AI tools for building AI agents: RAG and documents
Retrieval tools that let agents search documents, PDFs and knowledge bases and answer from them (RAG). Of the 204 tools on our building AI agents page, 22 fit this narrower job. By pricing: 19 open source, 1 source-available, 1 free or freemium, 1 pricing on the maker's site. The most-starred open repos here are RAGFlow (92,335 stars), Context7 (63,157 stars), PrivateGPT (57,594 stars). Most come from the frameworks (16), MCP & infra (3), productivity (1) categories.
RAGFlow
Open-source RAG engine with deep document parsing and agent features for building grounded question-answering over your files.
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Context7
MCP server and platform that feeds coding agents up-to-date, version-specific library documentation.
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PrivateGPT
Open-source API layer that turns local models into private AI applications, with RAG, tools, skills, MCP and text-to-SQL on any OpenAI-compatible server.
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LlamaIndex
Framework for agents over your data (RAG, document agents).
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AstrBot
Open-source agent chatbot platform and framework that connects LLMs, plugins and tools to mainstream messaging apps for assistants, support bots and knowledge bases.
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MindsHub
MindsDB's agent workspace for research, analysis, documents and coding, with a model router, a scoped vault for connected data and swappable open-source agent harnesses.
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PageIndex
Document index for reasoning-based, vectorless RAG that lets agents navigate long documents like a table of contents.
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DSPy
Stanford framework for programming rather than prompting language models, with optimizers that tune prompts and weights for RAG pipelines and agent loops.
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ScrapeGraphAI
Python library that uses LLMs and graph logic to build scraping pipelines: describe the data you want and it extracts it from websites or documents.
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Serena
MCP toolkit that gives coding agents semantic code retrieval and editing, like IDE features.
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Haystack
Open-source orchestration framework for building production LLM apps, RAG and agents.
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llmware
Framework for building private, local RAG and agent applications with small specialized models on AI PCs, edge and self-hosted setups.
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txtai
All-in-one Python framework for semantic search, LLM orchestration and agents built on an embeddings database of vector, graph and relational indexes.
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UltraRAG
Low-code MCP-based framework from OpenBMB for building and debugging complex RAG pipelines with visible reasoning logic.
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Kiln
Free desktop app and open-source library for building AI systems with evals, RAG, agents, fine-tuning and synthetic data in one workbench.
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DocETL
System for agentic, LLM-powered document processing and ETL pipelines from UC Berkeley.
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SimpleMem
Research-backed lifelong memory library for LLM agents that stores, compresses and retrieves text and multimodal memories, usable over MCP.
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Neuron AI
PHP framework for creating and orchestrating AI agents with LLMs, tools, vector stores and memory.
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Langchain.rb
Ruby library for building LLM-powered applications, RAG and assistants.
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Agentset
Open-source RAG platform for building agents and apps that answer accurately from your documents.
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BaseAI
Web AI framework from Langbase for building AI agents with memory (RAG) and deploying them serverless.
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Mastra
TypeScript framework for agents, workflows and RAG.
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GitHub repos (19)
| Repo | GitHub stars | Licence | Last push |
|---|---|---|---|
| RAGFlow ↗ | 92,335 | Apache License 2.0 | 2026-10-17 |
| Context7 ↗ | 63,157 | MIT | 2026-10-17 |
| PrivateGPT ↗ | 57,594 | — | — |
| LlamaIndex ↗ | 52,485 | MIT | 2026-10-14 |
| AstrBot ↗ | 42,095 | — | — |
| MindsHub ↗ | 39,800 | MIT | 2026-09-10 |
| PageIndex ↗ | 39,186 | MIT | 2026-10-16 |
| DSPy ↗ | 38,676 | — | — |
| ScrapeGraphAI ↗ | 31,882 | — | — |
| Serena ↗ | 30,329 | GPL-3.0-or-later for the Serena application; MIT for SolidLSP | 2026-10-15 |
| Haystack ↗ | 26,748 | Apache License 2.0 | 2026-10-16 |
| llmware ↗ | 14,814 | — | — |
| txtai ↗ | 13,024 | — | — |
| UltraRAG ↗ | 5,729 | — | — |
| Kiln ↗ | 5,195 | — | — |
Top 15 of 19 by stars. Stars and licence come from each repo, checked when the listing was last verified.
FAQ
What are the best AI tools for building AI agents focused on RAG and documents?
We list 22. The first three by GitHub stars and featured status are RAGFlow: Open-source RAG engine with deep document parsing and agent features for building grounded question-answering over your files.; Context7: MCP server and platform that feeds coding agents up-to-date, version-specific library documentation.; PrivateGPT: Open-source API layer that turns local models into private AI applications, with RAG, tools, skills, MCP and text-to-SQL on any OpenAI-compatible server.
Are there free or open-source options?
Yes: 19 open source, 1 source-available, 1 free or freemium, 1 pricing on the maker's site. Pricing is as each maker states it.
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