From b14841facfd83ce8c98c79d2da4b8273d8559193 Mon Sep 17 00:00:00 2001
From: Etherll <61019402+Etherll@users.noreply.github.com>
Date: Tue, 29 Jul 2025 10:39:38 +0300
Subject: [PATCH] Add gemma-3n chat template to chat_templates.py (#3051)

* Update chat_templates.py

* Update chat_templates.py
---
 unsloth/chat_templates.py | 72 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

diff --git a/unsloth/chat_templates.py b/unsloth/chat_templates.py
index e7849092cb..66d4b1c9aa 100644
--- a/unsloth/chat_templates.py
+++ b/unsloth/chat_templates.py
@@ -1190,6 +1190,78 @@ CHAT_TEMPLATES["qwen3"] = (qwen3_template, qwen3_template_eos_token, False, qwen
 DEFAULT_SYSTEM_MESSAGE["qwen3"] = None # No default system message for Qwen-3
 pass
 
+# =========================================== Gemma-3n
+# Obtained via
+# print(tokenizer.chat_template.replace("}\n", "####").replace("\n", "\\n").replace("####", "}\n"))
+gemma3n_template = \
+"""{{ bos_token }}
+{%- if messages[0]['role'] == 'system' -%}
+    {%- if messages[0]['content'] is string -%}
+        {%- set first_user_prefix = messages[0]['content'] + '\n\n' -%}
+    {%- else -%}
+        {%- set first_user_prefix = messages[0]['content'][0]['text'] + '\n\n' -%}
+    {%- endif -%}
+    {%- set loop_messages = messages[1:] -%}
+{%- else -%}
+    {%- set first_user_prefix = "" -%}
+    {%- set loop_messages = messages -%}
+{%- endif -%}
+{%- for message in loop_messages -%}
+    {%- if (message['role'] == 'user') != (loop.index0 % 2 == 0) -%}
+        {{ raise_exception("Conversation roles must alternate user/assistant/user/assistant/...") }}
+    {%- endif -%}
+    {%- if (message['role'] == 'assistant') -%}
+        {%- set role = "model" -%}
+    {%- else -%}
+        {%- set role = message['role'] -%}
+    {%- endif -%}
+    {{ '<start_of_turn>' + role + '\n' + (first_user_prefix if loop.first else "") }}
+    {%- if message['content'] is string -%}
+        {{ message['content'] | trim }}
+    {%- elif message['content'] is iterable -%}
+        {%- for item in message['content'] -%}
+            {%- if item['type'] == 'audio' -%}
+                {{ '<audio_soft_token>' }}
+            {%- elif item['type'] == 'image' -%}
+                {{ '<image_soft_token>' }}
+            {%- elif item['type'] == 'text' -%}
+                {{ item['text'] | trim }}
+            {%- endif -%}
+        {%- endfor -%}
+    {%- else -%}
+        {{ raise_exception("Invalid content type") }}
+    {%- endif -%}
+    {{ '<end_of_turn>\n' }}
+{%- endfor -%}
+{%- if add_generation_prompt -%}
+    {{'<start_of_turn>model\n'}}
+{%- endif -%}
+"""
+
+# Ollama from https://ollama.com/library/gemma3n/blobs/e0a42594d802
+gemma3n_ollama = \
+'''
+{{- range $i, $_ := .Messages }}
+{{- $last := eq (len (slice $.Messages $i)) 1 }}
+{{- if or (eq .Role "user") (eq .Role "system") }}<start_of_turn>user
+{{ .Content }}<end_of_turn>
+{{ if $last }}<start_of_turn>model
+{{ end }}
+{{- else if eq .Role "assistant" }}<start_of_turn>model
+{{ .Content }}{{ if not $last }}<end_of_turn>
+{{ end }}
+{{- end }}
+{{- end }}
+'''
+
+gemma3n_template_eos_token = "<end_of_turn>"
+CHAT_TEMPLATES["gemma-3n"] = (gemma3n_template, gemma3n_template_eos_token, False, gemma3n_ollama,)
+DEFAULT_SYSTEM_MESSAGE["gemma-3n"] = None # No system message in Gemma-3n
+
+CHAT_TEMPLATES["gemma3n"] = (gemma3n_template, gemma3n_template_eos_token, False, gemma3n_ollama,)
+DEFAULT_SYSTEM_MESSAGE["gemma3n"] = None # No system message in Gemma-3n
+pass
+
 def _change_system_message(template: str, type_chat_template: str, system_message: str = None):
     system_message_pattern = r"\{system_message\}"