How to Build Your Own AI Assistant Without Coding: A Step-by-Step Guide

Do you type the same explanation into a chatbot every Monday: who you are, what your company does and what tone you write in? Building your own AI assistant solves that, and you don’t need to code to do it. In this article you’ll learn, step by step, how to build a Gem in Gemini, a project in Claude or a project in ChatGPT, with examples for your job and your own business. You’ll also read what to watch out for with privacy, and why you’re better off not building a new GPT any more.

What exactly is your own AI assistant?

Your own AI assistant is a chatbot that you give fixed instructions and background knowledge once, so that it uses them in every conversation. That means you don’t have to explain what you want over and over again.

Think of it as a new colleague. On the first day you explain how you work, what tone you use in emails and where the price list is. After that, your colleague can get on with the job. With an AI assistant, you write that explanation down once.

As well as instructions, you can often add files too, such as a product overview, a style guide or a list of frequently asked questions. This is called your assistant’s knowledge. Not sure yet how to write a good request to AI? Then start with what a prompt is and how to get more out of it. Writing instructions works in exactly the same way, except that you save them.

Gem, Claude project or ChatGPT: what’s the difference?

All three do the same thing at heart: they store instructions and knowledge, so you get a chatbot tailored to you. The biggest differences are in how you use them, what they cost and how you share them.

Take care with ChatGPT. According to OpenAI’s help page on GPTs, personal accounts (Free, Go, Plus and Pro) can no longer create or publish new GPTs. And the FAQ on the retirement of GPTs says that OpenAI wants to phase out custom GPTs completely, planned for 11 December 2026. That’s why we recommend a project in ChatGPT.

What	Gem (Gemini)	Project (Claude)	Project (ChatGPT)
Free to create?	Yes, even with the free version	Yes, but with more limits than on a paid plan	Yes, but with fewer files per project than on a paid plan
Where do you create it?	On a computer via the website, then also usable in the app	On claude.ai	On chatgpt.com or in the app
Fixed instructions	Yes	Yes, as project instructions	Yes, as project instructions
Add your own files	Yes	Yes, as project knowledge	Yes
Handy for	Recurring tasks, such as rewriting emails or texts	A regular job or a client with lots of documents	People who already use ChatGPT every day

Prices, limits and features change often. So always check the current price and terms with the provider before you take out a subscription.

How can you build your own AI assistant in five steps?

You build your own AI assistant by first deciding on its purpose, then writing instructions, adding knowledge, testing and fine-tuning. This order works in every tool.

1. Choose a task. Start small, with a job you do every week. For example: checking quotes, writing LinkedIn posts or replying to customer emails.
2. Write the instructions. Describe the role (you are my editor), the audience, the tone and the result you want. Also say what the assistant must not do, such as making up prices.
3. Add knowledge. Only upload files that are really needed, such as an example text or a list of frequently asked questions. Remove personal data first.
4. Test with tricky questions. Also ask questions whose answer isn’t in your files. A good assistant will then say it doesn’t know. If necessary, put that in your instructions word for word.
5. Improve and save. Is something not right? Adjust the instructions and test again. After a few rounds you’ll often have an assistant that does what you want.

A tip few people know: let the AI interview you first. Ask the chatbot to put five questions to you about your task, then write the instructions together. This usually gives you better instructions than filling in a blank box yourself. Further on in this article you’ll find a ready-made prompt for this.

How to build a Gem in Gemini

You create a Gem on a computer via gemini.google.com, and then you can use it in the app on your phone too. All you need is a Google account.

1. Open Gemini in your browser and log in with your Google account.
2. In the menu, go to Gems and choose to create a new Gem. The buttons sometimes move, so also look in the settings if you can’t see it straight away.
3. Give your Gem a clear name, such as Quote check or Email helper.
4. Write your instructions. Not sure what to write? Click the magic wand: Gemini will help you expand the instructions.
5. If you like, add files as knowledge.
6. Test the Gem in the preview window and save it.

In its tips for Gems, Google recommends starting with a ready-made Gem, such as Brainstormer or Career guide. Is one of them already close to what you’re looking for? Then make a copy and adjust the instructions. That saves work if you don’t want to start from scratch.

How to create a project in Claude

A project in Claude is your own workspace with fixed instructions, your own files and its own conversation history. It’s ideal if you need the same background every time for a client or a job.

1. Go to claude.ai and log in.
2. In the menu on the left, click Projects and create a new project.
3. Give the project a name and a short description, for example Client Bakery De Vries.
4. Fill in the project instructions: who you are, what Claude should do and in what tone.
5. Upload the documents Claude needs to know, such as a briefing or earlier texts.
6. Start a conversation inside the project. Claude will then automatically use your instructions and files.

According to Anthropic’s explanation of projects, a project can also handle a lot of documents: if your project is nearly full, Claude finds the relevant parts itself. Note: separate conversations within a project know nothing about each other, unless you add the information to the project knowledge. Sharing projects with colleagues is possible on the business plans (Team and Enterprise).

Can you still create a custom GPT in ChatGPT?

Not with a personal account any more, and it isn’t wise to start one now anyway. OpenAI plans to phase out custom GPTs; the planned date is 11 December 2026. After that, GPTs and their pages can no longer be opened.

Do you use ChatGPT through a business workspace (Business, Enterprise or Edu)? Until now you could still create GPTs there if your administrator allowed it. But OpenAI plans to stop the creation of new GPTs there too, soon. As a successor, OpenAI points to plugins: bundles of fixed instructions, files and connected apps. Which options you get depends on your plan and workspace. Do you already have a GPT? Then follow the notice in your account about moving it over.

For most readers, a project in ChatGPT is the easiest route. Free users can also create projects, although they can add fewer files. Here’s how it works:

1. Log in to chatgpt.com and choose a new project in the menu on the left.
2. Give the project a clear name, such as Customer emails.
3. Open the project settings and paste in your fixed instructions.
4. Add the files ChatGPT needs to know.
5. From now on, start your conversations inside this project, so ChatGPT uses your instructions and files.

If you’re new to this chatbot, start with how to get started with ChatGPT in ten minutes.

Which AI assistant can you build for your job or business?

The best AI assistant takes over a job you do often and that goes roughly the same way each time. Here are five examples you can build today.

• Email helper for customer questions. Upload your frequently asked questions and terms of delivery. The assistant drafts a reply in your tone, which you check and send. Want to go further? Then read about AI customer service for freelancers and small businesses.
• Quote check. Give it your standard prices and terms. Paste in a draft quote and ask whether anything is missing.
• Social media writer. Add three posts that did well. The assistant writes new posts in the same style.
• Meeting summariser. Paste in your own notes and have it turn them into a short report with action points. Don’t use names or sensitive details.
• Plain-language coach. Have the assistant rewrite your texts in simple language, handy for newsletters or information for customers.

Your own assistant isn’t true automation that carries out tasks by itself. You still have to steer it yourself. But it does save you time, because you don’t have to explain what you want again and again.

What should you watch out for with privacy when building your own AI assistant?

Never put personal data about customers, job applicants or colleagues into your assistant, unless your organisation has made clear agreements about it. Everything you upload ends up on the provider’s servers.

That this isn’t just theory is clear from a warning by the Dutch Data Protection Authority (Autoriteit Persoonsgegevens). According to the Financieele Dagblad, the regulator received dozens of reports of data breaches in 2025 because employees put sensitive information into AI chatbots. At the municipality of Eindhoven, CVs and documents about youth care, among other things, ended up in free versions of chatbots.

• Remove data. Replace names, addresses and customer numbers with made-up examples before you upload anything.
• Check your settings. In ChatGPT, Gemini and Claude you can choose in the settings whether your conversations may be used to improve the AI. Turn that off if you don’t want it.
• Ask about the policy at work. Many employers have rules about which AI tools you may use. A business subscription often offers better agreements about your data.
• Check the answers. Even an assistant with your own files can make things up. Read everything through before you send it to a customer.

If you work with personal data, the rules of the GDPR (the European privacy law) apply as usual. Not sure whether something is allowed? Ask your data protection officer or a lawyer.

Try it yourself: let the AI write your instructions

With the prompt below, you let the chatbot interview you first. Afterwards you get instructions you can paste straight into your Gem or project. Fill in the parts in square brackets yourself.

Frequently asked questions

Can I build my own AI assistant for free?

Yes. In Gemini you can create a Gem with the free version, and Claude and ChatGPT also offer projects to free users, with more limits. Always check the current terms and price with the provider.

Why can’t I create a GPT in ChatGPT any more?

OpenAI has turned off the creation of new GPTs for personal accounts, including for paying Plus and Pro users. OpenAI also wants to phase out custom GPTs completely, planned for 11 December 2026, and points to plugins as the successor. A project in ChatGPT is a good alternative for most people.

Do I need to be able to code to build an AI assistant?

No. You write the instructions in plain language and upload files with a few clicks. If you can write a clear email, you can set up an AI assistant.

Is my information safe in a Gem or project?

Your files are stored on the provider’s servers. So don’t put personal data or confidential documents in them, and check in the settings whether your conversations may be used to train the AI.

Which tool is best for your own AI assistant?

For most beginners, a Gem in Gemini is an easy start, because it can be free and takes few steps. If you work with lots of documents per job or client, a project in Claude is a good fit. If you already work with ChatGPT every day, choose a project in ChatGPT.

Do you want to understand first how these chatbots actually work? Then read our explanation of what AI is, in plain language. After that, pick a task you still have to do this week and build your first assistant in a quarter of an hour.