pagepiper/app/services/synthesizer.py
pyr0ball 6fc8e7faa6 fix: wire bm25_score through Citation so Natural 20 easter egg fires
Citation dataclass gains bm25_score field populated from the retrieved
chunk. chat.py serializes it. api.ts interface updated to include it.
ChatView passes :bm25-score to CitationPanel so the Nat20 threshold
check in onMounted actually has data to evaluate.
2026-05-04 20:01:20 -07:00

60 lines
1.6 KiB
Python

# app/services/synthesizer.py
"""
LLM answer synthesis over retrieved chunks.
BSL 1.1 — requires LLMRouter (Ollama BYOK or cloud tier).
"""
from __future__ import annotations
from dataclasses import dataclass
from app.services.retriever import RetrievedChunk
_SYSTEM_PROMPT = (
"You are a helpful document assistant. "
"Answer the user's question using ONLY the provided document excerpts. "
"For each claim, cite the source page as [p.N]. "
"If the excerpts are insufficient, say so. Do not invent information."
)
@dataclass(frozen=True)
class Citation:
doc_id: str
page_number: int
snippet: str
bm25_score: float
@dataclass(frozen=True)
class SynthesisResult:
answer: str
citations: tuple[Citation, ...]
class Synthesizer:
def __init__(self, llm) -> None: # LLMRouter
self._llm = llm
def synthesize(
self,
message: str,
history: list[dict],
chunks: list[RetrievedChunk],
) -> SynthesisResult:
context_parts = [f"[p.{c.page_number}]\n{c.text[:500]}" for c in chunks]
context = "\n\n---\n\n".join(context_parts)
prompt = f"Document excerpts:\n\n{context}\n\nQuestion: {message}"
answer = self._llm.complete(prompt, system=_SYSTEM_PROMPT)
citations = tuple(
Citation(
doc_id=c.doc_id,
page_number=c.page_number,
snippet=c.text[:200],
bm25_score=c.bm25_score,
)
for c in chunks
)
return SynthesisResult(answer=answer, citations=citations)