Fatcat
Fatcat is a versioned, user-editable open catalog of published research works maintained by the Internet Archive. It tracks bibliographic metadata, links papers to full-text copies, and preserves access to scholarly publications including journal articles, conference proceedings, and datasets across millions of research works.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles Fatcat the way a machine reads it — 40 machine-readable artifacts across 1 API, 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 — Fatcat scores 33.1/100 (thin), with a separate agent-readiness read of 26/100 (agent aware). 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. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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title="Fatcat on API Evangelist — API profile and Kin Score">
<img src="https://apis.io/badge/fatcat/card.svg"
alt="Fatcat Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile Fatcat
Each block below is one kind of artifact we hold for Fatcat. 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 11
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.
Fatcat auth API
Helper methods and internal APIs for editor authentication. # TAGLINE
Fatcat changelog API
The **Changelog** is the ordered feed of editgroups which have been # TAGLINE accepted into the catalog. # TAGLINE
Fatcat containers API
**Container** entities represent publication venues like journals, # TAGLINE conference proceedings, book series, or blogs. They group publications # TAGLINE ("releases"). # TAG...
Fatcat creators API
**Creator** entities represent individuals (or organizations, or other # TAGLINE agents) who contribute to the creation of specific releases # TAGLINE (publications). # TAGLINE ...
Fatcat editgroups API
**Editgroups** are sets of changes, each to individual entities in the # TAGLINE catalog. Every edit must be part of an editgroup which is reviewed and # TAGLINE accepted (merge...
Fatcat editors API
**Editors** are human user accounts and bots that make changes to the # TAGLINE Fatcat catalog. # TAGLINE The API allows fetching (and updating) metadata about individual editor...
Fatcat files API
**File** entities represent unique digital files which are full # TAGLINE manifestations of specific releases (publications), such as fulltext PDF # TAGLINE files, JATS XML docu...
Fatcat filesets API
**Fileset** entities represent sets of digital files, as well as locations # TAGLINE where they can be found on the public web. Filesets most commonly # TAGLINE represent datase...
Fatcat releases API
**Release** entities represent specific published versions of a research # TAGLINE work, such as a pre-print, a journal article, a book (or chapter), or a # TAGLINE scholarly bl...
Fatcat webcaptures API
**Web Capture** entities represent archival snapshots of web pages (or # TAGLINE other web resources), which are usually complete manifestations of a # TAGLINE specific release ...
Fatcat works API
**Work** entities group several Release entities which are different # TAGLINE versions of the same abstract piece of research. For example, three # TAGLINE release entities rep...
Scroll within the panel for all 11 ·
Open Collections 12
Open, tool-agnostic collections carry the same runnable value as Postman without locking you to one client — the portable, forkable form of the same exercise.
Open, tool-agnostic API collections (OpenAPI-derived and Bruno).
API Collection
OPEN COLLECTIONfatcat auth API
OPEN COLLECTIONfatcat auth changelog API
OPEN COLLECTIONfatcat auth containers API
OPEN COLLECTIONfatcat auth creators API
OPEN COLLECTIONfatcat auth editgroups API
OPEN COLLECTIONfatcat auth editors API
OPEN COLLECTIONfatcat auth files API
OPEN COLLECTIONfatcat auth filesets API
OPEN COLLECTIONfatcat auth releases API
OPEN COLLECTIONfatcat auth webcaptures API
OPEN COLLECTIONfatcat auth works API
OPEN COLLECTIONScroll within the panel for all 12 ·
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 things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.
Published pricing tiers and plan structures.
Plans
PLANSRate 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.
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.
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.
context 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.
Fatcat API Rules
SPECTRALJSON Schema 5
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.
ContainerEntity
JSON SCHEMACreatorEntity
JSON SCHEMAEditgroup
JSON SCHEMAFileEntity
JSON SCHEMAReleaseEntity
JSON SCHEMAExamples 5
Real request and response payloads are what turn a spec from abstract into obvious — and they're one of the twelve things an agent needs to call an API correctly on the first try.
Example request and response payloads for these APIs.
Container Entity Example
EXAMPLECreator Entity Example
EXAMPLEEditgroup Example
EXAMPLEFile Entity Example
EXAMPLERelease Entity Example
EXAMPLESecurity Posture 1
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.
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 Fatcat — 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.
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Access & Security 1
Authentication, authorization, and security posture
Operate 2
Status, limits, changes, and where to get help
Other 1
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/fatcat · machine-readable index on apis.io
This is an independent, third-party profile of Fatcat, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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