chat_template.jinja

{%- set ns = namespace(has_head=true) -%}
{%- set loop_messages = messages -%}
{%- for message in loop_messages -%}
    {%- set content = message['content'] -%}
    {%- if loop.index0 == 0 -%}
        {%- if content == '' -%}
            {%- set ns.has_head = false -%}
        {%- elif message['role'] == 'system' -%}
            {%- set content = '<|startoftext|>' + content + '<|extra_4|>' -%}
        {%- endif -%}
    {%- endif -%}
    {%- if message['role'] == 'user' -%}
        {%- if loop.index0 == 1 and not ns.has_head -%}
            {%- set content = '<|startoftext|>' + content -%}
        {%- endif -%}
        {%- if loop.index0 == 1 and ns.has_head -%}
            {%- set content = content + '<|extra_0|>' -%}
        {%- else -%}
            {%- set content = '<|startoftext|>' + content + '<|extra_0|>' -%}
        {%- endif -%}
    {%- elif message['role'] == 'assistant' -%}
        {%- set content = content + '<|eos|>' -%}
    {%- endif -%}
    {{- content -}}
{%- endfor -%}