# AI providers and costs (/docs/get-started/api-keys)



Converting a PDF into an ADT relies on artificial intelligence — to structure content, describe images, generate narration, create quizzes, and translate. Those AI capabilities come from an external **AI provider**, which you connect to ADT Studio using an **API key**. This page explains what that means, how to set it up, and what to expect in terms of cost.

<Callout title="In short">
  **ADT Studio itself is free**, open-source software (AGPL-3.0). **The AI provider you connect may charge for usage** — that cost goes to the provider, not to ADT Studio or UNICEF. **Official ADT country programmes may be able to access API credits** instead of paying directly — see below.
</Callout>

## Why ADT Studio needs an AI provider [#why-adt-studio-needs-an-ai-provider]

ADT Studio does the orchestration: it reads your PDF, manages the pipeline, stores your work, and packages the result. But the intelligent steps — understanding the content, writing image descriptions, producing natural narration, generating comprehension questions — are performed by a large language model (an "LLM").

ADT Studio does not include its own AI model. Instead, it connects to a provider that offers one — so you choose the provider, you control the cost, and you can see exactly what each AI call does.

## What is an API key? [#what-is-an-api-key]

An **API key** is a private code that lets ADT Studio use your account with an AI provider. Think of it as a password that says "this tool is allowed to make AI requests on my behalf, and charge my account for them."

<Steps>
  <Step>
    ### Get a key from your provider [#get-a-key-from-your-provider]

    Sign up with the AI provider of your choice and generate an API key from their dashboard.
  </Step>

  <Step>
    ### Add it to ADT Studio [#add-it-to-adt-studio]

    Paste the key into ADT Studio's **Settings**. From that point on, ADT Studio can use the provider's AI model when you run the steps that need it.

    If this is your first time opening ADT Studio, you don't need to go looking for it — the setup wizard prompts you to add your API key directly the first time you launch the app.
  </Step>
</Steps>

Two things to keep in mind:

* **Keep it private.** Anyone with your key can use your AI account and run up costs. Treat it like a password — do not share it or post it anywhere public.
* **It stays on your machine.** ADT Studio stores your key locally. It is used only to talk to the provider you chose.

## Which AI providers can I use? [#which-ai-providers-can-i-use]

Today, the main conversion pipeline (extraction, image descriptions, translation, quizzes, and the rest) relies on **OpenAI**, with growing support for other providers.

The one step with real provider choice already available is &#x2A;*narration (text-to-speech)**: you can pick between **OpenAI**, **Google Gemini**, and **Azure** per language, and compare voices before committing. See [Speech](/docs/localize/speech).

As provider support expands, you'll be able to switch providers for more of the pipeline — without being tied to one choice for cost, quality, or language coverage.

## How much does it cost? [#how-much-does-it-cost]

There is no single answer — the cost depends on three things:

* **Provider and model.** Different providers charge different rates, and within a provider, more capable models cost more than lighter ones.
* **Document length.** AI providers charge based on the amount of content processed. A 20-page reader costs far less than a 300-page textbook.
* **Features you run.** Extracting and structuring text is the baseline. Narration, translation into several languages, image descriptions, and quizzes each add AI calls — and cost.

ADT Studio helps you stay in control of this in two ways. First, every AI call is **cached** — if you rerun a step without changing anything, it reuses the previous result at no extra cost. Second, the tool shows you the **cost of each call**, so you can see where your spending goes rather than facing a surprise bill.

For a typical short document, costs are modest — often a small number of dollars. Longer documents with many features enabled cost more. The best way to understand your own costs is to run a short document first and review the reported figures before scaling up.

## API credits for ADT country programmes [#api-credits-for-adt-country-programmes]

If you are part of an **official ADT country programme or an implementing partner**, you may be able to access API credits rather than paying for AI usage directly.

{/* TO VERIFY: the exact process and eligibility for API credits, and the right contact point. Confirm with the ADT team before publishing specifics. */}

To find out whether this applies to you and how to request access, contact the ADT team through the [Accessible Textbooks for All initiative](https://www.accessibletextbooksforall.org).

## Ready to continue? [#ready-to-continue]

Once your AI provider is connected, you are ready to convert your first PDF.

[Convert a PDF into an ADT →](/docs/convert-pdf/import-pdf)