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DeepEval is a simple-to-use, open-source evaluation framework for LLM applications. It is similar to Pytest but specialized for unit testing LLM applications. DeepEval evaluates performance based on metrics such as factual consistency, accuracy, answer relevancy, etc., using LLMs and various other NLP models. It's a production-ready alternative to RAGAS.

Whether your application is implemented via RAG or fine-tuning, LangChain or LlamaIndex, DeepEval has you covered. With it, you can easily determine the optimal hyperparameters to improve your RAG pipeline, prevent prompt drifting, or even transition from OpenAI to hosting your own Llama2 with confidence.

Getting Started 🚀

Let's pretend your LLM application is a customer support chatbot; here's how DeepEval can help test what you've built.

Installation

pip install -U deepeval

[Optional] Create an account

Creating an account on our platform will allow you to log test results, enabling easy tracking of changes and performances over iterations. This step is optional, and you can run test cases even without logging in, but we highly recommend giving it a try.

To login, run:

deepeval login

Follow the instructions in the CLI to create an account, copy your API key, and paste it into the CLI. All test cases will automatically be logged (find more information on data privacy here).

Writing your first test case

Create a test file:

touch test_chatbot.py

Open test_chatbot.py and write your first test case using DeepEval:

import pytest
from deepeval.metrics.factual_consistency import FactualConsistencyMetric
from deepeval.test_case import LLMTestCase
from deepeval.run_test import assert_test

def test_case():
    input = "What if these shoes don't fit?"
    context = "All customers are eligible for a 30 day full refund at no extra costs."

    # Replace this with the actual output from your LLM application
    actual_output = "We offer a 30-day full refund at no extra costs."
    factual_consistency_metric = FactualConsistencyMetric(minimum_score=0.7)
    test_case = LLMTestCase(input=input, actual_output=actual_output, context=context)
    assert_test(test_case, [factual_consistency_metric])

Run test_chatbot.py in the CLI:

deepeval test run test_chatbot.py

Your test should have passed ✅ Let's breakdown what happened.

The variable input mimics user input, and actual_output is a placeholder for your chatbot's intended output based on this query.
The variable context contains the relevant information from your knowledge base, and FactualConsistencyMetric(minimum_score=0.7) is an out-of-the-box metric provided by DeepEval. It helps you evaluate the factual accuracy of your chatbot's output based on the provided context.
The metric score ranges from 0 - 1. The minimum_score=0.7 threshold ultimately determines whether your test has passed or not.

Read our documentation for more information on how to use additional metrics, create your own custom metrics, and tutorials on how to integrate with other tools like LangChain and LlamaIndex.

View results on our platform

We offer a free web platform for you to log and view all test results from DeepEval test runs. Our platform allows you to quickly draw insights on how your metrics are improving with each test run and to determine the optimal parameters (such as prompt templates, models, retrieval pipeline) for your specific LLM application.

To begin, login from the CLI:

deepeval login

Follow the instructions to log in, create your account, and paste your API key into the CLI.

Now, run your test file again:

deepeval test run test_chatbot.py

You should see a link displayed in the CLI once the test has finished running. Paste it into your browser to view the results!

Contributing

Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.

Roadmap

Features:

Implement G-Eval
Referenceless Evaluation
Production Evaluation & Logging
Evaluation Dataset Creation

Integrations:

Authors

Built by the founders of Confident AI. Contact jeffreyip@confident-ai.com for all enquiries.

License

DeepEval is licensed under Apache 2.0 - see the LICENSE.md file for details.

tanduong / deepeval