Thanks for making a pull request! 😃
One of the maintainers will review and advise on the next steps.

and also say somewhere that this is a undocumented feature...i.e. in the schema you should try to add chat_template_base64 but add a note that this is something users should use if they know what they are doing.

Then it would become documented, wouldn't it?

Any way to check if the base64 decode happened correctly? or throw some error if it didn't result in a chat template?

The b64decode function will throw an Exception if it's an invalid base64 string. Example:

>>> from base64 import b64decode
>>> s = 'asdadasda'
>>> b64decode(s)
Traceback (most recent call last):
  File "<python-input-2>", line 1, in <module>
    b64decode(s)
    ~~~~~~~~~^^^
  File "/opt/homebrew/Cellar/python@3.13/3.13.1/Frameworks/Python.framework/Versions/3.13/lib/python3.13/base64.py", line 88, in b64decode
    return binascii.a2b_base64(s, strict_mode=validate)
           ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
binascii.Error: Invalid base64-encoded string: number of data characters (9) cannot be 1 more than a multiple of 4

The .decode("utf-8") function will also throw an Exception if it's not valid.

@HarikrishnanBalagopal Please add a unit test for the base64 chat template and also say somewhere that this is a undocumented feature...i.e. in the schema you should try to add chat_template_base64 but add a note that this is something users should use if they know what they are doing.

Any way to check if the base64 decode happened correctly? or throw some error if it didn't result in a chat template?

I have added tests

@HarikrishnanBalagopal requested minor name changes and post them please also fix the format error

@HarikrishnanBalagopal requested minor name changes and post them please also fix the format error

done