii=False)}")
    except requests.HTTPError as e:
        logger.error(f"Box AI API error: {ai_resp.status_code} {ai_resp.text}")
        return func.HttpResponse(
            f"Box AI API error: {ai_resp.status_code} {ai_resp.text}", status_code=502
        )
    except requests.Timeout:
        logger.error("Box AI API request timed out.")
        return func.HttpResponse("Box AI API request timed out.", status_code=504)
    except Exception as e:
        logger.error(f"Unexpected error calling Box AI: {e}", exc_info=True)
        return func.HttpResponse(f"Internal error: {e}", status_code=500)

    # --- Copilot Studio へレスポンスを返す ---
    citations = ai_data.get("citations", [])
    # 重複を除いたファイル名一覧を作成
    file_names = list(dict.fromkeys(c.get("name", "") for c in citations if c.get("name")))
    citation_text = "\n\n📎 参照ファイル：" + "、".join(file_names) if file_names else ""

    result = {
        "answer": ai_data.get("answer", "") + citation_text,
        "citations": citations,
    }
    return func.HttpResponse(
        json.dumps(result, ensure_ascii=False),
        mimetype="application/json",
        status_code=200,
    )

azure-functions
PyJWT
cryptography
requests

例）
社内の手順書・マニュアル・ナレッジについて質問されたとき。
Box Hubsのコンテンツをもとに回答する。

{
  dialogue_history: [],
  prompt: System.Activity.Text
}

{
  "answer": "回答テキスト",
  "citations": [
    {
      "type": "file",
      "id": "1234567890",
      "name": "ファイル名.pdf",
      "content": "引用テキスト"
    }
  ]
}

# NG
dialogue_history = body.get("dialogue_history", [])

# OK：nullや未指定でも空配列にフォールバック
dialogue_history = body.get("dialogue_history") or []