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RAGAS

RAGAS is a free, open-source Python library for evaluating RAG pipelines and AI agents with automated metrics and synthetic test data.

Reviewed by Mathijs Bronsdijk · Updated Apr 13, 2026

ToolOpen Source + PaidUpdated 1 month ago
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What is RAGAS?

RAGAS is an open-source Python framework for evaluating Retrieval-Augmented Generation (RAG) systems and other LLM applications. It is designed for developers and data scientists who need objective, systematic assessments of their AI pipelines without relying on manual human annotations. The framework provides reference-free metrics, synthetic test data generation, and production monitoring tools and is possible to measure retrieval and generation quality in a data-driven way. Unlike informal "vibe checks," RAGAS gives teams concrete numbers they can track across experiments and deployments.

Key Features

  • Context Precision: Measures how precisely the retrieved context matches what is needed to answer a query, helping identify when retrieval returns too much noise.
  • Context Recall: Evaluates whether all relevant information is present in the retrieved context, surfacing gaps in retrieval coverage.
  • Faithfulness: Assesses whether the generated answer is factually consistent with the retrieved context, detecting hallucinations.
  • Answer Relevancy: Scores how directly the generated response addresses the original question.
  • Synthetic Test Data Generation: Builds knowledge graphs from source documents to automatically produce diverse test datasets, covering single-hop factual queries and multi-hop abstract queries, without manual labeling.
  • Agent and Tool Evaluation: Includes metrics such as TopicAdherenceScore for validating tool calls and goal adherence in multi-turn agentic workflows.
  • Custom Metrics: Allows users to define their own metrics or extend the base Metric class, supporting binary outputs and adjustable strictness levels.
  • CI/CD and Production Monitoring: Supports an experiments-first workflow with integrations for continuous evaluation and monitoring of performance drift over time.

Use Cases

  • Developers building RAG pipelines: Run component-wise evaluations across retrieval and generation stages to identify which part of the pipeline is degrading answer quality, then iterate with confidence.
  • Data scientists debugging LLM systems: Use built-in metrics to trace errors, compare different LLM or retriever configurations, and select the best-performing components for a given task.
  • AI teams monitoring production systems: Track metrics over time to detect data drift or performance degradation before it reaches end users, using integrations with tools like LangSmith and Langfuse.

Strengths and Weaknesses

Strengths:

  • Covers both component-level and end-to-end evaluation for RAG and agentic workflows in a single library.
  • Automated synthetic data generation reduces the time needed to build test sets, with reported savings of up to 90% compared to manual approaches.
  • Works without ground-truth labels for many metrics, lowering the barrier to starting evaluations.
  • Integrates with widely used frameworks including LangChain and LlamaIndex, as well as observability tools.

Weaknesses:

  • Users have reported rate limiting errors when running evaluation code, sometimes requiring waits of up to an hour before retrying.
  • The app.ragas.io dashboard referenced in documentation has been reported as unreachable, with users uncertain whether it has been discontinued.
  • Migrating from v0.3 to v0.4 requires adapting to a new experiment-based architecture, which can break existing workflows.
  • Most metrics depend on an external LLM API (defaulting to OpenAI), so evaluation costs scale with token usage and are subject to third-party rate limits.

Getting Started

RAGAS is free and open-source, licensed under Apache 2.0. Install it with pip install ragas. There are no subscription fees or platform charges. Running evaluations does incur costs from whichever LLM provider you configure. For example, using GPT-4o at $5 per million input tokens and $15 per million output tokens, a sample evaluation run costs approximately $1.17 and a sample test set generation run costs approximately $0.21, based on examples in the official documentation. Office Hours support is available by signing up at the link in the RAGAS documentation for teams that need help configuring evaluations.

FAQ

What is RAGAS?

RAGAS is an open-source Python library for evaluating RAG (Retrieval-Augmented Generation) pipelines and LLM applications. It provides automated metrics, synthetic test data generation, and production monitoring without requiring manual human annotations.

What does RAGAS stand for?

The name refers to the framework's focus on RAG Assessment, though the official documentation does not expand the acronym explicitly. It is distinct from ragas in Indian classical music.

Is RAGAS free to use?

Yes. RAGAS is open-source and available at no cost under the Apache 2.0 license. You can install it with pip install ragas. Any costs you incur come from the LLM provider API you use to run the evaluations, not from RAGAS itself.

What metrics does RAGAS provide?

RAGAS includes metrics such as context precision, context recall, context entities recall, noise sensitivity, faithfulness, answer relevancy, and TopicAdherenceScore for multi-turn agent evaluation. Users can also define custom metrics.

Does RAGAS require labeled ground-truth data?

Many RAGAS metrics are reference-free, meaning they do not require human-annotated ground truth. The synthetic data generation feature can also create test datasets automatically from your source documents.

What LLM providers does RAGAS work with?

RAGAS defaults to OpenAI's API but supports custom LLMs via its llm_factory interface. It uses embeddings for similarity-based metrics and can be configured with different providers.

What frameworks does RAGAS integrate with?

RAGAS integrates with LangChain and LlamaIndex for pipeline construction, and supports observability tools such as LangSmith and Langfuse for production monitoring.

Can RAGAS evaluate AI agents?

Yes. RAGAS includes evaluation support for agentic workflows, covering multi-turn conversations, tool calls, and metrics like TopicAdherenceScore to assess goal adherence across agent interactions.

As of the data available to us, the RAGAS repository has over 13,200 stars and 1,300 forks, with 240 contributors and active development.

What problems do users report with RAGAS?

Reported issues include rate limiting errors during evaluation runs, broken links to the app.ragas.io dashboard, and breaking changes when migrating from version 0.3 to version 0.4 due to a new experiment-based architecture.

Is RAGAS suitable for production monitoring?

Yes. RAGAS includes tools for continuous monitoring of RAG performance in production, including detection of data drift and performance degradation over time.

What programming language is RAGAS written in?

RAGAS is written in Python and is available as a pip-installable package.

Are there tutorials available for RAGAS?

The official documentation at docs.ragas.io includes tutorials for evaluating prompts, simple RAG systems, AI workflows, and AI agents.

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