Robert Gerstenberger 15fb8e661d
updated paper reference in the LICENSE file (#31)
- updated paper reference in the LICENSE file
- improved documentation
2024-06-03 14:03:59 +02:00

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# 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](https://platform.openai.com/docs/models/overview). |
| prompt_token_cost | Price per 1000 prompt tokens based on [OpenAI pricing](https://openai.com/pricing), used for calculating cumulative price per LLM instance. |
| response_token_cost | Price per 1000 response tokens based on [OpenAI pricing](https://openai.com/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](https://platform.openai.com/docs/api-reference/completions/create#completions/create-temperature). |
| 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](https://platform.openai.com/docs/models/overview). More information can be found in the [OpenAI API reference](https://platform.openai.com/docs/api-reference/chat/create#chat/create-max_tokens). |
| 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](https://platform.openai.com/docs/api-reference/chat/create#chat/create-stop). |
| 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).
```python
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](https://huggingface.co/blog/how-to-generate). 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).
```python
lm = controller.Llama2HF(
"path/to/config.json",
model_name=<configuration key>
)
```
- Request access to LLaMA-2 via the [Meta form](https://ai.meta.com/resources/models-and-libraries/llama-downloads/) using the same email address as for the HuggingFace account.
- After the access is granted, go to [HuggingFace LLaMA-2 model card](https://huggingface.co/meta-llama/Llama-2-7b-chat-hf), 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).
```python
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).
```python
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`.
```python
def get_response_texts(self, query_response: Union[List[Any], Any]) -> List[str]:
# Retrieve list of raw strings from the LLM response structure
```