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language_models

Language Models

The Language Models module is responsible for managing the large language models (LLMs) used by the Controller.

Currently, the framework supports the following LLMs:

  • GPT-4 / GPT-3.5 (Remote - OpenAI API)
  • LLaMA-2 (Local - HuggingFace Transformers)

The following sections describe how to instantiate individual LLMs and how to add new LLMs to the framework.

LLM Instantiation

  • Create a copy of config_template.json named config.json.
  • Fill configuration details based on the used model (below).

GPT-4 / GPT-3.5

  • Adjust the predefined chatgpt or chatgpt4 configurations or create a new configuration with an unique key.
Key Value
model_id Model name based on OpenAI model overview.
prompt_token_cost Price per 1000 prompt tokens based on OpenAI pricing, used for calculating cumulative price per LLM instance.
response_token_cost Price per 1000 response tokens based on OpenAI pricing, used for calculating cumulative price per LLM instance.
temperature Parameter of OpenAI models that controls the randomness and the creativity of the responses (higher temperature = more diverse and unexpected responses). Value between 0.0 and 2.0, default is 1.0. More information can be found in the OpenAI API reference.
max_tokens The maximum number of tokens to generate in the chat completion. Value depends on the maximum context size of the model specified in the OpenAI model overview. More information can be found in the OpenAI API reference.
stop String or array of strings specifying sequences of characters which if detected, stops further generation of tokens. More information can be found in the OpenAI API reference.
organization Organization to use for the API requests (may be empty).
api_key Personal API key that will be used to access OpenAI API.
  • Instantiate the language model based on the selected configuration key (predefined / custom).
lm = controller.ChatGPT(
    "path/to/config.json", 
    model_name=<configuration key>
)

LLaMA-2

  • Requires local hardware to run inference and a HuggingFace account.
  • Adjust the predefined llama7b-hf, llama13b-hf or llama70b-hf configurations or create a new configuration with an unique key.
Key Value
model_id Specifies HuggingFace LLaMA-2 model identifier (meta-llama/<model_id>).
cache_dir Local directory where the model will be downloaded and accessed.
prompt_token_cost Price per 1000 prompt tokens (currently not used - local model = no cost).
response_token_cost Price per 1000 response tokens (currently not used - local model = no cost).
temperature Parameter that controls the randomness and the creativity of the responses (higher temperature = more diverse and unexpected responses). Value between 0.0 and 1.0, default is 0.6.
top_k Top-K sampling method described in Transformers tutorial. Default value is set to 10.
max_tokens The maximum number of tokens to generate in the chat completion. More tokens require more memory.
  • Instantiate the language model based on the selected configuration key (predefined / custom).
lm = controller.Llama2HF(
    "path/to/config.json", 
    model_name=<configuration key>
)
  • Request access to LLaMA-2 via the Meta form using the same email address as for the HuggingFace account.
  • After the access is granted, go to HuggingFace LLaMA-2 model card, log in and accept the license (a "You have been granted access to this model" message should appear).
  • Generate HuggingFace access token.
  • Log in from CLI with: huggingface-cli login --token <your token>.

Note: 4-bit quantization is used to reduce the model size for inference. During instantiation, the model is downloaded from HuggingFace into the cache directory specified in the config.json. Running queries using larger models will require multiple GPUs (splitting across many GPUs is done automatically by the Transformers library).

Adding LLMs

More LLMs can be added by following these steps:

  • Create a new class as a subclass of AbstractLanguageModel.
  • Use the constructor for loading the configuration and instantiating the language model (if needed).
class CustomLanguageModel(AbstractLanguageModel):
    def __init__(
        self,
        config_path: str = "",
        model_name: str = "llama7b-hf",
        cache: bool = False
    ) -> None:
        super().__init__(config_path, model_name, cache)
        self.config: Dict = self.config[model_name]
        
        # Load data from configuration into variables if needed

        # Instantiate LLM if needed
  • Implement the query abstract method that is used to get a list of responses from the LLM (remote API call or local model inference).
def query(self, query: str, num_responses: int = 1) -> Any:
    # Support caching 
    # Call LLM and retrieve list of responses - based on num_responses    
    # Return LLM response structure (not only raw strings)    
  • Implement the get_response_texts abstract method that is used to get a list of raw texts from the LLM response structure produced by query.
def get_response_texts(self, query_response: Union[List[Any], Any]) -> List[str]:
    # Retrieve list of raw strings from the LLM response structure