Authentication

OpenAlex data is free, and so is casual use of the API — you can make basic queries with no key at all. To use the API at any real scale, though, you’ll want a free API key: it raises your daily budget 10× and lets you track your usage. This page covers getting a key, sending it, and staying inside the rate limits. For what the API costs and how billing works — that’s a separate concern — see Pricing, with worked numbers on the Example costs page.

Getting an API key

It’s free. Make an account (about 30 seconds) and copy your key from openalex.org/settings/api.

Sending your key

Add it as an api_key query parameter:

curl "https://api.openalex.org/works?api_key=YOUR_KEY"

…or send it as a bearer token in the Authorization header:

curl -H "Authorization: Bearer YOUR_KEY" "https://api.openalex.org/works"

Both work identically. The openalex.org website runs on this same API, so anonymous browsing draws from the keyless budget; sign in and it uses your own key.

Rotating your key

You can replace your key with a new one anytime in Settings → API key. When you rotate, you choose when the old key stops working:

• Immediately (the default) — the old key dies on the spot. The right choice when a key has leaked.
• In 24 hours or in 7 days — both keys work during the window, so you can deploy the new key to your systems with no downtime. The old key keeps its normal limits, then stops for good. If you discover a leak mid-window, the Expire now button kills the old key early.

Organization keys work the same way, from the organization’s API settings. One thing to know about personal keys: your key is also your openalex.org sign-in credential, so rotating it logs you out on your other browsers and devices right away — the grace window applies to API requests only.

Rate limits

Basic use is free and generous, and a free key gives you 10× the keyless budget; you can raise it further with a paid plan. Two things return 429 Too Many Requests: exceeding your daily budget, or making more than 100 requests per second. For the budget numbers themselves — and what typical activity actually uses — see Example costs.

Individual queries also have hard limits:

To retrieve more than 10,000 results, use cursor paging.

Keeping tabs on your usage

Every response carries headers and a meta block showing where you stand:

The meta object also reports the cost of the call and the total result count, so you can estimate a full paginated pull before committing to it. For a running total, check the usage dashboard (the battery icon in the lower-left of openalex.org), or query it programmatically:

curl "https://api.openalex.org/rate-limit?api_key=YOUR_KEY"

Best practices

• Use per_page=100 to get more per request — it makes your budget go much further.
• Batch ID lookups with the OR syntax (up to 100 values per filter).
• Use select= to return only the fields you need, for faster responses.
• Implement exponential backoff when you hit a 429.
• The API is plain GET requests, so you can test any query in your browser — a JSON formatter extension (JSONVue for Chrome, JSONView for Firefox) makes responses easier to read.