The shortlist
Chat over your own documents — the most-built agent app there is. The open-source field offers a visual platform route and a code-first pipeline route; pick by who's going to maintain it.
153k stars · Open source · TypeScript
Visual builder, RAG pipelines, and agent workflows in one self-hostable platform — one of the most adopted projects in the index, strong when non-engineers need to iterate on prompts and flows.
— You need deep programmatic control beyond what a visual platform allows.
26k stars · Open source · Python
The mature Python framework for retrieval pipelines — full control over chunking, retrieval, and ranking when quality tuning matters more than a visual editor.
29k stars · Open source · TypeScript
A knowledge-base-first platform with strong out-of-the-box document Q&A — the quickest of the three to a working assistant on a folder of docs.
— You want to offer it as a SaaS — the license forbids that without commercial authorization.
RAG quality is a data problem before it's a model problem: bad chunking and stale documents produce confident wrong answers. Build a small eval set of real questions first, and re-index on a schedule — an assistant over last quarter's docs is worse than none.
