APIs.io
APIs.io is an open source API search engine and directory that uses APIs.json files to discover, index, and catalog APIs across the web. Built on the APIs.json specification, it provides a searchable entry point for developers to find public APIs by keyword, resource, action, persona, domain, and schema. The platform indexes 779 providers, 3,188 APIs, 587 capabilities, 36,602 schemas, 49 event specs, 2,078 vocabularies, and 450 rulesets. It is maintained by Kin Lane, Nicolas Grenier, and Steven Willmott and supports both API producers (submitting APIs) and API consumers (discovering APIs). APIs.io uses a Spectral-powered rating system to evaluate API documentation quality.
Solid contracts, transparent operations, and an easy start — typically complete on four or five facets with one clear soft spot.
API Evangelist profiles APIs.io the way a machine reads it — 81 machine-readable artifacts across 11 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 — APIs.io scores 66.4/100 (strong), 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 APIs.io
Each block below is one kind of artifact we hold for APIs.io. 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.
APIs.io APIs API
Index of HTTP application programming interfaces.
APIs.io Areas API
The API Evangelist areas taxonomy — curated topic collections (authentication, webhooks, payments, …), each a scored provider index with its own site. Pro.
APIs.io Artifact Types API
First-class, per-type artifact collections (OpenAPI, AsyncAPI, Arazzo, Postman, JSON Schema, and more). Each path filters and normalizes one artifact type across all providers.
APIs.io Industries API
Industry verticals grouping providers across the catalog.
APIs.io Insights API
Demand-side intelligence — what ~5,800 companies (Fortune 1000 + API providers) build, buy, and hire for around APIs, data, and AI, derived from job postings, press, and enginee...
APIs.io Providers API
Organizations publishing APIs on the network.
APIs.io Ratings API
The APIs.io API rating system — a 0–100 composite score, five bands, a trend marker, and six weighted facets measuring how complete, governed, and integration-ready each provide...
APIs.io Regions API
Geographic regions grouping providers across the catalog.
APIs.io Search API
Search using a cloud search engine.
APIs.io Synthesis API
Decision-grade composites over the catalog — provider comparison, gap analysis, catalog change feed, and recommended-stack design. Pro.
APIs.io Tags API
The tag taxonomy, with network-wide ranking metadata.
Scroll within the panel for all 11 ·
Arazzo Workflows 4
Real integrations are rarely a single call. Arazzo describes the multi-step sequences — auth, then create, then confirm — so both a human and an agent can follow the choreography, not just the endpoints.
Multi-step API workflows described with the Arazzo specification.
APIs.io Compare Keyword Coverage
Run two keyword searches against APIs.io and compare how many APIs the index holds for each term.
ARAZZOAPIs.io Paginate Search Results
Read the first page of a keyword search, learn the total page count, then fetch a following page of results.
ARAZZOAPIs.io Search APIs by Keyword
Search the APIs.io registry for APIs matching a keyword and branch on whether any results were returned.
ARAZZOAPIs.io Submit and Verify API
Submit a valid APIs.json to the APIs.io index, then search the registry to confirm the submitted API appears.
ARAZZOPricing 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.
Apis Io 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.
Apis Io Finops
FINOPSFeatures 7
The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.
Notable capabilities this provider offers.
API Search
Full-text search across 3,000+ indexed APIs by keyword, resource, action, persona, domain, and schema using a cloud search engine.
APIs.json Indexing
Automatically indexes APIs.json files submitted by API producers to build a comprehensive, machine-readable catalog of API operations.
API Submission
API producers can submit their APIs to the index by providing a valid APIs.json document via the Search API POST endpoint or GitHub issues.
Spectral API Ratings
Spectral-powered quality rating system that evaluates API documentation completeness and scores APIs to help consumers identify high-quality APIs.
Microservice Architecture
Built as a set of microservices including Search, Engine, Authentication, Publishing, Tags, Rules, Properties, Maintainers, and Ratings APIs.
Topic Search Nodes
Specialized search nodes for domain-specific API discovery including AI, Healthcare, Banking, Payments, Weather, CRM, Cloud, and many more topic areas.
Open Source
The platform is open source, licensed under Apache-2.0, with all microservice APIs available on GitHub under the api-search organization.
Scroll within the panel for all 7 ·
Semantic 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.
Apis Io Context
JSON-LDSpectral Rules 2
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.
APIs.io API Rules
SPECTRALAPIs.io API Rules
SPECTRALJSON Schema 13
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.
AddAPIsJSON
JSON SCHEMAAPIsJSON
JSON SCHEMAAPIs
JSON SCHEMAAPI
JSON SCHEMAContact
JSON SCHEMAInclude
JSON SCHEMALink
JSON SCHEMAMaintainer
JSON SCHEMAmetaInformation
JSON SCHEMAMeta
JSON SCHEMAProperty
JSON SCHEMASearch
JSON SCHEMATag
JSON SCHEMAScroll within the panel for all 13 ·
JSON Structure 13
JSON Structure captures the data shapes in a form built for tooling — a complement to JSON Schema that keeps the model machine-legible.
JSON Structure definitions describing this provider's data shapes.
Apis Io Search Add Ap Is Json Structure
JSON STRUCTUREApis Io Search Ap Is Json Structure
JSON STRUCTUREApis Io Search Ap Is Structure
JSON STRUCTUREApis Io Search Api Structure
JSON STRUCTUREApis Io Search Contact Structure
JSON STRUCTUREApis Io Search Include Structure
JSON STRUCTUREApis Io Search Link Structure
JSON STRUCTUREApis Io Search Maintainer Structure
JSON STRUCTUREApis Io Search Meta Information Structure
JSON STRUCTUREApis Io Search Meta Structure
JSON STRUCTUREApis Io Search Property Structure
JSON STRUCTUREApis Io Search Search Structure
JSON STRUCTUREApis Io Search Tag Structure
JSON STRUCTUREScroll within the panel for all 13 ·
Examples 13
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.
Apis Io Search Ap Is Example
EXAMPLEApis Io Search Api Example
EXAMPLEApis Io Search Link Example
EXAMPLEApis Io Search Meta Example
EXAMPLEApis Io Search Tag Example
EXAMPLEScroll within the panel for all 13 ·
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.
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.
Use Cases 5
What developers actually build with this provider — captured so the catalogue answers 'what is this for', not just 'what does this expose'.
What developers build with this provider.
API Discovery
Developers can search for APIs relevant to their project by keyword, discovering APIs across thousands of providers without knowing where to look.
API Submission
API producers can submit their APIs.json files to ensure their APIs are discoverable in the index and properly cataloged with metadata.
Quality Assessment
Development teams use the Spectral ratings system to identify high-quality APIs and avoid poorly documented or unmaintained options.
Catalog Building
Platform teams use APIs.io as a reference implementation for building their own internal API catalogs using the APIs.json format.
Domain-Specific Search
Developers searching for APIs in specific domains (healthcare, finance, AI) can use topic-specific search nodes for more targeted discovery.
Integrations 6
Pre-built integrations with other platforms tell you where this provider already fits in a stack.
Pre-built integrations with other platforms and tools.
APIs.json
Core integration with the APIs.json specification for machine-readable API description and discovery across the web.
OpenAPI
APIs indexed in APIs.io reference OpenAPI specifications as a key property, linking consumers to technical API contracts.
Spectral
Spectral ruleset integration powers the APIs.io rating system, evaluating API documentation quality against standardized rules.
GitHub
GitHub integration for API submission via issues, source of truth for indexed APIs.json files, and authentication via Personal Access Tokens.
Postman
Postman public workspace integration for running and testing the APIs.io Search API via pre-built collections.
AWS API Gateway
The APIs.io Search API is deployed and managed through AWS API Gateway for scalable, managed API access.
Resources
Every other property we hold for APIs.io — 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.
Get Started 2
Portal, sign-up, and the first successful call
Agent Surfaces 1
MCP servers, agent skills, and machine-readable catalogs
Design & Contract 7
Pagination, idempotency, versioning, errors, and events
Scroll within the panel for all 7 ·
Build 6
SDKs, sample code, and the tooling you integrate with
Access & Security 3
Authentication, authorization, and security posture
Operate 3
Status, limits, changes, and where to get help
Commercial 3
Pricing, plans, and the legal terms of use
Company 4
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/apis-io · machine-readable index on apis.io