APIs.io is a federated, agent-friendly directory of public-internet APIs. It indexes API providers from across the web — their APIs, JSON Schemas, event-driven specifications, governance rules, vocabularies, JSON-LD contexts, pricing plans, rate limits, FinOps profiles, the agent surfaces they publish (Agent Skills and MCP servers), and the industries and regions they serve — and exposes each slice of metadata at its own subdomain.
Every site is a separate Jekyll deploy on GitHub Pages. All share one upstream provider catalog, all carry the same agent-readiness baseline (llms.txt, RFC 9727 api-catalog, permissive robots.txt, schema.org JSON-LD), and all are publicly accessible at the URLs below.
The repos in this organization are private. The network is consumed via the public subdomains, the RFC 9727
api-cataloglinkset, thellms.txt/llms-full.txtagent feeds, and the per-subdomain sitemaps. Everything below is open-access content, free to search, ground LLMs against, train on, or republish — see https://apis.io/terms/ for the full terms.
| Site | What you'll find |
|---|---|
| apis.io | Search hub for the whole network — search by provider, schema, tag, or name; blog; cross-network insights |
| tags.apis.io | Tag index across the network — every provider and API that carries a tag, scored and ranked |
| industries.apis.io | 29 industry verticals (Financial Services, Healthcare, Manufacturing, Transportation, Energy, Government, …) |
| regions.apis.io | 17 macro sales regions (North America, LATAM, EMEA, APAC, Greater China, ANZ, …) |
| developer.apis.io | Developer portal & machine-readable feeds |
| Site | What you'll find |
|---|---|
| providers.apis.io | API provider profiles — one page per organization, with cross-links to every artifact that organization publishes |
| apis.apis.io | Individual API records — one page per published API, with the OpenAPI spec and provider link |
| schemas.apis.io | JSON Schemas extracted from every indexed API — Google Dataset Search ingestion-ready |
| asyncapi.apis.io | AsyncAPI event-driven specifications |
| events.apis.io | Event channels drilled out of every AsyncAPI spec — one page per channel |
| json-ld.apis.io | JSON-LD contexts and semantic vocabularies |
| rules.apis.io | Spectral governance rulesets |
| vocabularies.apis.io | Provider tag vocabularies powering the advanced search |
| examples.apis.io | API usage examples |
| Site | What you'll find |
|---|---|
| skills.apis.io | Official Claude Agent Skill index — SKILL.md files published by providers, with per-skill and per-provider pages |
| mcp.apis.io | Official Model Context Protocol server index — one page per MCP server, with install hints and source links |
| Site | What you'll find |
|---|---|
| plans.apis.io | API pricing-plan profiles (API Commons Plans format) |
| rate-limits.apis.io | API rate-limit profiles (API Commons Rate Limits format) |
| finops.apis.io | API FinOps profiles aligned with the FinOps Foundation FOCUS framework |
| Feed | URL |
|---|---|
RFC 9727 api-catalog linkset (full network) |
apis.io/.well-known/api-catalog |
api-catalog (providers slice) |
providers.apis.io/.well-known/api-catalog |
api-catalog (APIs slice) |
apis.apis.io/.well-known/api-catalog |
llms.txt (agent overview, per site) |
apis.io/llms.txt |
llms-full.txt (dense reference) |
apis.io/llms-full.txt |
| Sitemap index (all subdomains) | apis.io/sitemap_index.xml |
| APIs.json self-description | apis.io/apis.json |
Each subdomain publishes its own llms.txt, sitemap.xml, and (where relevant) search-index.json for client-side search.
A central build pipeline reads from a set of upstream provider repos at github.com/api-evangelist — Git-versioned APIs.json profiles, one per provider — and emits Jekyll collections into every subdomain site. Each site then renders independently from its own collection.
Every provider, API, schema, and operational profile page carries:
- A 1–3 paragraph generated prose
overview, derived deterministically from the structured frontmatter (unique per page; no LLM-randomness) - Schema.org JSON-LD typed to the entity —
Organization+ItemListon providers,WebAPIon APIs,Dataseton schemas and operational profiles,CollectionPageon industry and region pages,BlogPostingon posts, all withBreadcrumbListsiblings - Open Graph and Twitter Card metadata
- Cross-page internal links — "Other APIs from this provider", "Related industries", "Related regions"
- A per-collection title suffix that telegraphs page type in SERPs (e.g.
Stripe Charges API — Documentation, OpenAPI | APIs.io APIs)
Providers also get a composite rating (0–100, banded Exemplar / Strong / Developing / Thin / Minimal) recomputed on every build — see apis.io/rating/.
- APIs.json (github.com/apis-json) — the machine-readable API discovery format this network is built on
- API Commons (github.com/api-commons) — the standard vocabulary of common API operational properties (plans, rate limits, etc.)
- api-evangelist — the upstream provider profile repos this network is built from
APIs.io, APIs.json, and API Commons are projects led by Kin Lane and Steve Willmott — open infrastructure for the next generation of API discovery. Email info@apievangelist.com for site-related questions, or open issues at github.com/apis-json and github.com/api-commons for spec-level questions.
The catalog is licensed for public use including search indexing, AI grounding / RAG, and model training — see apis.io/terms/.