Today, we’re excited to introduce the enhanced CustomGPT API Suite — the #1 serverless RAG (Retrieval-Augmented Generation) API for accuracy and anti-hallucination, proven in independent benchmarks.
Rather than spending months building RAG pipelines from scratch, you can now create RAG-based AI solutions with just a few lines of code — all production-ready, scalable, and enterprise-grade.
And yes — we’ve continuously improved the platform. Over the past 12 months alone, we’ve shipped 964 new features and issue fixes, ensuring your deployments are stable, fast, and best-in-class.
Why Integrate the CustomGPT.ai API?
The CustomGPT API is built for developers, teams, and enterprises who want to integrate reliable, high-performing AI into their products — without reinventing the wheel.
Here’s why customers are choosing it:
- Low-Code Integration: Add powerful AI capabilities directly into your existing products, workflows, and solutions with just a few lines of code.
- Proven Accuracy: #1 in RAG accuracy and anti-hallucination, based on independent benchmarks.
- Production-Ready: Deploy at a fraction of the cost and time it would take to build in-house — because this is exactly what we do, at scale.
It’s the simplest and most reliable way to build real-world RAG-powered applications today.
How It Works
We’ve packaged the entire RAG pipeline into an easy-to-use serverless platform — so you can focus on innovation, not infrastructure.
Here’s what that means for you:
- The entire RAG process — from retrieval to grounding — is handled automatically behind the API.
- You don’t need to manage vector databases, embeddings, accuracy tuning, anti-hallucination, or the hundreds of other moving parts typically involved in RAG.
- The system is production-ready, low-cost, and scalable, letting you deploy instantly into your existing workflows and applications.
With CustomGPT.ai, you get everything — from precision retrieval to response integrity — out of the box.
What You Can Build
The possibilities are endless. The CustomGPT API gives you the building blocks to turn your company’s knowledge into intelligent, conversational, and interactive tools.
Here are a few popular use cases:
- AI / RAG Agents: Build custom agents that can understand and act on your content — websites, documents, videos, and more.
- AI-Powered Knowledge Discovery: Transform static knowledge bases into smart, searchable conversations that boost productivity, drive revenue, and cut costs.
- Easy Integrations: Add RAG-powered AI directly into your existing products and workflows, without needing to re-architect your stack.
Whether you’re powering customer support, internal knowledge systems, or product experiences, the API gives you the flexibility to deploy instantly and scale confidently.
What Our Customers Say
“We chose CustomGPT.ai because for us, it had the best spectrum of quality of answers, ease of use, scalability, and most importantly, API capabilities. We have many internal processes that rely on an automated connection to CustomGPT.ai and its API offers great value.” Prof. Dr. Michael Kraus, AI Expert at Dlubal
Get Started Today
It’s easy to begin building with the CustomGPT API.
- Get Your API Key — Free trial included.
- Explore the Documentation — Start integrating in minutes.
👉 Start Building → https://app.customgpt.ai/login
Want to connect with other CustomGPT.ai users? Join our Slack Community to share insights and best practices.
FAQS
Why can’t I just build this with Langchain?
You certainly can, but I would urge you to read these whitepapers we have authored and make a wise choice that is right for your business.
Build vs Buy — The AI Implementation Guide
Build It Or Buy It? Generative AI’s Million Dollar Question!
Langchain is NOT for production use. Here is why ..
Why wouldn’t I just build a RAG system myself?
With CustomGPT.ai’s RAG API, get up and running in minutes, not months. Benefit from continually optimized retrieval algorithms and state-of-the-art RAG pipeline without the need for in-house AI expertise. Redirect your valuable engineering resources towards developing unique features that set your product apart in the market. Read more about the argument for CustomGPT.ai here.
What kind of data do I need to provide to use the CustomGPT.ai RAG API?
You can provide any data that is relevant to your business operations, including files and websites or sitemaps. This includes product information, customer service logs, FAQs, and any other data that will help the AI understand and respond to queries specific to your business.
How can I start testing the RAG API?
We provide a sandbox environment via our documentation hub that allows you to test your API calls in a safe and controlled setting before going live. This environment queries your active projects in the application in real time.
How frequently is the RAG API updated?
We regularly update the API to introduce new features, enhance functionality, and incorporate feedback from our users. This is what has made us #1 in both accuracy AND hallucinations (a rare feat!)
We ensure that changes are backward compatible to protect existing integrations.
How do I get started with the CustomGPT.ai RAG API?
To start using the CustomGPT.ai API, you first need to sign up for an account on our platform. Once registered, you will be able to generate an API key which you can use to authenticate your API requests. Our documentation provides detailed guidelines on how to make API calls, manage your data, and configure your chatbot settings. Find out how to get started.
What are the RAG API rate limits and how are they managed?
Our API rate limits are designed to ensure optimal performance and service reliability for all users. The specific limits depend on your subscription plan. If you need higher limits, you can discuss upgrading your plan with our sales team. You can monitor your API usage through our dashboard, which provides real-time analytics.
How do I handle errors or unexpected responses from the RAG API?
Our API documentation includes a comprehensive list of potential errors, their meanings, and suggested actions to resolve them. If you encounter an unexpected response or an error that persists, please contact our technical support team for immediate assistance.
Can I customize the RAG API responses?
Yes, you can adjust the behavior and style of the chatbot’s replies via our innovative ‘Persona’. Additionally, you can build your own data pipeline via our API to integrate complex logic or additional data sources that influence the agent’s responses.
What data formats does the CustomGPT.ai RAG API support?
Our API supports thousands of file formats for data upload. In addition, unlike other RAG services, our API can ingest entire websites and web data via sitemaps. Responses are returned in JSON format for output. This format ensures compatibility with a wide range of systems and simplifies the integration process. Detailed examples of request and response structures are available in our API documentation.
Is your code open-source?
Our Python SDK is open-source, and we also have a separate cookbook repository showing in-depth examples of how to use the SDK. Our application and RAG system are proprietary and closed-source.
Is my data secure with CustomGPT.ai?
Yes. CustomGPT.ai is SOC-2 Type 2 certified. Your data is fully encrypted and files are stored only when you allow them to be. Files are encrypted in transit, and encrypted at rest. We use secure vendors like AWS and Stripe.
Moreover, your Agents are fully self-contained, which means they do not share ANY data with other Agents, even within your own account.
By default, your Agent is private, which means only authorized users can query. We understand the importance of your data security and privacy and are fully committed to ensure that the chatbot and your data are secure, confidential, and private. Read about our security standards.
What support is available for CustomGPT.ai users?
All plans include email support through our helpdesk. In addition, customers on the Enterprise plan are assigned a dedicated account manager. Our team can assist with integration, troubleshooting, and any questions you may have about optimizing the use of your chatbot.
How do I integrate CustomGPT.ai with my systems?
Integration is facilitated through our easy-to-use API, which can be connected to your existing systems without significant changes to your infrastructure. Our support team is available to guide you through the integration process step-by-step. Read more about our existing integrations.
How does CustomGPT.ai ensure the accuracy of its agents?
Our agents are continuously tested against industry benchmarks to ensure they provide the most accurate responses. In independent benchmarks, CustomGPT.ai scored #1 in both accuracy and hallucinations (a rare feat!) . We are constantly striving to maintain that leaderboard ranking via proprietary optimizations to our RAG pipeline.
Build smarter with the #1 serverless RAG API
The CustomGPT API gives you serverless, production-ready RAG performance — accurate, scalable, and easy to integrate in minutes.
Trusted by thousands of organizations worldwide
