Cancer.gov website screenshot

Cancer.gov

Cancer.gov is the web presence of the National Cancer Institute (NCI), the U.S. federal government's principal agency for cancer research and training. NCI and its partner programs expose a rich set of open APIs covering cancer clinical trials, genomic data, cancer-incidence surveillance, research data and models, terminology and vocabularies, and PDQ content — giving researchers, advocacy groups, clinicians, and application developers programmatic access to authoritative cancer data and content.

Cancer.gov publishes 12 APIs on the APIs.io network, including NCI SEER API, NCI MoDaC API, NCI EVS Terminology API, and 9 more. Tagged areas include Cancer, Federal-Government, Healthcare, Research, and Clinical Trials.

Cancer.gov’s developer surface includes authentication, engineering blog, CLI, changelog, documentation, API reference, signup flow, and 32 more developer resources.

51.8/100 developing ▬ flat Agent 29/100 agent ready saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessFreemiumSelf serve⚡ Free to try
9 APIs 1 MCP Servers
CancerFederal-GovernmentHealthcareResearchClinical TrialsGenomicsSurveillanceOpen Data

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Regulatory Posture applies to this provider. Its tags matched the Government & Public Sector 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/cancer-gov: 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 15

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

NCI Clinical Trials Search API

RESTful API that lets developers build applications, search tools, and digital platforms over NCI-supported cancer clinical trials data sourced from NCI's Clinical Trials Report...

NCI Genomic Data Commons (GDC) API

The external-facing REST interface for the NCI Genomic Data Commons. Drives the GDC Data Portal and GDC Submission Portal and is open for programmatic access. Provides query, do...

NCI SEER API

RESTful API for the Surveillance, Epidemiology, and End Results (SEER) Program. Supports SEER datasets plus staging APIs for cancer staging (TNM and Collaborative Stage algorith...

NCI MoDaC API

The NCI Model and Data Clearinghouse (MoDaC) API provides programmatic access to cancer research data, computational models, and associated tools hosted in MoDaC. Developers can...

NCI EVS Terminology API

Enterprise Vocabulary Services (EVS) exposes NCI Thesaurus and NCI Metathesaurus content — over 192,000 concepts, 154,000 textual definitions, 623,000 synonyms and 630,000 inter...

NCI Content Syndication Services

A suite of syndicated content channels — RSS feeds, the NCI Dictionary Widget, and syndicated publication content — that partner sites and health platforms can embed to deliver ...

Cancer.gov Diseases API

The Diseases API from Cancer.gov — 1 operation(s) for diseases.

Cancer.gov Interventions API

The Interventions API from Cancer.gov — 1 operation(s) for interventions.

Cancer.gov Terms API

The Terms API from Cancer.gov — 1 operation(s) for terms.

Cancer.gov Trials API

The Trials API from Cancer.gov — 2 operation(s) for trials.

NCI Glossary Term API

Serves the NCI Dictionary of Cancer Terms — the authoritative plain-language and health-professional definitions used across cancer.gov and by the NCI Dictionary Widget. Support...

NCI Drug Dictionary API

Serves the NCI Drug Dictionary — definitions of drugs and drug combinations used in cancer treatment and prevention, matched across generic names, brand names and code names. Su...

Cancer.gov Site-Wide Search API

The search service behind cancer.gov's own site search: full-text search and autosuggest across NCI web content, with per-collection scoping and status reporting. No credential ...

Cancer.gov Best Bets API

Returns NCI's editorially curated 'best bet' results for a search term — the promoted, hand-picked answers cancer.gov surfaces above algorithmic search results. No credential re...

NCI Resources for Researchers API

Backs NCI's Resources for Researchers directory — searchable metadata about NCI tools, datasets, repositories and services available to the cancer research community. No credent...

Scroll for all 15

Open Collections 6

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

API Collection

OPEN COLLECTION

MCP Servers 1

Model Context Protocol servers that expose these APIs to AI agents.

Pricing Plans 1

Published pricing tiers and plan structures.

Rate Limits 1

Documented rate limits and quota policies.

Cancer Gov Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Security Posture 2

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

Cancer Gov Authentication

apiKey/none · 5 schemes

SECURITY

Cancer Gov Domain Security

TLSv1.3 · HSTS · DNSSEC · DMARC

SECURITY

Agentic Access 1

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

Cancer Gov Agentic Access

6 operations · 1 acting

6 operations · 1 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Documentation 3

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Build 5

SDKs, sample code, and the tooling you integrate with

Access & Security 2

Authentication, authorization, and security posture

Operate 4

Status, limits, changes, and where to get help

Commercial 3

Pricing, plans, and the legal terms of use

Company 3

The organization behind the API

Other 7

Properties that don't map to a standard resource type

Scroll for all 7

Source (apis.yml)

apis.yml Raw ↑
aid: cancer-gov
name: Cancer.gov
url: https://raw.githubusercontent.com/api-evangelist/cancer-gov/refs/heads/main/apis.yml
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-09-03'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cancer-gov.png
type: Index
tags:
- Cancer
- Federal-Government
- Healthcare
- Research
- Clinical Trials
- Genomics
- Surveillance
- Open Data
tags_raw:
- Cancer
- Federal Government
- Healthcare
- Research
- Clinical Trials
- Genomics
- Surveillance
- Open Data
access: Open
created: '2024-07-02'
modified: '2026-09-05'
position: Producing
specificationVersion: '0.23'
description: Cancer.gov is the web presence of the National Cancer Institute (NCI), the U.S. federal government's principal
  agency for cancer research and training. NCI and its partner programs expose a rich set of open APIs covering cancer clinical
  trials, genomic data, cancer-incidence surveillance, research data and models, terminology and vocabularies, and PDQ content
  — giving researchers, advocacy groups, clinicians, and application developers programmatic access to authoritative cancer
  data and content.
apis:
- aid: cancer-gov:clinical-trials-api
  name: NCI Clinical Trials Search API
  description: RESTful API that lets developers build applications, search tools, and digital platforms over NCI-supported
    cancer clinical trials data sourced from NCI's Clinical Trials Reporting Program (CTRP). The same API powers NCI's public
    Clinical Trials Search. Developers register for a free API key through the CTS Developer Accounts portal.
  humanURL: https://clinicaltrialsapi.cancer.gov/
  baseURL: https://clinicaltrialsapi.cancer.gov/api/v2
  tags:
  - Clinical Trials
  - CTRP
  - Research
  properties:
  - type: Documentation
    url: https://clinicaltrialsapi.cancer.gov/
  - type: Signup
    url: https://clinicaltrialsapi.cancer.gov/
  - type: ParentPage
    url: https://www.cancer.gov/syndication/api
  - type: Support
    url: mailto:ctrp_support@mail.nih.gov
  - type: SDKs
    url: packages/cancer-gov-packages.yml
- aid: cancer-gov:gdc-api
  name: NCI Genomic Data Commons (GDC) API
  description: The external-facing REST interface for the NCI Genomic Data Commons. Drives the GDC Data Portal and GDC Submission
    Portal and is open for programmatic access. Provides query, download, and submission endpoints for cancer genomics datasets
    including TCGA, TARGET, CPTAC, and other NCI-funded genomic programs.
  humanURL: https://gdc.cancer.gov/developers/gdc-application-programming-interface-api
  baseURL: https://api.gdc.cancer.gov
  tags:
  - Genomics
  - TCGA
  - Research Data
  properties:
  - type: Documentation
    url: https://docs.gdc.cancer.gov/API/Users_Guide/Getting_Started/
  - type: Reference
    url: https://docs.gdc.cancer.gov/Encyclopedia/pages/REST_API/
  - type: Portal
    url: https://portal.gdc.cancer.gov/
  - type: GraphQL
    url: graphql/cancer-gov-gdc.graphql
  - type: ChangeLog
    url: changelog/cancer-gov-changelog.yml
  - type: StatusPage
    url: https://api.gdc.cancer.gov/status
  - type: CLI
    url: cli/cancer-gov-cli.yml
  - type: Support
    url: https://gdc.cancer.gov/support
  - type: GitHubOrganization
    url: https://github.com/NCI-GDC
  - type: APIReference
    url: https://docs.gdc.cancer.gov/API/Release_Notes/API_Release_Notes/
- aid: cancer-gov:seer-api
  name: NCI SEER API
  description: RESTful API for the Surveillance, Epidemiology, and End Results (SEER) Program. Supports SEER datasets plus
    staging APIs for cancer staging (TNM and Collaborative Stage algorithms), enabling developers to embed authoritative incidence,
    survival, and staging logic into their own systems.
  humanURL: https://api.seer.cancer.gov/
  baseURL: https://api.seer.cancer.gov
  tags:
  - Surveillance
  - Epidemiology
  - Staging
  - SEER
  properties:
  - type: Documentation
    url: https://api.seer.cancer.gov/docs
  - type: Portal
    url: https://api.seer.cancer.gov/
  - type: OpenAPI
    url: openapi/cancer-gov-seer-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-seer-overlay.yaml
  - type: TermsOfService
    url: https://api.seer.cancer.gov/terms
  - type: RateLimits
    url: rate-limits/cancer-gov-rate-limits.yml
  - type: APIReference
    url: https://api.seer.cancer.gov/docs
- aid: cancer-gov:modac-api
  name: NCI MoDaC API
  description: The NCI Model and Data Clearinghouse (MoDaC) API provides programmatic access to cancer research data, computational
    models, and associated tools hosted in MoDaC. Developers can search, retrieve metadata, and download model/data artifacts
    produced by NCI-funded research programs.
  humanURL: https://modac.cancer.gov/
  tags:
  - Research Data
  - Models
  - Clearinghouse
  properties:
  - type: Documentation
    url: https://modac.cancer.gov/swagger-ui/4.14.0/index.html
  - type: Portal
    url: https://modac.cancer.gov/
  - type: OpenAPI
    url: openapi/cancer-gov-modac-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-modac-overlay.yaml
  baseURL: https://modac.cancer.gov
- aid: cancer-gov:evs-api
  name: NCI EVS Terminology API
  description: Enterprise Vocabulary Services (EVS) exposes NCI Thesaurus and NCI Metathesaurus content — over 192,000 concepts,
    154,000 textual definitions, 623,000 synonyms and 630,000 inter-concept relationships — through a search and browse API
    used to code, analyze, and share cancer and biomedical research information.
  humanURL: https://evs.nci.nih.gov/
  tags:
  - Terminology
  - Vocabulary
  - NCI Thesaurus
  properties:
  - type: Documentation
    url: https://evs.nci.nih.gov/
  - type: Explorer
    url: https://evsexplore.semantics.cancer.gov/
  - type: WhitePaper
    url: https://evs.nci.nih.gov/ftp1/NCI_Metathesaurus/EVS%20Metathesaurus%20White%20Paper.pdf
  - type: OpenAPI
    url: openapi/cancer-gov-evs-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-evs-overlay.yaml
  - type: APIReference
    url: https://api-evsrest.nci.nih.gov/swagger-ui/index.html
  - type: SourceCode
    url: https://github.com/NCIEVS/evsrestapi
  - type: TermsOfService
    url: https://evs.nci.nih.gov/ftp1/NCI_Thesaurus/ThesaurusTermsofUse.htm
  baseURL: https://api-evsrest.nci.nih.gov
- aid: cancer-gov:syndication-services
  name: NCI Content Syndication Services
  description: A suite of syndicated content channels — RSS feeds, the NCI Dictionary Widget, and syndicated publication content
    — that partner sites and health platforms can embed to deliver authoritative cancer content sourced from cancer.gov.
  humanURL: https://www.cancer.gov/syndication
  tags:
  - Syndication
  - Content
  - Widgets
  - RSS
  properties:
  - type: Documentation
    url: https://www.cancer.gov/syndication
- aid: cancer-gov:cancer-gov-diseases-api
  name: Cancer.gov Diseases API
  description: The Diseases API from Cancer.gov — 1 operation(s) for diseases.
  humanURL: https://clinicaltrialsapi.cancer.gov/
  baseURL: https://clinicaltrialsapi.cancer.gov/api/v2
  tags:
  - Diseases
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-diseases-api-openapi.yml
- aid: cancer-gov:cancer-gov-interventions-api
  name: Cancer.gov Interventions API
  description: The Interventions API from Cancer.gov — 1 operation(s) for interventions.
  humanURL: https://clinicaltrialsapi.cancer.gov/
  baseURL: https://clinicaltrialsapi.cancer.gov/api/v2
  tags:
  - Interventions
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-interventions-api-openapi.yml
- aid: cancer-gov:cancer-gov-terms-api
  name: Cancer.gov Terms API
  description: The Terms API from Cancer.gov — 1 operation(s) for terms.
  humanURL: https://clinicaltrialsapi.cancer.gov/
  baseURL: https://clinicaltrialsapi.cancer.gov/api/v2
  tags:
  - Terms
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-terms-api-openapi.yml
- aid: cancer-gov:cancer-gov-trials-api
  name: Cancer.gov Trials API
  description: The Trials API from Cancer.gov — 2 operation(s) for trials.
  humanURL: https://clinicaltrialsapi.cancer.gov/
  baseURL: https://clinicaltrialsapi.cancer.gov/api/v2
  tags:
  - Trials
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-trials-api-openapi.yml
- aid: cancer-gov:glossary-api
  name: NCI Glossary Term API
  description: Serves the NCI Dictionary of Cancer Terms — the authoritative plain-language and health-professional definitions
    used across cancer.gov and by the NCI Dictionary Widget. Supports autosuggest, full-text search, alphabetical expansion
    and per-term retrieval by id or pretty URL name, in English and Spanish, for both Patient and HealthProfessional audiences.
    No credential required.
  humanURL: https://webapis.cancer.gov/glossary/v1/
  baseURL: https://webapis.cancer.gov/glossary/v1
  tags:
  - Glossary
  - Terminology
  - Content
  - Dictionary
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-glossary-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-glossary-overlay.yaml
  - type: SourceCode
    url: https://github.com/NCIOCPL/glossary-api
  - type: Documentation
    url: https://webapis.cancer.gov/glossary/v1/
- aid: cancer-gov:drug-dictionary-api
  name: NCI Drug Dictionary API
  description: Serves the NCI Drug Dictionary — definitions of drugs and drug combinations used in cancer treatment and prevention,
    matched across generic names, brand names and code names. Supports autosuggest, search, alphabetical expansion and retrieval
    by id or pretty URL name. No credential required.
  humanURL: https://webapis.cancer.gov/drugdictionary/v1/
  baseURL: https://webapis.cancer.gov/drugdictionary/v1
  tags:
  - Drugs
  - Terminology
  - Content
  - Dictionary
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-drug-dictionary-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-drug-dictionary-overlay.yaml
  - type: SourceCode
    url: https://github.com/NCIOCPL/drug-dictionary-api
  - type: Documentation
    url: https://webapis.cancer.gov/drugdictionary/v1/
- aid: cancer-gov:sitewide-search-api
  name: Cancer.gov Site-Wide Search API
  description: 'The search service behind cancer.gov''s own site search: full-text search and autosuggest across NCI web content,
    with per-collection scoping and status reporting. No credential required.'
  humanURL: https://webapis.cancer.gov/sitewidesearch/v1/
  baseURL: https://webapis.cancer.gov/sitewidesearch/v1
  tags:
  - Search
  - Content
  - Autosuggest
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-sitewide-search-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-sitewide-search-overlay.yaml
  - type: SourceCode
    url: https://github.com/NCIOCPL/sitewide-search-api
- aid: cancer-gov:best-bets-api
  name: Cancer.gov Best Bets API
  description: Returns NCI's editorially curated 'best bet' results for a search term — the promoted, hand-picked answers
    cancer.gov surfaces above algorithmic search results. No credential required.
  humanURL: https://webapis.cancer.gov/bestbets/v1/
  baseURL: https://webapis.cancer.gov/bestbets/v1
  tags:
  - Search
  - Content
  - Curation
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-best-bets-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-best-bets-overlay.yaml
  - type: SourceCode
    url: https://github.com/NCIOCPL/bestbets-api
- aid: cancer-gov:r4r-api
  name: NCI Resources for Researchers API
  description: Backs NCI's Resources for Researchers directory — searchable metadata about NCI tools, datasets, repositories
    and services available to the cancer research community. No credential required.
  humanURL: https://webapis.cancer.gov/r4r/v1/
  baseURL: https://webapis.cancer.gov/r4r/v1
  tags:
  - Research
  - Resources
  - Directory
  properties:
  - type: OpenAPI
    url: openapi/cancer-gov-r4r-openapi.yml
  - type: Overlay
    url: overlays/cancer-gov-r4r-overlay.yaml
  - type: SourceCode
    url: https://github.com/NCIOCPL/r4r-api
common:
- type: CapabilityMap
  url: capabilities/cancer-gov-capability-edges.yml
  name: Cancer.gov Business Capability Map
- type: AgenticAccess
  url: agentic-access/cancer-gov-agentic-access.yml
- type: DomainSecurity
  url: security/cancer-gov-domain-security.yml
- type: Authentication
  url: authentication/cancer-gov-authentication.yml
- type: GitHubOrganization
  url: https://github.com/NCIOCPL
- type: Website
  url: https://www.cancer.gov/
- type: SyndicationServices
  url: https://www.cancer.gov/syndication
- type: DataScience
  url: https://datascience.cancer.gov/
- type: PrivacyPolicy
  url: https://www.cancer.gov/policies/privacy-security
- type: LicensingAndReuse
  url: https://www.cancer.gov/policies/copyright-reuse
- url: https://www.cancer.gov/publishedcontent/rss/news-events/cancer-currents-blog.rss
  type: Blog
- type: Packages
  url: packages/cancer-gov-packages.yml
- type: SDKs
  url: packages/cancer-gov-packages.yml
- type: CLI
  url: cli/cancer-gov-cli.yml
- type: Components
  url: components/cancer-gov-components.yml
- type: MCPServer
  url: mcp/cancer-gov-mcp.yml
- type: ToolCrosswalk
  url: mcp/cancer-gov-tool-crosswalk.yml
- type: LLMsTxt
  url: llms/cancer-gov-llms.txt
- type: GraphQL
  url: graphql/cancer-gov-gdc.graphql
- type: Conformance
  url: conformance/cancer-gov-conformance.yml
- type: ErrorCatalog
  url: errors/cancer-gov-problem-types.yml
- type: Lifecycle
  url: lifecycle/cancer-gov-lifecycle.yml
- type: StatusPage
  url: https://api.gdc.cancer.gov/status
- type: Conventions
  url: conventions/cancer-gov-conventions.yml
- type: ChangeLog
  url: changelog/cancer-gov-changelog.yml
- type: DataModel
  url: data-model/cancer-gov-data-model.yml
- type: Plans
  url: plans/cancer-gov-plans-pricing.yml
- type: RateLimits
  url: rate-limits/cancer-gov-rate-limits.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Overlay
  url: overlays/cancer-gov-seer-overlay.yaml
- type: Documentation
  url: https://docs.gdc.cancer.gov/API/Users_Guide/Getting_Started/
- type: APIReference
  url: https://api.seer.cancer.gov/docs
- type: DeveloperPortal
  url: https://www.cancer.gov/syndication/api
- type: SignUp
  url: https://clinicaltrialsapi.cancer.gov/
- type: Support
  url: https://www.cancer.gov/contact
- type: TermsOfService
  url: https://api.seer.cancer.gov/terms
- type: Policies
  url: https://www.cancer.gov/policies
- type: OpenDataPolicy
  url: https://datascience.cancer.gov/data-sharing
- type: News
  url: https://www.cancer.gov/news-events
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
x-enrichment:
  date: '2026-09-05'
  status: enriched
  artifacts_added: 44
  pass: local-v3

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