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

task result pollIntervalMs must be a non-negative integer

Error message

task result pollIntervalMs must be a non-negative integer

What it means

Error "task result pollIntervalMs must be a non-negative integer" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py:323

        raise ProtocolViolation("task result is valid only for tools/call")
    required_strings = ("taskId", "status", "createdAt", "lastUpdatedAt")
    for field in required_strings:
        if not isinstance(result.get(field), str) or not result[field]:
            raise ProtocolViolation(f"task result requires non-empty {field}")
    if result["status"] not in {"working", "input_required", "completed", "cancelled", "failed"}:
        raise ProtocolViolation("task result has an unknown status")
    if "ttlMs" not in result:
        raise ProtocolViolation("task result requires ttlMs")
    ttl_ms = result["ttlMs"]
    if ttl_ms is not None and (
        isinstance(ttl_ms, bool) or not isinstance(ttl_ms, int) or ttl_ms < 0
    ):
        raise ProtocolViolation("task result ttlMs must be null or a non-negative integer")
    poll_interval = result.get("pollIntervalMs")
    if poll_interval is not None and (
        isinstance(poll_interval, bool) or not isinstance(poll_interval, int) or poll_interval < 0
    ):
        raise ProtocolViolation("task result pollIntervalMs must be a non-negative integer")


def select_era(
    observation: dict[str, Any],
    policy: str,
    legacy_allowed: bool = False,
    legacy_evidence: dict[str, Any] | None = None,
) -> str:
    if policy not in {"strict", "fallback"}:
        raise ValueError("policy must be strict or fallback")
    kind = observation.get("kind")
    if kind == "discover_success":
        return "modern"
    if kind == "jsonrpc_error" and observation.get("code") in MODERN_ERROR_CODES:
        return "modern"
    if policy == "strict":
        raise ProtocolViolation("modern support was not proven; strict policy forbids fallback")
    if kind not in {"empty", "timeout", "connection_closed", "unrecognized"}:

View on GitHub (pinned to 39ea8a1c6d)

When it happens

Trigger: Thrown at phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py:323 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/14983f59fc119da0. Report an issue: GitHub.