Enterprise RAG Architecture: A Complete Technical Guide by AgenixHub

Shubham — Thu, 18 Dec 2025 11:55:11 +0000

Introduction

Enterprise RAG (Retrieval-Augmented Generation) is an architecture that combines enterprise data retrieval systems with large language models to generate context-aware, grounded responses.

This guide shows you how to build production-grade RAG systems with security and compliance built-in.

Architecture Overview

┌─────────────┐     ┌──────────────┐     ┌─────────────┐
│  User Query │────▶│  Embedding   │────▶│   Vector    │
└─────────────┘     │    Model     │     │   Database  │
                    └──────────────┘     └──────┬──────┘
                                                 │
                                                 ▼
                    ┌──────────────┐     ┌──────────────┐
                    │     LLM      │◀────│  Permission  │
                    │  Generation  │     │   Filter     │
                    └──────┬───────┘     └──────────────┘
                           │
                           ▼
                    ┌──────────────┐
                    │   Response   │
                    │   + Sources  │
                    └──────────────┘

Implementation

Step 1: Document Ingestion

from langchain.text_splitter import RecursiveCharacterTextSplitter
from openai import OpenAI

client = OpenAI()

# Chunk documents semantically
text_splitter = RecursiveCharacterTextSplitter(
    chunk_size=512,
    chunk_overlap=50,
    separators=["\n\n", "\n", ".", "!","?", ",", " ", ""]
)

chunks = text_splitter.split_text(document.content)

# Generate embeddings
embeddings = client.embeddings.create(
    model="text-embedding-ada-002",
    input=chunks
)

# Store with metadata
for i, (chunk, embedding) in enumerate(zip(chunks, embeddings.data)):
    vector_db.insert(
        id=f"{document.id}_{i}",
        vector=embedding.embedding,
        metadata={
            "document_id": document.id,
            "permissions": document.permissions,  # Critical for security
            "classification": document.classification,
            "source": document.url
        }
    )

Step 2: Retrieval with Permission Filtering

def retrieve_with_permissions(query: str, user: User, top_k: int = 5):
    # Embed query
    query_embedding = client.embeddings.create(
        model="text-embedding-ada-002",
        input=query
    ).data[0].embedding

    # Search vector DB with permission filter
    results = vector_db.search(
        query_embedding=query_embedding,
        filter={
            "permissions": {"$in": user.roles},  # Only docs user can access
            "classification": {"$lte": user.clearance_level}
        },
        top_k=top_k
    )

    # Log retrieval for audit
    audit_log.record({
        "user_id": user.id,
        "query": query,
        "documents_accessed": [r.metadata["document_id"] for r in results],
        "timestamp": datetime.utcnow()
    })

    return results

Step 3: LLM Generation with Citations

def generate_response(query: str, retrieved_chunks: List[Chunk]):
    # Construct prompt with sources
    context = "\n\n".join([
        f"Source {i+1} ({chunk.metadata['source']}):\n{chunk.text}"
        for i, chunk in enumerate(retrieved_chunks)
    ])

    prompt = f"""Answer the question using ONLY the provided context.
You MUST cite sources using [Source N] notation.
If the answer is not in the context, say "I don't have enough information."

Context:
{context}

Question: {query}

Answer:"""

    response = client.chat.completions.create(
        model="gpt-4",
        messages=[{"role": "user", "content": prompt}],
        temperature=0.1  # Low temp for factual responses
    )

    return response.choices[0].message.content

Security Best Practices

Encrypt vectors in database (AES-256)
Filter by permissions before sending to LLM
Audit all queries with immutable logs
Scan responses for PII leakage
Rate limit to prevent data exfiltration

Performance Optimization

# Use re-ranking for better relevance
from sentence_transformers import CrossEncoder

reranker = CrossEncoder('cross-encoder/ms-marco-MiniLM-L-6-v2')

def rerank_results(query: str, results: List[Chunk], top_k: int = 5):
    # Score query-chunk pairs
    pairs = [[query, chunk.text] for chunk in results]
    scores = reranker.predict(pairs)

    # Return top-k after re-ranking
    ranked = sorted(zip(results, scores), key=lambda x: x[1], reverse=True)
    return [chunk for chunk, score in ranked[:top_k]]

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