---
title: "I Will Build Custom AI Agents and RAG Applications"
url: https://zinnhub.com/zinns/build-ai-agents-and-rag-applications-with-langchain-and-langgraph/
description: "Get a production-ready AI agent powered by LangChain, LangGraph, and your choice of OpenAI or a local open-source LLM — complete with source code, documentation, and a working frontend."
published: 2025-12-17T22:57:01+00:00
modified: 2026-10-19T17:40:51+00:00
language: en-GB
---

# I Will Build Custom AI Agents and RAG Applications

If your business needs an intelligent AI agent that actually works — one that answers questions, retrieves information from your own data, automates workflows, or handles customer conversations — this is the service for you.

Built by a full-stack AI engineer based in London, every solution is custom-developed using LangChain, LangGraph, LangSmith, and FastAPI. Whether you want to use the OpenAI API or keep everything private with a local open-source model such as LLaMA 3 or Mistral, your agent is configured to your exact requirements.

\*\*What you receive:\*\*

Every engagement includes a fully working AI agent integrated with your chosen LLM, user authentication, complete source code, and setup documentation. Depending on the package you select, your delivery can also include a Retrieval-Augmented Generation (RAG) pipeline [trained on your](https://zinnhub.com/zinns/create-ai-chatbot-websites-saas-with-langchain-manychat-generative-ai/) own documents, a pre-set conversational journey for guided interactions, and full CRM or database integration.

Frontend delivery is available in React.js with Tailwind CSS or as a Streamlit interface — whichever suits your team’s stack. The backend is served via a FastAPI application, deployable to your own server or cloud platform.

\*\*How the process works:\*\*

After placing your order, simply share your requirements, your preferred LLM (OpenAI or local), and any data or documents the agent should work with. Clear, direct communication happens through the order chat. You will receive regular updates, and revisions are included at every tier. If anything needs clarifying before work begins, you will be contacted promptly.

\*\*Who this is for:\*\*

This service is ideal for startups and established businesses that want AI-powered customer support, internal knowledge base agents, or intelligent automation — without having to manage the complexity of AI infrastructure themselves. It suits technical founders who want clean, handover-ready source code, as well as non-technical teams who simply need a working solution with documentation they can follow.

\*\*Why work with this seller:\*\*

Zinn Digital is a London-based AI engineering practice specialising end-to-end in generative AI, custom chatbots, RAG systems, and multi-agent LangGraph workflows. Every project is delivered with full source code — you own what you pay for. Solutions are built to integrate with real business systems, not just demonstrate a proof of concept.