# tinker_cookbook.tokenizer_utils.register_tokenizer

### [**tinker_cookbook.tokenizer_utils.register_tokenizer**](https://github.com/thinking-machines-lab/tinker-cookbook/blob/main/tinker_cookbook/tokenizer_utils.py#L123)( _name_, _factory_)

Register a custom tokenizer factory.

Once registered, [`get_tokenizer`](https://tinker-docs.thinkingmachines.ai/cookbook/api-reference/tokenizer_utils/get_tokenizer/) will call `factory()` instead of loading from HuggingFace when the given `name` is requested.

**Parameters:**

- [**name**](https://github.com/thinking-machines-lab/tinker-cookbook/blob/main/tinker_cookbook/tokenizer_utils.py#L124) ( _str_) – The tokenizer name (typically a HuggingFace model ID like `"Foo/foo_tokenizer"`).
- [**factory**](https://github.com/thinking-machines-lab/tinker-cookbook/blob/main/tinker_cookbook/tokenizer_utils.py#L125) ( _Callable[[], Tokenizer]_) – A callable that takes no arguments and returns a Tokenizer instance.

**Returns:** _None_

```
def my_tokenizer_factory():
    return MyCustomTokenizer()
register_tokenizer("Foo/foo_tokenizer", my_tokenizer_factory)
```

## Referenced by

- [tinker_cookbook.tokenizer_utils.get_registered_tokenizer_names](https://tinker-docs.thinking-machines.ai/cookbook/api-reference/tokenizer_utils/get_registered_tokenizer_names/)
- [tinker_cookbook.tokenizer_utils.get_tokenizer](https://tinker-docs.thinking-machines.ai/cookbook/api-reference/tokenizer_utils/get_tokenizer/)
- [tinker_cookbook.tokenizer_utils.is_tokenizer_registered](https://tinker-docs.thinking-machines.ai/cookbook/api-reference/tokenizer_utils/is_tokenizer_registered/)