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

-32020

-32020

Error message

conflicting duplicate HTTP header: {name}

What it means

Error "conflicting duplicate HTTP header: {name}" thrown in rohitg00/ai-engineering-from-scratch.

Source

Thrown at phases/13-tools-and-protocols/31-mcp-conformance-versioning-and-operations/code/main.py:150

def routing_name(body: dict[str, Any]) -> str | None:
    params = body.get("params", {})
    if not isinstance(params, dict):
        return None
    for key in ("name", "taskId", "uri"):
        value = params.get(key)
        if isinstance(value, str):
            return value
    return None


def normalized_headers(headers: dict[str, str]) -> dict[str, str]:
    normalized: dict[str, str] = {}
    for name, value in headers.items():
        key = name.lower()
        if key in normalized and normalized[key] != value:
            raise ProtocolViolation(f"conflicting duplicate HTTP header: {name}", -32020)
        normalized[key] = value
    return normalized


def encode_header_value(value: str) -> str:
    safe = all(0x20 <= ord(character) <= 0x7E for character in value)
    sentinel = value.startswith("=?base64?") and value.endswith("?=")
    if safe and value == value.strip() and not sentinel:
        return value
    encoded = base64.b64encode(value.encode("utf-8")).decode("ascii")
    return f"=?base64?{encoded}?="


def decode_header_value(value: str) -> str:
    starts = value.startswith("=?base64?")
    ends = value.endswith("?=")
    if starts or ends:
        if not (starts and ends):

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:150 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/8fe874c08eb3d185. Report an issue: GitHub.