> For the complete documentation index, see [llms.txt](https://docs.nested-knowledge.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nested-knowledge.com/guides/write-a-search-query/openalex.md).

# OpenAlex

Learn how to write an OpenAlex search query.

OpenAlex is a free, open index of scholarly literature spanning every discipline. Choose it when your review needs interdisciplinary coverage, when you want a fully open bibliographic metadata source, or when you want to search by concept rather than exact keyword. 

In Nested Knowledge, query OpenAlex the same way you would in the search bar at openalex.org; your query continues to run and pull in new matches as OpenAlex indexes new publications.

### Write A Query

Enter keywords, phrases, or Boolean logic directly.

#### Simple Keywords

Enter one or more terms to find papers that mention them:

```
diabetes
```

#### Boolean Operators

Operators must be capitalized.

* **AND** — both terms must appear: `diabetes AND alzheimer's`
* **OR** — either term may appear: `migraine OR headache`
* **NOT** — excludes a term: `dementia NOT vascular`

#### Quotation Marks

Use quotes for an exact phrase: `"randomized controlled trial"`

#### Grouping With Parentheses

Combine operators for a more complex query: `(diabetes OR obesity) AND "cardiovascular disease"`

These four behave the same way they do on PubMed; the differences from PubMed are covered below.

### Refine Your Search

#### Combine Search And Filters

Narrow a broad query with filters on date, access type, or full-text availability. For example, `diabetes AND alzheimer's` filtered to `from_publication_date:2020-01-01` and `is_oa:true` returns only open-access results published from 2020 onward.

#### Use Concept And Topic Tags

OpenAlex automatically tags works with concepts from its taxonomy. Filter by a concept to cover an entire field or subfield without listing every synonym yourself — for example, `concept:"cardiovascular disease"` captures all subtopics under cardiovascular research.

#### Restrict By Metadata

Narrow by recency, language, or open-access status — for example, `sleep AND neuroscience` filtered to publications from 2023 onward, open access only.

#### Stemming

OpenAlex applies stemming automatically, treating different word forms as equivalent — `studies` also matches *study* and *studying*, and `fish` also matches *fishing* and *fisheries*. You don't need to add every word variant yourself.

#### Stop-Words

Common stop-words (*the*, *a*, *in*, *of*) are ignored, so `"effects of sleep"` and `"effects sleep"` return the same results.

See OpenAlex's [quickstart tutorial](https://docs.openalex.org/quickstart-tutorial) for more.

### FAQs

<details>

<summary>Does OpenAlex only cover biomedical literature?</summary>

No — OpenAlex spans every discipline, which is one of the main reasons to search it alongside [PubMed](/guides/write-a-search-query/pubmed.md), [EuropePMC](/guides/write-a-search-query/europepmc.md), or [Embase](/guides/write-a-search-query/embase.md) rather than instead of them.

</details>

<details>

<summary>Do I need to include every synonym or word form in my query?</summary>

Not for word forms — OpenAlex's stemming handles those automatically. You still need to add true synonyms yourself, the same as on any other source.

</details>

<details>

<summary>Why didn't adding or removing "of" or "the" change my results?</summary>

OpenAlex ignores common stop-words, so a query with or without them returns the same matches.

</details>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.nested-knowledge.com/guides/write-a-search-query/openalex.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.