rohitg00/ai-engineering-from-scratch · error · ValueError

unexpected Messages API response contract

Error message

unexpected Messages API response contract

What it means

Error "unexpected Messages API response contract" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at certifications/claude/lessons/30-developer-application-capstone/code/main.py:102

                "name": "lookup_order",
                "description": "Read one visible order status. Never changes order state.",
                "input_schema": {
                    "type": "object",
                    "properties": {"order_id": {"type": "string", "pattern": "^[A-Z]-[0-9]{2,6}$"}},
                    "required": ["order_id"],
                    "additionalProperties": False,
                },
            }
        ],
    }


def run_live_wire(transport: MessagesTransport, request: str, model: str) -> dict[str, Any]:
    """Exercise the real serialization boundary and return only safe metadata."""
    response = transport.create_message(build_live_order_request(request, model))
    content = response.get("content")
    if response.get("type") != "message" or response.get("role") != "assistant" or not isinstance(content, list):
        raise ValueError("unexpected Messages API response contract")
    content_types = [block.get("type") for block in content if isinstance(block, dict)]
    return {
        "type": response["type"],
        "role": response["role"],
        "stop_reason": response.get("stop_reason"),
        "content_types": content_types,
        "message_id_present": isinstance(response.get("id"), str),
    }


@dataclass(frozen=True)
class TraceEvent:
    type: str
    detail: dict[str, Any]


@dataclass(frozen=True)
class SupportResult:

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at certifications/claude/lessons/30-developer-application-capstone/code/main.py:102 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of rohitg00/ai-engineering-from-scratch@39ea8a1c6d (2026-08-26). Data as JSON: /api/errors/252995ae0f904749. Report an issue: GitHub.