pagepiper/app/services/synthesizer.py
pyr0ball 17cdb552a3 fix: T7 quality — SynthesisResult.citations tuple, retriever comments, test assertion
- SynthesisResult.citations changed from list[Citation] to tuple[Citation, ...]
  so frozen=True dataclass is genuinely immutable end-to-end
- synthesize() now builds tuple via generator expression
- retriever._combined: add comment explaining L2 distance inversion
- retriever.hybrid_search: comment on _bm25._chunks private access
- test_synthesizer_builds_context_from_chunks: drop vacuous str(call_args)
  fallback; assert directly on call_args.args[0]
2026-05-04 17:51:22 -07:00

58 lines
1.5 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
@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],
)
for c in chunks
)
return SynthesisResult(answer=answer, citations=citations)