Architecting Deterministic Multi-Agent Swarms with LangGraph and Hybrid Vector RAG in Production

import asynciofrom typing import TypedDictfrom langgraph.graph import StateGraph, END class UnderwritingState(TypedDict):    document_url: str    extracted: dict    context: list[dict]    confidence: float async def vision_extract(state: UnderwritingState):    payload = await vision_agent.parse(state["document_url"])    return {"extracted": payload} async def hybrid_retrieve(state: UnderwritingState):    return {"context": await retriever.search(state["extracted"])} async def validate(state: UnderwritingState):    payload = UnderwritingPayload(**state["extracted"])    return {"confidence": payload.confidence} graph = StateGraph(UnderwritingState)graph.add_node("vision_extract", vision_extract)graph.add_node("hybrid_retrieve", hybrid_retrieve)graph.add_node("validate", validate)graph.set_entry_point("vision_extract")graph.add_edge("vision_extract", "hybrid_retrieve")graph.add_edge("hybrid_retrieve", "validate")graph.add_conditional_edges("validate", route_confidence, {    "push": "erp_push",    "review": END,})app = graph.compile()

from typing import Literalfrom pydantic import BaseModel, Field, field_validator class UnderwritingPayload(BaseModel):    applicant_id: str = Field(min_length=8)    loan_amount: float = Field(gt=0, le=5_000_000)    risk_tier: Literal["A", "B", "C", "D"]    confidence: float = Field(ge=0.0, le=1.0)     @field_validator("applicant_id")    @classmethod    def validate_id(cls, value: str) -> str:        if not value.startswith("APP-"):            raise ValueError("Invalid applicant identifier")        return value