Haystack vs LlamaIndex

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Haystack is an open-source AI orchestration framework for building production-ready LLM applications in Python.

Design modular pipelines and agent workflows with explicit control over retrieval, routing, memory, and generation. Build scalable RAG systems, multimodal applications, semantic search, question answering, and autonomous agents, all in a transparent architecture that lets you experiment, customize deeply, and deploy with confidence.

Table of Contents

• Installation
• Documentation
• Features
• Haystack Enterprise: Support & Platform
• Telemetry
• 🖖 Community
• Contributing to Haystack
• Organizations using Haystack

Installation

The simplest way to get Haystack is via pip:

pip install haystack-ai

Install nightly pre-releases to try the newest features:

pip install --pre haystack-ai

Haystack supports multiple installation methods, including Docker images. For a comprehensive guide, please refer
to the documentation.

Documentation

If you're new to the project, check out "What is Haystack?" then go
through the "Get Started Guide" and build your first LLM application
in a matter of minutes. Keep learning with the tutorials. For more advanced
use cases, or just to get some inspiration, you can browse our Haystack recipes in the
Cookbook.

At any given point, hit the documentation to learn more about Haystack, what it can do for you, and the technology behind.

Features

Agents built for production
Extend agent behavior with lifecycle hooks (before_llm, before_tool, on_exit, …) for guardrails and custom logic, and track step_count, token_usage, and tool calls out of the box for monitoring and cost control. Get started fast with ready-made agents from Agent Pack (e.g., a deep research agent, or an advanced RAG agent) or give your own agents progressive skill discovery via SkillToolset, so skill descriptions only enter context when needed.

Built for context engineering
Design flexible systems with explicit control over how information is retrieved, ranked, filtered, combined, structured, and routed before it reaches the model. Define pipelines and agent workflows where retrieval, memory, tools, and generation are transparent and traceable.

Native Async Support
One Pipeline runs synchronously or asynchronously and streams token by token. Agent can run concurrent tool calls.

Modular and customizable
Use built-in components for retrieval, indexing, tool calling, memory, and evaluation, or create your own. Add loops, branches, and conditional logic to precisely control how context moves through your pipelines and agent workflows.

Model- and vendor-agnostic
Integrate with OpenAI, Mistral, Anthropic, Cohere, Hugging Face, Google, Azure OpenAI, AWS Bedrock, local models, and many others. Swap models or infrastructure components without rewriting your system.

Extensible ecosystem
Build and share custom components through a consistent interface that makes it easy for the community and third parties to extend Haystack and contribute to an open ecosystem.

[!TIP]

Would you like to deploy and serve Haystack pipelines as REST APIs or MCP servers? Hayhooks provides a simple way for you to wrap pipelines and agents with custom logic and expose them through HTTP endpoints or MCP. It also supports OpenAI-compatible chat completion endpoints and works with chat UIs like open-webui.

Haystack Enterprise: Support & Platform

Get expert support from the Haystack team, build faster with enterprise-grade templates, and scale securely with deployment guides for cloud and on-prem environments with Haystack Enterprise Starter. Read more about it in the announcement post.

👉 Get Haystack Enterprise Starter

Need a managed production setup for Haystack? The Haystack Enterprise Platform helps you build, test, deploy and operate Haystack pipelines with built-in observability, collaboration, governance, and access controls. It’s available as a managed cloud service or as a self-hosted solution.

👉 Learn more about Haystack Enterprise Platform or try it free

Telemetry

Haystack collects anonymous usage statistics of pipeline components. We receive an event every time these components are initialized. This way, we know which components are most relevant to our community.

Read more about telemetry in Haystack or how you can opt out in Haystack docs.

🖖 Community

If you have a feature request or a bug report, feel free to open an issue in GitHub. We regularly check these, so you can expect a quick response. If you'd like to discuss a topic or get more general advice on how to make Haystack work for your project, you can start a thread in Github Discussions or our Discord channel. We also check 𝕏 (Twitter) and Stack Overflow.

Contributing to Haystack

We are very open to the community's contributions - be it a quick fix of a typo, or a completely new feature! You don't need to be a Haystack expert to provide meaningful improvements. To learn how to get started, check out our Contributor Guidelines first.

There are several ways you can contribute to Haystack:

• Contribute to the main Haystack project
• Contribute an integration on haystack-core-integrations
• Contribute to the documentation in haystack/docs-website

[!TIP]
👉 Check out the full list of issues that are open to contributions

Organizations using Haystack

Haystack is used by thousands of teams building production AI systems across industries, including:

• Technology & AI Infrastructure: Apple, Meta, Databricks, NVIDIA, Intel
• Public Sector AI Initiatives: European Commission, German Federal Ministry of Research, Technology, and Space (BMFTR), PD, Baden-Württemberg State
• Enterprise & Industrial AI Applications: Airbus, Lufthansa Industry Solutions, Infineon, LEGO, Comcast, Accenture, TELUS Agriculture & Consumer Goods
• Knowledge & Content Platforms: Netflix, ZEIT Online, Rakuten, Oxford University Press, Manz, YPulse

Are you also using Haystack? Open a PR or tell us your story

🗂️ LlamaIndex Framework 🦙

[!NOTE]
The current focus of LlamaIndex is to build the best AI-powered engine for document parsing and extraction. LlamaParse is our enterprise platform for agentic OCR, parsing, extraction, indexing and more. LiteParse represents our efforts to build the best free, fast, cheap text parser in the market. ParseBench and ExtractBench represent our commitment towards open benchmarking for parsing and extraction.

The company itself has undergone an evolution since when this OSS framework first launched 3 years ago in 2023. Since the early days, the framework has consisted of a broad set of orchestration tools enabling developers to build various RAG and agent applications.

While we still have the OSS framework available as an open toolkit that you're welcome to use, our primary focus has shifted towards LlamaParse, along with liteparse and our benchmarking efforts. We have a strong belief that agents are the new consumers of documents, and they fundamentally need the right tools to unlock context from the world's hardest documents accurately/cheaply at scale. Whether you're an AI startup processing documents or an enterprise looking to automate document workflows, come talk to us.

LlamaIndex Framework (by LlamaIndex, the company behind LlamaParse) is an open-source framework to build agentic applications. You can use LlamaParse with this framework or on its own; see LlamaParse below for signup and product links.

📚 Documentation:

• LlamaParse
• LlamaIndex Framework
• LlamaAgents

Building with LlamaIndex typically involves working with LlamaIndex core and a chosen set of integrations (or plugins). There are two ways to start building with LlamaIndex in
Python:

1. Starter: llama-index. A starter Python package that includes core LlamaIndex as well as a selection of integrations.

2. Customized: llama-index-core. Install core LlamaIndex and add your chosen LlamaIndex integration packages from the integrations page
   that are required for your application. There are over 300 LlamaIndex integration
   packages that work seamlessly with core, allowing you to build with your preferred
   LLM, embedding, and vector store providers.

The LlamaIndex Python library is namespaced such that import statements which
include core imply that the core package is being used. In contrast, those
statements without core imply that an integration package is being used.

## typical pattern
from llama_index.core.xxx import ClassABC  # core submodule xxx
from llama_index.xxx.yyy import (
    SubclassABC,
)  # integration yyy for submodule xxx

## concrete example
from llama_index.core.llms import LLM
from llama_index.llms.openai import OpenAI

LlamaParse (document agent platform)

LlamaParse is its own platform—focused on document agents and agentic OCR. It includes Parse (parsing), LlamaAgents (deployed document agents), Extract (structured extraction), and Index (ingest and RAG). You can use it with the LlamaIndex framework or standalone.

• Sign up for LlamaParse — Create an account and get your API key.
• Parse — Agentic OCR and document parsing (130+ formats). Docs
• Extract — Structured data extraction from documents. Docs
• Index — Ingest, index, and RAG pipelines. Docs
• Split — Split large documents into subcategories. Docs
• Agents — Build end-to-end document agents with Workflows and Agent Builder. Docs

Important Links

Documentation

X (formerly Twitter)

LinkedIn

Reddit

Discord

🚀 Overview

NOTE: This README is not updated as frequently as the documentation. Please check out the documentation above for the latest updates!

Context

• LLMs are a phenomenal piece of technology for knowledge generation and reasoning. They are pre-trained on large amounts of publicly available data.
• How do we best augment LLMs with our own private data?

We need a comprehensive toolkit to help perform this data augmentation for LLMs.

Proposed Solution

That's where LlamaIndex comes in. LlamaIndex is a "data framework" to help you build LLM apps. It provides the following tools:

• Offers data connectors to ingest your existing data sources and data formats (APIs, PDFs, docs, SQL, etc.).
• Provides ways to structure your data (indices, graphs) so that this data can be easily used with LLMs.
• Provides an advanced retrieval/query interface over your data: Feed in any LLM input prompt, get back retrieved context and knowledge-augmented output.
• Allows easy integrations with your outer application framework (e.g. with LangChain, Flask, Docker, ChatGPT, or anything else).

LlamaIndex provides tools for both beginner users and advanced users. Our high-level API allows beginner users to use LlamaIndex to ingest and query their data in
5 lines of code. Our lower-level APIs allow advanced users to customize and extend any module (data connectors, indices, retrievers, query engines, reranking modules),
to fit their needs.

💡 Contributing

Interested in contributing? Contributions to LlamaIndex core as well as contributing
integrations that build on the core are both accepted and highly encouraged! See our Contribution Guide for more details.

New integrations should meaningfully integrate with existing LlamaIndex framework components. At the discretion of LlamaIndex maintainers, some integrations may be declined.

📄 Documentation

Full documentation can be found here

Please check it out for the most up-to-date tutorials, how-to guides, references, and other resources!

💻 Example Usage

## custom selection of integrations to work with core
pip install llama-index-core
pip install llama-index-llms-openai
pip install llama-index-llms-ollama
pip install llama-index-embeddings-huggingface

Examples are in the docs/examples folder. Indices are in the indices folder (see list of indices below).

To build a simple vector store index using OpenAI:

import os

os.environ["OPENAI_API_KEY"] = "YOUR_OPENAI_API_KEY"

from llama_index.core import VectorStoreIndex, SimpleDirectoryReader

documents = SimpleDirectoryReader("YOUR_DATA_DIRECTORY").load_data()
index = VectorStoreIndex.from_documents(documents)

To build a simple vector store index using non-OpenAI LLMs, e.g. LLMs hosted through Ollama:

from llama_index.core import Settings, VectorStoreIndex, SimpleDirectoryReader
from llama_index.embeddings.huggingface import HuggingFaceEmbedding
from llama_index.llms.ollama import Ollama
from transformers import AutoTokenizer

## set the LLM
Settings.llm = Ollama(
    model="llama-3.1:latest",
    request_timeout=360.0,
)

## set tokenizer to match LLM
Settings.tokenizer = AutoTokenizer.from_pretrained(
    "meta-llama/Llama-3.1-8B-Instruct"
)

## set the embed model
Settings.embed_model = HuggingFaceEmbedding(
    model_name="BAAI/bge-small-en-v1.5"
)

documents = SimpleDirectoryReader("YOUR_DATA_DIRECTORY").load_data()
index = VectorStoreIndex.from_documents(
    documents,
)

To query:

query_engine = index.as_query_engine()
query_engine.query("YOUR_QUESTION")

By default, data is stored in-memory.
To persist to disk (under ./storage):

index.storage_context.persist()

To reload from disk:

from llama_index.core import StorageContext, load_index_from_storage

## rebuild storage context
storage_context = StorageContext.from_defaults(persist_dir="./storage")
## load index
index = load_index_from_storage(storage_context)

A note on Verification of Build Assets

By default, llama-index-core includes a _static folder that contains the nltk and tiktoken cache that is included with the package installation. This ensures that you can easily run llama-index in environments with restrictive disk access permissions at runtime.

To verify that these files are safe and valid, we use the github attest-build-provenance action. This action will verify that the files in the _static folder are the same as the files in the llama-index-core/llama_index/core/_static folder.

To verify this, you can run the following script (pointing to your installed package):

#!/bin/bash
STATIC_DIR="venv/lib/python3.13/site-packages/llama_index/core/_static"
REPO="run-llama/llama_index"

find "$STATIC_DIR" -type f | while read -r file; do
    echo "Verifying: $file"
    gh attestation verify "$file" -R "$REPO" || echo "Failed to verify: $file"
done

📖 Citation

Reference to cite if you use LlamaIndex in a paper:

@software{Liu_LlamaIndex_2022,
author = {Liu, Jerry},
doi = {10.5281/zenodo.1234},
month = {11},
title = {{LlamaIndex}},
url = {https://github.com/jerryjliu/llama_index},
year = {2022}
}