> ## Documentation Index
> Fetch the complete documentation index at: https://developers.openalex.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Authentication & Pricing

> API keys, pricing tiers, and usage limits

OpenAlex data is and will remain available at no cost. Our [data snapshot](/download/overview#openalex-snapshot) is totally free for bulk download. The API is a freemium service with free daily usage—$0.10/day with no key, or 10× that ($1/day) with a [free API key](#getting-an-api-key)—and after that you pay for what you use. [We sell services, not data.](https://openscholarlyinfrastructure.org/)

## Getting an API Key

To use the API at scale, you need a key. It's free—just [make an account](https://openalex.org/) (takes 30 seconds) and copy your key from [openalex.org/settings/api](https://openalex.org/settings/api). Then add `api_key=YOUR_KEY` to your API calls:

```bash theme={"dark"}
curl "https://api.openalex.org/works?api_key=YOUR_KEY"
```

## What You Can Do for Free Every Day

Your free API key gives you \$1 of free usage every day. With that, you can do a mix of:

| Action              | Calls     | Results   | Example                       |
| ------------------- | --------- | --------- | ----------------------------- |
| Get a single entity | Unlimited | Unlimited | Look up a work by DOI         |
| List+filter         | 10,000    | 1,000,000 | All works from MIT in 2024    |
| Search              | 1,000     | 100,000   | Full-text search for "CRISPR" |
| Content download    | 100       | 100 PDFs  | Download a paper's full text  |

Without a key you get \$0.10/day—a tenth of the above, enough to try the API. [Get a free key](#getting-an-api-key) for 10× the budget.

For full details on endpoint pricing, common activity costs, usage limit headers, query limits, and usage tips, see [Authentication & Pricing](/api-reference/authentication) in the API Reference.