# Agentic RAG Architecture and Implementation: A Complete Technical Guide

> Learn agentic RAG architecture and implementation. This guide details how autonomous agents dynamically reformulate queries, orchestrate retrieval, and validate outputs.

- Repository: [NirDiamant/RAG_Techniques](https://github.com/nirdiamant/rag_techniques)
- Tags: architecture
- Published: 2026-02-19

---

**Agentic RAG enhances traditional retrieval-augmented generation by embedding autonomous decision-making capabilities that dynamically reformulate queries, orchestrate retrieval strategies, and validate outputs through automated unit tests.**

The `NirDiamant/RAG_Techniques` repository provides a production-ready implementation of Agentic RAG architecture that transforms static RAG pipelines into intelligent, self-correcting systems. This guide examines the end-to-end implementation found in `all_rag_techniques/Agentic_RAG.ipynb`, detailing how five tightly-coupled components work together to deliver contextually grounded responses with minimal hallucinations.

## What Is Agentic RAG?

Agentic RAG moves beyond simple retrieve-then-generate workflows by embedding **agency** into the retrieval system. Instead of treating retrieval as a fixed preprocessing step, the architecture enables the system to reason about user intent, detect ambiguity, and autonomously decide whether to expand, decompose, or reformulate queries before retrieval occurs.

This approach addresses critical limitations in standard RAG implementations, particularly when handling complex, multi-topic, or ambiguous queries that would otherwise return irrelevant context.

## Core Architecture Components

The implementation in `Agentic_RAG.ipynb` defines five tightly-coupled components that provide clear separation of concerns while enabling tight integration.

### Parser

The **Parser** ingests heterogeneous documents—including PDFs, CSVs, tables, and images—and converts them into clean, searchable text chunks. In [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py), the `encode_pdf` and `encode_from_string` functions handle document ingestion, while `replace_t_with_space` performs text normalization to ensure consistent chunking.

### Reranker

After initial retrieval, the **Reranker** re-orders the candidate chunks to surface the most relevant evidence. The implementation utilizes LangChain's ranking utilities integrated into the retrieval chain, ensuring that the final context passed to the language model contains only high-signal information rather than noise from the initial retrieval pass.

### Grounded Language Model (GLM)

The **GLM** generates answers strictly grounded in the retrieved context, minimizing hallucinations. The `create_question_answer_from_context_chain` function in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py) implements this component using a strict prompt template that restricts the model to provided context only.

### LM-Unit Tests

**LM-Unit Tests** provide automated validation of answer correctness, grounding, and reliability. The `QuestionAnswerFromContext` Pydantic model in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py) defines the validation schema, enabling structured output verification after each generation cycle.

### Agentic Orchestrator

The **Agentic Orchestrator** serves as the central decision engine, determining how to treat incoming queries based on detected characteristics such as ambiguity, length, or multi-topic complexity. As described in cells 25-27 of `Agentic_RAG.ipynb`, the orchestrator triggers appropriate sub-pipelines for multi-turn dialogue, query expansion, or query decomposition.

## End-to-End Data Flow

Understanding the sequential data flow clarifies how these components interact during execution:

1. **User query** enters the system and undergoes **agentic decision-making** to detect ambiguity or complexity.
2. **Query reformulation** occurs through expansion or decomposition, producing an optimized search query.
3. **Parser** processes the document corpus into a searchable **FAISS** vector store using `OpenAIEmbeddings`.
4. **Retriever** fetches top-k chunks for the reformulated query.
5. **Reranker** refines the chunk list to maximize relevance.
6. **GLM** receives the final context and generates a concise answer using the `question_answer_prompt_template`.
7. **LM-Unit** validates the answer against predefined correctness criteria using the `QuestionAnswerFromContext` model.

The complete pipeline executes in under 15 minutes on a standard GPU-enabled Colab instance, making it suitable for both rapid prototyping and production-grade deployments.

## Implementation Deep Dive

The technical implementation relies on specific utilities and design patterns found in the repository's core files.

### Vector Store and Chunking Strategy

The system uses **FAISS** for vector storage, populated with cleaned chunks processed through `replace_t_with_space` for text normalization. Chunking granularity is controlled via `RecursiveCharacterTextSplitter` with configurable `chunk_size` and `chunk_overlap` parameters, allowing optimization for different document types and retrieval granularity requirements.

### Prompt Engineering for Grounding

The GLM component enforces strict grounding through a template-only approach defined in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py):

```python
question_answer_prompt_template = """
For the question below, provide a concise but sufficient answer based ONLY on the provided context:
{context}
Question
{question}
"""

```

This template ensures the language model cannot hallucinate information outside the provided context window.

### Structured Output Validation

The pipeline uses Pydantic models to enforce output structure. The `QuestionAnswerFromContext` model validates that generated answers meet specific format requirements, enabling automated testing and reliable downstream processing without manual inspection.

## Practical Code Examples

The following snippets demonstrate the most common operations when implementing Agentic RAG using the repository's helper functions.

### Creating a Vector Store from PDF Documents

```python
from helper_functions import encode_pdf

# Initialize vector store from financial report

vectorstore = encode_pdf(
    "data/nike_2023_annual_report.txt",
    chunk_size=1000,
    chunk_overlap=200
)

```

### Retrieving Context for Specific Questions

```python
from helper_functions import retrieve_context_per_question

# Configure retriever with top-5 results

retriever = vectorstore.as_retriever(search_kwargs={"k": 5})
context_chunks = retrieve_context_per_question(
    "What were Nike's FY2023 revenue trends?",
    retriever
)

```

### Building the Answer Generation Chain

```python
from helper_functions import create_question_answer_from_context_chain
from langchain_openai import ChatOpenAI

# Initialize grounded language model

llm = ChatOpenAI(model="gpt-4o-mini", temperature=0)
qa_chain = create_question_answer_from_context_chain(llm)

```

### Generating Grounded Answers

```python
from helper_functions import answer_question_from_context

# Execute the full retrieval and generation pipeline

answer = answer_question_from_context(
    question="What were Nike's FY2023 revenue trends?",
    context=" ".join(context_chunks),
    question_answer_from_context_chain=qa_chain,
)
print(answer["answer_based_on_content"])

```

### Validating Outputs with LM-Unit Tests

```python
from helper_functions import QuestionAnswerFromContext
from pydantic import ValidationError

# Validate answer structure and content

try:
    validated = QuestionAnswerFromContext(
        answer_based_on_content=answer["answer_based_on_content"]
    )
    print("LM-Unit test passed")
except ValidationError as e:
    print("LM-Unit test failed:", e)

```

## Key Source Files and References

Understanding the repository structure helps navigate the implementation:

| File | Purpose | Location |
|------|---------|----------|
| **Agentic_RAG.ipynb** | Complete walkthrough with architecture diagrams and Colab integration | `all_rag_techniques/Agentic_RAG.ipynb` |
| **helper_functions.py** | Core utilities including `encode_pdf`, `create_question_answer_from_context_chain`, and `QuestionAnswerFromContext` | [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py) |
| **evalute_rag.py** | Evaluation framework adaptable for LM-Unit testing | [`evaluation/evalute_rag.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/evaluation/evalute_rag.py) |
| **nike_2023_annual_report.txt** | Sample financial data for testing | [`data/nike_2023_annual_report.txt`](https://github.com/NirDiamant/RAG_Techniques/blob/main/data/nike_2023_annual_report.txt) |

## Summary

Agentic RAG architecture transforms static retrieval systems into intelligent pipelines capable of autonomous decision-making. Key implementation takeaways include:

- The **five-component architecture** (Parser, Reranker, GLM, LM-Unit Tests, and Agentic Orchestrator) provides clear separation of concerns while enabling tight integration.
- **Query reformulation** through the Agentic Orchestrator allows the system to handle complex, ambiguous, or multi-topic queries that would fail in traditional RAG.
- **Grounded generation** enforced through strict prompt templates and Pydantic validation (`QuestionAnswerFromContext`) minimizes hallucinations and enables automated testing.
- The **FAISS-based vector store** with configurable chunking (`RecursiveCharacterTextSplitter`) optimizes retrieval granularity for different document types.
- Complete execution in under 15 minutes on GPU-enabled instances makes this suitable for both prototyping and production deployment.

## Frequently Asked Questions

### What distinguishes Agentic RAG from standard RAG implementations?

Standard RAG follows a fixed retrieve-then-generate pattern, while Agentic RAG introduces an **Agentic Orchestrator** that analyzes incoming queries for ambiguity, complexity, or multi-topic structure. This orchestrator can trigger query expansion, decomposition, or multi-turn dialogue strategies before retrieval occurs, resulting in more accurate and contextually appropriate responses than static pipelines.

### How does the Grounded Language Model prevent hallucinations?

The GLM component uses a strict **prompt-template-only approach** defined in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py). The template explicitly instructs the model to provide answers "based ONLY on the provided context," effectively constraining generation to retrieved evidence. Additionally, the `QuestionAnswerFromContext` Pydantic model enforces structured output validation, creating a secondary safeguard against ungrounded content.

### What is the purpose of LM-Unit Tests in the pipeline?

LM-Unit Tests provide **automated validation** of generated answers against predefined correctness criteria, grounding requirements, and reliability standards. Implemented through the `QuestionAnswerFromContext` Pydantic model in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py), these tests execute after each generation cycle to ensure outputs meet structural and content requirements before being returned to users or downstream systems.

### Can I adapt this implementation for domains other than financial reports?

Yes. The architecture is domain-agnostic, relying on the `encode_pdf` and `encode_from_string` utilities in [`helper_functions.py`](https://github.com/NirDiamant/RAG_Techniques/blob/main/helper_functions.py) to handle heterogeneous document types including PDFs, CSVs, tables, and images. By adjusting the `chunk_size` and `chunk_overlap` parameters in `RecursiveCharacterTextSplitter` and customizing the `question_answer_prompt_template` for your specific domain terminology, you can adapt the pipeline for legal contracts, medical literature, research papers, or technical documentation.