def claims(oauth2_settings):
    """Set up web tokens claims options

    Accepts:
        oauth2_settings(dict): dictionary of OAuth2 settings

    Returns:
        claims(dict): a dictionary describing json token web claims
    """

    claims = dict(
        iss=dict(essential=True, values=",".join(oauth2_settings.get("issuers", []))),
        aud=dict(
            essential=oauth2_settings.get("verify_aud", False),
            values=",".join(oauth2_settings.get("audience", [])),
        ),
        exp=dict(essential=True),
    )
    return claims