LibreAI / AI Agents / ragas
// agents · vibrantlabsai/ragas

ragas

Supercharge LLM app evaluations with objective metrics, synthetic test data and feedback loops.

★ 16.0k stars⑂ 1.8k forksApache-2.0updated 2026-02
▦ visual — this project's README ships no embeddable screenshot,
so here's a placeholder. The guide below is complete regardless.
// project facts

Project facts

ragas is an open-source ai agents project by vibrantlabsai (vibrantlabsai/ragas on GitHub). It has 15,966 GitHub stars and 1,750 forks, is released under the Apache-2.0 license, and was last updated on GitHub on 24 February 2026.

GitHub stars
15,966
Forks
1,750
License
Apache-2.0
Last updated on GitHub
24 February 2026
Category
AI Agents
Listing
Full install guide
Official site
Official site
// how it works

How it works

  1. Clarify what quality means for your app

    Choose the aspects you need to measure, such as answer accuracy, faithfulness to retrieved context, or relevance for your RAG pipeline.

  2. Install ragas

    Add the library to your Python project from PyPI, or install it directly from the GitHub source.

  3. Create or generate a test set

    Bring examples from your application, or let ragas generate a production-aligned test dataset covering a range of scenarios.

  4. Score outputs and iterate

    Run pre-built or custom metrics over your app's outputs, read the scores and reasons, and use them to tune prompts, retrieval and models.

// features

Why people love it

Objective evaluation metrics

Evaluate LLM applications with both LLM-based and traditional metrics instead of subjective manual review.

Test data generation

Automatically create comprehensive test datasets, including production-aligned test set generation when you have no dataset ready.

Custom aspect metrics

Define your own evaluators, such as an Aspect Critique built with DiscreteMetric, to score any aspect of an output with a reason.

Quickstart project templates

The ragas quickstart command scaffolds a complete evaluation project, starting with a rag_eval template for RAG systems.

Framework integrations

Works with popular LLM frameworks like LangChain and major observability tools, so scores fit into existing pipelines.

Feedback loops from production

Leverage production data to continually improve your LLM applications rather than evaluating once and stopping.

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// run it

Run it yourself

  1. Clone the repository

    Clone the ragas source if you want to develop against it; most users install from PyPI instead.

    git clone https://github.com/vibrantlabsai/ragas.git
    cd ragas
  2. Install from PyPI

    Install the released package into your Python environment.

    pip install ragas
  3. Scaffold an evaluation project

    Use the quickstart command to create a ready-made RAG evaluation project, then add your data and run it.

    ragas quickstart rag_eval
// use cases

What you can build

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// faq

Questions, answered

Who maintains ragas?

Ragas is developed by vibrantlabsai (the team behind Ragas) together with open-source contributors.

Is ragas free to use?

Yes. The library is Apache-2.0 licensed and free, including for commercial use.

Does it need a paid API key?

Often, yes: many ragas metrics use an LLM as the judge, and the quickstart examples expect a provider key such as OPENAI_API_KEY. You pay your provider for those calls; traditional metrics do not need one.

How does ragas compare with LangSmith or manual review?

Ragas focuses on open-source, code-first metrics and test-set generation you run in your own pipeline, while hosted platforms bundle evaluation with tracing and dashboards; many teams use ragas metrics inside their existing observability stack.

How do I get started?

Run pip install ragas, then ragas quickstart rag_eval to scaffold a project, set your model provider key, and score your first outputs.

// keep exploring

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// alternatives

Alternatives in AI Agents

The most-starred other AI Agents projects in the LibreAI catalogue — the realistic shortlist if ragas is not the right fit.

Get ragas

Free and open — grab the source, star the repo, and start creating.