Bookshelf Séance

Description and use

Bookshelf Séance lets users ask questions of deceased authors, answering only with passages from the author’s own works and providing citations, all while keeping the data local.

Problem

How to converse with deceased authors using only passages from their own books, without uploading private EPUBs to external servers.

Outcome

The demo ran on a GitHub Actions runner with 2 CPU cores, no GPU, and completed a three‑question session in 44 seconds, demonstrating that the system can answer questions using only cited passages and silence when no relevant text exists.

Workflow

• 1. Run seance ingest to read each EPUB, extract metadata, split chapters into ~120‑word passages, and build a JSON index in ~/.seance.
• 2. Run seance summon <author> to rank passages with BM25 against the user’s question.
• 3. If no passage scores above a silence threshold, the program outputs “The spirits are silent on this.” and stops.
• 4. If passages qualify, send the top passages to a local Gemma model via Ollama with a prompt to answer in first person using only those passages and citing them as [n].
• 5. After the model returns, the program verifies that every cited [n] corresponds to a passage that was actually provided; if not, the answer is discarded and silence is returned.

Evidence

Bookshelf Séance lets you talk with the dead authors on your own bookshelf.

Source

The ghost may speak only through passages from its own books, and it must cite them.

Source

If no passage scores high enough, the program stops there. No model call, no guessing.

Source

The demo uses gemma4:e2b, the smallest Gemma 4, so it runs without a GPU: the run above took 44 seconds on 2 CPU cores.

Source

The only network request the program makes is to Ollama on localhost.

Source