Enterprise AI &
Custom LLM Engineering.

# Production LangGraph Cyclic Agent State Graph with Deterministic Validation
from typing import TypedDict, Annotated, Sequence
from langchain_core.messages import BaseMessage
from langgraph.graph import StateGraph, END
from langgraph.prebuilt import ToolNode

class AgentState(TypedDict):
    messages: Annotated[Sequence[BaseMessage], "add_messages"]
    domain_context: dict
    validation_attempts: int
    is_grounded: bool

def supervisor_router(state: AgentState):
    """Deterministic state router: verifies grounding before customer delivery"""
    if state["is_grounded"]:
        return "finalize_response"
    if state["validation_attempts"] >= 3:
        return "escalate_human_review"
    return "refine_retrieval"

workflow = StateGraph(AgentState)
workflow.add_node("research_agent", research_node)
workflow.add_node("grounding_evaluator", verify_grounding_node)
workflow.add_node("finalize_response", format_final_output)
workflow.add_node("escalate_human_review", trigger_slack_human_review)

workflow.set_entry_point("research_agent")
workflow.add_edge("research_agent", "grounding_evaluator")
workflow.add_conditional_edges(
    "grounding_evaluator",
    supervisor_router,
    {"finalize_response": "finalize_response", "refine_retrieval": "research_agent", "escalate_human_review": "escalate_human_review"}
)
app = workflow.compile()

# High-Precision Hybrid Retrieval: Qdrant Dense HNSW + BM25 Sparse + Cohere Rerank 3
from qdrant_client import QdrantClient, models
import cohere

qdrant = QdrantClient(url="https://qdrant.internal.vpc:6333", api_key=VAULT_KEY)
co = cohere.ClientV2(api_key=COHERE_KEY)

def hybrid_search_and_rerank(query: str, tenant_id: str, top_k: int = 5):
    # 1. Hybrid Dense + Sparse Search on Qdrant
    search_result = qdrant.query_points(
        collection_name="enterprise_kb",
        prefetch=[
            models.Prefetch(query=get_dense_embedding(query), using="dense", limit=25),
            models.Prefetch(query=get_sparse_bm25(query), using="sparse", limit=25),
        ],
        query=models.FusionQuery(fusion=models.Fusion.RRF),
        query_filter=models.Filter(must=[models.FieldCondition(key="tenant_id", match=models.MatchValue(value=tenant_id))])
    )
    
    # 2. Cross-Encoder Re-Ranking for Zero Hallucination Context
    documents = [p.payload["text"] for p in search_result.points]
    reranked = co.rerank(model="rerank-v3.5", query=query, documents=documents, top_n=top_k)
    
    return [documents[r.index] for r in reranked.results if r.relevance_score > 0.85]

# In-Flight Presidio PII Masking & NeMo Prompt Injection Interceptor
from presidio_analyzer import AnalyzerEngine
from presidio_anonymizer import AnonymizerEngine
from presidio_anonymizer.entities import OperatorConfig

analyzer = AnalyzerEngine()
anonymizer = AnonymizerEngine()

def sanitize_inbound_prompt(raw_user_input: str) -> str:
    # Detect SSN, Email, Credit Cards, Medical IDs
    results = analyzer.analyze(
        text=raw_user_input,
        entities=["PHONE_NUMBER", "EMAIL_ADDRESS", "CREDIT_CARD", "US_SSN"],
        language="en"
    )
    
    # Mask with cryptographic surrogate tokens
    anonymized = anonymizer.anonymize(
        text=raw_user_input,
        analyzer_results=results,
        operators={"DEFAULT": OperatorConfig("replace", {"new_value": "<REDACTED_PII>"})}
    )
    return anonymized.text

# Anthropic Model Context Protocol (MCP) Secure Enterprise Tool Server
from mcp.server.fastmcp import FastMCP
from pydantic import BaseModel, Field

mcp = FastMCP("Enterprise Billing Gateway")

class InvoiceQuery(BaseModel):
    customer_id: str = Field(..., description="UUID of the customer account")
    fiscal_quarter: str = Field(..., regex=r"^Q[1-4]-202[0-9]$")

@mcp.tool()
async def get_customer_invoices(query: InvoiceQuery) -> str:
    """Safely queries enterprise ERP for quarterly invoice line-items"""
    invoices = await db_pool.fetch(
        "SELECT id, total_usd, status FROM invoices WHERE cust_id = $1 AND quarter = $2",
        query.customer_id, query.fiscal_quarter
    )
    return format_json_response(invoices)