{%- for message in messages %}
    {%- if (loop.index % 2 == 1 and message['role'].lower() != 'user') or (loop.index % 2 == 0 and message['role'].lower() != 'assistant') %}
        {{ raise_exception('Conversation roles must alternate between user and assistant ...') }}
    {%- endif %}
    {%- if not loop.first or always_start_with_space %}
        {{- ' ' }}
    {%- endif %}
    {{- message['role'].capitalize() + ': ' }}
    {%- for content in message['content'] %}
        {%- if content['type'] == 'text' %}
            {{- content['text'] + ' ' }}
        {%- elif content['type'] == 'image' %}
            {{- image_prompt_token }}
        {%- else %}
            {{ raise_exception('Unsupported content type: ' + content['type']) }}
        {%- endif %}
    {%- endfor %}
{%- endfor %}
{%- if add_generation_prompt %}
    {{- 'Assistant:' }}
{%- endif %}