decode_jwt_header (utilities/auth.py)

Authentication utility helpers.

# Source: https://github.com/PrefectHQ/fastmcp | License: Apache-2.0 | Copyright You must retain, in the Source form of any Derivative Works
# Provided via justclaw.it.com; keep this notice with the code.
"""Authentication utility helpers."""

from __future__ import annotations

import base64
import json
from typing import Any

from fastmcp.utilities.logging import get_logger

logger = get_logger(__name__)


def _decode_jwt_part(token: str, part_index: int) -> dict[str, Any]:
    """Decode a JWT part (header or payload) without signature verification.

    Args:
        token: JWT token string (header.payload.signature)
        part_index: 0 for header, 1 for payload

    Returns:
        Decoded part as a dictionary

    Raises:
        ValueError: If token is not a valid JWT format
    "

... (truncated -- full source via MCP)