# Scientific Papers API

2 implementations from Crossref and OpenAlex, with no charge per call.

## Implementations

- [DOI metadata search](/providers/crossref/search-works.md): `crossref/search-works`, no charge per call. Search 160M+ Crossref records (journal articles, books, proceedings) by free text: DOI, title, authors, publication date, journal, publisher, citation count. Needs query. Served by Crossref.
- [Scholarly works search](/providers/openalex/search-works.md): `openalex/search-works`, no charge per call. Full-text search over 250M+ scholarly works (papers, books, datasets): title, DOI, year, citations, open access status, authors with institutions, venue. Needs query. Served by OpenAlex.

## Other capabilities

- [Wikipedia, books & web archives](/tools/knowledge/reference.md): 4 tools, with no charge per call.

## Providers

- [Crossref](/providers/crossref.md): 1 tool, with no charge per call.
- [OpenAlex](/providers/openalex.md): 1 tool, with no charge per call.

## Questions

### Which tool should my agent use?

Your agent compares the 2 implementations by price and inputs with inspect_tool and proposes one before it runs.

### How is it billed?

These tools have no charge per call. A workspace is still needed so your agent can run them.

[Knowledge & research](/tools/knowledge.md) · [Connection guide](/connect.md) · [Billing](/docs/billing.md)

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[HTML page](/tools/knowledge/papers) · [Agent index](/llms.txt)