# APIs.io

**Canonical:** https://apis.io/providers/apis-io/  
**Website:** https://apis.io  
**APIs profiled:** 11

APIs.io is an open-source API search engine and federated discovery network built on the APIs.json specification. It indexes API providers and their individual APIs across the public internet along with the machine-readable artifacts they publish — OpenAPI, AsyncAPI, GraphQL, Arazzo workflows, Postman collections, JSON Schema, JSON-LD contexts, Spectral rulesets, vocabularies, OAuth scopes, plans, rate limits and FinOps profiles — and lets developers and agents search that catalog by keyword, capability, tag, industry, region, artifact type and quality band. As of August 2026 the network published roughly 26,414 providers, 109,100 APIs and 120,595 schemas across 71 industries and 77 curated areas. Every provider is scored with the Kin Score, a 0–100 composite across six weighted facets plus a standalone agent-readiness score. The same read-only OpenAPI 3.1 contract powers three surfaces — a REST API at https://apis.io/api/v1, a Streamable-HTTP MCP server at https://apis.io/mcp, and a set of published Agent Skills — alongside an RFC 9727 api-catalog linkset, an llms.txt and an APIs.json self-description. It is maintained by API Evangelist and serves both API producers submitting profiles and API consumers discovering APIs.

## Kin Score — 65.1 / 100 (strong)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+1.2 from 63.9).

| Facet | Score |
|---|---|
| Discoverability | 92.6 |
| Contract Quality | 73.0 |
| Governance | 41.7 |
| Contract Governance | 41.7 |
| Operational Transparency | 47.4 |
| Developer Ergonomics | 71.4 |
| Commercial Clarity | 60.5 |
| Access Clarity | 60.5 |

## Agent readiness — 53.4 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | verified |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | documented |
| OpenAPI Examples | partial |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | yes |
| Well Known Catalog | yes |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Freemium · Self-serve signup — onboarding: self-serve, pricing: freemium, trial: no (confidence: high).

## APIs (11)

- **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.

## MCP servers (1)

- **APIs.io MCP Server**

## Agentic access (1)

- **Apis Io Agentic Access** — 64 operations · 1 acting

## Security (2)

- **Apis Io Authentication** — apiKey · 2 schemes
- **Apis Io Domain Security** — TLSv1.3

## Plans (1)

- **Apis Io Plans Pricing**

## Use cases (5)

- **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.

## Tags

API Aggregation, API Directory, API Discovery, API Indexing, API Rating, API Search, APIs.json, Search Engines, API Catalog, Agent Discovery, MCP, Agent Skills, OpenAPI, API Governance

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/apis-io/). Scores are computed from the provider's own public artifacts under a published rubric.