LlamaIndex
by LlamaIndex, Inc. · Framework · also known as llama_index, GPT Index, LlamaIndex Framework
Open-source Python framework for retrieval-augmented agents over your data, with connectors, indexes, query engines and event-driven workflows, alongside the commercial LlamaParse document platform
Overview
LlamaIndex is an MIT-licensed Python toolkit for building LLM agents and retrieval pipelines over private data. Its building blocks are data connectors (loaders for files, APIs and databases), indexes backed by many vector stores, query and chat engines, agents with tools, and Workflows, an event-driven system for multi-step processes with branching, retries and human review that can be deployed as services. A retrieval pipeline is treated as one tool among others that an agent may call. Documentation moved in 2026 from docs.llamaindex.ai to developers.llamaindex.ai, and a TypeScript edition exists alongside the Python core.
The company behind the framework sells LlamaParse, a hosted document-processing platform (formerly named LlamaCloud) that parses, extracts, classifies and splits documents and offers a managed index; its output feeds directly into framework indexes. Plans for the hosted platform range from a free tier through Starter, Pro and Enterprise, while the framework itself stays free. LlamaIndex is a good fit when documents are the center of the problem; teams needing generic agent orchestration may find LangGraph or Pydantic AI more direct, and the breadth of integrations means dependency management deserves attention.
Capabilities
- Data connectors for files, APIs and databases
- Indexes over many vector stores with query and chat engines
- Agents with tools and event-driven Workflows
- Evaluation and observability hooks
- Integration with LlamaParse for document parsing and extraction
- Python core with a TypeScript edition
Typical workflows
- Index a folder of PDFs and answer questions with citations
- Build a workflow that parses invoices, extracts fields and routes exceptions to a human
- Combine a retrieval tool with web search in one agent
Strengths
- Document-centric design with mature retrieval abstractions
- MIT license and broad integration catalog
- Commercial parsing service available when needed
Limitations
- Many optional dependencies to manage
- Hosted LlamaParse features are proprietary and metered
- Product renames (LlamaCloud to LlamaParse) date older guides
Prerequisites
- Python 3.10+
- An LLM and embedding provider or local equivalents
Who it is for
- Developers building RAG applications
- Teams processing document-heavy workflows
- Researchers indexing corpora for question answering
Alternatives & comparison
- LangChain
Open-source Python and JavaScript framework whose create_agent harness builds tool-using agents on the LangGraph runtime with swappable model providers and middleware
Open sourceOpen source - LangGraph
Low-level orchestration framework and runtime for stateful, long-running agents expressed as graphs, with durable execution, checkpointing, human-in-the-loop and streaming
Open sourceOpen source - Pydantic AI
Type-safe Python agent framework from the Pydantic team with validated structured outputs, dependency injection, swappable model providers, MCP, durable execution and evals
Open sourceOpen source - Ragas
Open-source Python library for evaluating LLM and RAG applications with LLM-driven and custom metrics, experiments, dataset management and result tracking
Open sourceOpen source
Sources & verification
Primary sources consulted for this record. Claims are tied to the fields each source supports; the automated link checker re-verifies every URL on a schedule.
- Licensehttps://github.com/run-llama/llama_index/blob/main/LICENSEchecked Nov 1, 2026
Supports: license_spdx, source_model
- Official documentationLlamaIndex Framework documentationchecked Nov 1, 2026
https://developers.llamaindex.ai/python/framework
Supports: capabilities, license_spdx, languages
States MIT license and the LlamaCloud→LlamaParse rename
- Official sitechecked Nov 1, 2026
- Pricing pagehttps://www.llamaindex.ai/pricingchecked Nov 1, 2026
Supports: pricing_model
- Confidence
- High
- Reviewed
- Nov 1, 2026
- Links
- Verified · Nov 2, 2026
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