# NCBI Entrez E-utilities API

**Canonical:** https://apis.io/apis/ncbi/ncbi-entrez-e-utilities-api/  
**Provider:** National Center for Biotechnology Information (NCBI) — https://apis.io/providers/ncbi/  
**Base URL:** https://eutils.ncbi.nlm.nih.gov/entrez/eutils/  
**Documentation:** https://www.ncbi.nlm.nih.gov/books/NBK25497/

NCBI Entrez E-utilities API is one of 14 APIs that [National Center for Biotechnology Information (NCBI)](https://apis.io/providers/ncbi/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Entrez, PubMed, GenBank, Gene, and Taxonomy. The published artifact set on APIs.io includes API documentation, a getting-started guide, and rate-limit docs.

The Entrez Programming Utilities (E-utilities) are the public API to the NCBI Entrez system, providing access to over 38 Entrez databases including PubMed, GenBank (Nuccore), Gene, Taxonomy, and Protein. Nine server-side programs support text search, record retrieval, batch download, database linking, spelling correction, and citation matching. Requests can be authenticated with an API key to raise rate limits from 3 to 10 requests per second.

## Machine-readable artifacts (5)

- **Documentation** — https://www.ncbi.nlm.nih.gov/books/NBK25497/
- **GettingStarted** — https://www.ncbi.nlm.nih.gov/books/NBK25500/
- **RateLimits** — https://kinlane.github.io/ncbi/rate-limits/e-utilities.yml
- **Plans** — https://kinlane.github.io/ncbi/plans/e-utilities.yml
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/ncbi/refs/heads/main/apis.yml

## Other National Center for Biotechnology Information (NCBI) APIs (12)

- [NCBI BLAST URL API](https://apis.io/apis/ncbi/ncbi-blast-url-api/)
- [PubChem PUG REST API](https://apis.io/apis/ncbi/pubchem-pug-rest-api/)
- [PMC Open Access API (OA Service)](https://apis.io/apis/ncbi/pmc-open-access-api-oa-service/)
- [PMC ID Converter API](https://apis.io/apis/ncbi/pmc-id-converter-api/)
- [PMC OAI-PMH Service](https://apis.io/apis/ncbi/pmc-oai-pmh-service/)
- [National Center for Biotechnology Information (NCBI) BioSample API](https://apis.io/apis/ncbi/ncbi-biosample-api/)
- [National Center for Biotechnology Information (NCBI) Gene API](https://apis.io/apis/ncbi/ncbi-gene-api/)
- [National Center for Biotechnology Information (NCBI) Genome API](https://apis.io/apis/ncbi/ncbi-genome-api/)
- [National Center for Biotechnology Information (NCBI) Organelle API](https://apis.io/apis/ncbi/ncbi-organelle-api/)
- [National Center for Biotechnology Information (NCBI) Prokaryote API](https://apis.io/apis/ncbi/ncbi-prokaryote-api/)
- [National Center for Biotechnology Information (NCBI) Taxonomy API](https://apis.io/apis/ncbi/ncbi-taxonomy-api/)
- [National Center for Biotechnology Information (NCBI) Version API](https://apis.io/apis/ncbi/ncbi-version-api/)

## Tags

Entrez, PubMed, GenBank, Gene, Taxonomy, Sequences, Literature

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/ncbi/ncbi-entrez-e-utilities-api/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/ncbi/.