- Free allowance
- Public REST APIs over 'one of the largest open scholarly record collections worldwide', with no registration described on the documentation landing page.
- Verdict
- ★ qualifiesusable as stated; the read path was probed
- Cost
- free tier
- Identity
- anonymousno card, no phone
- Binding limit
- request-ratenone published on the docs landing page; two calls here (size=1 and size=100) both returned 200 with no throttling header
- Evidence
- measured3 sources; a live request was made and its output kept
- Freshness
- stale on 2026-11-23checked 2026-10-23 (live); stale on 2026-11-23
| Free tier | Public REST APIs over 'one of the largest open scholarly record collections worldwide', with no registration described on the documentation landing page. The Graph itself is 'openly available and can be used by third-parties to create added value services'. unit unlimited; metered on none; No key and no numeric rate limit appear on the docs landing page. |
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| Price | USD 0 |
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| Limits | - request-rate (binding) none published on the docs landing page; two calls here (size=1 and size=100) both returned 200 with no throttling header source
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| Binding | request-rate At 8.38 MB per call and 4.2 s per call, one connection moves about 2 MB/s; with no published cap the unknown is how many calls the service tolerates before a 429, which is what decides the day. |
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| Identity | anonymous No key, no account: both calls answered 200 anonymously. Nothing on the docs page asks for registration. |
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| Egress | Free and unmetered for the public API endpoints. free allowance: no byte allowance published |
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| Per-object cap | not applicable: XML or JSON per query. size=100 returned 8,384,696 bytes in one response here, so a page is megabytes rather than kilobytes. |
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| Retention | the graph is rebuilt from source repositories and deduplicated; records reflect the last harvest, not a fixed snapshot |
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| Interface | rest, cli GET https://api.openaire.eu/search/publications?title=...&size=N (XML by default, format=json available); the newer Graph API sits under https://api.openaire.eu/graph/. |
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| Tooling | curl/python-requests; the openaire python client exists but the endpoints are plain HTTP. |
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| Composes with | The widest single metadata source per call: 8.4 MB per size=100 page means a few thousand calls moves tens of GB of linked records, which is a different order from Crossref's 0.77 MB pages. |
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| Reliability | Responses are large XML by default, so a client that forgets format=json spends bandwidth on tags; the search endpoint and the newer graph endpoint are different APIs with different shapes. |
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| Notes | The highest bytes-per-call of any metadata API by an order of magnitude, which makes it the best candidate for filling a day with metadata when the file hosts are the bottleneck. |
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| Evidence note | measured Two calls were made and their byte counts recorded, one of them 8.4 MB. The absence of a rate limit is an absence of evidence: no sustained run was attempted. |
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| Parsed numbers | - has-free-tier 1
- price USD 0
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