Crossref

Crossref is a non-profit organization that provides digital infrastructure for scholarly communications. Best known for Digital Object Identifier (DOI) registration, Crossref also operates a public REST API offering searchable, filterable access to metadata for tens of millions of scholarly works, journals, members, funders, prefixes, types, licenses, and DOI registration agency information. The Crossref REST API supports free-form queries, field queries, filters, facets, deep-paging cursors, and selection of specific elements, and is used by reference managers, repositories, discovery layers, and analytics platforms.

Crossref publishes 8 APIs on the APIs.io network, including Agency API, Funders API, Journals API, and 5 more. Tagged areas include Citations, DOI, Funders, Identifiers, and Journals.

The Crossref catalog on APIs.io includes 1 JSON-LD context and 2 Spectral governance rulesets.

Crossref’s developer surface includes documentation, engineering blog, and 13 more developer resources.

🌐 Visit website 📡 Source on GitHub

50.2/100 developing ▼ -6.0 Agent 22/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6

AccessFreemium

8 APIs

CitationsDOIFundersIdentifiersJournalsLicensesMembersMetadataOpen AccessORCIDPrefixesPublishersReference LinkingRORScholarly

Kin Score

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

Composite quality — 50.2/100 · developing

Contract Quality 13.4 / 25

Developer Ergonomics 4.3 / 20

Commercial Clarity 10.0 / 20

Operational Transparency 6.8 / 13

Governance 8.3 / 12

Discoverability 7.4 / 10

Agent readiness — 22/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

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

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/crossref: 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 8

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

Rate Limits 1

Documented rate limits and quota policies.

Crossref Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

JSON Schema 1

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

AGENTIC

Resources

Documentation 3

Reference material describing how the API behaves

JSONSchema

JSONSchema

Documentation

Documentation

APIDocumentation

APIDocumentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

Vocabulary

Vocabulary

JSONLD

JSONLD

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

VulnerabilityDisclosure

VulnerabilityDisclosure

DomainSecurity

DomainSecurity

Operate 2

Status, limits, changes, and where to get help

StatusPage

StatusPage

Community

Community

Commercial 1

Pricing, plans, and the legal terms of use

TermsOfService

TermsOfService

Company 3

The organization behind the API

LinkedIn

Website

Website

Blog

Blog

Source (apis.yml)

aid: crossref
name: Crossref
kind: company
description: Crossref is a non-profit organization that provides digital infrastructure for scholarly communications. Best
  known for Digital Object Identifier (DOI) registration, Crossref also operates a public REST API offering searchable, filterable
  access to metadata for tens of millions of scholarly works, journals, members, funders, prefixes, types, licenses, and DOI
  registration agency information. The Crossref REST API supports free-form queries, field queries, filters, facets, deep-paging
  cursors, and selection of specific elements, and is used by reference managers, repositories, discovery layers, and analytics
  platforms.
url: https://raw.githubusercontent.com/api-evangelist/crossref/refs/heads/main/apis.yml
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/crossref.png
tags:
- Citations
- DOI
- Funders
- Identifiers
- Journals
- Licenses
- Members
- Metadata
- Open Access
- ORCID
- Prefixes
- Publishers
- Reference Linking
- ROR
- Scholarly
created: '2024-07-02'
modified: '2026-05-19'
specificationVersion: '0.20'
type: Index
access: Public
position: Provider
apis:
- aid: crossref:crossref-agency-api
  name: Crossref Agency API
  description: The Agency API from Crossref — 1 operation(s) for agency.
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Agency
  properties:
  - type: OpenAPI
    url: openapi/crossref-agency-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-funders-api
  name: Crossref Funders API
  description: Endpoints that expose funder related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Funders
  properties:
  - type: OpenAPI
    url: openapi/crossref-funders-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-journals-api
  name: Crossref Journals API
  description: Endpoints that expose journal related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Journals
  properties:
  - type: OpenAPI
    url: openapi/crossref-journals-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-licenses-api
  name: Crossref Licenses API
  description: Endpoints that expose license related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Licenses
  properties:
  - type: OpenAPI
    url: openapi/crossref-licenses-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-members-api
  name: Crossref Members API
  description: Endpoints that expose member related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Members
  properties:
  - type: OpenAPI
    url: openapi/crossref-members-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-prefixes-api
  name: Crossref Prefixes API
  description: Endpoints that expose prefix related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Prefixes
  properties:
  - type: OpenAPI
    url: openapi/crossref-prefixes-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-types-api
  name: Crossref Types API
  description: Endpoints that expose type related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Types
  properties:
  - type: OpenAPI
    url: openapi/crossref-types-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
- aid: crossref:crossref-works-api
  name: Crossref Works API
  description: Endpoints that expose works related data
  humanURL: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  baseURL: https://api.crossref.org
  tags:
  - Works
  properties:
  - type: OpenAPI
    url: openapi/crossref-works-api-openapi.yml
  - type: Documentation
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
  - type: SwaggerUI
    url: https://api.crossref.org/swagger-ui/
  - type: PolitePool
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/#etiquette
  - type: Tips
    url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/tips-for-using-the-crossref-rest-api/
  - type: Rules
    url: rules/crossref-rules.yml
  - type: Capabilities
    url: capabilities/crossref-capabilities.yml
  - type: JSONSchema
    url: json-schema/crossref-work-schema.json
  - type: JSONLD
    url: json-ld/crossref-context.jsonld
common:
- type: AgenticAccess
  url: agentic-access/crossref-agentic-access.yml
- type: VulnerabilityDisclosure
  url: security/crossref-vulnerability-disclosure.yml
- type: DomainSecurity
  url: security/crossref-domain-security.yml
- type: LinkedIn
  url: https://www.linkedin.com/company/crossref
- type: Vocabulary
  url: vocabulary/crossref-vocabulary.yml
- type: JSONLD
  url: json-ld/crossref-context.jsonld
- type: JSONSchema
  url: json-schema/crossref-work-schema.json
- type: Website
  url: https://www.crossref.org/
- type: Documentation
  url: https://www.crossref.org/documentation/
- type: APIDocumentation
  url: https://www.crossref.org/documentation/retrieve-metadata/rest-api/
- type: Blog
  url: https://www.crossref.org/blog/
- type: GitHubOrganization
  url: https://github.com/CrossRef
- type: StatusPage
  url: https://status.crossref.org/
- type: Community
  url: https://community.crossref.org/
- type: TermsOfService
  url: https://www.crossref.org/operations-and-sustainability/terms/
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com