United States National Library of Medicine

The United States National Library of Medicine (NLM) is the world's largest biomedical library. It serves as a vital resource for researchers, healthcare professionals, and the general public by providing access to a vast collection of biomedical literature and resources. The NLM offers a wide range of services and resources including online databases, digital archives, and research tools that support medical research, education, and patient care. Key APIs include the NCBI E-Utilities (PubMed, Entrez), NCBI Datasets (genomes, genes), BLAST sequence alignment, and the ClinicalTrials.gov API.

United States National Library of Medicine publishes 10 APIs on the APIs.io network, including BLAST API, Fetch API, Gene API, and 7 more. Tagged areas include Federal Government, Biomedical Research, Healthcare, Genomics, and Literature.

The United States National Library of Medicine catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

United States National Library of Medicine’s developer surface includes authentication, developer portal, and 3 more developer resources.

🌐 Visit website 📡 Source on GitHub

38.1/100 thin ▬ flat Agent 37/100 agent ready Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemiumSelf serve⚡ Free to try

10 APIs

Federal GovernmentBiomedical ResearchHealthcareGenomicsLiterature

Kin Score

Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6

Composite quality — 38.1/100 · thin

Contract Quality 15.3 / 25

Developer Ergonomics 3.9 / 20

Commercial Clarity 7.9 / 20

Operational Transparency 4.1 / 13

Governance 2.5 / 12

Discoverability 7.4 / 10

Agent readiness — 37/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/united-states-national-library-of-medicine: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 10

Individual APIs this provider publishes, each with its own machine-readable definition.

Rate Limits 1

Documented rate limits and quota policies.

United States National Library Of Medicine Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

Examples 3

Example request and response payloads for these APIs.

Get Started 1

Portal, sign-up, and the first successful call

Portal

Portal

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Company 1

The organization behind the API

LinkedIn

Source (apis.yml)

aid: united-states-national-library-of-medicine
url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/apis.yml
apis:
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-blast-api
  name: United States National Library of Medicine BLAST API
  description: BLAST sequence search submission and retrieval
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - BLAST
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-blast-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-fetch-api
  name: United States National Library of Medicine Fetch API
  description: Retrieve records from Entrez databases
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Fetch
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-fetch-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-gene-api
  name: United States National Library of Medicine Gene API
  description: Gene records and sequence data
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Gene
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-gene-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-genome-api
  name: United States National Library of Medicine Genome API
  description: Genome assembly data and metadata
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Genome
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-genome-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-info-api
  name: United States National Library of Medicine Info API
  description: Database information and statistics
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Info
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-info-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-link-api
  name: United States National Library of Medicine Link API
  description: Find linked records across databases
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Link
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-link-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-metadata-api
  name: United States National Library of Medicine Metadata API
  description: API metadata and field definitions
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Metadata
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-metadata-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-search-api
  name: United States National Library of Medicine Search API
  description: Search Entrez databases
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-search-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-studies-api
  name: United States National Library of Medicine Studies API
  description: Clinical trial study search and retrieval
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Studies
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-studies-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
- aid: united-states-national-library-of-medicine:united-states-national-library-of-medicine-taxonomy-api
  name: United States National Library of Medicine Taxonomy API
  description: NCBI taxonomy information
  humanURL: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Taxonomy
  properties:
  - type: OpenAPI
    url: openapi/united-states-national-library-of-medicine-taxonomy-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
  - type: Portal
    url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  - type: SpectralRules
    url: https://raw.githubusercontent.com/api-evangelist/united-states-national-library-of-medicine/refs/heads/main/rules/ncbi-e-utilities-rules.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/
  - type: SwaggerUI
    url: https://www.ncbi.nlm.nih.gov/datasets/docs/v2/api/rest-api/
  - type: Repository
    url: https://github.com/ncbi/datasets
  - type: Documentation
    url: https://blast.ncbi.nlm.nih.gov/doc/blast-help/developerinfo.html
  - type: Documentation
    url: https://clinicaltrials.gov/data-api/api
  - type: Portal
    url: https://clinicaltrials.gov/data-api/api#introduction
name: United States National Library of Medicine
tags:
- Federal Government
- Biomedical Research
- Healthcare
- Genomics
- Literature
kind: contract
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: high
  source:
  - plans
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/united-states-national-library-of-medicine.png
common:
- type: AgenticAccess
  url: agentic-access/united-states-national-library-of-medicine-agentic-access.yml
- type: DomainSecurity
  url: security/united-states-national-library-of-medicine-domain-security.yml
- type: Authentication
  url: authentication/united-states-national-library-of-medicine-authentication.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/national-library-of-medicine-nlm
- url: https://www.ncbi.nlm.nih.gov/home/develop/api/
  type: Portal
created: 2024/01/01
modified: '2026-05-19'
position: Consuming
access: 3rd-Party
description: The United States National Library of Medicine (NLM) is the world's largest biomedical library. It serves as
  a vital resource for researchers, healthcare professionals, and the general public by providing access to a vast collection
  of biomedical literature and resources. The NLM offers a wide range of services and resources including online databases,
  digital archives, and research tools that support medical research, education, and patient care. Key APIs include the NCBI
  E-Utilities (PubMed, Entrez), NCBI Datasets (genomes, genes), BLAST sequence alignment, and the ClinicalTrials.gov API.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
specificationVersion: '0.19'

United States National Library of Medicine

APIs 10

Open Collections 4

Pricing Plans 1

Rate Limits 1

FinOps 1

Semantic Vocabularies 1

Spectral Rules 2