OpenFable – Open-source RAG engine using tree-structured indexes
Hi HN, I built OpenFable, an open-source retrieval engine that implements the FABLE algorithm (https://arxiv.org/abs/2601.18116) for RAG pipelines. I'm using it in another project and thought that others might benefit. Most RAG systems chunk documents into flat segments and retrieve by vector similarity. This works for simple lookups but breaks when answers span multiple sections, when relevant content is buried in a subsection, or when you need to control how many tokens you're sending to an LLM. OpenFable takes a different approach: when you ingest a document, it uses…
OpenFable – Open-source RAG engine using tree-structured indexes launched on April 8, 2026 with 5 votes, #1,846 of 21,248 launches that month and more than 75% of that year's launches.
What it does
An open-source retrieval engine implementing FABLE — structured, hierarchy-aware RAG - alainbrown/openfable
In the maker’s words, at launch
Hi HN, I built OpenFable, an open-source retrieval engine that implements the FABLE algorithm (https://arxiv.org/abs/2601.18116) for RAG pipelines. I'm using it in another project and thought that others might benefit. Most RAG systems chunk documents into flat segments and retrieve by vector…
Does a similar job
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