APIs.io API

APIs.io API

Read-only discovery API over the APIs.io catalog of providers, APIs, tags, artifacts, and curated dimensions — with a free discovery tier and a Pro synthesis tier.

A first-class, read-only discovery API over the APIs.io network.

The catalog is assembled from per-provider repositories and exposed here as the providers , apis , and tags resources, a first-class collection per artifact type (/openapis, /asyncapis, /arazzo, /postman, /json-schemas, …), and a unified /search endpoint that spans them.

Design notes:

• Identifiers. aid is the stable id. A provider is twilio; an API is twilio:twilio-accounts-api (<provider>:<api-slug>).
• Artifacts by reference. API records carry a properties list of artifacts (type + url). By default only references are returned; pass include=content to inline an artifact's body.
• Selectable artifacts. Use artifact_types to return only the artifact types you care about (e.g. OpenAPI,Postman).
• Free, Pro, and Business tiers. Raw discovery — /search, /providers, /apis, /tags, the curated taxonomy dimensions (/industries, /regions, /areas), /resolve, /enrich, /vcs, /insights, and most artifact-type collections (/openapis, /mcp, /skills, /examples, /json-schemas, …) — is free. The rating data (/ratings, /providers/{slug}/rating), the ranked …/leaders views within a dimension, the synthesis composites (/compare, /gaps, /changes), the per-company insight depth, the saved workspace (/me/*), and the high-value security artifact collections (/scopes, /security) are Pro. /stack is freemium: free callers get the top pick per capability, Pro gets the full blueprint and /stack/export. Bulk dataset pulls (/export) are Business , the license tier above Pro. Each operation declares its tier via x-tier; the rubric (/ratings/rubric) stays free. Send X-API-Key for a paid tier; keyless callers get the free tier. A gated call returns 402 Payment Required (not 403 — CloudFront rewrites 403/404). See x-apis-io for the full tier / MCP-tool / skill map.
• Also an MCP server + Agent Skills. Every operation maps 1:1 to an MCP tool at https://apis.io/mcp (see each operation's x-mcp-tool) and, where one exists, an Agent Skill (x-agent-skill). This is the API → MCP → Agent-Skill experience chain.

Tags

[

Providers

Organizations publishing APIs on the network.

](/developer/api/providers)[

APIs

Individual APIs, each owned by a provider and described by artifacts.

](/developer/api/apis)[

Tags

The tag taxonomy, with network-wide ranking metadata.

](/developer/api/tags)[

Industries

Industry verticals grouping providers across the catalog.

](/developer/api/industries)[

Regions

Geographic regions grouping providers across the catalog.

](/developer/api/regions)[

Areas

The API Evangelist areas taxonomy — curated topic collections (authentication, webhooks, payments, …), each a scored provider index with its own site. Pro.

](/developer/api/areas)[

Synthesis

Decision-grade composites over the catalog — provider comparison, gap analysis, catalog change feed, and recommended-stack design. Pro.

](/developer/api/synthesis)[

Ratings

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 provider's public API surface is. Rubric v0.3.

](/developer/api/ratings)[

Artifact Types

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.

](/developer/api/artifact-types)[

Search

Unified cross-resource search.

](/developer/api/search)[

Insights

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 engineering blogs. Discovery is free; per-company depth, gaps, and provider matches are Pro.

](/developer/api/insights)[

Venture Capital

Venture-capital firms as a first-class entity — fund identity plus a network-matched, rated PORTFOLIO GRAPH. Browse firms, walk a fund's portfolio (filter to API providers / by rating band), and follow the reverse edge from a provider to the VCs that back it. Free discovery.

](/developer/api/venture-capital)[

Resolve & Enrich

Agent ergonomics — resolve any identifier (domain, URL, GitHub org) to a provider, and enrich a provider in one call by choosing field groups. Free (the rating and insights enrichment groups are Pro).

](/developer/api/resolve-enrich)[

Saved Workspace

A Pro dimension — per-user saved searches, lists, and net-new deltas. The same capability the MCP exposes as tools; turns apis.io from stateless lookup into a persistent research workspace. Requires an API key.

](/developer/api/saved-workspace)[

Export

Bulk data export — the license tier above Pro. The whole ratings or providers dataset in one pull, with the attribution string a published figure must carry. Business tier.

](/developer/api/export)

CC BY 4.0

ContactAPI Evangelisthttps://apis.io

Servers https://apis.io/api/v1

Production server.