# Quality Check with Filters

This sample provides a practical demonstration how to perform quality check on LLM results for such tasks as text summarization and translation with Semantic Kernel Filters.

Metrics used in this example:

- [BERTScore](https://github.com/Tiiiger/bert_score) - leverages the pre-trained contextual embeddings from BERT and matches words in candidate and reference sentences by cosine similarity.
- [BLEU](https://en.wikipedia.org/wiki/BLEU) (BiLingual Evaluation Understudy) - evaluates the quality of text which has been machine-translated from one natural language to another.
- [METEOR](https://en.wikipedia.org/wiki/METEOR) (Metric for Evaluation of Translation with Explicit ORdering) - evaluates the similarity between the generated summary and the reference summary, taking into account grammar and semantics.
- [COMET](https://unbabel.github.io/COMET) (Crosslingual Optimized Metric for Evaluation of Translation) - is an open-source framework used to train Machine Translation metrics that achieve high levels of correlation with different types of human judgments.

In this example, SK Filters call dedicated [server](./python-server/) which is responsible for task evaluation using metrics described above. If evaluation score of specific metric doesn't meet configured threshold, an exception is thrown with evaluation details.

[Hugging Face Evaluate Metric](https://github.com/huggingface/evaluate) library is used to evaluate summarization and translation results.

## Prerequisites

1. [Python 3.12](https://www.python.org/downloads/)
2. Get [Hugging Face API token](https://huggingface.co/docs/api-inference/en/quicktour#get-your-api-token).
3. Accept conditions to access [Unbabel/wmt22-cometkiwi-da](https://huggingface.co/Unbabel/wmt22-cometkiwi-da) model on Hugging Face portal.

## Setup

It's possible to run Python server for task evaluation directly or with Docker.

### Run server

1. Open Python server directory:

```bash
cd python-server
```

2. Create and active virtual environment:

```bash
python -m venv venv
source venv/Scripts/activate # activate on Windows
source venv/bin/activate # activate on Unix/MacOS
```

3. Setup Hugging Face API key:

```bash
pip install "huggingface_hub[cli]"
huggingface-cli login --token <your_token>
```

4. Install dependencies:

```bash
pip install -r requirements.txt
```

5. Run server:

```bash
cd app
uvicorn main:app --port 8080 --reload
```

6. Open `http://localhost:8080/docs` and check available endpoints.

### Run server with Docker

1. Open Python server directory:

```bash
cd python-server
```

2. Create following `Dockerfile`:

```dockerfile
# syntax=docker/dockerfile:1.2
FROM python:3.12

WORKDIR /code

COPY ./requirements.txt /code/requirements.txt

RUN pip install "huggingface_hub[cli]"
RUN --mount=type=secret,id=hf_token \
    huggingface-cli login --token $(cat /run/secrets/hf_token)

RUN pip install cmake
RUN pip install --no-cache-dir --upgrade -r /code/requirements.txt

COPY ./app /code/app

CMD ["fastapi", "run", "app/main.py", "--port", "80"]
```

3. Create `.env/hf_token.txt` file and put Hugging Face API token in it.

4. Build image and run container:

```bash
docker-compose up --build
```

5. Open `http://localhost:8080/docs` and check available endpoints.

## Testing

Open and run `QualityCheckWithFilters/Program.cs` to experiment with different evaluation metrics, thresholds and input parameters.