Jevとは？使い方・料金・LLMとの違いを実装例で解説

# jev_request.py — Python 3.10以降、標準ライブラリのみ# TYPESAFE_API_KEY は環境変数から読み込む。ソースには書かない。import jsonimport osfrom pathlib import Pathfrom urllib.request import Request, urlopen
payload = {    "model": "jev-1.13.0",  # 記事確認時の版に固定    "state": {        "message": "請求書の宛名を変更したいです。手順を教えてください。"    },    "questions": {        "department": {            "type": "choice",            "instructions": "問い合わせの主な用件を担当する窓口を選ぶ。",            "criteria": {                "billing": "請求書、支払い、返金の相談",                "technical": "不具合、接続、操作上の技術的な相談",                "sales": "新規導入や契約プランの相談",                "review": "複数の用件が混在する、情報不足、または該当なし",            },        },        "refund_requested": {            "type": "noul",            "instructions": "問い合わせの本文で、利用者は返金を明示的に求めているか。",        },    },}
def evaluate_message(message):    if not isinstance(message, str) or not message.strip():        raise ValueError("問い合わせ本文が空です。")    key = os.environ.get("TYPESAFE_API_KEY")    if not key or key == "YOUR_API_KEY":        raise RuntimeError("有効なTYPESAFE_API_KEYを環境変数に設定してください。")    body = {**payload, "state": {"message": message}}    request = Request(        "https://api.typesafe.ai/v1/systemone",        data=json.dumps(body, ensure_ascii=False).encode("utf-8"),        headers={            "Authorization": f"Bearer {key}",            "Content-Type": "application/json",        },        method="POST",    )    with urlopen(request, timeout=30) as response:        return json.load(response)
def main():    result = evaluate_message(payload["state"]["message"])    # 成功した応答を保存。2つ目の例で読み込める。    Path("jev-response.json").write_text(        json.dumps(result, ensure_ascii=False, indent=2), encoding="utf-8"    )    print("jev-response.json に保存しました。")
if __name__ == "__main__":    main()

{  "model": "jev-1.13.0",  "answers": {    "department": {      "type": "choice",      "choice": "billing",      "probabilities": {        "billing": 0.96,        "technical": 0.02,        "sales": 0.01,        "review": 0.01      },      "confidence": 0.9    },    "refund_requested": {      "type": "noul",      "noul": 0.05    }  },  "usage": {    "input_tokens": 1000,    "output_tokens": 40  }}

# jev_route.py — 応答を検査し、候補窓口だけを表示するimport jsonimport mathimport sysfrom jev_request import payload
# 説明用の仮値。自社データで評価してから決める。MIN_CONFIDENCE = 0.85MAX_REFUND_PROBABILITY = 0.20ALLOWED_DEPARTMENTS = {"billing", "technical", "sales"}EXPECTED_OPTIONS = ALLOWED_DEPARTMENTS | {"review"}
def valid_probability(value):    return (type(value) in (int, float)            and 0 <= value <= 1 and math.isfinite(value))
def validate_response(result):    # この問い合わせ例の応答契約を検査。判断内容の正しさは別に評価する。    try:        if result["model"] != payload["model"]:            raise ValueError("検証対象と異なるモデルです。")        answers = result["answers"]        department = answers["department"]        refund = answers["refund_requested"]        if department["type"] != "choice" or refund["type"] != "noul":            raise ValueError("回答の型が一致しません。")        queue = department["choice"]        probabilities = department["probabilities"]        if not isinstance(queue, str) or queue not in EXPECTED_OPTIONS:            raise ValueError("未知の候補です。")        if not isinstance(probabilities, dict) or set(probabilities) != EXPECTED_OPTIONS:            raise ValueError("確率分布の候補が一致しません。")        values = [department["confidence"], refund["noul"], *probabilities.values()]        if not all(valid_probability(value) for value in values):            raise ValueError("確率またはconfidenceが範囲外です。")        if not math.isclose(sum(probabilities.values()), 1.0, abs_tol=1e-6):            raise ValueError("確率の合計が1ではありません。")        if probabilities[queue] != max(probabilities.values()):            raise ValueError("選択結果と確率分布が一致しません。")        usage = result["usage"]        for key in ("input_tokens", "output_tokens"):            if type(usage[key]) is not int or usage[key] < 0:                raise ValueError("使用量が不正です。")        return department, refund    except (KeyError, TypeError) as error:        raise ValueError("応答の必須項目が欠けているか型が違います。") from error
def choose_queue(result):    try:        department, refund = validate_response(result)    except ValueError:        return "human_review"    # 返金の可能性がある相談は人へ。返金処理そのものは実行しない。    if refund["noul"] > MAX_REFUND_PROBABILITY:        return "human_review"    if department["confidence"] < MIN_CONFIDENCE:        return "human_review"    queue = department["choice"]    return queue if queue in ALLOWED_DEPARTMENTS else "human_review"
if __name__ == "__main__":    # python jev_route.py jev-response.json    # 読み込み失敗時も窓口を決めず、人の確認に戻す。    try:        with open(sys.argv[1], encoding="utf-8") as file:            result = json.load(file)    except (IndexError, OSError, ValueError):        result = None    print(choose_queue(result))

# jev_shadow.py — 同じフォルダの前掲2ファイルと組み合わせるimport hashlibimport jsonimport sysimport uuidfrom datetime import datetime, timezonefrom http.client import HTTPExceptionfrom pathlib import Pathfrom time import perf_counterfrom urllib.error import HTTPError, URLErrorfrom jev_request import evaluate_message, payloadfrom jev_route import (choose_queue, validate_response,                       MIN_CONFIDENCE, MAX_REFUND_PROBABILITY)
def observe(ticket_ref, message):    started = perf_counter()    event = {        "event_id": str(uuid.uuid4()),        "ticket_ref": ticket_ref,  # 個人名を含めない問い合わせ参照番号        "at": datetime.now(timezone.utc).isoformat(),        "mode": "observe",        # 担当先は変更しない        "model_requested": payload["model"],        "question_version": "support-v1",        "policy_version": "routing-v1",        "input_sha256": hashlib.sha256(message.encode()).hexdigest(),        "thresholds": {"min_confidence": MIN_CONFIDENCE,                       "max_refund_p": MAX_REFUND_PROBABILITY},        "status": "pending_review",        "suggested_queue": "human_review",        "applied": False,    }    try:        response = evaluate_message(message)        validate_response(response)        event.update(            status="evaluated",            model_used=response["model"],            answers=response.get("answers"),            usage=response.get("usage"),            suggested_queue=choose_queue(response),        )    except (HTTPError, URLError, HTTPException, TimeoutError, OSError, ValueError, RuntimeError) as error:        # エラー本文や認証情報は記録しない。候補は人の確認に戻す。        event["error_type"] = type(error).__name__        if isinstance(error, HTTPError):            event["http_status"] = error.code    event["elapsed_ms"] = round((perf_counter() - started) * 1000, 1)    return event
if __name__ == "__main__":    # 架空の本文を ticket.txt に保存して実行する例:    # python jev_shadow.py T001 < ticket.txt    if len(sys.argv) != 2:        raise SystemExit("使い方: python jev_shadow.py 問い合わせ参照番号 < 本文ファイル")    event = observe(sys.argv[1], sys.stdin.read())    # 観測用の記録。問い合わせ本文は複製しない。    with Path("jev-decisions.jsonl").open("a", encoding="utf-8") as file:        file.write(json.dumps(event, ensure_ascii=False) + "\n")    print(event["suggested_queue"], "（記録のみ・担当変更なし）")