def member_joined_organization_message(payload):
    """
    Build a Slack message informing about a new member.

    """
    member_name = payload['user']['name']
    member_url = payload['user']['url']
    org_name = payload['organization']['name']
    org_url = payload['organization']['url']

    message = 'Say hi! <{}|{}> just joined the <{}|{}> organization.'
    message = message.format(member_url, member_name, org_url, org_name)

    attachments = [
        {
            'fallback': message,
            'color': 'good',
            'author_name': 'Mode',
            'author_link': 'https://modeanalytics.com/',
            'title': 'New Org Member :wave:',
            'text': message
        }
    ]

    return attachments