trustgraph/trustgraph-base/trustgraph/base/reranker_service.py
cybermaggedon 01cc8dbc64
feat: replace LLM edge scoring with cross-encoder reranker in GraphRAG (#1005)
Replace the three-prompt LLM scoring pipeline (kg-edge-scoring,
kg-edge-reasoning, kg-edge-selection) with a cross-encoder reranker
service backed by FlashRank. The new hop_and_filter() method performs
iterative graph traversal with semantic scoring at each hop, replacing
the previous follow_edges/get_subgraph approach.

- Add reranker service (trustgraph-base client/service, FlashRank processor)
- Add gateway dispatch for reranker via API and WebSocket
- Rewrite GraphRAG pipeline: hop_and_filter() with per-hop cross-encoder scoring
- Remove kg_prompt() and edge_score_limit from prompt client
- Update provenance: add tg:EdgeSelection type, tg:concept, tg:score predicates
- Update CLIs (tg-invoke-graph-rag, tg-show-explain-trace) for new metadata
- Add tg-invoke-reranker CLI tool
- Add tech spec and UX developer guidance
- Update all unit and integration tests
2026-06-30 14:36:37 +01:00

109 lines
2.7 KiB
Python

from __future__ import annotations
from argparse import ArgumentParser
import logging
from .. schema import (
RerankerRequest, RerankerResponse, RerankerResult, Error,
)
from .. exceptions import TooManyRequests
from .. base import FlowProcessor, ConsumerSpec, ProducerSpec, ParameterSpec
logger = logging.getLogger(__name__)
default_ident = "reranker"
default_concurrency = 1
class RerankerService(FlowProcessor):
def __init__(self, **params):
id = params.get("id")
concurrency = params.get("concurrency", 1)
super(RerankerService, self).__init__(**params | {
"id": id,
"concurrency": concurrency,
})
self.register_specification(
ConsumerSpec(
name = "request",
schema = RerankerRequest,
handler = self.on_request,
concurrency = concurrency,
)
)
self.register_specification(
ProducerSpec(
name = "response",
schema = RerankerResponse
)
)
self.register_specification(
ParameterSpec(
name = "model",
)
)
async def on_request(self, msg, consumer, flow):
try:
request = msg.value()
id = msg.properties()["id"]
logger.debug(f"Handling reranker request {id}...")
model = flow("model")
results = await self.on_rerank(
request.queries, request.documents,
request.limit, model=model,
)
await flow("response").send(
RerankerResponse(
error = None,
results = results,
),
properties={"id": id}
)
logger.debug("Reranker request handled successfully")
except TooManyRequests as e:
raise e
except Exception as e:
logger.error(f"Exception in reranker service: {e}", exc_info=True)
logger.info("Sending error response...")
await flow.producer["response"].send(
RerankerResponse(
error=Error(
type = "reranker-error",
message = str(e),
),
results=[],
),
properties={"id": id}
)
@staticmethod
def add_args(parser: ArgumentParser) -> None:
parser.add_argument(
'-c', '--concurrency',
type=int,
default=default_concurrency,
help=f'Concurrent processing threads (default: {default_concurrency})'
)
FlowProcessor.add_args(parser)