diff --git a/extensions/openai/completions.py b/extensions/openai/completions.py
index 46502bdc..cabfce99 100644
--- a/extensions/openai/completions.py
+++ b/extensions/openai/completions.py
@@ -1,9 +1,12 @@
 import copy
+import functools
 import json
 import time
 from collections import deque
+from pathlib import Path
 
 import tiktoken
+import yaml
 from pydantic import ValidationError
 
 from extensions.openai.errors import InvalidRequestError
@@ -22,6 +25,18 @@ from modules.presets import load_preset_memoized
 from modules.text_generation import decode, encode, generate_reply
 
 
+@functools.cache
+def load_chat_template_file(filepath):
+    """Load a chat template from a file path (.jinja, .jinja2, or .yaml/.yml)."""
+    filepath = Path(filepath)
+    ext = filepath.suffix.lower()
+    text = filepath.read_text(encoding='utf-8')
+    if ext in ['.yaml', '.yml']:
+        data = yaml.safe_load(text)
+        return data.get('instruction_template', '')
+    return text
+
+
 def convert_logprobs_to_tiktoken(model, logprobs):
     # more problems than it's worth.
     # try:
@@ -234,6 +249,8 @@ def chat_completions_common(body: dict, is_legacy: bool = False, stream=False, p
         instruction_template = body['instruction_template']
         instruction_template = "Alpaca" if instruction_template == "None" else instruction_template
         instruction_template_str = load_instruction_template_memoized(instruction_template)
+    elif shared.args.chat_template_file:
+        instruction_template_str = load_chat_template_file(shared.args.chat_template_file)
     else:
         instruction_template_str = shared.settings['instruction_template_str']
 
diff --git a/modules/shared.py b/modules/shared.py
index de0820af..bc7ea8ba 100644
--- a/modules/shared.py
+++ b/modules/shared.py
@@ -215,6 +215,7 @@ group.add_argument('--sampler-priority', type=str, default=_d['sampler_priority'
 group.add_argument('--dry-sequence-breakers', type=str, default=_d['dry_sequence_breakers'], metavar='N', help='DRY sequence breakers')
 group.add_argument('--enable-thinking', action=argparse.BooleanOptionalAction, default=True, help='Enable thinking')
 group.add_argument('--reasoning-effort', type=str, default='medium', metavar='N', help='Reasoning effort')
+group.add_argument('--chat-template-file', type=str, default=None, help='Path to a chat template file (.jinja, .jinja2, or .yaml) to use as the default instruction template for API requests. Overrides the model\'s built-in template.')
 
 # Handle CMD_FLAGS.txt
 cmd_flags_path = user_data_dir / "CMD_FLAGS.txt"
@@ -376,6 +377,11 @@ default_settings = copy.deepcopy(settings)
 
 
 def do_cmd_flags_warnings():
+    # Validate --chat-template-file
+    if args.chat_template_file and not Path(args.chat_template_file).is_file():
+        logger.error(f"--chat-template-file: file not found: {args.chat_template_file}")
+        sys.exit(1)
+
     # Security warnings
     if args.trust_remote_code:
         logger.warning(
diff --git a/modules/training.py b/modules/training.py
index c9f32e64..87539461 100644
--- a/modules/training.py
+++ b/modules/training.py
@@ -226,7 +226,7 @@ def clean_path(base_path: str, path: str):
 def get_instruction_templates():
     path = shared.user_data_dir / 'instruction-templates'
     names = set()
-    for ext in ['yaml', 'yml', 'jinja']:
+    for ext in ['yaml', 'yml', 'jinja', 'jinja2']:
         for f in path.glob(f'*.{ext}'):
             names.add(f.stem)
     return ['None', 'Chat Template'] + sorted(names, key=utils.natural_keys)
@@ -235,10 +235,10 @@ def get_instruction_templates():
 def load_template(name):
     """Load a Jinja2 template string from {user_data_dir}/instruction-templates/."""
     path = shared.user_data_dir / 'instruction-templates'
-    for ext in ['jinja', 'yaml', 'yml']:
+    for ext in ['jinja', 'jinja2', 'yaml', 'yml']:
         filepath = path / f'{name}.{ext}'
         if filepath.exists():
-            if ext == 'jinja':
+            if ext in ['jinja', 'jinja2']:
                 return filepath.read_text(encoding='utf-8')
             else:
                 data = yaml.safe_load(filepath.read_text(encoding='utf-8'))