# OpenAI Chat Completion

*author: Jael*

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## Description

A LLM operator generates answer given prompt in messages using a large language model or service.
This operator uses a pretrained [Dolly](https://github.com/databrickslabs/dolly) to generate response.
It will download model from [HuggingFace Models](https://huggingface.co/models).

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## Code Example

Use the default model to continue the conversation from given messages.

*Write a pipeline with explicit inputs/outputs name specifications:*

```python
from towhee import pipe, ops

p = (
    pipe.input('messages')
        .map('messages', 'answer', ops.LLM.Dolly())
        .output('messages', 'answer')
)

messages=[
        {'question': 'Who won the world series in 2020?', 'answer': 'The Los Angeles Dodgers won the World Series in 2020.'},
        {'question': 'Where was it played?'}
    ]
answer = p(messages)
```

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## Factory Constructor

Create the operator via the following factory method:

***LLM.Dolly(model_name: str)***

**Parameters:**

***model_name***: *str*

The model name in string, defaults to 'databricks/dolly-v2-12b'. Supported model names:
- databricks/dolly-v2-12b
- databricks/dolly-v2-7b
- databricks/dolly-v2-3b
- databricks/dolly-v1-6b

***\*\*kwargs***

Other Dolly model parameters such as device_map.

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## Interface

The operator takes a piece of text in string as input.
It returns answer in json.

***\_\_call\_\_(txt)***

**Parameters:**

***messages***: *list*

​	A list of messages to set up chat.
Must be a list of dictionaries with key value from "system", "question", "answer". For example, [{"question": "a past question?", "answer": "a past answer."}, {"question": "current question?"}]

**Returns**:

*answer: str*

​	The answer generated.

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