Bring Your Own AI Key (BYOK) Explained: What It Is, How It Works and Whether It Suits You

Bring your own key, usually shortened to BYOK, is a simple idea with a slightly technical name. When an AI chatbot answers a visitor, a language model does the writing, and that model belongs to a provider such as OpenAI, Anthropic, Google, Groq or DeepSeek. The provider charges for every reply. In a BYOK product, you create your own account with the provider, paste your key into the chatbot platform and the provider bills you directly for what your assistant uses. The platform charges only for its software. This guide explains how BYOK works in plain terms, what you gain and what you take on, how keys are kept safe, how to pick a provider and model, what it costs, how to set it up step by step and when a bundled plan may suit you better. It also explains how Crescelo does it: no markup on AI usage, and keys stored encrypted.

The idea in one picture

A key is a long secret string, like a password for software. It lets the platform ask the provider to write replies on your account.

Why people choose BYOK

• Visible cost: the provider's dashboard shows exactly what each day of chats costs.
• No markup: you pay wholesale rates instead of a bundle's margin.
• Choice and change: you can pick a model and switch when a better or cheaper one appears.
• Privacy control: you decide which provider sees your visitors' messages, and can pick one whose terms suit you.
• Existing accounts and credits: if you already have an account or credits, you can use them.

See BYOK versus bundled pricing for a worked cost model.

What you take on

• Creating and managing an account with a provider, including payment.
• Watching usage and setting spending limits so a surprise bill cannot happen.
• Choosing a model, and revisiting the choice.
• Reading the provider's terms about data and privacy.
• Keeping the key secret and rotating it if it might have leaked.

None of this is difficult, and each step takes minutes, but it is more than a bundled plan asks of you.

How the key is used and protected

1. You paste the key into the platform's AI settings once.
2. The platform encrypts it before storing it. Crescelo stores provider keys encrypted with AES-256-GCM.
3. When a visitor asks a question, the server decrypts the key in memory, sends the request to the provider and discards the plaintext.
4. The key is never sent to the visitor's browser and never appears in your website code.

Good practice on your side: create a key just for this assistant, give it only the permissions it needs, set a monthly spending limit at the provider and revoke and replace the key if a team member with access leaves. See how a bring-your-own-key vault works for the technical detail.

Which providers

Crescelo supports these and offers a free engine so you can test before connecting your own. Model names and prices change often, so check each provider's current pages. See which AI model to connect.

What it costs in practice

For a grounded assistant answering from your documents, the AI cost per conversation is usually a fraction of a cent to a few cents on a small or mid-range model. A small business with a few hundred conversations a month typically sees AI usage in the low single or double digits of dollars, while the platform subscription is the larger part of the bill. Premium models cost many times more for little gain on simple questions, which is why testing a cheaper model is worthwhile. The cost is visible in your provider's dashboard, so you can check it against the conversations you had.

Setup in five steps

1. Choose a provider and create an account; add a payment method or credits.
2. Create a new API key named for this assistant.
3. Set a monthly spending limit or alert at the provider if offered.
4. Paste the key into the assistant's AI settings in the platform.
5. Test with twenty real questions, including some the documents cannot answer, and watch the provider's usage page.

The provider guides in the help centre walk through each provider: OpenAI, Gemini and the others.

Privacy: where your visitors' messages go

With BYOK, the platform sends the visitor's message and the retrieved passages from your documents to the provider you chose, under your account and that provider's terms. Read those terms: whether API data is stored, for how long, whether it is used for training and where it is processed. Many providers do not train on API data by default for business use, but confirm. Tell visitors they are talking to an AI and link to your privacy policy. See the GDPR checklist for website chatbots.

When a bundled plan may suit you better

• You want the simplest setup and never to think about a provider account.
• Your volume is very low and predictable.
• You prefer one invoice.
• Nobody on your team is comfortable managing keys and limits.

Both models are legitimate. BYOK is best when you value visibility, choice and no markup, and are willing to spend ten minutes on setup.

Common mistakes

• Sharing one key across several projects.
• Forgetting a spending limit.
• Choosing the most expensive model by default.
• Pasting the key into a chat, email or website code.
• Never checking usage.
• Not reading the provider's data terms.

Frequently asked questions

Try the assistant on your documents in the playground, see the AI assistant feature and check pricing.

Further reading

• OpenAI API documentation: Models, pricing and limits for the OpenAI API.
• Google Search Central: creating helpful, people-first content: What Google looks for in useful pages.