ChatGPT Application Development Services

ChatGPT application development that ships a product, not a browser tab.

ChatGPT is a model, not a product. What you need is a product built on top of it, with your data, your use cases, your safeguards, and your user experience. Generic ChatGPT integrations fail because they bolt the model onto an existing workflow without redesigning the workflow around what AI can actually do.
We build custom ChatGPT applications that are designed around your specific use case, from the prompt architecture to the data layer to the interface your users actually interact with.

  • GPT-4o, GPT-4 Turbo, and OpenAI API integration with your proprietary data

  • Custom prompt engineering and fine-tuning for your domain

  • RAG (retrieval-augmented generation) for accurate, source-backed responses

  • 20+ AI products shipped using OpenAI models

Recent outcomes

Conversational AI · B2B SaaS startup

70% queries automated

Built a domain-trained AI assistant that handled 70% of routine support queries without human intervention. Shipped in 12 weeks.

AI Document Processing · Financial services

20,000+ daily transactions

Built a GPT-4o extraction pipeline processing contracts and invoices. 20,000+ daily transactions, manual review eliminated.

Internal Knowledge Assistant · Professional services

12 weeks to production

Deployed a RAG-powered knowledge assistant on proprietary SOPs and policy documents. Staff find answers in seconds instead of searching SharePoint.

4.9
on Clutch
See our work

The problem

Sound familiar?

  • Your team is using ChatGPT manually when it should be automated into your workflow?

  • Generic AI chatbots giving wrong answers because they don't know your business?

Short answer

RaftLabs builds custom ChatGPT applications using GPT-4o and the OpenAI API for clients across the US, UK, Europe, Canada, GCC, South Africa, and Southeast Asia. We integrate proprietary data via RAG, engineer prompts for your use case, and ship the full product. 20+ AI products delivered. A focused application costs $20,000 to $50,000.

Key takeaways

  • RaftLabs has shipped 20+ AI products using OpenAI models including GPT-4o and GPT-4 Turbo.
  • A focused ChatGPT application typically costs $20,000 to $50,000 and ships in 12 weeks.
  • Full AI platforms with multiple use cases and custom integrations run $60,000 to $150,000.
  • RAG pipelines ground responses in your proprietary documents, eliminating hallucinations from unknown data.
  • One deployed AI assistant automated 70% of routine support queries without human intervention.

Trusted by

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The document that gets pasted into ChatGPT, then pasted back out.

Someone on your team opens ChatGPT.com, pastes in a contract, asks a question, and pastes the answer into an email. It works. It also happens dozens of times a day, by different people, with no record of what was asked or whether the answer was right.

A custom application removes the copy-paste. The model receives the document automatically, retrieves the answer from data you control, and writes the result into the workflow where it belongs. Your data is indexed and searchable, the prompts are engineered for your use case, and nobody guesses.

The gap between using ChatGPT and building on it is the gap between a browser tab and a product.

ChatGPT is a model, not a product. What ships value is the application built on top of it: your data, your use case, your safeguards, and the interface your users actually touch. RaftLabs has shipped 20+ AI products using OpenAI models like GPT-4o and GPT-4 Turbo, part of 100+ products delivered over 9+ years for clients including Vodafone, T-Mobile, Aldi, Nike, Cisco, and Lockheed Martin, rated 4.9/5 on Clutch. The team that scopes your application ships it: no offshore handoff after the contract is signed.

According to McKinsey's 2024 Global AI survey, 91% of employees report their organizations use at least one AI technology, yet only 6% of companies qualify as high performers achieving meaningful financial impact. The gap is almost always in the implementation: organizations using AI as a manual tool rather than a product embedded in their workflows.

If your use case requires retrieving accurate answers from a large document library, we build the RAG pipeline that connects GPT to your data. For integrations using Claude, Gemini, or open-source models, see our generative AI integration service.

This pays off when a real use case is already running by hand.

Everything on the left should already be true for your operation. Even one thing on the right, and copy-pasting into ChatGPT.com is still the smarter first step.

A fit
01

A specific, repeatable use case, support triage, document extraction, or internal knowledge search, that your team currently runs by hand in ChatGPT.com.

02

Proprietary data (documents, records, SOPs) the model needs to ground its answers in, plus systems to connect it to.

03

You need consistent, source-backed output at scale and budget for a build from $20,000.

Not a fit
  • A one-off task you run occasionally, where pasting into ChatGPT.com is already good enough.
  • No proprietary data to ground answers in, so a generic model would do the job.
  • You need a quick FAQ widget, not an application embedded in your workflow.

What we build

What we build with ChatGPT and OpenAI

  • 01
    Internal knowledge assistants
    An AI assistant that answers questions from your internal documents, policies, product knowledge, and SOPs, including content that lives in SharePoint. Staff get instant, accurate answers with sources cited, grounded in documents you control rather than a colleague's memory.
  • 02
    Customer support AI
    An AI layer that handles the first line of customer queries using your product documentation, FAQs, and support history. Complex queries escalate to human agents with context, so support volume and response time drop while CSAT rises.
  • 03
    Document processing and extraction
    AI that reads your documents, contracts, invoices, reports, and forms, and extracts structured data from them: reviewing contracts for specific clauses, classifying support emails by topic, or pulling line items from purchase orders. What took hours takes seconds.
  • 04
    AI copilots for existing software
    An AI assistant embedded in your existing CRM, ERP, or project management tool that helps users draft communications, generate reports, answer questions, or suggest next actions. The AI knows the context of what the user is doing because it can see the application data.
  • 05
    Content generation with approval workflows
    AI-generated content, product descriptions, email campaigns, social posts, and reports, with human review and approval before publishing. The AI does the first draft, humans edit and approve, and you get the volume without losing quality control.
  • 06
    Conversational data interfaces
    Query your database in plain English instead of writing SQL or waiting on the BI team for a report. Business users ask questions in natural language and get answers from your data, and we build the query translation layer, the data access controls, and the result presentation.

Building with ChatGPT vs. using ChatGPT

Most businesses start with ChatGPT.com. Teams use it manually, someone copies a document into the chat, asks a question, and pastes the answer somewhere else. That works until you want consistency, scale, or the AI to act on your data rather than public training data.

A custom ChatGPT application replaces the manual step with a product. The model receives your documents automatically, your data is indexed and searchable, the prompts are engineered for your use case, and the output flows into your workflow without anyone copying and pasting.

The difference between "using ChatGPT" and "building with ChatGPT" is the gap between a tool and a product.

Have a ChatGPT use case? Let's scope the application.

Tell us what you want to automate or improve with AI. We'll design the architecture and give you a fixed cost to build it.

How it works

How we work

  1. Step 01
    01

    Use case scoping

    We define exactly what the ChatGPT application needs to do, inputs, outputs, accuracy requirements, and what happens when the AI gets it wrong. Most projects fail because the use case is too vague. We get specific before we design anything.

    • Use case definition with input/output specification

    • Accuracy requirements and acceptable failure modes

    • User workflow mapping (who uses this, when, and why)

    • Fixed-cost scope agreed before any development begins

  2. Step 02
    02

    Data architecture & RAG

    If your application needs to answer questions from your proprietary data, we design the RAG pipeline, indexing your documents, database records, or knowledge base into a vector store that the model can search before generating a response. Your data, not public training data, drives the answers.

    • Knowledge base audit and ingestion pipeline design

    • Chunking strategy and embedding model selection

    • Vector store setup and indexing

    • Hybrid retrieval for maximum accuracy

  3. Step 03
    03

    Prompt engineering

    We build and test the system prompts that define how the model behaves for your use case, what it answers, how it answers, when it declines, and how it cites sources. Good prompt engineering is the difference between a useful product and an inconsistent demo.

    • System prompt design and constraint definition

    • Few-shot examples for domain-specific behaviour

    • Guardrail design for out-of-scope inputs

    • Output format specification for downstream use

  4. Step 04
    04

    Application build

    We build the application interface and backend, the UI your users interact with, the API layer that handles model calls, the approval workflows for human review, and the logging infrastructure for monitoring. The ChatGPT capability is embedded in a product, not a raw chat window.

    • Frontend interface design and development

    • API layer and request handling

    • Human review and approval workflows where needed

    • Usage logging and audit trail

  5. Step 05
    05

    Testing & monitoring

    We test the application against real inputs, including the edge cases that break most AI products. Hallucination patterns, out-of-scope queries, and high-stakes decisions are all tested before launch. Post-launch monitoring tracks response quality, latency, cost, and user adoption.

    • Systematic hallucination testing

    • Edge case and adversarial input testing

    • User acceptance testing

    • Production monitoring for quality, cost, and latency

What clients say

What our clients say

Three-year average engagement. Founders and operators describing the work in their own words. No marketing varnish.

Amer Abu Khajil
Amer Abu Khajil
Canada flagCanada
Founder, Peak Studios & Perceptional

I found RaftLabs to be the perfect partner for Perceptional, with their expertise in helping startup founders build MVPs, a free consultation, a prototype that matched my vision, and their unwavering support.

01 / 03

Where you land in that range depends on scope, not negotiation:

Focused first application, $20,000-$50,000
An internal knowledge search assistant or a document summarisation tool, scoped, built, and shipped in 12 weeks.
Full AI platform, $60,000-$150,000
Multiple use cases, custom integrations, and a user interface built around the AI capability.

What it costs

Custom ChatGPT applications, fixed cost, scoped before we start.

A focused first application in 12 weeks, or a full AI platform with the integrations and interface your use case needs.

$20,000-$150,000

Fixed cost by project. A focused first application ships in 12 weeks. We scope every project before pricing it.

You know the number before development starts, and a scope change is a priced change request, not a surprise on the final invoice.

Fixed price

We scope the work, calculate the cost, and lock it in writing before any development starts. A scope change is a priced change request, agreed or dropped, never absorbed into the final invoice.

Compliance built in

GDPR, HIPAA, and SOC 2 requirements are scoped in week 1, not retrofitted before launch. We have shipped HIPAA-compliant systems for US healthcare clients and GDPR-compliant products for European markets.

ChatGPT Application Development Services, scoped in one call.

Tell us what's broken. Within one business day you get a straight take on cost, timeline, and the right first step. No deck, no pressure.

Stay on topic

More on AI chatbots

Frequently asked questions

We build custom applications that use OpenAI's GPT models for specific business use cases: AI assistants for customer support or internal knowledge search, document processing tools that summarise, extract, or classify content, AI copilots embedded in existing software, automated content generation tools with approval workflows, and conversational interfaces for complex data queries. The use case determines the architecture, not all ChatGPT applications are chatbots.

Out-of-the-box ChatGPT doesn't know your business. We make it accurate through three approaches: (1) RAG (retrieval-augmented generation), the model retrieves relevant documents from your knowledge base before generating a response, so answers are grounded in your actual data. (2) System prompts and fine-tuning, we engineer prompts that constrain the model's behaviour and, where appropriate, fine-tune a model on your domain-specific examples. (3) Guardrails, we build validation layers that catch and handle responses that fall outside expected parameters.

Yes. We build RAG pipelines that index your internal documents, PDFs, Word files, SharePoint content, database records, website content, into a vector store that the model can search before generating responses. The model doesn't guess based on its training data, it retrieves the right information from your sources and uses that to generate the response. Answers include source citations so users can verify them.

Hallucination is a real risk with any language model. We reduce it through RAG (answers are grounded in your actual documents, not model memory), confidence scoring (responses that don't find relevant sources are flagged or escalated), human review workflows for high-stakes decisions, and response logging so you can identify and fix systematic errors. We don't promise zero errors, but we design systems with the failure modes in mind.

A focused first application, for example, an internal knowledge search assistant or a document summarisation tool, typically runs $20,000--$50,000. A full AI platform with multiple use cases, custom integrations, and a user interface typically runs $60,000--$150,000. The cost depends on the number of use cases, the complexity of the data pipeline, and the user interface requirements. We scope every project before pricing it.

Yes, you can. The API is well documented and the basic integration is straightforward. The hard part is: designing prompts that produce consistent, accurate results for your use case; building the RAG pipeline that connects the model to your data; handling failure modes (timeouts, rate limits, wrong answers); building the user interface and approval workflows around the AI capability; and testing and monitoring the system in production. These are engineering and product problems, not just API calls. We've solved them 20+ times.

Work with us

Tell us what you need. We'll tell you what it would take.

We scope ChatGPT Application Development Services in 30 minutes. You walk away with a clear cost, timeline, and approach. No commitment required.

  • Scope and cost agreed before work starts. No surprises. No obligation.
  • Working prototype within 3 weeks of kickoff.
  • Pay by milestone. You see progress before each invoice.
  • 60-day post-launch warranty. Bug fixes, UI tweaks, and deployment support. No retainer.
  • All conversations are NDA-protected.