National Library of Medicine

The National Library of Medicine, part of the National Institutes of Health, is the world's largest biomedical library. It collects, organizes, and provides access to medical literature and information to support research and decision-making in healthcare, including PubMed and ClinicalTrials.gov.

National Library of Medicine publishes 4 APIs on the APIs.io network, including Discovery API, History API, Retrieve API, and 1 more. Tagged areas include Federal-Government, Health, Library, and Medicine.

National Library of Medicine’s developer surface includes developer portal and 5 more developer resources.

🌐 Visit website 📡 Source on GitHub

27.8/100 thin ▬ flat Agent 17/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

1 APIs

Federal-Government Health LibraryMedicine

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 27.8/100 · thin

Contract Quality 9.1 / 19

Developer Ergonomics 5.7 / 15

Access Clarity 2.4 / 15

Operational Transparency 1.0 / 10

Contract Governance 0.0 / 9

Discoverability 4.4 / 8

Regulatory Posture 1.1 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 17/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 0 / 9

Stable Error Semantics 0 / 8

Request/Response Examples 0 / 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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Regulatory Posture applies to this provider. Its tags matched the Health regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/national-library-of-medicine: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 4

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

National Library of Medicine Discovery API

Discover database metadata, related records, and citations.

National Library of Medicine History API

Manage server-side history sets via the Entrez History server.

National Library of Medicine Retrieve API

Retrieve full or summary records from Entrez databases.

National Library of Medicine Search API

Search Entrez databases for matching records.

Open Collections 6

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

NCBI E-utilities Discovery API

OPEN COLLECTION

NCBI E-utilities Discovery History API

OPEN COLLECTION

NCBI E-utilities Discovery Retrieve API

OPEN COLLECTION

NCBI E-utilities Discovery Search API

OPEN COLLECTION

NCBI E-utilities API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

National Library Of Medicine Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

National Library Of Medicine Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

National Library Of Medicine Finops

FINOPS

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

National Library Of Medicine Domain Security

TLSv1.3 · HSTS · DNSSEC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

National Library Of Medicine Agentic Access

9 operations · 1 acting

AGENTIC

Resources

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

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Company 2

The organization behind the API

LinkedIn

Website

Website

Source (apis.yml)

aid: national-library-of-medicine
name: National Library of Medicine
description: The National Library of Medicine, part of the National Institutes of Health, is the world's largest biomedical
  library. It collects, organizes, and provides access to medical literature and information to support research and decision-making
  in healthcare, including PubMed and ClinicalTrials.gov.
type: Index
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/national-library-of-medicine.png
url: https://raw.githubusercontent.com/api-evangelist/national-library-of-medicine/refs/heads/main/apis.yml
created: '2024-12-03'
modified: '2026-05-19'
specificationVersion: '0.23'
tags:
- Federal-Government
- Health
- Library
- Medicine
tags_raw:
- Federal Government
- Health
- Library
- Medicine
apis:
- aid: national-library-of-medicine:national-library-of-medicine-discovery-api
  name: National Library of Medicine Discovery API
  description: Discover database metadata, related records, and citations.
  humanURL: https://www.ncbi.nlm.nih.gov/home/develop/api
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Discovery
  properties:
  - type: OpenAPI
    url: openapi/national-library-of-medicine-discovery-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/home/develop/api
  - type: GettingStarted
    url: https://www.ncbi.nlm.nih.gov/books/NBK25500/
  - type: Reference
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
- aid: national-library-of-medicine:national-library-of-medicine-history-api
  name: National Library of Medicine History API
  description: Manage server-side history sets via the Entrez History server.
  humanURL: https://www.ncbi.nlm.nih.gov/home/develop/api
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - History
  properties:
  - type: OpenAPI
    url: openapi/national-library-of-medicine-history-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/home/develop/api
  - type: GettingStarted
    url: https://www.ncbi.nlm.nih.gov/books/NBK25500/
  - type: Reference
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
- aid: national-library-of-medicine:national-library-of-medicine-retrieve-api
  name: National Library of Medicine Retrieve API
  description: Retrieve full or summary records from Entrez databases.
  humanURL: https://www.ncbi.nlm.nih.gov/home/develop/api
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags: []
  tags_raw:
  - Retrieve
  properties:
  - type: OpenAPI
    url: openapi/national-library-of-medicine-retrieve-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/home/develop/api
  - type: GettingStarted
    url: https://www.ncbi.nlm.nih.gov/books/NBK25500/
  - type: Reference
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
- aid: national-library-of-medicine:national-library-of-medicine-search-api
  name: National Library of Medicine Search API
  description: Search Entrez databases for matching records.
  humanURL: https://www.ncbi.nlm.nih.gov/home/develop/api
  baseURL: https://eutils.ncbi.nlm.nih.gov/entrez/eutils
  tags:
  - Search
  properties:
  - type: OpenAPI
    url: openapi/national-library-of-medicine-search-api-openapi.yml
  - type: Documentation
    url: https://www.ncbi.nlm.nih.gov/home/develop/api
  - type: GettingStarted
    url: https://www.ncbi.nlm.nih.gov/books/NBK25500/
  - type: Reference
    url: https://www.ncbi.nlm.nih.gov/books/NBK25497/
common:
- type: AgenticAccess
  url: agentic-access/national-library-of-medicine-agentic-access.yml
- type: DomainSecurity
  url: security/national-library-of-medicine-domain-security.yml
- type: GitHubOrganization
  url: https://github.com/NIH-NLM
- type: LinkedIn
  url: https://www.linkedin.com/company/national-library-of-medicine-nlm
- type: Website
  url: https://www.nlm.nih.gov/
- type: Portal
  url: https://www.ncbi.nlm.nih.gov/home/develop/api/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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