openalex.topics
stable Advanced
Search OpenAlex topics.
GET /v1/openalex/topics
What you get#
A list of Openalex results in Onekey's unified shape, in data (an array). An empty array is a normal, successful answer and is charged like any other; a source that reports "nothing found" as an error returns a free 404 not_found instead.
What it costs#
- Advanced · 5 credits for a fresh fetch, charged only when it succeeds.
- Free when served from cache (0.2 credit for a cached response over 100 KB).
- Free if the request is invalid (never charged) or the source fails or reports not found (refunded).
Parameters#
| Name | Type | Required | Default | What it is | Constraints |
|---|---|---|---|---|---|
q | string | yes | (required) | Search query | max 200 chars; must match [^\x00-\x1f\x7f]{1,200}; trimmed, repeated spaces collapsed |
Request#
curl "https://api.onekey.dev/v1/openalex/topics?q=machine%20learning" \
-H "x-api-key: YOUR_API_KEY"Try it
Add your key to run this call right here. No key? Get one free. The key stays in this tab.
Recorded response#
A real Openalex response, recorded and returned in Onekey's shape. Fields the platform does not provide are null.
{
"success": true,
"data": [
{
"entity": {
"id": "https://openalex.org/T11948",
"name": "Machine Learning in Materials Science",
"url": null,
"description": "This cluster of papers focuses on the application of materials informatics, machine learning, and high-throughput computational techniques to accelerate materials innovation. It encompasses topics such as property predictions, crystal structures, molecular dynamics, and data mining in the context of materials science and engineering."
},
"ext": {
"works": 122446
},
"engagement": {
"citations": 1103711
}
},
{
"entity": {
"id": "https://openalex.org/T12254",
"name": "Machine Learning in Bioinformatics",
"url": null,
"description": "This cluster of papers focuses on the prediction of protein subcellular localization using various computational methods such as amino acid composition, machine learning algorithms like support vector machines, and the analysis of signal peptides and transmembrane topology. The research aims to improve the accuracy and reliability of predicting the subcellular location of proteins, which has significant implications for understanding protein function and cellular processes."
},
"ext": {
"works": 158962
},
"engagement": {
"citations": 727383
}
}
],
"metadata": {
"platform": "openalex",
"endpoint": "topics",
"cached": false,
"stale": false,
"age_s": 0,
"fetched_at": "2026-01-01T12:00:00+00:00",
"credits_charged": 5,
"request_id": "7f3a9c2e5b1d4c8fa2e6d0b9c4f18e37"
},
"error": null
}Field mapping#
How this endpoint's source fields become Onekey's unified schema. Fields the source lacks come back as null.
| Source path | Onekey field | Transform |
|---|---|---|
id | entity.id | - |
display_name | entity.name | - |
homepage_url | entity.url | safeUrl |
works_count | ext.works | toNumber |
cited_by_count | engagement.citations | toNumber |
description | entity.description | - |
Caching and freshness#
- Fresh for about 2 minutes. Repeat calls in that window are served from cache and are free.
- Between 2 minutes and 15 minutes the cached copy is still served instantly and marked
stale: truewhile Onekey refreshes it in the background. - If the source is down when a refresh is needed, the last copy can be served for up to 1 hour more (marked stale).
- A "not found" is remembered for 1 minute and is free.
- The cache is shared across all customers, which is what keeps repeat calls cheap.
What can go wrong#
| Status | Code | What to do |
|---|---|---|
| 401 | unauthorized | Check the x-api-key header. |
| 402 | insufficient_credits | Add credits; your balance must cover the price. |
| 404 | not_found | Unknown endpoint path. |
| 422 | invalid_params | Fix the parameters using the table above. Free. |
| 429 | rate_limited | Wait Retry-After seconds, then retry. |
| 502 | upstream_error | The source failed. Refunded; retry with backoff. |
See Errors for the full list and retry guidance.
Status: stable (verified against the live source).