WorldCat
OCLC WorldCat REST API for searching 500 million+ library holdings worldwide, accessing bibliographic records, finding library locations, and retrieving rich metadata for books, videos, music, and other media. Provides access to the WorldCat Search API, WorldCat Metadata API, WorldCat Knowledge Base API, and WorldCat Entities data API for libraries and developers building discovery and cataloging applications.
Real signal across most facets with visible, nameable gaps — the contract exists but is thin, or the portal is good while governance and commercial terms are absent.
API Evangelist profiles WorldCat the way a machine reads it — 33 machine-readable artifacts across 20 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — WorldCat scores 55.9/100 (developing), with a separate agent-readiness read of 48/100 (agent ready). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile WorldCat
Each block below is one kind of artifact we hold for WorldCat. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 20
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
WorldCat Knowledge Base API
Provides developer-level access to a library's information in the WorldCat Knowledge Base, combining data about a library's e-content with access through linking features. Suppo...
WorldCat Bibliographic Resources API
The Bibliographic Resources API from WorldCat — 6 operation(s) for bibliographic resources.
WorldCat Local Bib Resources API
The Local Bib Resources API from WorldCat — 2 operation(s) for local bib resources.
WorldCat Local Holdings Resources API
The Local Holdings Resources API from WorldCat — 3 operation(s) for local holdings resources.
WorldCat Manage Bibliographic Records API
The Manage Bibliographic Records API from WorldCat — 5 operation(s) for manage bibliographic records.
WorldCat Manage Institution API
The Manage Institution API from WorldCat — 9 operation(s) for manage institution.
WorldCat Manage Local Bibliographic Data API
The Manage Local Bibliographic Data API from WorldCat — 2 operation(s) for manage local bibliographic data.
WorldCat Manage Local Holdings Records API
The Manage Local Holdings Records API from WorldCat — 2 operation(s) for manage local holdings records.
WorldCat Member Enabled Collections API
The Member Enabled Collections API from WorldCat — 2 operation(s) for member enabled collections.
WorldCat Member Enabled Providers API
The Member Enabled Providers API from WorldCat — 2 operation(s) for member enabled providers.
WorldCat Member Enabled Title by OpenURL API
The Member Enabled Title by OpenURL API from WorldCat — 1 operation(s) for member enabled title by openurl.
WorldCat Member Enabled Titles API
The Member Enabled Titles API from WorldCat — 2 operation(s) for member enabled titles.
WorldCat Member Enabled Titles by OpenURL API
The Member Enabled Titles by OpenURL API from WorldCat — 1 operation(s) for member enabled titles by openurl.
WorldCat Member General Holdings API
The Member General Holdings API from WorldCat — 3 operation(s) for member general holdings.
WorldCat Member Shared Print Holdings API
The Member Shared Print Holdings API from WorldCat — 1 operation(s) for member shared print holdings.
WorldCat Retrieve entity API
The Retrieve entity API from WorldCat — 1 operation(s) for retrieve entity.
WorldCat Search Bibliographic Resources API
The Search Bibliographic Resources API from WorldCat — 4 operation(s) for search bibliographic resources.
WorldCat Search Local Holdings Resources API
The Search Local Holdings Resources API from WorldCat — 4 operation(s) for search local holdings resources.
WorldCat Search Member General Holdings API
The Search Member General Holdings API from WorldCat — 2 operation(s) for search member general holdings.
WorldCat Search Member Shared Print Holdings API
The Search Member Shared Print Holdings API from WorldCat — 1 operation(s) for search member shared print holdings.
Scroll within the panel for all 20 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the six things the Kin Score reads for commercial clarity.
Published pricing tiers and plan structures.
Rate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Worldcat Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Worldcat Finops
FINOPSSemantic Vocabularies 1
JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.
JSON-LD contexts and semantic vocabularies used across these APIs.
Worldcat Context
JSON-LDSpectral Rules 1
Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.
WorldCat API Rules
SPECTRALJSON Schema 4
Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.
Standalone JSON Schema definitions for this provider's data models.
Security Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for WorldCat — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
Documentation 1
Reference material describing how the API behaves
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Build 1
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 2
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 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/worldcat · machine-readable index on apis.io